Effects of obesity on the impact of short-term changes in anthropometric measurements on coronary heart disease in women.

OBJECTIVE: To assess the impact of short-term changes in body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio on the risk of future coronary heart disease (CHD) among women.

PARTICIPANTS AND METHODS: The study sample consisted of 2468 women aged 30 years or older without cardiovascular disease at baseline who underwent 2 consecutive examinations, the first between January 31, 1999, and August 21, 2001, and second between October 20, 2001, and September 22, 2005, and were followed up until March 31, 2010. Cox proportional hazard regression was performed to estimate the hazard ratios (HRs) of the anthropometric measures for CHD events.

RESULTS: During a mean follow-up of 6.6 years, CHD occurred in 127 of the study participants (5.1%). There were significant interactions between a BMI of 30 kg/m(2) or greater and anthropometric changes in prediction of CHD events (all P<.04). Among nonobese individuals, a 1-SD increase in HC changes, independent of WC and BMI changes, was inversely associated with risk of CHD events (HR, 0.60 [95% CI, 0.44-0.83]). Among obese individuals, a 1-SD increase in WC, independent of other changes, increased the risk of CHD. Conversely, a 1-SD increase in BMI decreased the risk of CHD by 35% (HR, 0.65 [95% CI, 0.45-0.94]).

CONCLUSION: In this study, the impact of changes in anthropometric measures on CHD was modified by obesity at baseline. Among nonobese women, increases in HC could significantly reduce the risk of CHD events. Among obese individuals, although increases in WC were associated with a higher risk of CHD, increases in BMI decreased the risk.