Metabolic syndrome, circulating RBP4, testosterone, and SHBG predict weight regain at 6 months after weight loss in men.

Plain Language Summary

Metabolic syndrome (MetS) is a cluster of conditions including increased blood pressure, high blood sugar, excess body fat around the waist and abnormal cholesterol or triglyceride levels, leading to an increased risk of heart disease and type 2 diabetes. Weight loss helps to reduce MetS in the obese, but most people who lose weight regain it again, possibly due to changes in hormones and cell signalling proteins produced by fat cells, known as adipokines. The aim of this study was to examine the changes in sex hormones and adipokines and their role as predictors of weight regain in men. The study consisted of a weight-loss phase of 8 weeks on a low-calorie diet, followed by a follow-up phase of 6 months on one of four diets differing in protein content and glycaemic index. From each diet group, the researchers selected 6 men who had regained weight and 6 who had continued to lose weight during the follow-up period, and compared metabolic and hormonal markers between them. The researchers found that men who had MetS at the start of the study were nearly 3 times more likely to regain weight after the initial weight loss. A tendency to regain weight was correlated with high levels of retinol-binding protein, and low levels of both sex hormone binding globulin (SHBG) and testosterone. Among the hormones and proteins tested, SHBG showed the strongest correlation with obesity and MetS. The authors concluded that the hormones and proteins studied may play roles in the link between MetS and weight regain.