Association of sarcopenic obesity with the risk of all-cause mortality: A meta-analysis of prospective cohort studies

Many prospective studies have investigated the relationship between sarcopenic obesity (SO) and risk of mortality. However, the results have been controversial. The aim of the present study was to evaluate the association between SO and all-cause mortality in adults by a meta-analysis of prospective cohort studies. A systematic literature search was carried out through electronic databases up to September 2014. A total of nine articles with 12 prospective cohort studies, including 35287 participants and 14306 deaths, were included in the meta-analysis. Overall, compared with healthy subjects, subjects with SO had a significant increased risk of all-cause mortality (pooled HR 1.24, 95% CI 1.12-1.37, P<0.001), with significant heterogeneity among studies (I-2=53.18%, P=0.0188), but no indication for publication bias (P=0.7373). Heterogeneity became low and no longer significant in the subgroup analyses by three SO definitions. More importantly, SO, defined by mid-arm muscle circumference and muscle strength criteria, significantly increased the risk of mortality (HR 1.46, 95% CI 1.23-1.73 and 1.23, 1.09-1.38, respectively). The risk of all-cause mortality did not appreciably change considering the geography (USA cohorts and non-USA cohorts) or the duration of follow up (10 years and <10 years). However, the risk estimate was only significant in men (HR 1.23, 95% CI 1.08-1.41, P=0.0017), not in women (HR 1.16, P=0.1332). The results of the present study show that subjects with SO are associated with a 24% increase risk of all-cause mortality, compared with those without SO, in particular in men; the significant association was found independent of geographical location and duration of follow up.