FNDC5 and diabetes mellitus: However, patients with diabetes (n=41) (14485 [813–29398] pg/ml) had lower irisin levels than those without diabetes (n=45; 19724 [865–47683] pg/ml) (p=0.002).The subgroup analysis in patients with diabetes has further revealed that those who use oral antidiabetic agents (n=23) had higher irisin levels compared to those on insulin therapy (n=18) (16975 [1089–29398] vs. 4880 [813–26078], pg/ml, p<0.001) (Table 4 and Fig. 2).