Ph.D. - Epidemiology

Permanent URI for this collectionhttps://hdl.handle.net/10125/36911

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Hepatitis C and syringe sharing: A systematic review (USA, 1988–2019) and cross-sectional descriptions (Hawaiʻi, 2019) of risk behaviors among people who inject drugs
(University of Hawai'i at Manoa, 2025) Salek, Thomas Paul; Katz, Alan; Epidemiology
The multiperson use, or sharing, of needles and drug injection equipment among people who inject drugs (PWID) increases the risk of transmitting bloodborne diseases, including the hepatitis C virus (HCV) and human immunodeficiency virus (HIV). Quantifying the characteristics associated with injection-related sharing behaviors and HCV seroprevalence is critical for monitoring trends and addressing drug-related public health concerns within this population. This dissertation presents a secondary data analysis that includes a systematic review and two cross-sectional assessments of data from the Hawai‘i Health & Harm Reduction Center’s (HHHRC) annual syringe exchange program (SEP) survey. The analysis aims to identify factors associated with syringe sharing and injection-related HCV risk behaviors among PWID, with the goal of informing the development of targeted harm reduction strategies and interventions.Study 1 presents a systematic review designed to document and aggregate existing research on needle and drug injection equipment sharing behaviors, as well as injection-related HIV/HCV risk behaviors, in the United States (U.S.). This review covers the period from the initiation of comprehensive needle exchange programs through the years immediately preceding the Coronavirus disease (COVID-19) pandemic (1988–2019). To be included in the review, eligible sources had to be published between January 1, 1988, and December 31, 2019, conducted within the U.S., and written in English. Eligible sources were collected from Ovid MEDLINE®, Web of Science, Education Resources Information Center (ERIC), PsycINFO, Google Scholar, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and had to report one or more of the nine pre-defined data items and outcomes. Out of 9,385 sources screened, 1,329 unique research studies spanning 46 U.S. states, two territories, and Washington, D.C., were included. The number of sources reporting on each of the nine outcomes was as follows: 1) syringe sharing (n=1,057); 2) non-syringe drug injection equipment sharing (n=469); 3) drug injection equipment cleaning practices (n=362); 4) syringe-mediated drug-splitting (SMDS) (n=218); 5) having a sharing partner (n=228); 6) having an injection partner (n=266); 7) shooting gallery attendance (n=375); 8) HIV and/or HCV injection serosorting (n=77); and 9) syringe or drug injection equipment reuse (n=138). Study 1 identified inconsistent terminology and the absence of operational definitions in the literature on drug injection equipment sharing and proposed a new, detailed typology for future data collection and reporting on these behaviors. Study 2 utilizes a cross-sectional approach, analyzing SEP data collected by HHHRC between January 1, 2019, and December 31, 2019, including 105 sampled needle exchange clients across four main Hawaiian Islands. Study 2 examines two main binary dependent variables: distributive syringe sharing (yes or no) and receptive syringe sharing (yes or no), both self-reported and recalling the risk period within the previous month. The primary objective was to estimate the prevalence proportions of distributive and receptive syringe sharing and to characterize risk behaviors associated with syringe sharing among needle exchange clients in Hawai‘i. The secondary objective was to examine the relationship between the type of shared drug injection equipment and the directionality of sharing transactions, with the aim of establishing an overall risk profile for sharing behaviors among PWID in Hawai‘i. Self-reported data on independent variables were collected through an interview-administered questionnaire. Log-binomial regressions were employed to estimate crude point prevalence proportions and univariable prevalence proportion ratios (PPRs). A test of independence was conducted to assess the relationship between the hypothesized sharing risk profile, categorized by equipment type and directionality sharing transactions, using cross-tabulation. The overall crude point prevalence proportion of past-month distributive syringe sharing was estimated to be 24.8% (95% confidence interval [CI], 17.4–34%) and past-month receptive syringe sharing had an overall crude point prevalence proportion of 21.8% (95% CI, 14.9–30.8%). Statistically significant correlations were observed between the sharing of syringes, cookers, and cottons. The association between shared equipment type and sharing directionality was statistically significant (P<0.0001). Study 3 also applies a descriptive approach using the same cross-sectional data set as Study 2. The main dependent variable in Study 3 was anti-HCV serostatus (positive or negative), detected through a rapid, point-of-care Food and Drug Administration (FDA)-approved screening test. The primary objective was to estimate the mean point seroprevalence proportion of anti-HCV positivity and to characterize risk behaviors associated with being screened positive for anti-HCV serostatus among needle exchange clients from Hawai‘i. The secondary objective was to estimate the cumulative incidence of HCV infection among those with a known history of seronegative anti-HCV serostatus. Log-binomial regressions were used to estimate prevalence proportion ratios, with and without adjustment for the total duration of engaging in injection drug use. The estimated overall mean crude point seroprevalence proportion of being screened as anti-HCV positive was 54.3% (95% CI, 44.8–63.5%). Among 40 previously seronegative individuals, 10 had incident anti-HCV positive seroprevalence screening results between 2010 and 2019 (cumulative incidence, 25%; 95% CI, 14.2–40.2%). Comparison with 2012 data from the same population and setting showed no significant differences in HCV seroprevalence or incidence. Receptive past-month equipment sharing behaviors were not found to be associated with anti-HCV seroprevalence. The analysis identified age as a confounding variable in the relationship between injection duration and anti-HCV serostatus, suggesting the need for age-specific stratification. Mantel-Haenzel age-adjustment analysis indicated injection duration was significantly associated with screened anti-HCV seropositivity for individuals with more than five years of injection history compared to those with five years or fewer (Mantel-Haenzel PPR=2.12, 95% CI, 1.10–4.08, P=0.007). Study 1 concludes that the findings of this systematic review provide a valuable resource for researchers, health policy leaders, and health service providers to enhance the understanding of syringe sharing and other injection-related HIV/HCV behaviors. This knowledge can be used to optimize harm reduction strategies for individuals who inject drugs. Study 2 highlights the persistence of drug injection equipment sharing in Hawaiʻi, with at least one in five syringe exchange clients reporting sharing in the past month. Study 3 underscores the hyperendemic nature of HCV among PWID in Hawaiʻi, demonstrating ongoing transmission within this population.
