Association Between Serum Adipsin Levels and Insulin Resistance in Subjects With Various Degrees of Glucose Intolerance.

Context: The association between adipsin and glucose metabolism in human subjects remains unclear.

Objective: We investigated the associations between adipsin and insulin resistance/ β -cell function in subjects with various degrees of glucose intolerance.

Design: Fasting blood samples were collected for measurements of fasting plasma glucose (FPG), insulin, and adipsin. An oral glucose tolerance test was conducted in subjects with no history of diabetes.

Setting: This study was conducted at a medical center.

Patients: We enrolled 240 subjects with no history of diabetes and 80 patients with known type 2 diabetes (T2D) on diet control or metformin monotherapy.

Main Outcome Measure: β -cell function and insulin resistance were assessed using the homeostasis model assessment (HOMA- β and HOMA-IR, respectively).

Results: Levels of serum adipsin were higher in subjects with normal glucose tolerance (4.0 ± 1.1 µg/mL) or prediabetes (4.0 ± 1.5 µg/mL) compared with subjects with newly diagnosed diabetes (3.8 ± 1.1 µg/mL) or with known T2D on diet control (3.4 ± 1.0 µg/mL) or metformin monotherapy (3.0 ± 1.0 µg/mL, P < 0.001). There was no significant association between adipsin and HOMA- β . In contrast, there was an independent negative association between adipsin and HOMA-IR ( β coefficient -0.414, 95% CI -0.720 to -0.109, P = 0.008). The association was more prominent in subjects with a body mass index (BMI) ≥25 kg/m2 or an FPG ≥100 mg/dL ( P interaction < 0.001 and 0.014, respectively).

Conclusions: Serum adipsin levels were negatively associated with insulin resistance, especially in subjects with a BMI ≥25 kg/m2 or an FPG ≥100 mg/dL.