Determinants of left ventricular mass and presence of metabolic risk factors in normotensive individuals

Abstract

Background: Insulin resistance and obesity are recognized as left ventricular (LV) mass determinants independent of blood pressure (BP). Prevalence of LV hypertrophy (LVH) and the relationship between LV mass to body composition and metabolic variables were evaluated in normotensive individuals as participants of a population-based study.

Methods: LV mass was measured using the second harmonic image by M-mode 2D guided echocardiography in 326 normotensive subjects (mean 47+/-9.4 years). Fasting serum lipids and glucose, BP, body composition and waist circumference (WC) were recorded during a clinic visit.

Results: Applying a normalization criterion not related to body weight (g/height raised to the power 2.7) and the cut-off points of 47.7 (men) and 46.6 g/m(2.7) (women), LVH was found in 7.9% of the sample. Univariate analysis showed LV mass (g/m(2.7)) related to age, body mass index (BMI), WC, fat and lean body mass, systolic and diastolic BP, and metabolic variables (cholesterol, HDL-c, triglycerides and glucose). In multivariate analysis only BMI and age-adjusted systolic BP remained as independent predictors of LV mass, explaining 31% and 5% of its variability. Removing BMI from the model, WC, age-adjusted systolic BP and lean mass remained independent predictors, explaining 25.0%, 4.0% and 1.5% of LV mass variability, respectively. After sex stratification, LV mass predictors were WC (8%) and systolic BP (5%) in men and WC (36%) and systolic BP (3%) in women.

Conclusion: BMI in general and particularly increased abdominal adiposity (WC as surrogate) seems to account for most of LV mass increase in normotensive individuals, mainly in women.