Associations of Insulin Levels With Left Ventricular Structure and Function in American Indians: The Strong Heart Study

We evaluated the association of insulin and echocardiographic left ventricular (LV) measurements in 1,388 (45% men) nondiabetic American Indian participants in the Strong Heart Study (SHS). Significant (all P 10 fasting insulin and LV mass ( r = 0.24 and 0.26), left atrial diameter ( r = 0.25 and 0.28), posterior wall thickness ( r = 0.20 and 0.26), septal thickness ( r = 0.19 and 0.24), LV diameter ( r = 0.17 and 0.16), and cardiac output ( r = 0.20 and 0.24) and in women relative wall thickness ( r = 0.11) and peripheral resistance ( r = −0.17). In regression analyses, adjusting for BMI, age, height, and systolic pressure, fasting insulin was independently correlated with cardiac output in men and relative wall thickness and septal thickness in women (all P P = 0.05), higher cardiac output (5.5 vs. 4.9 l/min; P P = 0.01), paralleling results of regression analyses. Positive relations between insulin and heart size in nondiabetic adults are largely due to associations with body size; after adjustments for covariates, fasting insulin levels are related to greater LV size and cardiac output in men and more concentric LV geometry in women.