Is there a relationship between left ventricular mass and plasma glucose and lipids independent of body mass index? Results of the Gubbio Study.

BACKGROUND AND AIMS: The association between left ventricular (LV) mass (M) and variables described as features of the insulin resistance syndrome, such as obesity and measures o lipid and carbohydrate metabolisms, has been reported in hypertensives. The aim of the present study was to investigate in a large, population based group of non hypertensive people, the prevalence of LV hypertrophy (H) and the relationship of LVM with some of the variables described in the insulin resistance syndrome, independently of obesity. For this reason we investigated the normotensive subjects in the age range 45-54 yrs (n = 435) of the total population of participants in the Gubbio Population Study.

METHODS AND RESULTS: Serum lipids, cholesterol (Chol), triglyceride (Tg), HDL cholesterol, fasting blood glucose (FBG), blood pressure (BP), body weight and height were measured and body mass index (BMI) was calculated; LVM was assessed by M-mode echocardiography. Using a normalization criterion not related to body weight (g/m2.7) and the cut-off of 49.2 g/m2.7 for men and 46.7 g/m2.7 for women, LVH was found in 25% of the sample whilst, when LVM was corrected by body surface area (cut-off 116 g/m2 for men and 104 g/m2 for women), the prevalence of LVH was quite lower (10.3%). In the univariate analyses LVMi was closely related to BP, BMI and metabolic variables whilst in the multivariate analysis only BP, BMI, and age were detected as independent predictors of LVMi. When the sample was divided into obese and non-obese subjects on the basis of BMI (cut-off 30 kg/m2), no difference in metabolic variables was seen between subjects with and without LVH within each BMI class. Regarding left ventricular geometry, RWT was positively related to triglycerides and blood glucose and inversely to HDL-chol.

CONCLUSIONS: The present study in the middle age normotensive sample of the general population of Gubbio extends to normotensives the relationship between left ventricular mass and metabolic parameters already seen in hypertensives. BMI seems to account for most of the increases in LVM since the prevalence of LVH, which was definitely high when LVM was not normalized to body weight, fell to approximately 4% when the influence of body weight was excluded. Moreover differences in metabolic values between subjects with and without LVH disappeared when the subjects were stratified by BMI. Left ventricular geometry, on the other hand, seems to be related to some metabolic variables.