Association between Cardiovascular-Kidney-Metabolic Syndrome and Relative Muscle Loss in American Adults

Cardiovascular-kidney-metabolic (CKM) syndrome is associated with numerous adverse health outcomes. However, the relationship between the different stages of CKM syndrome and relative muscle loss risk remains unclear. This cross-sectional study evaluated the association between CKM syndrome and relative muscle loss, including 4,322 participants from the National Health and Nutrition Examination Survey conducted in 2011-2018. The Foundation for the National Institutes of Health defined relative muscle loss as characterized by the appendicular lean mass adjusted by the body mass index. We constructed weighted multivariate logistic regression models to examine the association between different stages of CKM syndrome and relative muscle loss. Furthermore, we explored the effects of its individual components on the risk of relative muscle loss. Of 4,322 participants, 397 (9.0%) were diagnosed with relative muscle loss. Within the multivariate model, participants in CKM syndrome stages 1-4 exhibited significantly higher risks for relative muscle loss compared with those in stage 0, with odds ratios (95% confidence intervals) of 3.91 (1.96-7.81), 4.16 (2.08-8.32), 4.95 (2.37-10.34), and 7.74 (2.61-22.92), respectively. Notably, metabolic disorders were most strongly associated with relative muscle loss. Participants with clinical cardiovascular disease, chronic kidney disease, and metabolic disorders had significantly higher risks of relative muscle loss than those without these conditions. These findings remained robust across various subgroup analyses.Patients with CKM syndrome stages 1-4 exhibited a higher risk of relative muscle loss than those in stage 0. Moreover, metabolic disorders may be the most significant risk factor for relative muscle loss.