Prevalence and risk factors of lower back pain in middle-aged and elderly people with sarcopenia: a nationwide cross-sectional study

Background: Although sarcopenia and lower back pain (LBP) are common geriatric conditions for older adults, the relationship between them remains unclear. This study aimed to clarify the prevalence and risk factors of LBP in elderly with sarcopenia using the China Health and Retirement Longitudinal Study (CHARLS). Methods: The CHARLS is an ongoing, nationally representative survey conducted among residents of China from 2008 to 2020. Sarcopenia status was assessed based on physical examination findings, and participants aged 45 years or older who reported experiencing low back pain (LBP) were identified. This national study analysed data from 8,113 participants collected in 2015. One-way ANOVA and Pearson’s chi-squared test were employed to compare LBP prevalence rates. At the same time, a multiple logistic regression model was used to identify factors associated with LBP in individuals with sarcopenia. Results: The prevalence of LBP was 24.19% (95% CI 22.94–25.44) among individuals with sarcopenia, significantly higher than 16.40% (15.19–17.61) in those without sarcopenia. LBP was more prevalent in females (28.91% [27.13–30.69]) than in males (18.43% [16.74–20.11], p < 0.001 for gender difference). Additionally, individuals with more than four chronic conditions had a significantly higher prevalence of LBP (44.83% [40.87–48.79]) compared to those without chronic conditions (13.02% [11.02–15.02], p < 0.001). Risk factors for LBP in the sarcopenia population included a history of chronic diseases such as heart attack (odds ratio 1.40 [95% CI 1.11–1.77]), kidney disease (1.80 [1.30–2.49]), stomach disease (1.62 [1.35–1.94]), and arthritis or rheumatism (1.76 [1.48–2.10]). Additional significant risk factors were sleeping time of less than 5 h (2.06 [1.36–3.10]), living in the rural area (1.54 [1.20–1.96]), illiteracy (1.64 [1.21–2.22]) and depression (3.16 [2.56–3.89]). Conclusions: The current study highlighted the high prevalence of LBP in the sarcopenia population. Chronic diseases, sleep time, residence, educational level, depression, and history of falls are major risk factors for LBP in the sarcopenia population.