Results:

Those with a longer exposure to obesity were more likely to be younger at baseline, female, black, achieve less education, have a higher waist circumference at baseline and during follow-up, and were less physically active and consumed less alcohol. In addition, a longer duration of obesity was associated with higher levels (averaged during follow-up) of blood pressure, glucose, insulin, C-reactive protein, high-density lipoprotein cholesterol, and triglycerides. Presence of diabetes and medication use for hypertension and dyslipidemia also was more frequent among those with a longer duration of obesity. Smoking and total cholesterol level were unrelated to obesity duration. During follow-up, 40.4% and 41.0% developed overall and abdominal obesity, respectively. Rates of CAC per 1,000 person-years were higher for those who experienced more than 20 years versus 0 years of overall obesity (16.0 vs. 11.0, respectively) and abdominal obesity (16.7 vs. 11.0). Approximately 25.2% and 27.7% of those with more than 20 years of overall and abdominal obesity, respectively, experienced progression of CAC versus 20.2% and 19.5% of those with 0 years. After adjustment for BMI or waist circumference and potential confounders, the hazard ratios for CAC for each additional year of overall or abdominal obesity were 1.02 (95% confidence interval [CI], 1.01-1.03) and 1.03 (95% CI, 1.02-1.05), respectively. The adjusted odds ratios for CAC progression were 1.04 (95% CI, 1.01-1.06) and 1.04 (95% CI, 1.01-1.07), respectively. Associations were attenuated but largely persisted following additional adjustment for potential intermediate metabolic factors during follow-up.