Impact of Heart Disease on Hand Grip Strength in COPD
Background: Heart disease (HD) and muscle dysfunction contributing to muscle weakness are common comorbidities among subjects with COPD. However, the relationship between muscle weakness, measured as hand grip strength (HGS), and HD in COPD is unclear.
Aim: To evaluate the impact of HD on HGS among subjects with and without COPD.
Methods: Data was collected from the OLIN COPD study, where subjects with COPD have been invited to annual examinations since 2005 together with age- and sex-matched referents without COPD. During 2009, 441 subjects with COPD (post-bronchodilator FEV1/VC<0.70) and 570 without COPD participated in structured interviews, spirometry and measurements of HGS.
Results: Among COPD subjects and non-COPD subjects, both men and women with HD had significantly lower HGS compared to those without HD (in COPD: men: 42 kg vs. 47 kg, p=0.003; women: 23 kg vs. 26 kg p=0.005 and in non-COPD: men: 41 kg vs. 48 kg, p<0.001; women: 24 kg vs. 28 kg, p=0.002). In a linear regression model, HGS was associated with age, beta coefficient (B) =-0.46 (p<0.001), male sex, B=19.85 (p<0.001), FEV1% predicted, B=0.06 (p=0.007), and HD, B=-1.83 (p=0.052) among COPD-subjects, while among non-COPD-subjects corresponding beta coefficients were: age, B=-0.51 (p<0.001), male sex, B=19.63 (p<0.001), HD, B=-1.17 (p=0.713) and FEV1% predicted B=0.02 (p=0.324). Smoking habits were not significant in either group.
Conclusions: In this population-based study hand grip strength was, as expected, associated with age and sex among both COPD and non-COPD-subjects. However, among those with COPD may, besides FEV1% predicted, also heart disease have an impact on hand grip strength.