Relation among left ventricular mass, insulin resistance, and hemodynamic parameters in type 2 diabetes

Abstract

Increased left ventricular mass (LVM) is an independent cardiovascular risk marker, which often occurs independently of arterial bloodpressure in type 2 diabetes. To investigate the factors related to the disproportionate increase in LVM in type 2 diabetes, we conducted a cross-sectional study. We studied 40 male type 2 diabetic patients aged 36 to 70 years with controlled blood pressure. Magnetic resonance imaging was used to measure LVM accurately. Radial arterial waveforms were recorded non-invasively by applanation tonometry to assess the hemodynamic status, radial augmentation index (AI) and time from forward peak to reflection peak (TPP). Glycemic control status and insulin resistance were evaluated by plasma HbA1c and homeostasis model assessment (HOMA) score, respectively. EIE′, an echocardiographic parameter for left ventricular (LV) diastolic function, was also analyzed by echocardiography. Univariate analyses showed that HbA1c and TPP had trends toward a positive correlation with LVM indexed for body surface area (LVMI), whereas AI did not. When patients' age, heart rate, and systolic blood pressure were simultaneously included in the linear regression model, the TPP and HOMA score were independently related to LVMI (p<0.05 for each variable). Increased LVMI was accompanied with impaired LV diastolic function assessed by EIE′. In conclusion, the TPP and HOMA score were associated with a modest but clinically relevant increase in LVM in type 2 diabetes independently of arterial blood pressure. Pulse wave analysis may reveal hemodynamic alterations that affect LVM but that cannot be identified using a sphygmomanometer.