RESUMO
OBJECTIVE: This study aimed to investigate the serum irisin levels and diet quality of newly-diagnosed type 2 diabetes mellitus (T2DM) patients in comparison with healthy controls and to identify the correlations between serum irisin levels with diet quality, anthropometric measurements and biochemical parameters. SUBJECTS/METHODS: This case-control study was conducted with 38 newly-diagnosed T2DM patients and 38 healthy control individuals. Diet quality was calculated from the semi-quantitative food frequency questionnaire by using the Healthy Eating Index (HEI) 2015. The anthropometric measurements were taken and body composition was analyzed with bioelectric impedance analysis (BIA) method. Biochemical parameters and serum irisin levels were analyzed in blood samples which were obtained after overnight fasting. RESULTS: Irisin levels were higher in the T2DM group compared to the healthy control group (2.57 ± 0.44 ng/mL and 2.15 ± 0.44 ng/mL, respectively; p < 0.001). The optimal cut-off value for irisin to predict T2DM was 2.195 ng/mL (specificity = 71.1%, sensitivity = 78.9%). In both groups, irisin levels were not associated with overall HEI 2015; however, they were positively associated with total and whole fruit scores in the T2DM group (p < 0.05). After adjustment according to age, sex and BMI, in the T2DM group HDL cholesterol positively affected by irisin levels, while in the control group triglyceride positively affected irisin levels (p < 0.05). CONCLUSION: High levels of irisin in newly diagnosed T2DM patients compared to healthy individuals indicate that irisin may have a role in the monitoring and treatment of T2DM. Though irisin levels were not associated with total diet quality, they were associated with fruit consumption.