CLINICAL STUDY Circulating IGF binding protein-1 is inversely associated with leptin in non-obese men and obese postmenopausal women

Objective: Hyperleptinaemia and hyperinsulinaemia interrelate to insulin-like growth factor binding protein 1 (IGFBP-1), and disturbances in the growth hormone–IGF-I axis are linked to obesity and cardiovascular diseases. However, whether the association between leptin and the GH–IGF-I axis is altered with increasing obesity is not known. We therefore examined the relationship between leptin, IGF-I, IGFBP-1, insulin and proinsulin in men and women with or without obesity in a population study. Design and subjects: Healthy subjects \u85n 158; 85 men and 73 pre- and postmenopausal women) from the Northern Sweden MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) population were studied with a cross-sectional design. Methods: Anthropometric measurements (body mass index (BMI) and waist circumference) and oral glucose tolerance tests were performed. Radioimmunoassays were used for the analyses of leptin, IGF-I and IGFBP-1, and ELISAs for specific insulin and proinsulin. Results: Leptin inversely correlated to IGFBP-1 in non-obese men \u85P, 0:05 and obese postmenopausal women \u85P, 0:05: In contrast, leptin did not correlate to IGF-I. IGFBP-1 wa