Investigating enculturation and assessing the impact of Hawaiian cultural affiliation on mental health among Native Hawaiian youth
(University of Hawai'i at Manoa, 2025) Yang, Katherine; Hurwitz, Eric; Epidemiology
This dissertation integrates four studies focused on Native Hawaiian youth, aiming to develop an enculturation framework and validate the Hawaiian cultural scale for adolescents to assess mental health outcomes. The first study, a scoping review, identified a significant gap in research concerning enculturation frameworks for Native Hawaiian youth, emphasizing the urgent need for foundational research in this area. The second study attempted to validate a theoretical model of enculturation but faced challenges due to data constraints, leading to a revised focus solely on Hawaiian cultural affiliation instead of a broader enculturation model.The third study successfully validated the Hawaiian Cultural Scale for Adolescents (HCS-A) through rigorous confirmatory and exploratory factor analyses, refining it into a robust four-factor model that measures various aspects of Hawaiian culture. The fourth study employed Structural Equation Modeling (SEM) to examine the relationship between components of Hawaiian cultural affiliation and three different mental health outcomes, including depressive symptoms, anxiety, and self-esteem. Findings suggest that stronger engagement with activities associated with the Customs/Beliefs & Hawaiian Activities/Social Events subscale, in particular, may serve as a protective factor against depressive symptoms and anxiety. Overall, this dissertation highlights the critical role of cultural connectedness in promoting mental health among Native Hawaiian youth and emphasizes the importance of incorporating culturally sensitive frameworks in health research and interventions to better support Indigenous youth well-being.
Epidemiology and prevention of clostridioides difficile infection at a single military treatment facility in Hawai‘i
(University of Hawai'i at Manoa, 2025) Schweikert II, Michael; Hurwitz, Eric; Epidemiology
Clostridioides difficile (C. difficile) is a bacterium that can cause gastrointestinal infection and is considered an urgent threat to public health by the Centers for Disease Control and Prevention. C. difficile infection is the most common cause of antibiotic-associated diarrhea and is one of the most common healthcare-associated infections in the United States. Though estimated cases of C. difficile requiring hospitalization or affecting already hospitalized patients have decreased over the last decade, prevention of C. difficile infection continues to be a major initiative for healthcare facilities throughout the nation. With the advent of highly sensitive laboratory tests to detect C. difficile, diagnostic stewardship is also a key initiative to mitigate unnecessary testing, overdiagnosis, and overreporting of C. difficile. This dissertation presents an analysis of risk factors for C. difficile infection, healthcare-facility onset (HO) C. difficile infection, and impact of implementing a clinical decision support tool on HO C. difficile infection and diagnostic stewardship practices at a single military treatment facility in Hawai‘i. Study 1 found that diarrhea, antibiotics, fever, and end-stage renal disease were statistically significantly associated with C. difficile infection. Study 2 did not find statistically significant associations in the multivariable model but noted potential associations with racial/ethnic findings, recent laxative use, and proton pump inhibitor use that warrant further research. Study 3 found a higher prevalence ratio of HO C. difficile infection after implementation of the clinical decision support tool but promising improvements to diagnostic stewardship practices, particularly in regard to case ascertainment.
THE ASSOCIATION OF JAPANESE DIET WITH RISK OF COMMON CANCER AMONG THE JAPANESE LIVING IN THE UNITED STATES AND JAPAN: THE MULTIETHNIC COHORT STUDY AND THE JAPAN PUBLIC HEALTH CENTER- BASED PROSPECTIVE STUDY
(University of Hawai'i at Manoa, 2024) Okada, Yuito; Le Marchand, Loic; Wilkens, Lynne; Epidemiology
【Introduction】Japanese migrants to the United States and their descendants have experienced an increased risk of cancer compared to Japan. This study aimed to describe the incidences and dietary risk factors for six common cancers among Japanese in two population-based cohort studies on-going since the 1990’s, the Multiethnic Cohort Study (MEC) and the Japan Public Health Center-based Prospective Study (JPHC). The common cancers among Japanese were defined as stomach cancer (SC), colorectal cancer (CRC), hepatocellular carcinoma (HCC), lung cancer (LC), breast cancer (BC, women only), prostate cancer (PC, men only). 【Methods】 We analyzed the data from the questionnaire collected at baseline for the MEC and at 5- year follow-up for the JPHC. These included demographics, life-style related risk factors such as smoking, drinking, and physical activity, and a self-reported quantitative food frequency questionnaire including more than 150 items in both studies. First, we assessed the incidences of common cancers of the Japanese Americans and the Japanese residing in Japan. Second, the association of rice with CRC risk was examined. Rice consumption(g/1000kcal/day) was categorized into quartiles and Hazard Ratios (HR) and 95% confidence intervals (95%CI) were computed to assess overall risk trends in cancer risk. Third, the study explored the relation of the Japanese Diet Index-8 (JDI) and common cancer risk. The JDI was developed and validated in Japan to assess the adherence to the traditional Japanese diet using eight food items. According to the JDI score group, the HR, 95%CI, and trend p value was computed. We hypothesized that the Japanese diet might reduce cancer risk of common cancers. 【Results】 In total, 57,017 Japanese Americans (26,982 men and 30,035 women) in the MEC and 10,4504 Japanese residing in Japan (49,751 men and 57,753 women) from the JPHC composed the study population. The MEC Japanese men and women were older and had fewer risk factors for cancer, such as smoking and alcohol consumption, but consumed a less traditional Japanese diet compared to the JPHC. In the MEC, rates of SC, CRC, HCC, LC both in men and women, were lower than those in the JPHC but MEC had a higher incidence of PC in men and BC in women than the JPHC. CRC incidence was similarly high in both studies. Rice consumption was not consistently associated with overall CRC cancer risk but was significantly associated with a reduced risk of distal colon cancer among the men without diabetes in both the MEC and JPHC. The trend was not observed in women of the MEC and JPHC. Lastly, the JDI score was associated with increased risk of SC and reduced risk of BC among women in the MEC but not in JPHC. Other common cancers were not significantly associated with the JDI. 