Relation among left ventricular mass, insulin resistance, and blood pressure in nonobese subjects

Because left ventricular (LV) mass (LVM) is a powerful predictor of future cardiovascular events, it is important to identify hemodynamic and nonhemod ynamic factors that increase LVM. Ne studied the separate contribution to L VM of daily arterial blood pressure (BP) and insulin resistance in a consec utive series of 29 (mean +/- SD age, 43 +/- 13 yr) nonobese (body mass inde x, 24 +/- 1.8 kg/m(2)), nondiabetic, glucose-tolerant subjects with untreat ed borderline or mild hypertension. The insulin sensitivity index (SI) was quantitatively determined from the frequently sampled iv glucose tolerance test. BP was characterized by ambulatory 24-h BP monitoring, and LVM index (LVMI) was determined by two-dimensional directed M-mode echo-cardiography. LVMI was directly related to 24-h mean BP (r = 0.47; P = 0.01). LMVI was a lso significantly related to Sr (r = -0.43; P = 0.02). In this nonobese gro up, neither LVMI nor S-I was related to body mass index or age. After adjus tment for the influence of BP on LVMI, a significant relation remained betw een LVMI and S-I (P < 0.05). We conclude that in nonobese subjects with high normal BP, insulin sensitiv ity is related to LVM independently of BP and may be an important modulator of LV growth. In addition to a reduction of arterial BP, optimal preventio n of LV hypertrophy in hypertensives may require improved insulin sensitivi ty.