The Impact of Hepatic Steatosis in Underweight Patients

Recent research indicates that hepatic steatosis in underweight patients significantly increases long-term mortality risk. While clinicians traditionally associate fatty liver with obesity, this multi-center retrospective study challenges that paradigm. Researchers analyzed data from over 8,500 patients who underwent abdominal ultrasonography between 2010 and 2015. They specifically focused on those with a low body mass index (BMI) to determine if ultrasound-detected hepatic steatosis (UDHS) affected their survival.

Notably, the study revealed a startling correlation between liver fat and poor outcomes in lean individuals. Specifically, underweight patients with UDHS faced a higher risk of death compared to those with normal weight and similar liver conditions. Furthermore, the Cox proportional hazards model identified UDHS as an independent risk factor for mortality in the low BMI group. Consequently, these findings suggest that metabolic dysfunction can occur regardless of total body fat, potentially due to visceral adiposity or genetic factors.

Clinical Screening for Hepatic Steatosis in Underweight Patients

Consequently, clinicians should not overlook the possibility of metabolic-associated steatotic liver disease (MASLD) in thin patients. Although these individuals may appear healthy, their metabolic profile might indicate significant risk. The study underscores the importance of using abdominal ultrasonography as a routine screening tool, even in patients who do not meet the criteria for overweight or obesity. Early detection remains crucial for implementing lifestyle interventions and managing comorbidities.

In addition, the research highlights a \"lean NAFLD paradox\" where lower body weight does not necessarily offer protection. Instead, the presence of hepatic fat in an underweight frame might signal a more aggressive or metabolically unstable phenotype. Therefore, medical professionals in regions like India, where lean MASLD is increasingly prevalent, must remain vigilant. Prioritizing comprehensive metabolic evaluations for all patients, irrespective of their BMI, can improve long-term prognostic outcomes.

FAQs

Can thin people really develop fatty liver disease?

Yes, individuals with a low or normal BMI can develop hepatic steatosis, often referred to as \"lean NAFLD.\" This condition is frequently linked to visceral fat accumulation and genetic predispositions.

Why is hepatic steatosis in underweight patients particularly dangerous?

Underweight patients with fatty liver often have higher mortality rates because their condition may go undetected for longer. Additionally, they might possess metabolic vulnerabilities that are not immediately apparent through weight alone.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice. Always seek the advice of a qualified healthcare provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Higashino M et al. Hepatic Steatosis Detected by Abdominal Ultrasonography Is Associated With Worse Prognosis in Underweight Patients. Hepatol Res. 2026 Jun 22. doi: 10.1111/hepr.70220. PMID: 42325065.

Kim D, et al. Lean and Non-Obese Nonalcoholic Fatty Liver Disease. Gut and Liver. 2021.

Nguyen VH, et al. Differential Mortality Outcomes in Real-world Patients with Lean, Nonobese, and Obese Nonalcoholic Fatty Liver Disease. J Clin Transl Hepatol. 2023.