【Discussion】 This study showed that Japanese Americans had higher risks of PC and BC than the JPHC and high incidence of CRC in men and women. The MEC had higher percentages of early- stage diagnosis of PC and BC, possibly indicating a screening effect. Consuming more rice might reduce distal colon cancer in men without diabetes because of resistant starch. Furthermore, a combination traditional Japanese diet, such as rice, miso soup, fish, and green tea, might increase the risk of SC and reduce the risk of BC only in the Japanese Americans women. Adoption of a westernized diet in Japan might increase the risk of distal colon cancer in men and BC in women. More nutrition specific investigations are needed to prevent common cancers among the Japanese Americans.
TIMELINESS OF INFECTIOUS DISEASES CASE REPORTING IN THE WASHINGTON STATE DISEASE REPORTING SYSTEM
(University of Hawai'i at Manoa, 2023) Ingalls, Kacey Kathleen; Hurwitz, Eric; Epidemiology
Objectives: The objective of this dissertation was to investigate if an increase in the 7-day case rate for COVID-19 cases led to an increase in the 7-day average of time (in days) between the specimen collection date and the investigation create date in the Washington State Disease Reporting System (WDRS) for COVID-19 cases reported through electronic laboratory reporting (ELR), COVID-19 cases manually entered, Hepatitis B cases reported through ELR, and Hepatitis C cases reported through ELR. Additionally, this dissertation analysis will retroactively assign the COVID-19 reinfection case classification to cases between January 2020 and September 2021. MethodsThere were two data sources used for this analysis. Laboratory result data housed in WDRS were requested from the Washington State Department of Health. The second data source used was the public facing Washington State COVID-19 dashboard. All analysis were completed in R. A rolling 7-day average lag time variable was created by subtracting the investigation create date from the specimen collection date. A time series analysis, scatterplots, and Pearson’s Correlations were completed using the 7-day average lag times and case rate data available from the COVID-19 dashboard. All analyses were completed for ELR, manual, year-specific, and wave-specific datasets. To reassign the COVID-19 case classification a total count of laboratory results were created using R and a 90-day rolling cut off. Data were then manually reviewed and cleaned using Excel. ResultsOverall, we found that there was a lag between the specimen collection date and the investigation create date and there was an association with the 7-day COVID-19 case rate average. Magnitude of relationship varied based on year and how data were broken into differing timeframes. There was also a difference seen between disease type and mode of laboratory result, either ELR or manually entered. We also found that there were approximately 7,165 laboratory results that could be considered reinfections in the first year and a half of the pandemic response by applying the updated COVID-19 reinfection case classification. ConclusionsIn conclusion this dissertation outlines a practical application of including a lag time metric into a surveillance system evaluation during a pandemic response. These analyses highlighted there was a significant lag between when tests were completed and when they were received in the surveillance system. Future research should focus on identifying where along the informatics pipeline the lag is occurring so that we can work to improve efficiency and be better prepared to respond to the next pandemic.
Lifestyle Etiology Of Thyroid Cancer In A Multiethnic Population
(University of Hawaii at Manoa, 2022) Abe, Janine V.; Wilkens, Lynne; Epidemiology
Thyroid cancer is ranked 9th cancer in the world, 12th in the United States and in the top 10 for Hawaii. It is the most common endocrine cancer and the most common in persons under 40 years old, with an over 98% 5-year survival. Globally the age standardized incidence rates have been going up in the last 30 years in all age groups and in both sexes. Hawaii has high rates of thyroid cancer, with only 1 case control study that was conducted in Hawaii. There are sex and racial/ethnic disparities; with a 3:1 ratio: women compared to men having higher incidence than men, and Filipinos having higher incidence rates compared to other racial/ethnic groups. This research will add to the existing gap in the body of literature on diverse disaggregated racial/ethnic groups. The disparities, rising trends, and financial, emotional, and physical burdens makes this research of public health importance. This dissertation uses the Multiethnic Cohort Study which is a prospective cohort study that has high risk racial/ethnic groups: such as Filipinos, and a wide range of exposures. The only established risk factor is radiation, although there are probable lifestyle risk factors in the literature. Study 1 examined the association of lifestyle risk factors by sex and race/ethnicity. In study 1 there was a statistically significant increased risk of adiposity and diabetes, and suspected increased risk among high neighborhood socioeconomic status and farming occupation, with a protective effect for smoking pack years and alcohol consumption. Some of these associations were statistically significant in some racial/ethnic groups, but heterogeneity was not significant. Reproductive factors in women have been hypothesized as contributors for higher incidence rates compared to men, as rates peak around menopausal age, 40-49, in women contrary to men at 60-69; thus study 2 examined the association of reproductive factors and thyroid cancer in women by race/ethnicity. There was a statistically significant increased risk of thyroid cancer for women having a surgical menopause, oophorectomy, hysterectomy, and nulliparity; with suggestive increased risk for former users of MHT, and women with a history of induced abortion and stillbirth. In final study of survival among thyroid cancer cases, overall, 5-year survival was over 70%. All-cause mortality was higher in men compared to women and with disparities observed among AA, NH and Filipinos compared to JA that mirror mortality in the general population. When TC cases were compared to matched controls with no TC in the MEC, men and Filipino TC cases exhibited an excess mortality due to TC.
