Relationship between sex hormone-binding globulin (SHBG) and insulin-like growth factor-I (IGF-I) with metabolic syndrome

Abstract

GLUCOSE intolerance, insulin resistance, hypertension, visceral obesity, and dyslipidemia are the major components of metabolic syndrome (MS). To evaluate the association between serum SHBG and IGF-1 levels and the risk of MS, Furthermore, to determine the correlations between SHBG and IGF-1 and the main components of MS. A total of 402 subjects with and without MS were enrolled in this study (MS=156, Non-MS=246) aged > 18 years. The age, height, weight, BMI, HC, WC, and incidence of diabetes, hypertension and dyslipidemia of all cases were recorded. The collected serum samples were used to assess lipid profile, glucose and insulin levels. The levels of LDL-cholesterol were calculated using Friedewald's formula. Insulin resistance was measured (as HOMA score). The levels of serum SHBG and IGF-1 were measured using Elisa technique. A positive relationship between SHBG and MS was detected, however no such correlation was observed concerning IGF-1. There were positive correlations between SHBG and main components of MS; with insulin, HOMA-index, TC, TG and HDL. Conversely, IGF-1 showed negative correlations. Finally, SHGB was more sensitive (63.5%), accurate (61.9%) than IGF-1 (51.9%), accuracy (59%). Our study reveals that lower SHBG is more strongly associated with metabolic syndrome and its main components than lower IGF-1. SHBG could be the essential driver of these relations, conceivably reflecting its association with insulin sensitivity; however more studies are required to confirm this relationship.