Association between sarcopenia and hemoglobin level: a systematic review and meta-analysis

Background: Sarcopenia is a disease characterized by decreased skeletal muscle mass and function in elderly individuals. Decreased hemoglobin levels is a marker of anemia. According to reports, there may be an association between anemia and sarcopenia, but research is inconsistent. Therefore, this meta-analysis aims to explore the association between sarcopenia and low hemoglobin levels. Methods: We searched PubMed, Embase, the Cochrane Library, Web of Science, Ovid, China National Knowledge Infrastructure (CNKI), and Wan Fang databases until September 2022. The present study included cross-sectional and case-control studies regarding low hemoglobin levels and sarcopenia. The studies were selected using inclusion and exclusion criteria. Studies were meta-analyzed by Review Manager 5.4 and Stata 16.0. We performed the heterogeneity test using the I-2 test. Subgroup analysis was carried out to explore the cause of heterogeneity. Egger test was used to evaluate publication bias. Results: Out of 1,550 initial studies, 16 studies were meta-analyzed. Sarcopenia participants had significantly lower levels of hemoglobin than controls (MD = -0.53, 95% CI: -0.68 to -0.37, p < 0.001). Subgroup analysis, performed in China population reported lower hemoglobin levels in the sarcopenia population (MD = -0.49, 95% CI: -0.65 to -0.33, p < 0.001). And sarcopenia based on AWGS criteria reported lower hemoglobin levels (MD = -0.49, 95% CI: -0.65 to -0.33, p < 0.001). Among the population from hospitals and communities, patients with sarcopenia have lower hemoglobin levels. Conclusion: Our meta-analysis found evidence that sarcopenia is associated with low hemoglobin levels. However, further large-scale prospective studies should be conducted in the future to further confirm our conclusions.