Associations Of Adiposity Phenotypes With Genetic Ancestry, Glucose Metabolism, And Diet Quality In The Multiethnic Cohort Adiposity Phenotype Study
(University of Hawaii at Manoa, 2022) Guillermo, Cherie Joyce T.; Grandinetti, Andrew; Epidemiology
Obesity is associated with adverse health outcomes such as cardiovascular disease, diabetes, and multiple cancers. While body mass index is commonly used as a measure of obesity, measures of body fat distribution through imaging techniques such as magnetic resonance imaging and dual energy x-ray absorptiometry scans have shown that certain types of fat (trunk and abdominal visceral fat) have been associated with greater likelihood of developing certain obesity-related diseases compared to increasing total body weight. Just as race/ethnicity contributes to health disparities, racial/ethnic differences in body fat distribution have been documented but more work is needed to evaluate admixed individuals. In-2013-2016, 1861 non-smoking Multiethnic Cohort participants returned for a clinic visit in which study participants donated fasting blood samples and completed body fat quantification for the Multiethnic Cohort Adiposity Phenotype Study. Using this study, three aims are presented in this dissertation: 1. To explore the association between genetic ancestry proportions with five adiposity phenotypes (total fat mass, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), VAT/SAT, and liver fat) and muscle mass index. 2. To evaluate the association between genetic ancestry proportions and type 2 diabetes (T2D) status to determine if the relationship is similar or different as the relation of self-reported race/ethnicity with VAT/SAT as a mediator. 3. To study the additive effect of the genetic ancestry proportions and diet quality as measured by the Healthy Eating Index 2015 (HEI-2015) on VAT and VAT/SAT. In this study, the first aim found that genetic ancestry proportions were associated with adiposity. African genetic ancestry was associated with lower VAT and higher SAT. Among self-reported African American participants, higher proportions of African genetic ancestry were associated with greater muscle mass index. Main Islands Japanese genetic ancestry was associated with lower VAT/SAT, but Okinawan Japanese genetic ancestry was associated with higher VAT/SAT among self-reported Japanese American participants. Of the self-reported Native Hawaiian participants, Native Hawaiian genetic ancestry was associated with total fat mass, VAT, SAT, and muscle mass index. In the second aim, higher Main Islands Japanese and Okinawan Japanese genetic ancestries were associated with higher odds of T2D whereas Southern European and Northern European genetic ancestries were associated with lower odds of T2D. Furthermore, the presence of increased VAT/SAT contributes to the statistically significant associations of African, Main Islands Japanese, Okinawan Japanese, and Native Hawaiian genetic ancestries on fasting blood glucose and homeostatic model assessment for insulin resistance (HOMA-IR). In the third aim, better diet quality was associated with lower VAT and VAT/SAT for self-reported Native Hawaiian and Japanese American participants. Lastly, there is a weak additive effect of African, Main Islands Japanese, and Okinawan Japanese genetic ancestries and HEI-2015 on VAT and VAT/SAT.
Examining The Role Of Sleep Duration On The Risk Of Hypertension, Stroke, And Mortality
(University of Hawaii at Manoa, 2021) Kawai, Yosuke; Grandinetti, Andrew; Epidemiology
Sleep duration and quality have been recently gaining interest as modifiable risk factors for morbidity and mortality. Many epidemiological studies suggest that sleep duration, both short and long hours, is an important risk factor for type 2 diabetes, obesity, cancer, cardiovascular disease, hypertension, stroke, and mortality. While the exact mechanism linking sleep and disease is unclear, it is believed to involve complex interactions between metabolic, endocrine, and immune pathways. The three studies presented in this dissertation examined the association between sleep duration and hypertension, stroke, and mortality and informed the hypotheses that sleep durations deviating from the recommended 7 to 8 hours would be associated with increased risk for these outcomes. In each of these studies, the potential for demographic characteristics and medical conditions to modify the relationship between sleep duration and the main study outcomes were investigated. All three study aims in this dissertation used data from the Multiethnic Cohort (MEC) study, a large, ethnically diverse prospective cohort study of middle-aged and elderly adults in Hawai’i and Los Angeles. In the first study, sleep duration was found to be weakly associated with prevalent hypertension, but not incident hypertension. There was also no evidence of effect modification by age, sex, ethnicity, or BMI. In the second study, sleep duration was associated with a 13% and 39% increased risk of incident stroke in those who reported ≤5 and ≥10 hours of sleep, respectively. There were no significant differences across age, sex, ethnicity, BMI, hypertension status, or diabetes status. In the third study, sleep duration was associated with an increased risk of all-cause, cardiovascular, and stroke mortality. Those reporting ≥10 hours of sleep were at a 43%, 48%, 66% increased risk of all-cause, cardiovascular, and stroke mortality, respectively.
