Sarcopenic obesity (SO), which refers to the coexistence of sarcopenia and obesity. It can lead to physical disability, morbidity, and even mortality. This systematic review and meta-analysis aimed to estimate the global prevalence of SO in older adults.
We searched PubMed, Embase, and Web of Science for studies reporting the prevalence of SO from inception to December 2020. Two researchers independently screened the literature, evaluated study quality, and extracted data. A random-effects model was used to pool the estimates for the prevalence of SO. Subgroup analysis, sensitivity analysis, and meta-regression analysis were conducted. Publication bias was assessed using a funnel plot and the Egger test. All statistical analyses were performed using Stata 15.0 software.
This review included 50 studies, we found that the global prevalence of SO in older adults was 11%. Subgroup analyses showed that the prevalence of SO was higher among studies using diagnostic criteria of muscle mass alone (15%) to diagnose sarcopenia, using dual-energy X-ray absorptiometry (15%) to assess muscle mass, and those focused on age ≥ 75 years old (23%), hospitalized (16%), South Americans (21%) and North Americans (19%). There were no significant differences in the prevalence of SO among studies using body fat percentage (10%), body mass index (13%), waist circumference (16%) to diagnose obesity and in female (14%), male (10%) patients. Sensitivity analysis showed that none of the studies affected the overall pooled results. Meta-regression analysis found that publication year, geographical region, study setting, and the diagnostic criteria of sarcopenia were sources of heterogeneity.
This meta-analysis indicated SO affects more than one in ten older adults globally. Therefore, we should attach importance to the screening and early diagnosis of SO in older adults, then selecting appropriate interventions to reduce the occurrence of it and various adverse outcomes in this demographic.

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