Hyperinsulinemia acutely increases serum macrophage inhibitory cytokine‐1 concentration in anorexia nervosa and obesity

Abstract

CONTEXT: Macrophage inhibitory cytokine-1 (MIC-1) plays a role in the regulation of cellular responses to stress signals and inflammation. MIC-1 has also been implicated in mediation of tumour-induced anorexia and weight loss. Increased serum concentrations of MIC-1 were found in patients with anorexia nervosa (AN), obesity and type 2 diabetes. OBJECTIVE: To estimate serum MIC-1 concentration in women with AN and obese women, its regulation by hyperinsulinemia and relationship with insulin sensitivity. PATIENTS: We examined 20 women with AN, 28 healthy normal-weight female controls and 28 obese women. MEASUREMENTS: Serum MIC-1 concentration was measured in the fasting state and after 2-h euglycemic hyperinsulinemic clamp. RESULTS: At baseline, serum MIC-1 was higher in AN in comparison with other groups (normal-weight, P = 0·018; obese, P = 0·01). Hyperinsulinemia resulted in a significant increase in serum MIC-1 concentration in the entire study population (P < 0·001) and in AN (P < 0·001), normal-weight (P = 0·002) and obese (P < 0·001) groups analysed separately. Postclamp serum MIC-1 was still higher in AN women in comparison with other groups (normal-weight, P = 0·012; obese, P = 0·023). When normal-weight and obese women were analysed together, with the exclusion of AN group, an inverse correlation between insulin sensitivity and the change in serum MIC-1 during the clamp was observed (r = -0·27, P = 0·042). CONCLUSIONS: Hyperinsulinemia resulted in a significant increase in serum MIC-1 in different states of adiposity. Increased serum MIC-1 in AN women might be an additional factor responsible for weight loss in this group.