Serum and adipose tissue chemerin is differentially related to insulin sensitivity

Objective The aim of the study was to assess serum chemerin concentration and s.c. adipose tissue (SAT) chemerin expression in relation to insulin sensitivity and obesity in young healthy subjects. Design We performed a cross-sectional study including 128 subjects, 44 with normal weight, 44 with overweight and 40 with obesity. Methods Hyperinsulinemic-euglycemic clamp and SAT biopsy were performed. Next, 30 subjects with obesity underwent 12-week weight-reducing dietary intervention. Results Serum chemerin was higher and SAT chemerin expression was lower in subjects with obesity in comparison with other groups. The relationship of serum chemerin with SAT expression and insulin sensitivity were positive in normal weight and overweight individuals, and negative in individuals with obesity. In the entire study population, serum chemerin was also positively related to hsCRP, serum fetuin A and alanine aminotransferase. SAT chemerin was positively related to insulin sensitivity, SAT insulin signaling and adipogenic genes. Weight loss decreased serum chemerin, whereas SAT chemerin increased in subjects with the highest increase in insulin sensitivity. Conclusions Serum and SAT chemerin is differentially associated with insulin sensitivity and the relationship between serum chemerin and insulin sensitivity depends on adiposity. SAT chemerin is positively associated with insulin sensitivity across a wide range of BMIs and may be proposed as a biomarker of metabolically healthy SAT. Our results suggest that SAT is not the main source of serum chemerin in obesity.