Relationship of left ventricular mass to insulin sensitivity and body mass index in healthy individuals

Abstract

Objective-The objective of this study was to investigate the contribution of insulin resistance, hyperinsulinaemia and obesity, independently of other major factors, to changes in left ventricular mass a cardiovascular risk indicator, in a healthy population without co-morbid states such as diabetes or hypertension. Methods and results-This cross-sectional relational study was perfomed in 153 healthy subjects, comprising 76 men and 77 women with ages ranging from 23 to 67 years. All of them were normotensive and had a normal oral glucose tolerance test, none had cardiovascular disease and none were taking any medication. Weight, height and waist circumference were measured and BMI was calculated.A blood sample was drawn in the fasting state: plasma glucose, insulin, serum total and high density lipoprotein (HDL), low density lipoprotein cholesterol and triglycerides were measured. Insulin resistance was determined by the 'Homeostasis Assessment Model' (HOMA-IR). Subjects were studied by echocardiography. The left ventricular mass was calculated by using the anatomically validated formula of Devereux et al. Results - Left ventricular mass significantly and positively correlated with BMI, age, systolic and diastolic blood pressure and fasting blood glucose. The correlation of left ventricular mass with fasting blood glucose was not maintained after controlling for BMI. BMI, fasting blood glucose, HOMAIR, systolic and diastolic blood pressure showed significant differences with higher values for people with left ventricular hypertrophy. The logistic regression analysis showed a strong association between left ventricular hypertrophy and BMI (p < 0.05). Conclusion - Insulin resistance and fasting insulin is not associated with left ventricular hypertrophy in healthy people, independent of obesity. Obesity appears to be an independent risk factor for left ventricular hypertrophy.