Ph.D. - Epidemiology

Permanent URI for this collection

Browse

Recent Submissions

Now showing 1 - 10 of 14
  • Item
    EXAMINING THE ROLE OF SLEEP DURATION ON THE RISK OF HYPERTENSION, STROKE, AND MORTALITY
    ( 2021) Kawai, Yosuke ; Grandinetti, Andrew ; Epidemiology
  • Item
    Examination of Healthy Growth among Children of the U.S. Affiliated Pacific Region
    ( 2020) Yamanaka, Ashley Brooke ; Novotny, Rachel ; Epidemiology
  • Item
  • Item
  • Item
  • Item
    Comparison of Behavioral and Sexual Networking Risks among Patients with Syphilis or Gonorrhea: The Social and Sexual (SSN) Study, Baltimore
    ([Honolulu] : [University of Hawaii at Manoa], [December 2016], 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.
  • Item
    Health among Lesbian, Gay, Bisexual and Questioning Teens in Hawai‘i: The Role of Social Support in Reducing Problematic Alcohol Use and Suicide Attempts
    ([Honolulu] : [University of Hawaii at Manoa], [December 2015], 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.
  • Item
    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
    ([Honolulu] : [University of Hawaii at Manoa], [May 2015], 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.
  • Item
    The Effects of Delivery Method and Infant Feeding on Weight Gain during the First Year of Life
    ([Honolulu] : [University of Hawaii at Manoa], [May 2015], 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.
  • Item
    Determinants of plasma Leptin and age at menarche in adolescent girls in Hawaii
    ([Honolulu] : [University of Hawaii at Manoa], [December 2010], 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.