Physical activity, body mass index and waist circumference change, and normal-range glycated hemoglobin on incident diabetes: Jackson Heart Study.

Increases in BMI over time and higher A1C within the normal range were associated with incident diabetes. Serial monitoring of BMI, as well as A1C, even among those with a 'normal' A1C, may be warranted by clinicians. Future work evaluating this novel three-way model (physical activity, BMI and WC) should consider utilizing an objective measure of physical activity.