The Association of Adiposity and RAAS With Incident Diabetes in African Americans: The Jackson Heart Study.

BACKGROUND: The renin-angiotensin-aldosterone system (RAAS) and adiposity measures are independently associated with the development of diabetes in African American adults. However, studies have not examined the combined interaction between RAAS and adiposity measures in relation to diabetes risk in African American adults. OBJECTIVE: We examined the longitudinal association of combined RAAS and adiposity measures with incident diabetes among African American adults in the Jackson Heart Study. METHODS: African American adults were assessed at baseline (2000-2004) and over 12 years of follow-up. RAAS, anthropometric (waist circumference [WC], body mass index), and adipokine (adiponectin, leptin, leptin to adiponectin ratio [LAR]) measures were collected at baseline. Aldosterone, WC, and LAR were chosen as the best predictor variables. The final model, adjusting for age, sex, education, occupation, systolic blood pressure, smoking, physical activity and RAAS-altering medications, incorporated these variables and their interactions (WC*aldosterone + LAR*aldosterone) to explore their impact on incident diabetes. RESULTS: Among 3219 participants without diabetes at baseline, there were 554 incident cases over a median follow-up period of 7.5 years. Aldosterone, WC, and LAR were positively associated with incident diabetes (all P < .05). A significant interaction was found between WC and aldosterone, with a greater association among individuals with lower WC. This interaction was significant in participants with prediabetes but not in those with normoglycemia. No significant interaction was found between log-LAR and aldosterone with risk of incident diabetes. CONCLUSION: Higher aldosterone in participants is associated with greater risk of diabetes, particularly among individuals with prediabetes and lower WC.