SARCOPENIA IS A KEY DETERMINANT MARKER OF LEAN MASLD: A COMPARATIVE ANALYSIS OF CLINICAL PROFILE, BODY COMPOSITION BY DEXA, AND MUSCLE STRENGTH IN LEAN, OVERWEIGHT, AND OBESE MASLD PATIENTS

Introduction and Objectives

Lean MASLD affects 10–15% of patients, presenting metabolic alterations despite normal BMI.

Characterize the MASLD phenotype according to BMI.

Materials and Methods

68 patients with MASLD were divided into groups: lean (n=18); overweight (n=28); obese (n=22). Were evaluated: anthropometric measurements, comorbidities, liver fibrosis by transient elastography, body composition by DEXA, and muscle strength by handgrip dynamometry. The Kruskal-Wallis test was used for statistical analysis.

Results

Female sex was predominant. There were no significant differences in mean age or the prevalence of comorbidities (T2DM/IR/dyslipidemia) among groups (p>0.05), except for arterial hypertension, more prevalent in the obese (p≤0.05). Aminotransferase levels were similar: ALT (p=0.440) and AST (p=0.427). Mild hepatic fibrosis (F0/F1) predominated in all groups (p=0.418); however, there was a trend toward higher liver stiffness suggesting advanced fibrosis in the lean (22.2%, 7.14%, 13.64%; p=0.340). Visceral adipose tissue area >100 cm² was observed in 38.9% of lean, compared to 100% in the other groups (p≤0.05). Low muscle mass was more prevalent in the lean (55.6%, 14.3%, 4.5%; p≤0.05), and sarcopenia, defined as the coexistence of low lean mass and reduced muscle strength, was also more prevalent in lean (27.8%, 7.14% in overweight, 4.5% in obese; p≤0.05).

Conclusions

Lean MASLD presents a higher prevalence of sarcopenia and a distinct body composition profile, despite similar comorbidities and age compared to other groups. These findings highlight the role of lean mass in the pathophysiology of lean MASLD and underscore the limitations of BMI as a sole evaluative parameter.

Conflict of interest: None