Adipocyte chemerin release is induced by insulin without being translated to higher levels in vivo

Chemerin is an adipokine that regulates insulin sensitivity and insulin secretion. Prolonged hyperinsulinaemia is associated with higher systemic chemerin, and insulin induces adipose tissue chemerin release. These findings led us to hypothesize that systemic chemerin may be associated with post-prandial glucose metabolism and/or may even be induced after oral glucose load. Therefore, the effect of insulin on adipocyte chemerin levels and systemic chemerin in mice was analysed. Further, systemic levels of chemerin after oral glucose load in nondiabetic individuals were studied.

Chemerin levels were determined in adipocytes after short-term and long-term treatment with insulin. Effects of acute hyperinsulinaemia were studied in mice. Chemerin was measured during oral glucose tolerance test in 66 healthy, nondiabetic individuals stratified for established body mass index categories.

Insulin induces chemerin release from adipocytes within 24 h, while cellular levels are not affected. Short-term hyperinsulinaemia also upregulates adipocyte chemerin in vitro but has no effect on adipose tissue and chemerin serum levels of mice. Systemic chemerin is higher in overweight/obese than normal-weight controls and positively correlates with total cholesterol. Chemerin is not associated with markers of insulin sensitivity like fasting glucose or insulin. Fasting chemerin levels are similar to concentrations measured 1 and 2 h after oral glucose uptake in overweight and obese donors.

Post-prandial hyperinsulinaemia does not contribute to higher chemerin levels in nondiabetic individuals.