In general, the categories with sarcopenia status (SPPB score ≤ 8 or SARC-F score ≥ 4) were associated with higher levels of P3NP, CAF22, osteonectin, FABP3 and MIF and lower levels of irisin in the individual cohorts of healthy controls, COPD and CHF patients. The gene discussed is FNDC5; the disease is sarcopenia.