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.
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.