Abstract 5160: Obesity is Related to Concentric Left Ventricular Hypertrophy: Results from the Multi-Ethnic Study of Atherosclerosis (MESA)
Obesity is a risk factor for cardiovascular disease but its association with left ventricular (LV) morphologic adaptations is debated because of obesity-associated co-morbidities. We evaluated the relationship of obesity to ventricular size and remodeling independent of other risk factors for LV hypertrophy. 5004 participants (age 45– 84 years; 52% female) of the MESA study free of clinical cardiovascular disease underwent cardiac MRI to assess LV size and function. The association of LV indices with measures of obesity, including fat mass (FM), body mass index (BMI) and waist circumference (WC), was determined using generalized additive models adjusted for established risk factors for LV hypertrophy and fat-free mass (FFM). FFM of participants was estimated based on height-weight models derived from bioelectrical impedance studies and FM was obtained by subtracting FFM from weight. LV mass and end diastolic volume were positively associated with FM, BMI and WC after adjustment for risk factors and FFM. For a given FFM, LV mass/volume ratio increased with FM up to approximately 50 kg FM (Figure⇓). Cardiac output and stroke volume were also positively associated with FM (slopes: CO 0.02 L/min per kg FM, SV 0.16 ml per kg FM, p<0.001 for each). Ejection fraction showed no significant association with FM. The associations of fat mass to increased LV mass and LV mass/volume were similar in patients with and without obesity associated co-morbidities. Obesity is associated with concentric LV hypertrophy, marked by increased LV mass/volume ratio, increased cardiac output and preserved ejection fraction.