Examination of Healthy Growth among Children of the U.S. Affiliated Pacific Region
(University of Hawaii at Manoa, 2020) Yamanaka, Ashley Brooke; Novotny, Rachel; Epidemiology
Child growth, from birth to adolescence, has profound implications on adult health (1). Healthy growth is measured in many countries as an expected linear growth relative to a growth reference, depicting how children grow (2). Measuring how a child grows has many challenges when comparing children from different countries and ethnic backgrounds. Multiple growth references with varying recommendations, including a widely accepted growth standard describing how a child should grow, are available but lead to inconsistencies in growth classifications, which is a limitation in global trends for children. The dual burden of malnutrition, which is the coexistence of undernutrition and overnutrition, frequently assessed by growth, has also been a health concern in child growth (3). A shift in diet and activity level in the last century, caused by environmental changes and increase in wealth, known widely as nutrition transition, has led to behavior changes and adverse health outcomes (4). Child overweight and obesity (COWOB) is a growing epidemic influenced by nutrition transition, especially in the US affiliated Pacific (USAP) region, with the likelihood of these children developing diabetes and cardiovascular disease early in life and in adult years. Limited data on child growth in USAP region are available. The findings in this dissertation will expand the limited growth data for USAP children and explore appropriate anthropometric classifications by: 1) comparing two growth references and growth standard charts; 2) examining waist circumference among children with acanthosis nigricans, an indicator for insulin resistance; and 3) assessing height among children with acanthosis nigricans or obesity.
Prevalence, Patterns, and Outcomes of Opioid Use by Injured Workers in Tennessee
(University of Hawaii at Manoa, 2018-05) Durand, Zoe W.; Epidemiology
In this dissertation, three separate but related studies describe opioid use by injured workers in TN, identify patterns of opioid use by injured workers that are associated with nonfatal overdose, and develop a predictive model for the development of long-term opioid use in injured workers who were opioid-free at the time of injury. These studies link statewide databases to connect Workers’ Compensation records of injured workers to their prescription history in TN’s prescription drug monitoring program, hospital and emergency room records in TN’s Hospital Discharge Data System, and death certificates in TN’s Vital Statistics death certificates dataset. In a cross-sectional study, the prevalence of opioid use in injured workers is calculated and Poisson regression is used to assess prevalence ratios of the association between demographic and injury variables with opioid use. In a case-control study, the incidence of nonfatal overdose is calculated and conditional logistic regression is used to examine demographic, injury, and opioid use patterns that are associated with overdose. In a cohort study, unconditional logistic regression is used to build a predictive model of demographic, injury, and opioid use patterns that are associated with the development of long-term opioid use in previously opioid-free injured workers. These studies found that opioid use is widespread in injured workers after injury, but occurs largely within limits set by prescribing guidelines and tends to be discontinued within a month or two. Overdose and the development of long-term opioid use are rare, but affect vulnerable subsets of the population which may benefit from a different prevention and treatment approach than the overall population. These studies were supported by funding from the Centers for Disease Control and Prevention’s Prescription Drug Overdose: Prevention for States program, grant number 5 NU17CE002731-02-00
The Impact of Weight Status Perception on Perceived Risk for Diabetes and Diabetes Screening
(University of Hawaii at Manoa, 2017-12) Starr, Ranjani R.; Epidemiology
Self-perceived weight status refers to how an individual assesses his or her own body weight and size. Misperception of weight status can occur in either direction, with underperception of weight status being more prevalent. Underperception of weight status is closely associated with BMI category, with those who are categorized as obese having a higher prevalence ratio (PR) of misperceiving their weight status of 5.31 (95% CI, 3.41-8.25) compared to those who have a healthy weight, even after adjusting for other covariates. Males, those identifying as Native Hawaiian or Other Pacific Islander and those who have ever served in the US Military are more likely to underperceive their weight status, even after adjusting for BMI category, whereas those in older age groups are less likely to underperceive their weight status compared to younger adults. Weight status underperception is associated with diabetes risk perception. Individuals who overperceive their weight status are more likely to perceive themselves to be at risk for diabetes (PR 1.42, 95% CI 1.14-1.76), whereas those who underperceive their weight status are less likely to do so (PR 0.76, 95% CI 0.60-0.97) compared to those with accurate weight status perception. Other factors associated with diabetes risk perception include being diagnosed at risk (PR 1.97, 95% CI 1.58-2.45), having a family history of diabetes (PR 1.77, 95% CI 1.39-2.24), and BMI category, with obese individuals being more likely to perceive themselves to be at risk compared to those who have a healthy weight (PR 2.07, 95% CI 1.46-2.93). Higher diabetes risk perception is associated with greater receipt of diabetes screening in the past three years (PR 1.31, 95% CI 1.05-1.62) even after adjusting for age and other potential confounders. The findings have important implications for correcting weight status perception and enhancing awareness of diabetes risk, with the goal of motivating those at risk to engage in lifestyle change efforts targeted at reducing their risk for diabetes.
