Modifiable Lifestyle Risk Factors and Incident Diabetes in African Americans

The associations of modifiable lifestyle risk factors with incident diabetes are not well investigated in African Americans (AAs). This study investigated the association of modifiable lifestyle risk factors (exercise, diet, smoking, TV watching, and sleep-disordered breathing burden) with incident diabetes among AAs.

Modifiable lifestyle risk factors were characterized among 3,252 AAs in the Jackson Heart Study who were free of diabetes at baseline (2000-2004) using baseline questionnaires and combined into risk factor categories: poor (0-3 points), average (4-7 points), and optimal (8-11 points). Incidence rate ratios (IRR) for diabetes (fasting glucose ≥126 mg/dL, physician diagnosis, use of diabetes drugs, or glycosylated hemoglobin A1c ≥6.5%) were estimated using Poisson regression modeling adjusting for age, sex, education, occupation, systolic blood pressure, and BMI. Outcomes were collected 2005-2012 and data analyzed in 2016.

Over 7.6 years, there were 560 incident diabetes cases (mean age=53.3 years, 64% female). An average or optimal compared to poor risk factor categorization was associated with a 21% (IRR=0.79, 95% CI=0.62, 0.99) and 31% (IRR=0.69, 95% CI=0.48, 1.01) lower risk of diabetes. Among participants with BMI <30, IRRs for average or optimal compared to poor categorization were 0.60 (95% CI=0.40, 0.91) and 0.53 (95% CI=0.29, 0.97) versus 0.90 (95% CI=0.67, 1.21) and 0.83 (95% CI=0.51, 1.34) among participants with BMI ≥30.

A combination of modifiable lifestyle factors are associated with a lower risk of diabetes among AAs, particularly among those without obesity.