Body weight categories and fat distribution in relation to all-cause mortality among adults with metabolic dysfunction-associated steatotic liver disease: a population-based analysis of NHANES, 2007–2018
Martin Tze Wah Kueh, Made Ayu Utami Intaran, Rachel Goh, Gwyneth Kong, Hui Lian Koh, Yip Han Chin, Mark Y Chan, Carel W Le Roux, Anurag Mehta, Muhammad Shahzeb Khan, Mark D Muthiah, Nicholas WS ChewObjective
Although body mass index (BMI)-defined non-obesity metabolic dysfunction-associated steatotic liver disease (MASLD) predicts poor prognosis, the role of visceral adiposity and weight-based phenotypes is unclear. This study aimed to examine the clinical correlates of four unique MASLD phenotypes based on BMI and waist-to-height ratio (WHtR) and to assess the prognostic value of this classification with respect to mortality.
Design
Population-based cross-sectional study with prospective mortality follow-up.
Setting
Nationally representative US population derived from the National Health and Nutrition Examination Survey (NHANES), 2007–2018.
Participants
6300 adults with MASLD, sampled from NHANES 2007 to 2018.
Methods
Participants were allocated into four phenotypes based on obesity/lean and central adiposity status. Obesity was defined as BMI≥30 kg/m², while those without obesity were determined as lean. High central adiposity was defined as WHtR≥0.6.
Primary outcome measure
The primary outcome was all-cause mortality. This was ascertained through National Death Index linkage with follow-up censored at 31 December 2019.
Results
Among adults with MASLD, 72.1% had obesity with high central adiposity (mean follow-up: 6.9±3.5 years). The non-obesity, high central adiposity phenotype (9.6%) exhibited the highest rates of hypertension (60.2%), type 2 diabetes (31.8%) and chronic kidney disease (23.3%). This phenotype portended the poorest 6-year survival (p<0.001) and was independently associated with higher all-cause mortality (adjusted HR (aHR) 3.1, 95% CI 1.3 to 7.7). A J-shaped association was observed between BMI and mortality, with increasing WHtR linked to elevated risk.
Conclusion
Non-obesity MASLD with high central adiposity confers the poorest survival and cardiometabolic burden.