Introduction: Hand grip strength (HGS) and fatigue are both related to COPD, but the relationship between HGS and fatigue among subjects with COPD is unknown.
Aim: To evaluate the relationship between HGS and fatigue among subjects with and without COPD.
Methods: Subjects with COPD and age- and sex-matched referents without COPD have been followed annually since 2005 in the OLIN COPD study. COPD was defined as post-bronchodilator FEV1/VC<0.70. In 2014, 304 subjects with and 362 subjects without COPD were clinically examined including interviews, spirometry, HGS and the FACIT-Fatigue questionnaire (0-52, lower scores represent increased fatigue, and clinically relevant fatigue (CRF) a score ≤43). Linear regression with HGS as outcome was used to estimate adjusted Beta coefficients for CRF.
Results: Among subjects with COPD those with CRF had lower mean HGS than those without CRF; in men 38.6 vs 43.1 kg (p=0.001) and in women 21.9 vs 23.7kg (p=0.051), corresponding to 42.0 vs 44.2 kg (p=0.114) and 23.1 vs 25.1 kg (p=0.069) in non-COPD. Among subjects with COPD, HGS remained associated with CRF (Beta coefficient (95%CI)) among men -2.658 (-4.612 to -0.703), but not among women -0.924 (-2.557 to 0.708), when adjusted for age, height and smoking habits. The corresponding coefficients among subjects without COPD were non-significant: -0.944 (-3.086 to 1.198) among men and -0.961 (-2.767 to 0.845) among women.
Conclusions: In this population-based study hand grip strength was associated with clinically relevant fatigue among subjects with COPD but not among subjects without COPD, and among men with COPD the association between hand grip strength and fatigue remained significant also when adjusted for confounders.