Jia Liu, Fan Zhang

Department of Geriatrics, Peking University Third Hospital, Beijing, People’s Republic of China

Correspondence: Fan Zhang, Department of Geriatrics, Peking University Third Hospital, 49 North Garden Road, Beijing, 100191, People’s Republic of China, Email zhangfan_puh3@yeah.net

Background: Emerging evidence suggests a link between muscle health and the autonomic nervous system, but research is scarce. This study examines the connection between long-term heart rate variability (HRV) measured autonomic function and sarcopenia in the elderly, focusing on muscle mass and strength.
Patients and Methods: This retrospective cross-sectional study comprised 132 elderly hospitalized patients. Sarcopenia was defined according to the European Working Group on Sarcopenia in Older People (EWGSOP2) criteria, involving reduced muscle mass and strength. HRV was assessed using standard deviation of NN intervals (SDNN), with values below 100 milliseconds indicating reduced HRV. Multivariate logistic regression and Pearson’s correlation analyses were conducted to explore the associations between sarcopenia, muscle metrics, and HRV parameters.
Results: Among elderly hospitalized patients, 45.45% had reduced HRV, with sarcopenia patients showing a fivefold higher risk (OR: 5.042; p = 0.034). Grip strength and SARC-CalF scores were independent factors associated with reduced HRV. Moderate correlations were noted between grip strength and HRV indices, particularly with SDNN (r = 0.393, p = 0.001) and the triangular index (r = 0.385, p < 0.001), while a weaker correlation was found with very low frequency power (VLF) (r = 0.283, p = 0.006). No significant correlations were identified between HRV and muscle mass. Regression analyses revealed significant independent associations between HRV parameters and the decline in muscle strength and the onset of sarcopenia.
Conclusion: Reduced HRV is closely linked to sarcopenia and diminished muscle strength in the elderly, with the triangular index and SDNN as key indicators, highlighting HRV’s potential in muscle health assessment.

Keywords: muscle strength, SDNN, triangular index, muscle mass