Associations between fasting glucose rate-of-change and the missense variant, rs373863828, in an adult Samoan cohort.

BACKGROUND: The A allele of rs373863828 in CREB3 regulatory factor is associated with high Body Mass Index, but lower odds of type 2 diabetes. These associations have been replicated elsewhere, but to date all studies have been cross-sectional. Our aims were (1) to describe the development of type 2 diabetes and change in fasting glucose between 2010 and 2018 among a longitudinal cohort of adult Samoans without type 2 diabetes or who were not using diabetes medications at baseline, and (2) to examine associations between fasting glucose rate-of-change (mmol/L per year) and the A allele of rs373863828. METHODS: We describe and test differences in fasting glucose, the development of type 2 diabetes, body mass index, age, smoking status, physical activity, urbanicity of residence, and household asset scores between 2010 and 2018 among a cohort of n = 401 adult Samoans, selected to have a ~2:2:1 ratio of GG:AG: AA rs373863828 genotypes. Multivariate linear regression was used to test whether fasting glucose rate-of-change was associated with rs373863828 genotype, and other baseline variables. RESULTS: By 2018, fasting glucose and BMI significantly increased among all genotype groups, and a substantial portion of the sample developed type 2 diabetes mellitus. The A allele was associated with a lower fasting glucose rate-of-change (ß = -0.05 mmol/L/year per allele, p = 0.058 among women; ß = -0.004 mmol/L/year per allele, p = 0.863 among men), after accounting for baseline variables. Mean fasting glucose and mean BMI increased over an eight-year period and a substantial number of individuals developed type 2 diabetes by 2018. However, fasting glucose rate-of-change, and type 2 diabetes development was lower among females with AG and AA genotypes. CONCLUSIONS: Further research is needed to understand the effect of the A allele on fasting glucose and type 2 diabetes development. Based on our observations that other risk factors increased over time, we advocate for the continued promotion for diabetes prevention and treatment programming, and the reduction of modifiable risk factors, in this setting.

Assessing the impact of high blood pressure referrals on hypertension awareness and management, BMI, and blood pressure values in adult Samoans 2010-2019.

The Samoan population has experienced rapid increases in the prevalence of non-communicable diseases (NCDs) and NCD risk factors over the last 30 years. However, understanding how increased awareness and treatment of these conditions in reducing disease burden remains understudied. Using data from a longitudinal study (2010-2019) of cardiometabolic health among Samoan adults, we assess the impact of a referral for elevated blood pressure (BP) on changes in BP, physician's diagnoses of hypertension and medication use, body mass index (BMI), and other risk factors for elevated BP. Analyses compared adult Samoans (n = 328) who in 2010 either (1) received a referral for elevated BP (BP ≥ 140/90 mmHg) or (2) had measured BP indicative of pre-hypertension (BP ≥ 120/80 mmHg) but were not referred. Data were analysed using linear and logistic regression, paired T- and McNemar's tests, and Wilcoxon Rank Sum assessments. Referrals in 2010 significantly increased the odds of reporting a physician's diagnosis of hypertension (OR 2.16; 1.18, 3.95) and hypertension medication use (OR 3.52; 1.86, 6.73) in 2018; however, referrals, medication use, and diagnoses were not associated with BP values or reduced odds of having elevated BP. Despite the referral having positive effects on hypertension-related health care, our results demonstrate that other factors are influencing effective BP/hypertension control. We advocate for greater engagement of health researchers with local health sector actors to improve the probability that researcher-provided health referrals will result in long-term health improvements.