In the subgroup analyses of patients with acromegaly, those with IR had significantly lower serum irisin (2.80 vs. 4.18 μg/ml, p = 0.047) and myostatin (81.46 vs. 429.58 ng/L, p = 0.018) concentrations than those without IR (Table 4). Here, MSTN is linked to acromegaly.