Cognitive Disease, Metabolic Disease, and Inflammation in the Honolulu Asia Aging Study: Connnecting the Dots between Insulin Resistance, Type 2 Diabetes, Alzheimer's Disease, Dementia, and Fibrinogen
(University of Hawaii at Manoa, 2017-05) Lee, Thomas H. W.; Epidemiology
Metabolic diseases and cognitive diseases are two of the leading causes of morbidity and mortality worldwide. As medical technology and research continues to evolve and improve, the proportion of persons over 65 years of age will continue to increase. This dissertation presents analysis aimed to understand connections between inflammation, insulin resistance, type 2 diabetes, and Alzheimer’s disease/dementia. The first study looks at the relationship between insulin resistance and Alzheimer’s disease/dementia. The relationship between inflammation, via fibrinogen, and insulin resistance is investigated in the second study. Finally, the third study investigates the association between fibrinogen and type 2 diabetes. This dissertation utilized data from the Honolulu Asia Aging study, a longitudinal cohort of Japanese-American men who were identified using 1960 U.S. Census data and selective service registration records from World War II. The author found that subjects who were insulin resistant at later life had decreased odds of Alzheimer’s disease and dementia. Carriers of the APOE ε4 allele had at 50% increased odds of dementia and 60% increased odds of Alzheimer’s disease. Subjects with elevated fibrinogen levels at later life observed increased odds of prevalent insulin resistance and type 2 diabetes, even after adjusting for potential confounders.
Comparison of Behavioral and Sexual Networking Risks among Patients with Syphilis or Gonorrhea: The Social and Sexual (SSN) Study, Baltimore
(University of Hawaii at Manoa, 2016-12) Krishnan, Vinogiri
Syphilis is caused by the bacterium Treponema pallidum and is associated with significant complications if left untreated besides also facilitating the transmission and acquisition of ‘Human Immunodeficiency Virus’ (HIV) infection. Gonorrhea (infection due to Neisseria gonorrhoeae) is the second most commonly reported sexually transmitted disease (STD) in the United States. The purpose of this dissertation is to develop an epidemiologic profile among patients with syphiliis and gonorrhea from STD clinics in Baltimore. Networking risks and behavioral factors associated with sexual risk taking were investigated. The first of three studies sought to determine the associations between the presence of syphilis vs. gonorrhea with sexual characteristics and associations between the presence of syphilis vs. gonorrhea with peer influences on condom use before any sexual intercourse. The second study attempted to determine the associations between the network characteristics of the social contacts with the presence of syphilis vs. gonorrhea, describe differences in asscociations between sexual behaviors with presence of syphilis vs. gonorrhea by different types of networks (more sexual networks than non-sexual networks and vice versa) and determine the associations between some sexual behaviors with presence of syphilis vs. gonorrhea among men having sex with men (MSM) from this study. Finally, study three aimed to determine if depression and drug abuse are co-morbid with the presence of syphilis vs. gonorrhea among patients with syphilis or gonorrhea, describe differences in the associations of drug abuse with syphilis vs. gonorrhea between people with different types of networks and to determine if sexual abuse is associated with depression among these patients. Findings from all three studies covered in this dissertation confirm that there are behavioral factors with sexual risk and networking risks among patients with syphilis or gonorrhea. They also provided thorough information on their network characteristics and associated risk factors in different types of social networks (individuals named as part of sexual or non-sexual network). All three studies provided suggestions for future research in order to increase understanding of sexual and networking risks among patients with STDs.
Health among Lesbian, Gay, Bisexual and Questioning Teens in Hawai‘i: The Role of Social Support in Reducing Problematic Alcohol Use and Suicide Attempts
(University of Hawaii at Manoa, 2015-12) Lowery St John, Tonya
Sexual minorities (SMs), gay, lesbian, bisexual and questioning individuals, experience poorer mental and physical health outcomes and increased likelihood of engaging in risky sexual behaviors, tobacco, alcohol and other illicit drug use compared to heterosexuals. The Minority Stress Model explains this excess risk by positing that unique external stressors in the SM population combine with internal stress responses to produce physiological responses and behaviors that impact the mental and physical health of SMs. These negative stressors can be mediated by personal internal and external environmental factors and mitigated by social supports. This dissertation uses data from the 2011 and 2013 Hawaii Youth Risk Behavior Survey of public high school students to explore key health issues among SM youth (SMY). The first study examined how the operationalization of the construct of sexual orientation impacts the odds of current cigarette smoking, current alcohol use and suicide attempt in the past 12 months among SMY compared to their heterosexual counterparts. There were significant differences in risk behaviors by sex, and operational definition of sexual orientation. Self-identification as SMY and sexual behavior seem to capture distinct risks. Students who are not sexually active, or who are questioning their sexual identity, should be included as a separate category in analyses rather than grouped with SMY. The second study explores alcohol use among SMY, uses the CRAFFT brief screening tool for adolescents to discern problematic alcohol use and examines the role of social supports in mediating problematic alcohol use among SMY. Social supports were important predictors of problematic use and parental disapproval of underage drinking was strongly associated with lower problematic alcohol use. The final study describes suicidal behavior among SMY and scrutinizes the role of social supports in mediating the excess risk of recent suicide attempts, controlling for measures of victimization. Victimization was strongly associated with suicide risk; adult support outside of school was protective. Together these studies may help set standards for appropriate analytical methods for SMY and contribute to the body of research on the role of interpersonal social supports in reducing the negative effects of stress on the health of SMY.
