Relationship between high-sensitivity C-reactive protein, regular exercise, and handgrip strength in Korean older adults: a nationwide cross-sectional study

Background: Dynapenia increases the risk of frailty, disability, and mortality in older adults. Chronic inflammation and physical inactivity are considered major contributors. This study examined the associations of high-sensitivity C-reactive protein (hs-CRP) levels and regular exercise with dynapenia in older Korean adults. Methods: We analyzed data from 4,935 adults aged ≥65 years who participated in the 2015-2018 Korea National Health and Nutrition Examination Survey. Dynapenia was defined as handgrip strength <28 kg in men and <18 kg in women. Serum hs-CRP levels were categorized as <1, 1-3, and >3 mg/L. Multivariable logistic regression was used to evaluate the associations of hs-CRP levels and exercise with dynapenia. Results: The prevalence of dynapenia was 27.4%. Participants with dynapenia had higher adjusted mean hs-CRP levels than those without (1.60 mg/L vs. 1.25 mg/L, P=0.008). Compared with hs-CRP <1 mg/L, hs-CRP >3 mg/L was independently associated with dynapenia (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.26-2.10). Lack of resistance exercise (OR, 1.99; 95% CI, 1.52-2.61) and aerobic exercise (OR, 1.45; 95% CI, 1.20-1.75) were also independently associated with dynapenia. Participants with both hs-CRP >3 mg/L and no regular exercise had higher odds of dynapenia (OR, 2.69; 95% CI, 1.89-3.83) compared with those with hs-CRP <1 mg/L who exercised regularly. Conclusion: Elevated hs-CRP levels and lack of regular exercise were independently associated with dynapenia, suggesting that reducing systemic inflammation and promoting regular exercise may help preserve muscle strength in older adults.