Redefining Obesity Improves the Identification of Advanced Fibrosis Among <scp>MAFLD</scp> / <scp>MASLD</scp> Patients

Abstract

We read with great interest the paper by Mantovani et al., which demonstrates a higher prevalence of advanced liver fibrosis in metabolic dysfunction-associated steatotic (fatty) liver disease MAFLD/MASLD patients with type 2 diabetes mellitus (T2DM) than comparators with type 1 diabetes mellitus (T1DM) [1]. This study supports body mass index (BMI) as a surrogate biomarker of insulin resistance, underscoring the urgent need to reevaluate how obesity is defined, given its strong link to the progression of liver disease. Recently, the Lancet Diabetes & Endocrinology Commission proposed a new clinical definition of obesity that goes beyond simple BMI thresholds to include central adiposity [2]. In this framework, individuals with excess adiposity and cardiometabolic risk are classified as having clinical obesity, while those without established metabolic dysfunction or target organ damage are categorised as having preclinical obesity. This updated definition could significantly impact the reported prevalence of obesity and its associated risks for cardiometabolic and liver diseases in population studies [3]. Therefore, it is crucial to evaluate how this new definition of obesity affects the progression of liver disease [4]. We explored the implications of this updated definition in our own cohort of 373 individuals. Obesity was assessed using both BMI and anthropometric measurements, along with a comprehensive evaluation of metabolic profiles and vibration-controlled transient elastography (VCTE). We assessed the impact of this new obesity definition on the prevalence of obesity and fibrosis risk. The revised criteria increased the estimated prevalence of obesity from 22.3% under BMI criteria to 56% (Figure 1A), reclassifying a substantial proportion of individuals previously labelled as non-obese. The prevalence of obesity according to the new definition ranged from 46.9% in males to 53.1% in females. Advanced fibrosis was identified in 55 patients (14.7%) with liver stiffness measurement (LSM) > 10 kPa. When stratified by BMI-defined obesity, the prevalence was 17 (30.9%), compared with 58.2% using the new obesity definition (p < 0.001) (Figure 1B). Our findings suggest that relying solely on BMI may underestimate the burden of obesity and advanced fibrosis in populations at high metabolic risk. This might be particularly relevant in the Middle East region, where metabolic diseases have surged to epidemic proportions, thereby amplifying liver-related morbidity [5]. In conclusion, these insights provide compelling real-world evidence that integrating a contemporary, adiposity-based obesity definition into MAFLD/MASLD risk stratification may refine prognostic assessment and improve early detection of advanced fibrosis. However, further studies are needed to evaluate the clinical and cost implications of adopting these criteria. Alaa M. Mostafa prepared the initial draft; and Yasser Fouad and Mohammed Eslam critically revised the manuscript. The authors have nothing to report. The authors declare no conflicts of interest. This article is linked to Mantovani et al. papers. To view this article, visit https://doi.org/10.1111/liv.70514. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.