Adult Health Publications
If you can not access any of the full publications, please contact Nicola Hawley.
1. Cardiovascular disease risk factors and DNA methylation at the LINE-1 repeat region in peripheral blood from Samoan Islanders.
Cash, H., McGarvey, S.T., Housemann, E.A., Marsit, C.J., Hawley, N.L., Lambert-Messerlian, G.M., Viali, S., Tuitele, J. & Kelsey, K.T. (2011) Epigenetics 6 (10): 1257-1264 https://pubmed.ncbi.nlm.nih.gov/21937883/
We sequenced DNA in peripheral blood samples from men and women in American Samoa and Samoa to study the relationship between LINE-1 methylation and factors associated with cardiovascular and metabolic diseases, like LDL and HDL. The findings confirm that DNA “global” loss of methylation, which was previously observed in cardiovascular disease, is associated with altered levels of HDL and LDL, and indicate the need for further research in understanding the relationship between LINE-1 methylation and risk factors for cardiovascular disease.
2. Genome-wide association study of adiposity in Samoans: Prevalence of non-communicable disease and associated risk factors.
Hawley, N.L., Minster, R.L., Weeks, D.E., Viali, S., Reupena, M.S., Deka, R., & McGarvey, S.T. (2014). American Journal of Human Biology 26: 491-501. https://pubmed.ncbi.nlm.nih.gov/24799123/
This study described the prevalence of obesity-related noncommunicable diseases and associated risk factors in a sample of 3,475 Samoan adults aged 24 to <65 as part of a genome-wide association study for obesity-related traits. Findings show that obesity was highly prevalent in the sample studied—64.6% of females and 41.2% of males were obese according to Polynesian cutoffs—and also address the prevalence of diabetes, hypertension and dyslipidemia. The study concludes phenotypic characteristics of this sample provide further evidence previously reported trends toward obesity and its associated disorders.
3. Cutoff levels for hyperandrogenemia among Samoan women: an improved methodology for deriving normative data in an obese population.
Maredia, H., Lambert-Messerlian, G., Palomaki, G.E., Viali, S., Hawley, N.L., & McGarvey, S.T. (2016) Clinical Biochemistry 49 (10-11): 782-786. https://pubmed.ncbi.nlm.nih.gov/26908216/
This study aimed to define biochemical hyperandrogenemia (HA) among a sample of 464 Samoan women, aged 25–39, who were a part of a larger genome-wide association study of adoposity. We analyzed the distribution of free androgen index to establish normative androgen data among Samoan women and defined HA as free androgen index greater than the 95th percentile. According to this HA definition, 14% of women were classified as hyperandrogenemic. This study is the first to define normative androgen values among Samoan women quantitative assessment of the relationship between adiposity and androgen levels.
4. A thrifty variant in CREBRF strongly influences body mass index in Samoans.
Minster R.L.*, Hawley N.L.*, Su, C., Sun, G., Kershaw E.E., Chen, H., Buhule, O.D., Lin, J., Reupena, M.S., Naseri, T., Urban, Z., Deka, R., Weeks, D.E. & McGarvey, S.T. (2016) Nature Genetics 48 (9): 1049-54. *Co-First Authors. https://pubmed.ncbi.nlm.nih.gov/27455349/
This study conducted a genome-wide association study in 3,072 Samoans and discovered a variant, rs12513649, strongly associated with BMI. We replicated this association in another 2,102 Samoans and identified a strongly associated missense variant, rs373863828, in CREBRF. The variant is rare in other populations but is common in Samoans, and in comparison to the wild-type CREBRF, shows decreased energy use and increased fat storage in adipocyte cells. The findings from the data, alongside evidence of positive selection of the allele encoding the missense variant, support a thrifty' variant hypothesis as a factor in human obesity.
5. Dietary patterns are associated with metabolic outcomes among adult Samoans in a cross-sectional study.
Wang D., Hawley, N.L., Thompson A.A., Lameko V., Reupena M.S., McGarvey S.T. & Baylin, A. (2017). Journal of Nutrition 147 (4): 628-635. https://pubmed.ncbi.nlm.nih.gov/28202634/
This study aimed to identify dietary patterns in Samoa and to evaluate their associations with metabolic outcomes. We studied dietary patterns using a 104-item food questionnaire and identified a modern pattern (high intake of imported and processed foods), a mixed-traditional pattern (high intake of neotraditional foods), and a mixed-modern pattern (loaded with imported and processed foods but also with neotraditional foods.) The study’s findings indicate mixed dietary patterns containing healthier foods, rather than a largely imported and processed modern diet, may help prevent metabolic syndrome in Samoa.
