FNDC5 and sarcopenia: Moreover, in Model 4, a lower level of coenzyme Q10 was significantly associated with an increased risk of sarcopenia (odds ratio: 3.70, p = 0.04), and after additionally adjusting for confounders (age, males, tobacco use, alcohol use, and physical activity), the level of irisin, creatine kinase, and coenzyme Q10 was significantly associated with an increased risk of sarcopenia (Model 5, irisin, odds ratio: 6.46, p < 0.01; creatine kinase, odds ratio: 3.31, p = 0.04; coenzyme Q10, odds ratio: 9.79, p = 0.01).