ABSTRACT
Hyperinsulinemia and insulin resistance may contribute to the development of cardiac hypertrophy which is a major cardiovascular risk factor. In humans, however, the evidence is inconclusive. Antihypertensive drugs have different effects on insulin metabolism, sensitivity, and on left ventricular mass [LVM]. To study the association between LVM and insulin resistance as well as some other cardiovascular risk factors. Also, to compare the effects of two drugs [Atenolol, lisinopril], which have different effects on insulin sensitivity on LVM. The study included four groups: Group [I] control group included 10 healthy lean females aged 35.7+3.4 years. Group [II] included 28 obese normotensive female patients aged 35.39+3.9 1 years, body mass index [BMI] 36.18+3.93 Kg/m2. Group [III] included 28 newly diagnosed obese hypertensive female patients aged 35.85+ 7.8 years, BMI 39.34+4.12 Kg/m2. Group [IV] included 28 newly diagnosed lean hypertensive female patients aged 34.36+4.45 years, BMI 22.98+1.60 Kg/m2. Patients in groups III and IV were randomized to treatment with atenolol or lisinopril [14 patients in each group]. The following parameters were assessed BMI, WHR, systolic and diastolic blood pressure, fasting plasma glucose and insulin, fasting insulin resistance index [FIRI], LVM and left ventricular mass index [LVMI]. Obese and hypertensive patients had significant increase in insulin resistance, LVM and LVMI compared to controls [P<0.05]. Abdominal obesity as repesented by WHR, was directly associated with insulin resistance, LVM, and LVMI [r = 0.749, P<0.001; r = 0.523,P<0.O01; r = 0.656, P<0.001 respectively]. LVM was positively correlated with systolic and diastolic blood pressure, BMI. WHR, and insulin resistance [r = 0.749, P<0.001; r = 0.639, P<0.001; r = 0.224, P = 0.041, r = 0.523, P<0.001; r = 0.509, P<0.001 respectively]. After adjustment for systemic blood pressure and obesity, LVM was independently associated with insulin resistance [P<0.001]; Lisinopril, but not atenolol was associated with favorable effect on insulin resistance and led to more significant regression of LVM in lean [P<0.001] and obese [p = 0:004] hypertesnive patients. LVM has a positive independent correlation with hyperinsulinemia and insulin resistance. Hyperinsulinemia has independent role in promoting left ventricular hypertrophy. Agents and maneuvers which improve insulin sensitivity might be beneficial in management of left ventricular hypertrnphy and other deleterious effects of hyperinsulinemia