Serum irisin levels are correlated with insulin resistance in women with gestational diabetes mellitus

INTRODUCTION: The aim of this study was to determine the serum irisin level in pregnant women with gestational diabetes mellitus (GDM) and those with a normal glucose tolerance test (NGT).
METHODS: Forty-three pregnant women who underwent a 50-g glucose challenge test (GCT) at 24-28 gestational weeks were included the study. If the serum glucose level result of the 50-g GCT was >140 mg/dL, a 100-g oral glucose tolerance test (OGTT) was applied. Diagnosis of GDM was confirmed if any 2 of the blood glucose test results were above the following levels: fasting serum glucose ≥92 mg/dL, 1-hour glycemia ≥180 mg/dL, or 2-hour glycemia ≥153 mg/dL. Patients with a result below this value were accepted as NGT. Nine pregnant patients with 50-g GCT results below 140 mg/dL and 5 pregnant women with a history of chronic hypertension were excluded. The remaining 29 pregnant women underwent a 100-g OGTT and were divided into 2 groups according to their results: 15 had GDM and 14 had a NGT. Maternal serum irisin was measured using an enzyme immunoassay method. The correlation between biochemical and demographic parameters and the serum irisin level in all participants were analyzed.
RESULTS: There were no significant difference between the GDM and NGT groups in terms of the maternal serum irisin level (8.71±1.34 µg/mL vs 8.17±1.01 µg/mL; p>0.32). The levels of fasting insulin, fasting glucose, and the 2-hour glucose level, as well as the homeostatic model assessment of insulin resistance (HOMA-IR) results of patients with GDM were higher than those of the NGT group. The maternal serum irisin level of the GDM subjects were positively and significantly correlated with the HOMA-IR value (r: 0.65; p<0.05), fasting insulin level (r: 0.44; p<0.05), and body mass index (BMI) (r: 0.81; p<0.05). A negative but significant correlation between the serum irisin level and diastolic blood pressure of the GDM subjects was also seen. Insignificant associations were found between the HOMA-IR score, fasting insulin level, BMI, and the serum irisin level of the NGT subjects.
DISCUSSION AND CONCLUSION: The maternal serum irisin level may regulate the HOMA-IR value, fasting insulin level, and diastolic blood pressure in women with GDM.