The Relation of Smoking to Waist-to-Hip Ratio and Diabetes Mellitus among Elderly Women

Background.Smoking is associated with lower body weight, but an increased risk of diabetes in some studies. Because smoking may increase waist-to-hip ratio (WHR), a risk factor for diabetes, we postulated that the relation between smoking and diabetes may be mediated in part by smoking-associated differences in body fat distribution. Methods.We conducted a cross-sectional analysis of baseline data from 9,435 elderly nonblack women enrolled in the Study of Osteoporotic Fractures. Data were collected by self-report and physical examination. Linear and logistic models were used to determine the relation of smoking to WHR and prevalence of self-reported diabetes. Results.Current and past smokers had greater WHRs compared with never smokers. In multivariate models that adjusted for body mass index, the prevalence of diabetes was lower among smokers of ≤10 cigarettes/day [odds ratio (OR) = 0.57, 95% confidence interval (CI) 0.31–1.03] and higher among smokers of >10 cigarettes/day (OR = 1.38, 95% CI 0.99–1.92) compared with never smokers. The relation of smoking <10 cigarettes/day to prevalence of diabetes was slightly attenuated after further adjustment for WHR. Conclusions.Smoking-associated differences in WHR may mediate, at least in part, the prevalence of diabetes among smokers of >10 cigarettes/day. The decreased prevalence of diabetes that we observed among smokers of ≤10 cigarettes/day was not explained by differences in obesity and requires confirmation.