6. Reproductive health, obesity, and cardiometabolic risk factors among Samoan women.
Maredia, H., Hawley, N.L., Lambert-Messerlian, G., Fidow, U., Reupena, M.S., Naseri, T. & McGarvey, S.T. American Journal of Human Biology (in press). https://pubmed.ncbi.nlm.nih.gov/29663637/
This study estimated the prevalence of menstrual irregularity and of polycystic ovarian syndrome (PCOS) in Samoan women (with high obesity prevalence) and explored the association of these reproductive health conditions with adiposity, cardiometabolic risk factors, and androgen levels. Studying a cross-sectional sample of 470 Samoan women, ages 25–39, we found the prevalence of menstrual irregularity and PCOS to be less than hypothesized, but confirmed Samoan women with menstrual irregularity and other features of PCOS have significantly poorer metabolic health.
7. Nonmydriatic fundus photography in a high-risk population of Samoans with diabetes: the Soifua Manuia Eye Screening Program.
LaMonica, L., Hawley, N.L., Bhardwaj, M., Naseri, T., Reupena, M.S. & Ramsey, D. (2019). Clinical and Experimental Ophthalmology 47 (7): 954-956. https://pubmed.ncbi.nlm.nih.gov/31034672-nonmydriatic-fundus-photography-in-a-high-risk-population-of-samoans-with-diabetes-the-soifua-manuia-eye-screening-program/
In this study, the research team piloted a low‐cost, smartphone‐based remote retinal diagnosis system to screen for diabetic retinopathy in a high‐risk population of Samoans with diabetes and elevated blood glucose levels. Their objective was to determine the percentage of radable images that could be obtained using the PanOptic iExaminer System. This study was undertaken alongside an ongoing longitudinal study of the genetics of obesity and diabetes among Samoans, the Soifua Manuia (“Good Health”) study, and 206 of the approximately 700 adults in the overall study partook. A total of 393 eyes, or 95.4%, from these 206 participants were successfully imaged using the PanOptic iExaminer. The researchers found that clinically useful fundus images could be successfully obtained in the majority of participants and that the durability and maintainability of the PanOptic iExaminer System in the field proves promising as a cost‐effective device for use in low‐ to middle‐income countries.
8. The Household Water InSecurity Experiences (HWISE) Scale: development and validation of a household water insecurity measure using data from 23 low- and middle-income countries.
Young, S.L., Collins, S.M., Boateng, G.O., Neilands, T.B., Jamaluddine, Z., Miller, J.D., Brewis, A., Frongillo, E.A., Jepson, W.E., Melgar-Quinonez, H., Schuster, R.C., Stoler, J., Wutich, A. & HWISE Consortium Authors. (2019). BMJ Global Health 4:e001750. https://gh.bmj.com/content/4/5/e001750
The purpose of this study is to develop the Household Water Insecurity Experiences (HWISE) Scale to measure household water insecurity in an equivalent way across disparate cultural and ecological settings. The researchers implemented cross-sectional surveys in 8127 households across 28 sites in 23 low-income and middle-income countries. They collected data related to water insecurity in the prior month; sociodemographics; water acquisition, use, and storage; household food insecurity and perceived stress. The research team retained twelve items about experiences of household water insecurity for the HWISE Scale, and concluded that the scale will have the ability to quantify the prevalence, causes, and consequences of household water insecurity.
9. Tobacco smoking patterns in Samoa in 2010: Implications for interventions.
Adia, A.C., Hawley, N.L., Naseri, T., Reupena, M.S. & McGarvey, S.T. Tobacco Prevention and Cessation (in press). http://www.tobaccopreventioncessation.com/Tobacco-smoking-patterns-in-Samoa-in-2010-Implications-for-ninterventions,114093,0,2.html
In this study, the researchers describe current smoking and daily tobacco use in adults from Samoa, with a focus on sex and age stratified analyses of the influence of occupation, education, census region, household asset ownership, and alcohol use in order to help develop targeted interventions. The nationwide survey included 3745 adults, aged 25–65 years from 33 villages, and was completed in Samoa in 2010. Interviews were used to assess current smoking status, daily tobacco use, current alcohol use, and a variety of sociodemographic factors. The team found that more than half of men, or 51.3%, and 21.8% of women were current tobacco users. On average, men and women smoked on average 10.9 and 8.7 cigarettes each day, respectively. In men, being married, a subsistence farmer/laborer, an alcohol user, and having low household assets were all independently associated with being a tobacco smoker. In women, not completely secondary education, being 25–34 years old, residing in urban atypia, and being an alcohol user were all independently associated with being a tobacco smoker. The researchers conclude that the high rates of tobacco usage in Samoa warrant the development of interventions for cessation that are specific to sex, age, education, and household socioeconomic status.