Differential effects of BMI on diabetes risk among black and white Americans.
OBJECTIVE
To determine whether the associations of BMI and fat distribution with diabetes risk are modified by race.


METHODS
Data from the National Health and Nutrition Examination Survey, Epidemiologic Follow-up Study (1971-1992), were used to investigate potential interactions of BMI and fat distribution with race. Incident diabetes was defined by self-report of physician-diagnosed diabetes, hospital and nursing home discharge records, and death certificates.


RESULTS
Among the 1,531 black and 9,852 white subjects who were nondiabetic at baseline, 1,139 (10.0%) developed diabetes during 20 years of follow-up. Although the cumulative risk of diabetes increased with baseline BMI in all four race-sex groups, the sex-specific odds ratios (ORs) for black:white subjects decreased with increasing BMI. In particular, for BMI of 22 kg/m2, the OR of diabetes for black:white individuals was 1.87 and 1.76 (P < 0.01) for men and women, respectively; for BMI of 32 kg/m2, the OR decreased to 0.99 and 1.20 (NS) for men and women, respectively. Skinfold ratio was also associated with increased diabetes risk in all race-sex groups, but did not modify the association between race and diabetes.


CONCLUSIONS
These findings suggest that the effect of BMI on diabetes risk is different for black and white Americans, with a larger risk for blacks than whites at low BMI and an equivalent risk for both groups at high BMI. A lower degree of visceral adiposity among blacks at higher BMI or a greater impact of visceral adiposity among blacks at low BMI may help explain the interaction of race and BMI on diabetes risk.
Resnick
H E
HE
Epidemiology, Demography, and Biometry Program, National Institute on Aging, Bethesda, Maryland 20892, USA. resnickh@nih.gov
Valsania
P
P
Halter
J B
JB
Lin
X
X
D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D044383:Black People; D015992:Body Mass Index; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data