MO924: Association Between Dynapenia, Cardiovascular Hospitalizations and All-Cause Mortality Among Patients on Hemodialysis
Authors: Yoshikoshi Shun , Yamamoto Shohei , Suzuki Yuta , Imamura Keigo , Harada Manae , Osada Shiwori , Kamiya Kentaro , Matsunaga Atsuhiko 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Low muscle strength is associated with adverse clinical outcomes in patients on hemodialysis (HD). However, the association between dynapenia, characterized by both low handgrip strength (HGS) and leg strength (LS) and long-term clinical outcomes in patients on HD has not yet been reported. Therefore, this study investigated whether dynapenia was associated with higher cardiovascular (CV) hospitalization risk and all-cause mortality in patients on HD.

METHOD
This retrospective study used the data of outpatients on HD from two dialysis facilities between October 2002 and March 2020. This study was approved by the Institutional Review Board/Ethics Committee of Kitasato University of Allied Health Sciences and was conducted in accordance with the principles of the Declaration of Helsinki. All participants provided written informed consent before inclusion in the study. Low muscle strength was defined as an HGS of &lt; 28 kg for men and &lt; 18 kg for women and an LS of &lt; 40% dry weight. Furthermore, dynapenia was categorized into three groups: robust (‘high HGS and high LS’), either low HGS or low LS (‘low HGS only’ or ‘low LS only’) and dynapenia (‘low HGS and low LS’). The outcomes were all-cause mortality and a composite of CV hospitalizations and mortality. These associations were examined using Cox proportional hazards and negative binomial models.

RESULTS
Data from 616 patients (mean age, 65.4 ± 12.2 years; men, 61%) were analyzed. During the follow-up (median, 3.0 years), 163 deaths and 288 CV hospitalizations occurred. Figure 1 shows the results of the Kaplan–Meier survival analyses of the robust, either low HGS or low LS, and dynapenia groups. The log-rank test showed significantly worse survival in the either low HGS or low LS and dynapenia groups than in the robust group (P &lt; 0.001). After adjusting for age, sex, body mass index, HD vintage, comorbidity index, serum albumin, serum hemoglobin, serum creatinine and C-reactive protein levels, patients with either low HGS or low LS [hazard ratio (HR), 1.81; 95% confidence intervals (95% CIs), 1.51–2.17] and dynapenia (HR 2.77, 95% CI 2.48–3.08) were found to have a higher mortality risk than those in the robust group. Similarly, compared with the robust group, either the low HGS or low LS [incidence rate ratio (IRR) 1.45, 95% CI 1.04–2.03] and dynapenia (IRR 2.06, 95% CI 1.48–2.89) groups had higher multiple CV hospitalization and all-cause mortality risks.

CONCLUSION
Dynapenia, characterized by both low HGS and LS, was significantly associated with increased CV hospitalization and mortality risk in patients on HD. Clinical assessments of muscle strength and screening patients with low muscle strength are crucial for disease management in this population. Measuring the muscle strength of the entire extremity, and not only the upper or lower extremities, may be necessary for accurate prognostic stratification.