Eight-year prevalence and incidence of obesity, high blood glucose and high blood pressure in five African-origin populations: data from the Modeling the Epidemiologic Transition Study.

Introduction: Obesity, high blood glucose and high blood pressure are major drivers of global morbidity. Characterising temporal trends in these conditions among people of African origin can direct public health efforts. This longitudinal cohort study aimed to characterise the prevalence and incidence of obesity, high blood glucose and high blood pressure over 8 years in five African-origin middle-aged populations spanning the Human Development Index and to explore temporal between-site and within-site differences. Methods: In 2009-2011, the Modeling the Epidemiologic Transition Study (METS) enrolled adults aged 25-45 years from Ghana, South Africa, Jamaica, Seychelles and the USA (n=500 each), with follow-up in 2018-2019. Standardised measurements included anthropometrics, blood pressure and capillary (baseline)/plasma (follow-up) glucose. We calculated prevalence and raw incidence rates (IRs). Generalised estimating equations (GEE) assessed longitudinal associations between outcomes, site and timepoint, adjusting for age, sex and covariates. Results: In 855 participants with complete data, the IR per 1000 person-years was 22.0 for obesity, 4.7 for high blood glucose and 27.4 for high blood pressure. Obesity prevalence and incidence were higher among women than among men. In GEE, the adjusted risk of obesity was significantly higher at follow-up than at baseline for Ghana, Jamaica and Seychelles. The prevalence of high blood glucose more than doubled between timepoints; the IR ranged from 3.0 (South Africa) to 7.1 (USA), with no statistically significant site differences in GEE analysis. For high blood pressure, Ghana, Jamaica and Seychelles showed a greater change in risk between baseline and follow-up, compared with the USA. Conclusions: The risk of obesity, high blood glucose and high blood pressure increased among middle-aged individuals over 8 years; in Ghana, Jamaica and Seychelles, the change in obesity and high blood pressure risk was statistically significantly greater than in the USA. This highlights the importance of non-communicable disease prevention and management, irrespective of country's HDI.