Association between myosteatosis or sarcopenia based on abdominal CT and hypertension in systemic lupus erythematosus patients.

Background: Hypertension and obesity are common in systemic lupus erythematosus (SLE) patients, with obesity-related changes potentially driving hypertension. However, the specific adiposity measures associated with hypertension in SLE patients remain unclear. This study assessed the association between myosteatosis and sarcopenia detected on abdominal CT and hypertension in SLE patients. Mediators of the association between myosteatosis and hypertension were also investigated.

Methods: This was a retrospective study involving SLE patients enrolled from January 2017 to August 2023 and who underwent abdominal CT at the L3 level to track myosteatosis and sarcopenia based on the skeletal muscle mean radiodensity (SMD) and skeletal muscle index considered as binary and continuous variables. The association between these body composition measures and hypertension was tested using logistic regression analyses, while mediation modeling was used to assess the mediators.

Results: A total of 279 adult SLE patients (median age, 41.00 [30.00, 51.00] years; 245 women) were included in this study. Hypertension was associated with myosteatosis (adjusted OR: 3.54; 95% CI: 1.18-10.61 for the binary variable and 1.31; 95% CI: 1.02-1.68 for the continuous variable). No statistically significant association was observed between hypertension and sarcopenia (adjusted OR: 0.48; 95%CI: 0.23-1.01 for the binary variable and 0.95; 95%CI: 0.78-1.16 for the continuous variable). Mediation analyses revealed eGFR could mediate the association between myosteatosis (considered as a continuous variable) and hypertension in SLE patients when taken alone (95% CI: 0.0177-0.2765) or in combination with the TyG index (95% CI: 0.0032-0.0614).

Conclusions: Myosteatosis was associated with hypertension in SLE patients. eGFR alone or in combination with the TyG index may mediate this association.