Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a significant health challenge in India and other Asian nations. Although obesity is a classic risk factor, lean MASLD diagnosis is often missed due to a normal Body Mass Index (BMI). New research highlights the diagnostic utility of Body Fat Percentage (BF%) and the Triglyceride-Glucose (TyG) index in this specific population.

The cross-sectional analysis utilized data from the NAGALA cohort and a Chinese health check-up study. Researchers identified MASLD through imaging in adults with a BMI below 23 kg/m². Furthermore, they examined the incremental value of adding BF% and TyG index to standard clinical assessments. Consequently, the findings suggest that these metrics provide a more nuanced understanding of metabolic health than BMI alone.

Improving Lean MASLD Diagnosis with the TyG Index

The study found that both higher body fat and elevated TyG index values correlate strongly with hepatic steatosis. Specifically, the TyG index serves as a robust surrogate marker for insulin resistance. Because insulin resistance is a core driver of liver fat accumulation, this index helps identify at-risk lean individuals. Moreover, combining these tools improves the area under the receiver operating characteristic curve (AUC) for screening.

Clinicians should note that lean Asian patients often exhibit \"metabolically obese\" characteristics despite having a normal weight. Therefore, incorporating BF% and TyG index into routine check-ups could facilitate earlier intervention. Additionally, these tools are cost-effective and easy to implement in primary care settings across India. While BMI remains a standard metric, it does not account for fat distribution. In contrast, BF% offers a direct measure of adiposity.

Practical Implementation in Clinical Settings

To optimize screening, physicians should look beyond weight. Simultaneously, the TyG index reflects the synergistic impact of lipids and glucose. Together, these markers empower doctors to detect MASLD before it progresses to advanced fibrosis or cirrhosis. If clinicians rely solely on BMI, a significant portion of the Asian population remains undiagnosed and untreated.

Frequently Asked Questions

What is the clinical significance of lean MASLD?

Lean MASLD refers to liver fat accumulation in individuals with a normal BMI. Despite their appearance, these patients face high risks of cardiovascular disease and liver-related mortality. In many cases, their prognosis is equal to or worse than their obese counterparts due to delayed diagnosis.

Why is the TyG index useful for lean patients?

The TyG index is a simple calculation based on fasting triglycerides and glucose. It serves as an accessible surrogate for insulin resistance. This is particularly useful for lean Asian adults who may have metabolic dysfunction without overt obesity.

How does body fat percentage change the diagnostic approach?

Body fat percentage identifies individuals with low muscle mass and high adiposity, often termed \"sarcopenic obesity.\" This measurement provides a clearer picture of metabolic risk than BMI, which cannot distinguish between fat and muscle mass.

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

References

1. Kong XR et al. Estimated Body Fat Percentage and Triglyceride-Glucose Index for Identifying MASLD in Lean Asian Adults: A Cross-Sectional Analysis. Kaohsiung J Med Sci. 2026 May 26. doi: 10.1002/kjm2.70240. PMID: 42192212.


2. Lim S et al. The Global Landscape of Lean MASLD: Insights from Asia and the West. Frontiers in Medicine. 2024.


3. Li J et al. Diagnostic Accuracy of the Triglyceride–Glucose Index (TyG) for Liver Steatosis Detection. MDPI Journals. 2024.