Hyperinsulinaemia, regional adipose tissue distribution and left ventricular mass in normotensive, elderly, obese subjects

Abstract

Obesity is a metabolic condition, related to abnormalities of the glyco-insulinaemic metabolism, and plays a substantial role in the development of cardiovascular disease. The aim of this study was to establish a correlation among left ventricular mass, evaluated echocardiographically according to Penn Convention criteria, blood pressure, evaluated by ambulatory blood pressure monitoring, anthropometric indices for evaluation of body mass index and waist to hip ratio circumference, regional adipose tissue distribution, evaluated by ultrasound measurements of visceral adipose tissue, and insulin resistance, evaluated by hyperinsulinaemia by oral glucose tolerance test. We selected two groups of elderly male subjects well matched for age (68.5 +/- 6.4 years): 29 obese and 20 lean, with a body mass index, respectively, of 34.6 +/- 2.9 and 23.4 +/- 2.3. Statistical analysis was carried out by Student's t-test and linear regression analysis. In spite of the fact that statistical analysis showed a higher, though not statistically significant, systolic and diastolic mean blood pressure in the lean subjects, we found an increased left ventricular mass in obese subjects (P < 0.0001). The area under the insulin curve was higher in obese than in lean subjects (P < 0.0001) while the area under the glucose curve was not significantly different in the two groups. Furthermore, linear regression analysis showed that in obese subjects left ventricular mass was strictly correlated with visceral adipose tissue (r = 0.607; P < 0.0001) and hyperinsulinaemia (r = 0.615; P < 0.0001). In conclusion, our data suggest that centripetal adipose tissue distribution and hyperinsulinaemia, independent of blood pressure values, are closely correlated with left ventricular mass.

Sex-Related Differences in the Relations of Insulin Resistance and Obesity to Left Ventricular Hypertrophy in Japanese Hypertensive Patients

“…A potential limitation of the present study is that the insulin levels were assessed in the fasting state but not in response to glucose loading. Several studies have found a positive association between postload insulin levels or area under the postload insulin curve and LV structural variables (22)(23)(24). In a recent investigation, the HOMA value was related to LV mass in women alone, but this relation was largely accounted for by obesity (9).…”

Left Ventricular Structure and Function in Obese Adolescents: Relations to Cardiovascular Fitness, Percent Body Fat, and Visceral Adiposity, and Effects of Physical Training

“…In adults, previous studies reported that VAT was correlated with LVM and LV internal dimension during diastole. 24,25 Cardiovascular involvement (ie, hypertension, increased LVM, cardiac malfunction) can be identified in early stages of obesity. Possible rationales may include volume overload or humoral activation.…”

Insulin resistance and vascular remodelling, in relation to left ventricular mass, geometry and function: an answer to LIFE?

“…Indeed, these studies reported that the significance of a relation between LVM and insulin sensitivity disappeared after body mass or size was adjusted for, suggesting that insulin or insulin sensitivity was a covariate to body mass or size rather than LVM. 12,16,[18][19][20][21] In fact, few studies have even reported that obesity is related to LVM, independent of high BP. [22][23][24] In a substudy to the Captopril Prevention Project (CAPPP), 20 there were no significant relations between LVM, LVM index, and insulin levels, insulin sensitivity (assessed by euglycaemic insulin clamp) or insulin turnover in 51 previously untreated middle-aged nondiabetic hypertensive patients.…”

“…18 Furthermore, another study in normotensive elderly patients (mean age 68 years) has also indicated a strong relation (independent of BP values) between LVMHt 2.7 and insulin sensitivity in obese subjects (especially in those with centripetal adipose tissue distribution), but not in lean normotensive subjects. 19 Thus, obesity appears to play a central role in these interactions. Indeed, in a cohort of 322 healthy, normotensive junior high school aged children undergoing euglycaemic insulin clamp procedures, LVM was not related to insulin resistance, fasting insulin, BP, or lipid levels when the correlations were adjusted for adiposity.…”