Correlation between Blood Activin Levels and Clinical Parameters of Type 2 Diabetes

Aims. Activins A and B, and their binding protein, follistatin, regulate glucose metabolism and inflammation. Consequently, their role in type 2 diabetes (T2D) was examined. Methods. Blood was taken from fasted participants (34 males; 58 females; 50–75 years) with diabetes or during an oral glucose tolerance test (OGTT). Clinical parameters were assessed, and blood assayed for activins, follistatin, and C-reactive protein. Results. Serum levels of activin A (93.3 ± 27.0 pg/mL, mean ± SD), B (81.8 ± 30.8 pg/mL), or follistatin (6.52 ± 3.15 ng/mL) were not different (P > 0.05) between subjects with normal OGTT (n = 39), impaired glucose tolerance and/or fasting glucose (n = 17), or T2D (n = 36). However, activin A and/or activin B were positively correlated with parameters of insulin resistance and T2D, including fasting glucose (P < 0.001), fasting insulin (P = 0.02), glycated hemoglobin (P = 0.003), and homeostasis model assessment of insulin resistance (HOMA-IR; P < 0.001). Follistatin was positively correlated with HOMA-IR alone (P = 0.01). Conclusions. These data indicate that serum measurements of activin A, B, or follistatin cannot discriminate risk for T2D in individual patients, but the activins display a positive relationship with clinical parameters of the disease.