# Association Between Sarcopenia and Buttock Pain Among Middle-Aged and Older Chinese People: Evidence from the China Health and Retirement Longitudinal Study

## TL;DR

This study finds that sarcopenia, or muscle loss, is linked to an increased risk of developing buttock pain in older Chinese adults.

## Contribution

The study is the first to show a longitudinal association between sarcopenia and incident buttock pain in a large Chinese population.

## Key findings

- Possible sarcopenia was associated with prevalent buttock pain.
- Sarcopenia predicted incident buttock pain after 5 years of follow-up.
- Low handgrip strength was linked to incident pain in males.

## Abstract

Background: Sarcopenia and buttock pain are highly prevalent in older adults and exert profound negative effects on quality of life. Little is known about the association between sarcopenia and buttock pain. Methods: This study performed cross-sectional and longitudinal analyses based on prospective cohort study data from the 2015 and 2020 waves of the China Health and Retirement Longitudinal Study (CHARLS). A total of 12,884 community-dwelling adults aged ≥45 years were included in the cross-sectional analysis, and 10,511 of these participants, free of buttock pain at baseline, were further investigated to assess incident buttock pain. Sarcopenia status was categorized as non-sarcopenia, possible sarcopenia, and sarcopenia according to the 2019 Asian Working Group for Sarcopenia and the 2021 Chinese consensus criteria. Logistic regression models adjusted for sociodemographic and health-related covariates were performed to estimate associations between sarcopenia status and buttock pain. Results: After adjusting for covariates, possible sarcopenia, but not sarcopenia, was associated with prevalent buttock pain (OR 1.23, 95% CI 1.03–1.48). After 5 years of follow-up, participants with sarcopenia were more likely to develop incident buttock pain (OR 1.37, 95% CI 1.03–1.81). Among sarcopenia components, poor physical performance was linked to prevalent pain (OR 1.25, 95% CI 1.05–1.50) and low handgrip strength predicted incident pain in males (OR 1.31, 95% CI 1.07–1.60). Appendicular muscle mass was not independently associated with either prevalent or incident buttock pain. Conclusions: In middle-aged and older Chinese adults, sarcopenia is an independent risk factor for incident buttock pain. Early screening and interventions of sarcopenia may help to mitigate the burden of buttock pain and its associated disability.