Maternal Prepregnancy Nutritional Status as a Key Link of Intergenerational Risk of Obesity and Chronic Disease in Childhood and Later Life among US Pacific Islanders: A Life Course Approach Study
(University of Hawaii at Manoa, 2015-05) Techur Pedro, Angela
The rising prevalence of obesity in women and its adverse effects on the health of their offspring may be a key link to intergenerational risk of obesity and chronic disease in childhood and later life among the US Pacific Islanders in Hawai‘i and the US-Affiliated Pacific Islands. In a population with a high burden of chronic disease, there is a huge knowledge gap on modifiable factors associated with obesity and chronic diseases. However, many studies in other populations support the life course model of chronic disease suggesting that poor maternal prepregnancy underweight and obesity are early fetal origins of obesity and chronic disease in childhood and later life. The purpose of this dissertation is investigate maternal prepregnancy underweight and obesity as key links of intergenerational risks of obesity and chronic disease in childhood among the US Pacific Islanders using the life course model of chronic disease. The first study sought to estimate race-ethnic differences in the prevalence of underweight and obesity in women of reproductive age and their associations with demographic, socioeconomic, lifestyle, and health behaviors among Native Hawaiians and Other Pacific Islanders compared to White women in Hawai‘i. The second study sought to estimate race-ethnic differences in the prevalence of maternal prepregnancy underweight and obesity and their associations with low and high birth weight among Samoan and Micronesian women in Hawai‘i. The third study sought to estimate the prevalence of maternal prepregnancy underweight and obesity and their associations with low birth weight, high birth weight, and childhood overweight plus obesity adjusting for the mediating effect of early adiposity rebound. Overall, these studies consistently found high prevalence of prepregnancy obesity among the US Pacific Islander women in Hawai‘i and in the US-Associated Pacific Islands. The high prevalence of prepregnancy obesity was positively associated with high birth weight and childhood overweight plus obesity in the offspring. These findings are strongly suggestive that maternal prepregnancy obesity may be a key link of intergenerational risk of obesity and chronic disease in childhood among US Pacific Islanders in Hawai‘i and in Palau. Further studies are needed. However, preventive actions should begin during early fetal life.
The Effects of Delivery Method and Infant Feeding on Weight Gain during the First Year of Life
(University of Hawaii at Manoa, 2015-05) Daida, Yihe
Rapid weight gain in the first year of life sets the growth trajectory and is a risk factor for obesity. New evidence suggests that obesity in mice and humans is characterized by altered gut bacteria, compared to their lean counterparts. Two early factors that influence gut bacteria are delivery method and infant feeding. Since delivery method and infant feeding affect the initial colonization of gut bacteria, and gut bacteria is associated with obesity, the purpose of my dissertation is to study the effects of delivery method, breast feeding intensity, and their joint effects on infant growth in the first year of life. This is a secondary analysis of data from the Infant Feeding Practices Study II (IFPS), a longitudinal follow-up study of new mothers conducted by the US Food and Drug Administration from 2005-2006. Participants were from a consumer panel of 500,000 households. Survey questionnaires were sent to pregnant women 10 times at regular intervals during the year after they gave birth. All participants were women >18 years of age who delivered a healthy infant. Delivery methods were reported as spontaneous vaginal, induced vaginal, planned C-section and emergency C-section. Breastfeeding intensity was reported at months 1-7, 9, 10 and 12 months. Emergency C-section and induced vaginal deliveries were associated with lower breastfeeding intensity, compared to women who had spontaneous vaginal delivery. However, no differences in breastfeeding intensity were found between planned C-section and spontaneous vaginal delivery. In the second study, infants who received 0% and 1-49%% milk feeds from formula gained more weight than those fed 100% breast milk. The adjusted weight gain of these 2 groups was also higher than a cut-off point for risk of later obesity. Finally, weight gain was similar for infants born by vaginal deliveries and C-sections. Infants fed at least 50% breast milk gained less weight after 5 months of age. Joint effects of delivery method and breastfeeding intensity did not significantly affect infant weight gain. All three studies provide suggestions for future research needed to fully understand how delivery method and infant feeding affect gut colonization which in turn may affect infant development.
Determinants of plasma Leptin and age at menarche in adolescent girls in Hawaii
(University of Hawaii at Manoa, 2010-12) Vijayadeva, Vinutha
This study investigates the association of the Leptin (LEP) and Leptin receptor (LEPR) polymorphisms LEP A19G, LEP G-2548A and LEPR Q223R with plasma leptin concentration, body fat and age at menarche (AAM). The study was part of a larger cohort study that followed 349 multiethnic adolescent girls (ages 9-14yr at baseline) and an additional 180 girls at exam 3 in Hawaii (Female Adolescent Maturation Study). Anthropometry was obtained by measurement, Tanner stages by clinical examination, dietary intake by 3-day diet record and physical activity by a standardized questionnaire. DNA was obtained from mouthwash or blood and was genotyped using a fluorescent 5' endonuclease assay and the ABI FAST 7900HT Real-Time PCR System for allelic discrimination. Dual energy X ray Absorptiometry (DXA) was used to determine body fat mass. The study did not show association between LEP/LEPR variants and plasma leptin. However, the association between plasma leptin and body fat measures (measured using both DXA and anthropometry) was substantiated. A difference in LEPR rare homozygote genotype (AA) and the common homozygote genotype (GG) in DXA trunkto-periphery fat ratio (TPFR) was found (girls with LEPR Q223R AA genotype had lower TPFR compared to GG). It was also found that protein intake (adjusted for BMI) was negatively associated with plasma leptin level. In a COX regression model, girls with AG genotype for LEP G-2548A reached menarche earlier than the AA genotype. The study also substantiated the evidence of heavier and taller girls reaching menarche early. Importantly, this study demonstrated these associations in understudied girls of Asian White ancestry. This present study provides new information on the LEP/LEPR genetic variants, body fat and age at menarche in an Asian White population.
