Clinical Characteristics of Dynapenia and Sarcopenia in Hospitalized Patients with Cardiovascular Disease

Dynapenia, defined as reduced muscle strength despite preserved muscle mass, is increasingly being recognized alongside sarcopenia in older adults. Clinical differences between dynapenia and sarcopenia in hospitalized cardiovascular disease (CVD) patients remain unclear. This study aimed to compare the clinical characteristics among Normal, Dynapenia, and Sarcopenia phenotypes.This prospective, single-center cohort study included patients admitted to the cardiology ward at Seirei Hamamatsu General Hospital (July 2024-September 2025) who received physical therapy and completed body composition assessment at discharge. The patients were divided into Normal, Dynapenia, and Sarcopenia groups classified using a previously reported flowchart and cutoff values for grip strength and skeletal muscle mass index (SMI) based on the Asian Working Group for Sarcopenia 2025 criteria. Three-group comparisons were conducted using multiple comparison methods, and no adjustment was made due to the exploratory nature of the analyses. Adjusted comparisons were conducted using analysis of covariance controlling for age, sex, B-type natriuretic peptide, and SMI.Among the 316 patients, 133 (42.1%) were Normal, 31 (9.8%) Dynapenia, and 152 (48.1%) Sarcopenia. Unadjusted comparisons showed graded differences across the 3 groups for physical function, cognitive function, and activities of daily living, with the decreasing order being Normal > Dynapenia > Sarcopenia. After adjustment, differences between the Dynapenia and Sarcopenia groups were no longer significant, whereas Dynapenia remained lower than Normal for grip strength, walking speed, and phase angle.Dynapenia may represent a distinct phenotype with preserved muscle mass but reduced strength, influenced by comorbidities and systemic CVD effects. Identifying dynapenia could support phenotype-specific rehabilitation strategies, although further studies are needed to clarify the underlying mechanisms.