Abstract 1468: Baseline Obesity and Weight Loss Are Associated With Coronary Artery Calcium Progression in the Multi-Ethnic Study of Atherosclerosis
Background: While obesity and weight gain have been associated with increased cardiovascular risk, there are conflicting data about the effects of weight loss on cardiovascular risk.
Hypothesis: We assessed the hypothesis that individuals with stable and increasing abdominal obesity have greater coronary artery calcification (CAC) progression than those with decreasing abdominal obesity, among participants in the Multi-Ethnic Study of Atherosclerosis (MESA).
Methods: MESA is a prospective cohort study of 6,814 individuals free of clinical cardiovascular disease at entry who underwent serial risk factor assessment and CAC testing. Follow-up measures of body-mass index (BMI), waist-hip ratio (WHR), and waist circumference (WC), were categorized as stable (within±0.05 of baseline WHR, ±2.5 cm of baseline WC, or ±2 kg/m2 of baseline BMI), increased, or decreased. We assessed the independent relationships between baseline obesity and changes in weight with the development of incident CAC using relative risk regression, and with absolute CAC change (for those with baseline CAC>0) using multivariable linear regression. Individuals who did not undergo follow-up CAC testing (767 participants) were excluded.
Results: Our study population consisted of 6,047 individuals (62±10 years, 47% males), and mean follow-up was 3.1±1.3 years. Increasing baseline BMI, WC and WHR were associated with incident CAC, and increasing baseline BMI and WC correlated with increased CAC change (Table⇓). However, a reduction in all obesity measures was associated with an increased risk of incident CAC compared to those with stable weight, whereas only an increase in WC was significantly associated with absolute CAC change among those with CAC>0 at baseline.
Conclusion: In conclusion, high baseline abdominal obesity in our cohort was associated with CAC progression, but decreasing obesity over time was associated with increased incident CAC relative to stable or increasing obesity.