Birth size, infant growth, and child Bmi at age 5 years in a multiethnic population
(University of Hawaii at Manoa, 2012-12) Oshiro, Caryn Etsuko Shima
Child overweight is a public health concern and it is imperative that steps are taken to examine early factors that may contribute to this unhealthful start to life. Prenatal and postnatal determinants of overweight (e.g., maternal overweight, birth weight, and increased weight gain during infancy) have been studied. However, few studies have examined the effect of other measures of birth size (birth length, indices of weight/length, gestational age) and infant growth patterns on BMI at age five years in a multiethnic population. This is a retrospective, longitudinal study using data from the Kaiser Permanente Hawaiʻi Electronic Medical Record. Singleton children, born in years 2004 and 2005 at Kaiser Permanente, with birth and linked maternal information were initially included (n = 894). Subsequently, children with measured weights (n = 597) and lengths (n = 473) from ages 2 to 4 and 22 to 24 months were included. A higher birth weight was associated with a higher BMI at age five years after controlling for gestational age, age, sex, race/ethnicity, and maternal factors (prepregnancy weight, age, education, and smoking). Birth length was not associated with BMI at age five after adjusting for birth weight and gestational age. A higher prepregnancy maternal weight was also associated with a higher child BMI at age five years. For every 100 g/month increase in weight and 1 cm increase in length over the infant period of 20 months, BMI increased by 1 kg/m2 at age five years. However, this was not true for change in BMI during infancy. The effect of birth weight on BMI at age five years was not mediated by infant growth and the interaction was not significant. Birth weight, change in infant weight, and BMI at age five varied by race/ethnicity, but not by sex. Birth weight and change in infant weight was higher in Whites and Other Pacific Islanders, with most differences observed after age two years. Early indicators such as a higher birth weight and change in infant weight and length, and higher maternal pre-pregnancy weight, are key indicators associated with a higher child BMI at age five.
Using pregnancy risk assessment monitoring system data to investigate prescription drug use during pregnancy in Hawaiʻi
(University of Hawaii at Manoa, 2014-05) Roberson, Emily Kathleen
Both legal and illicit use of prescription drugs during pregnancy is thought to be increasingly common in the state of Hawaiʻi, based on trends demonstrated elsewhere in the country and throughout the world. Prescription opioids, along with antianxiety and antidepressant medications are of special concern, both for their prevalence and for the potential risks associated with using these drugs during pregnancy. The purpose of this dissertation is to investigate prescription drug use during pregnancy in Hawaiʻi, with a focus on opioids and antianxiety and antidepressant medications. The first of three studies sought to determine the prevalence of prescription opioid drug use during pregnancy in Hawaiʻi, describe differences in prescription opioid drug use during pregnancy in Hawaiʻi by maternal demographic characteristics, and investigate possible predictors of prescription opioid drug use during pregnancy through the use of multivariable logistic regression. The second study aimed to determine whether prescription opioid use during pregnancy was associated with poorer birth outcomes among users when compared to non-users in Hawaiʻi; specifically focusing on associations between prescription opioid use during pregnancy and risk of small for gestational age, preterm, or low birth weight deliveries among women giving birth to live, singleton infants in Hawaiʻi. Study three attempted to describe the under-studied topics of anxiety and depression before, during, and after pregnancy, along with related help-seeking behaviors and treatment strategies, for which there is a scarcity of information in Hawaiʻi. Findings from the three studies covered in this dissertation confirm that use of prescription opioids and antianxiety and antidepressant medications is relatively common during pregnancy in Hawaiʻi. They also provide more detailed information on usage patterns, differences by demographic characteristics, and associated risk factors and birth and maternal health outcomes. All three also provide suggestions for future research avenues in order to more fully understand the complete landscape of prescription drug use during pregnancy in Hawaiʻi.
Tracking obesity related behaviors from childhood to adolescence: the fun 5 study
(University of Hawaii at Manoa, 2014-05) Anwar, MD Mahabub Ul
Obesity in the United States has increased dramatically, and has become a public health crisis. Studies documented that healthy lifestyle, including healthy eating, increased physical activity (PA), and decreased sedentary behavior (SB), can lower the risk of becoming obese, as well as developing obesity related diseases. In order to explore the changing pattern of PA and fruit and vegetable consumption (FVC) from childhood to adolescence, as well as to investigate how childhood PA, FVC, and SB influence adolescence PA, FVC, and SB, this dissertation utilized the data of Fun 5 study, which is a longitudinal cohort study. Two cohorts of data were utilized for this dissertation, where students were followed up for five years. Using piecewise growth mixer modeling, and random coefficient model, paper one of this dissertation did not find any significant pattern of PA change from childhood to adolescent. Structural equation modeling revealed the applicability of theory of planned behavior (TPB) for childhood PA. Findings also documented that self confidence is the strongest variable to influence childhood PA followed by attitudes. Paper one did not find any impact of childhood and adolescent PA on adolescent obesity. Using piecewise growth mixer modeling, and random coefficient model, paper two revealed a declining pattern of FVC from childhood to adolescent. Structural equation modeling revealed the applicability of TPB for childhood FVC. Findings also documented that self confidence is the strongest variable to influence childhood FVC followed by subjective norms. Paper two did not find any impact of childhood and adolescent FVC on adolescent obesity. Using structural equation modeling, paper three of this dissertation revealed that all three childhood behaviors (PA, FVC, SB) predicted the same adolescent behaviors, which implies that these behaviors develop at childhood and continue to adolescence. Findings suggest to target early childhood for intervention activities regarding increasing PA, FVC, and decreasing SB, as well as target children's self confidence, subjective norms, and attitudes towards PA and FVC. Findings also recommend further studies to explore the change of obesity related behaviors from childhood to adolescent, as well as the predictive ability of these behaviors to adolescent obesity.

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