Examining the Relationship Between Anthropometric and Body Composition measures with Coronary Heart Disease Events: The Multi-Ethnic Study of Atherosclerosis.

Abstract

Background: Obesity, traditionally measured using body mass index (BMI), is considered a significant risk factor for the development of cardiovascular disease. However, there have been mixed findings regarding the association between obesity and cardiovascular events in part due to the way it is measured. Major limitations exist with the use of BMI as it cannot assess body composition or fat distribution, and thus fails to account for the separate roles of muscle and fat mass.

Objective: To examine the relationship between various measures of body composition including fat mass (FM), fat free mass (FFM), waist-to-height ratio, waist circumference, and BMI, and coronary heart disease (CHD) events, from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort.

Methods: MESA is a population-based cohort study of 6814 men and women, aged between 45 and 85 years, without clinically apparent CVD. FM and FFM at baseline (Exam 1) was estimated using multiplicative power equations formulated from bioelectrical impedance analysis (BIA) measurements. Multivariable Cox regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for 10-year incident hard CHD events (non-fatal myocardial infarction (MI), resuscitated cardiac arrest, and death resulting from CHD) for FM/FFM, waist-to-height ratio, waist circumference, and BMI.

Results: Higher FM was associated with higher risk of hard CHD events, with a hazard ratio of 1.64 (1.09-2.48) per standard deviation (SD) unit increase (P-value 0.019). FFM was associated with a lower risk of CHD, with a hazard ratio of 0.24 (0.08-0.76) per SD unit increase of FFM (P-value 0.014). Waist-to-height ratio had a hazard ratio of 1.21 (1.08-1.35) (P-value 0.001) per SD unit increase in the ratio and was significantly associated with a higher risk of hard CHD events, as was waist circumference with a hazard ratio of 1.14 (1.03-1.28) (P-value 0.016) per SD unit increase. BMI had a hazard ratio of 1.08 (0.97-1.21) (P-value 0.158) and was not significantly associated with a 10-year risk of hard CHD events.

Conclusion: Higher FM, waist-to-height ratio, and waist circumference were associated with increased risk for hard CHD events while higher FFM was associated with decreased risk. This highlights the potential importance of lifestyle interventions to build muscle and minimize adiposity for the prevention of CVD and strengthens the call for the inclusion of alternative methodologies to define obesity and measure body composition in the clinical setting.