Associations Between Metabolic Obesity Phenotypes and Sarcopenia in Middle-Aged and Older Chinese Adults:Age- and Sex-Dependent Interaction Trends.

Objective To investigate the associations between metabolic obesity phenotypes and the risk of developing sarcopenia among middle-aged and older Chinese adults,and further examine the potential moderating roles of age and sex in the associations. Methods On the basis of the data from the China Health and Retirement Longitudinal Study conducted in 2011-2012,a total of 7 421 participants aged 45 years and older were enrolled in this study.Sarcopenia was diagnosed according to the 2019 criteria established by the Asian Working Group for Sarcopenia.According to the body mass index and overall metabolic status,the participants were classified into four metabolic obesity phenotypes:metabolically healthy normal weight,metabolically healthy overweight/obesity,metabolically unhealthy normal weight,and metabolically unhealthy overweight/obesity (MUOO).A multivariate logistic regression model was adopted to assess the association between each metabolic phenotype and the risk of sarcopenia.Stratified analyses were performed by sex and age groups,accompanied by heterogeneity testing.Additionally,Bayesian statistical methods were utilized to verify the reliability and robustness of the findings,particularly within the older age subgroup. Results The analysis revealed a significant moderating effect of age on the association between MUOO and sarcopenia risk.Specifically,among individuals younger than 60 years old,those with MUOO exhibited a significantly elevated risk of sarcopenia (OR=1.56,95%CI=1.03-2.37).This association was further supported by Bayesian analysis,which confirmed the consistency and robustness of the observed trend in the older age group.Stratified analyses by both sex and age uncovered notable heterogeneity:MUOO was identified as a significant risk factor for sarcopenia among men under 60 years old (OR=2.01),whereas it was associated with a significantly lower risk of sarcopenia among women aged 75 years and older (OR=0.13). Conclusions The association between MUOO and sarcopenia risk is markedly influenced by both age and sex.Middle-aged men with MUOO show increased susceptibility to sarcopenia,while MUOO may exert a potential protective effect among older women.These findings underscore the importance of incorporating metabolic status,age,and sex into the design of sarcopenia prevention and management strategies,advocating for personalized precision interventions.