Circulating Biomarkers of Handgrip Strength and Lung Function in Chronic Obstructive Pulmonary Disease.

Purpose: COPD is a multisystem disease and there is a need for clinical serum markers that can assess the decline in lung and muscle function in COPD. The goal of this study was to evaluate the potential association of serum club-cell protein 16 (CC16), α-1 acid glycoprotein (AGP) and total sialic acid (TSA) with spirometry, hand-grip strength and quality of life to assess important disease outcomes. Methods: This is a population-based cross-sectional study and data were collected from the patients at teaching hospitals of Gomal University and the University of Health Sciences in Pakistan. The study population included 1582 participants (Non-COPD; N = 788, COPD; N = 845) >55 years of age from both sexes, with data from structural interviews, clinical examinations, laboratory investigations, spirometry and hand-grip strength measurements. Results: Serum TSA and CC16 were significant predictors of FEV1% (p < 0.05) and hand-grip strength in advanced stages of COPD (p < 0.05 each) in both sexes. Men had higher absolute and adjusted hand-grip strength than women in all groups (p < 0.05). Hand-grip strength was significantly associated with FEV1% in both genders (p < 0.05) with stronger effect in women (r2 = 0.075). Serum HDL-C was an independent predictor of hand-grip strength and FEV1% (p < 0.05) in both genders. Participants with extreme problem on EQ-5D parameters had more severe COPD and reduced hand-grip strength (all p values < 0.05). Conclusion: Taken together, these studies show that the serum expressions of TSA and CC16 have correlations with spirometry and muscle decline in COPD. Further studies should be conducted to establish their efficacy in monitoring disease progression in COPD.