Prevalence and Trends of Obesity and Metabolic Dysfunction-Associated Steatotic Liver Disease among Adults in the United States.
Level 4 - case-series / case-control
Serial cross-sectional observational survey using NHANES data
PubMed 41511844 · doi:10.14423/SMJ.0000000000001924
What was done
Retrospective analysis of serial cross-sectional data from NHANES cycles (1999–2018) including 17,824 US adults aged 20 years and older. MASLD was defined by US Fatty Liver Index (USFLI) ≥30 or cardiometabolic risk factors (≥1) with controlled attenuation parameter ≥288 dB/m (2017–2018 only). Multivariable logistic regression assessed temporal trends and the association between obesity (BMI ≥30 kg/m²) and MASLD, adjusting for age, sex, race/ethnicity, and survey design variables.
What was found
Among 17,824 participants, 36.62% had obesity and 33.49% met MASLD criteria (USFLI ≥30). MASLD prevalence increased from 30.20% (95% CI 26.57%–33.83%) in 1999–2000 to 38.64% (95% CI 35.47%–41.80%) in 2017–2018, mirroring rising obesity rates (30.26% to 43.51%). Obesity was associated with 14.05-fold higher odds of MASLD (adjusted OR 14.05, 95% CI 12.62–15.65). Prevalence was highest among older adults, males, and Mexican Americans.
Why it matters
Quantifies the parallel rise of MASLD and obesity across US adults over two decades. The findings highlight high-risk demographic groups and emphasize the importance of population-level obesity management strategies.
Limits
The cross-sectional design cannot establish causality or track individual progression. Steatosis was defined predominantly using a surrogate biomarker index (USFLI) rather than imaging or liver biopsy for most cycles, with controlled attenuation parameter measurements limited to 2017–2018.