Association between fat-free mass, lipid profile and cardiovascular risk indices in women with systemic lupus erythematosus: a multicenter cross-sectional study

INTRODUCTION/OBJECTIVE: Women with systemic lupus erythematosus (SLE) exhibit increased cardiovascular risk, partly explained by adverse fat distribution. This multicenter cross-sectional study investigated whether fat-free mass (FFM) is independently related to lipid metabolism and cardiovascular risk and identified metabolic clusters combining body composition and lipid parameters in women with SLE from an Ibero-American cohort. METHODS AND PROCEDURES: In this cross-sectional study, clinical, biochemical, anthropometric, and body composition data from 285 adult women with SLE from Brazil, Mexico, and Spain were analyzed. Multivariable linear regression models examined associations between FFM (%) and lipid parameters and cardiovascular risk indices. Model 1 was adjusted for age and center; Model 2 additionally for disease activity and duration; and Model 3 further for hydroxychloroquine dose. RESULTS: Higher FFM was independently associated with a more favorable lipid profile. In the fully adjusted model, FFM was inversely associated with LDL-C (p = 0.032), Castelli I (p = 0.032), Castelli II (p = 0.026), and LAP (p < 0.001), and positively associated with HDL-C (p = 0.048). Associations with triglycerides observed in partially adjusted models were attenuated after full adjustment. CONCLUSIONS: In women with SLE, greater fat-free mass was associated with a more favorable lipid profile and selected atherogenic indices, independent of demographic and disease-related factors. Although causality cannot be inferred due to the cross-sectional design, these findings suggest that lean mass may represent an important component of cardiometabolic health in SLE.