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/-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

-cell function and insulin resistance were assessed using the homeostasis model assessment (HOMA- 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, < 0.001). There was no significant association between adipsin and HOMA-. In contrast, there was an independent negative association between adipsin and HOMA-IR ( coefficient -0.414, 95% CI -0.720 to -0.109, = 0.008). The association was more prominent in subjects with a body mass index (BMI) ≥25 kg/m or an FPG ≥100 mg/dL ( 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/m or an FPG ≥100 mg/dL.