SERUM-INSULIN, IGF-I, IGF-II AND GROWTH-HORMONE, AND LEFT-VENTRICULARMASS IN NONINSULIN-DEPENDENT DIABETES-MELLITUS

OBJECTIVE: To investigate whether serum insulin, insulin-like-growth f actor I (IGF-I), insulin-like-growth factor II (IGF-II) and growth hor mone (GH) - each of which is a known trophic factor in vitro for the c ardiomyocyte, and levels of which can be altered in noninsulin-depende nt diabetes mellitus (NIDDM)- are related to left ventricular (LV) mas s in patients with NIDDM. DESIGN: Observational study. SETTING: Univer sity teaching hospital. PATIENTS AND METHODS: Patients with NIDDM with out signs, symptoms or past history of hypertension, ischemic or valvu lar heart disease, or heart failure were recruited from the diabetes c linic of university hospital. Fasting patients had blood drawn for det ermination of serum insulin, IGF-I, IGF-II and GH by radioimmunoassay. Height, weight and blood pressures were recorded. An electrocardiogra m was obtained and echocardiography was performed for calculation of L V mass. RESULTS: Patients' average age was 54.7+/-1.6 years, and durat ion of NIDDM was 9.3+/-1.2 years. LV mass was 113.7+/-8.9 g/m(2) in me n (n = 13) and 104.1+/-10.8 g/m(2) in women (n = 10). Serum insulin wa s 25.3+/-1.8 ng/ml, IGF-I was 255+/-15 ng/mL, IGF-II was 0.62+/-0.05 m u g/L and GH was 5.4+/-0.5 ng/mL. There were no significant difference s in LV mass among patients with serum insulin, IGF-I, IGF-II or GH in the upper compared with the lower 50 th percentile. There were no sig nificant differences in serum insulin, IGF-I, IGF II or GH among patie nts in the upper compared with the lower 50th percentile fur LV mass. Standardization of LV mass for body size, either by height or body sur face area, did not alter the relationships. The correlation coefficien ts from linear least squares regression analysis between these hormone s and LV mass were low (r<0.003), suggesting that even much larger sam ple sizes might not alter these findings. CONCLUSIONS: These data sugg est that circulating total serum concentrations of growth factors (ins ulin, IGF-I, IGF-II and GH) are not determinants of LV mass in nonhype rtensive patients with NIDDM.