Effects of short-term very low calorie diet on the level of serum sex hormone binding globulin in patients with metabolic syndrome

Abstract

Objective To investigate the effect of short-term very low calorie diet (VLCD) on the level of serum sex hormone binding globulin (SHBG) in patients with metabolic syndrome. Methods Sixty- two inpatients (22 male and 40 female), average age (39±9)yrs with metabolic syndrome were received 9 days VLCD from December 2013 to December 2014. Anthropometric and biochemical parameters were collected before and after VLCD. The level of serum SHBG was measured with chemiluminescent assay. Homeostasis model of assessment for insulin resistance index (HOMA-IR) was employed to evaluate the insulin sensitivity. Pearson correlation analysis was used to test the correlation of variables. Results After short-term VLCD, average body weight decreased from (77.2±2.4) kg to (72.6±2.3) kg (t=15.83, P<0.001); waist circumference reduced by 4.94 cm (t=14.90, P<0.001). Blood pressure, total cholesterol, triglycerides, fasting blood glucose, fasting insulin, and HOMA-IR were all reduced significantly after VLCD. The level of serum SHBG was negatively associated with body weight, waist circumference, fasting insulin, HOMA-IR, and triglycerides(r=- 0.447-- 0.271, P<0.057), while it was positively associated with high density lipoprotein cholesterol (HDL - C) (r=0.364, P<0.05). After short-term VLCD, the level of serum SHBG increased significantly from (27.6±2.1) to (46.2±3.3) mmol/L(t=8.134, P<0.001). The variation amplitude of serum SHBG was negatively associated with basal fasting insulin, HOMA-IR, and triglycerides (r=-0.440, -0.317, -0.337, all P<0.05) , while positively associated with basal serum SHBG level(r=0.338, P< 0.05). Conclusions Short-term VLCD improves metabolic markers including serum SHBG level in patients with metabolic syndrome. Patients with higher level of baseline serum SHBG benefit more SHBG increment from VLCD, while patients with higher level of baseline fasting insulin, HOMA-IR, triglycerides benefit less. Key words: Metabolic syndrome; Sex hormone binding globulin; Low calorie diet