Blood pressure-independent relations of left ventricular geometry to the metabolic syndrome and insulin resistance: a population-based study

OBJECTIVE: Insulin resistance independently predicts heart failure and coronary disease, and has been related to thick left ventricular walls, mainly in studies of hypertensive samples not fully accounting for the influence of blood pressure. This study investigated whether the metabolic syndrome and insulin resistance are related to left ventricular geometry independently of blood pressure. DESIGN: Cross-sectional study. SETTING: A community-based sample of 820 70-year-old men and women (the Prospective Investigation of the Vasculature in Uppsala Seniors, PIVUS) free from valvular disease, heart failure and myocardial infarction. MAIN OUTCOME MEASURES: Relations of the National Cholesterol Education Program-defined metabolic syndrome and homeostasis model assessment of insulin resistance (HOMA-IR) to echocardiographic left ventricular geometry. Models were adjusted for sex, height, intra-arterial systolic and diastolic blood pressures, and antihypertensive medication. RESULTS: Left ventricular mass index was increased in persons with the metabolic syndrome in the total sample (49.7 (SD 13.1) vs 39.7 (SD 11.5) g/m(2.7), p<0.001) and in subgroups of normotensive and hypertensive persons, mainly accounted for by an increased relative wall thickness. HOMA-IR was related to left ventricular mass index in the total sample (r = 0.31; p<0.001) and in hypertensive persons, but with borderline significance in normotensive persons. HOMA-IR was related to relative wall thickness in the total sample (r = 0.27; p<0.001), in normotensive and hypertensive persons. CONCLUSIONS: Left ventricular mass and relative wall thickness were increased in persons with the metabolic syndrome and were related to HOMA-IR in a large population-based sample of men and women of the same age, accounting for covariates including intra-arterial blood pressure levels.