Different Weight Histories and Risk of Incident Coronary Heart Disease and Stroke: Tehran Lipid and Glucose Study

BACKGROUND This study aimed to determine the association between different weight histories, including cumulative excess weight, cumulative excess waist circumference (WC), duration of general and central adiposity, current and maximum body mass index, and current and maximum WC, and incident coronary heart disease (CHD) and stroke. METHODS AND RESULTS The study population consisted of 4398 adults aged ≥40 years without CHD or stroke at baseline. Associations between different weight histories and CHD and stroke were determined by multivariable time-varying Cox regression models after adjustment for age, sex, and time-varying confounders. Further adjustment was also done for mediators (eg, diabetes mellitus, hypercholesterolemia, and hypertension). During median follow-up of 13.9 years, 718 incident CHD and 158 stroke events were documented. Multivariable adjusted hazard ratios (HRs) were calculated in the sex and confounder adjusted model for CHD per 1-SD increase in cumulative excess weight (HR: 1.02; 95% confidence interval [CI], 0.96-1.07), cumulative excess WC (HR: 1.14; 95% CI, 1.04-1.24), duration of general adiposity (HR: 1.00; 95% CI, 0.92-1.08), duration of central adiposity (HR: 1.01; 95% CI, 0.93-1.09), current body mass index (HR: 1.03; 95% CI, 0.99-1.07), current WC (HR: 1.21; 95% CI, 1.11-1.32), maximum body mass index (HR: 1.01; 95% CI, 0.95-1.07), and maximum WC (HR: 1.17; 95% CI, 1.07-1.28). After further adjustment for mediators, current and maximum WC still showed a significant risk (HR: 1.13 [95% CI, 1.03-1.23] and 1.09 [95% CI, 1.00-1.20], respectively). Moreover, in the sex and confounder adjusted model, cumulative excess WC and maximum WC were associated with higher risk of stroke (hazard ratio: 1.21 [95% CI, 0.99-1.48] and 1.25 [95% CI, 1.02-1.55], respectively). CONCLUSIONS Exposure to cumulative excess weight and cumulative excess WC confers little additional risk beyond their current and maximum values. Even current and maximum WC were associated with incident CHD in the presence of obesity mediators, and the latter was a significant predictor of stroke in the presence of confounders.