TOPLINE:

A high BMI measured after diagnosis of metabolic dysfunction-associated steatotic liver disease (MASLD) was associated with a lower mortality risk, whereas a high BMI before diagnosis or in early adulthood was associated with a higher mortality. Persistent obesity throughout adulthood conferred a significant increase in mortality risk compared with persistent non-obesity.

METHODOLOGY:

• The relationship between MASLD and obesity is complex: Although patients with obesity often show better survival than those without obesity, many prior studies used a single BMI measurement after MASLD diagnosis, not accounting for weight changes over time.
• Researchers analyzed patients with MASLD aged ≥ 40 years from three population cohorts: the National Health and Nutrition Examination Survey (NHANES) III (n = 2190), NHANES 1999-2018 (n = 5210), and UK Biobank (n = 8962), to assess how BMI at different adulthood stages, annual changes, and trajectories were associated with mortality outcomes.
• BMI was recorded at several points, and those measurements were used to assess weight changes and long-term weight trajectories.
• Long-term BMI trajectories were classified as persistent non-obesity, onset of mid-adulthood obesity, onset of early adulthood obesity, persistent obesity, and rapid increase in BMI.
• The outcomes of interest were all-cause mortality and cause-specific mortality due to cardiovascular disease and cancer.

TAKEAWAY:

• A higher BMI in mid-to-late adulthood or after a MASLD diagnosis was associated with a lower risk for all-cause mortality; however, a higher BMI in early adulthood or before diagnosis of MASLD was linked to a higher risk for all-cause mortality.
• Modest annual gains in BMI (up to an average increase of 0.5) were generally associated with a lower risk for mortality, whereas annual increases exceeding 0.5 tended to elevate the risk.
• The persistent obesity group had a higher risk for all-cause mortality than the persistent non-obesity group (hazard ratio [HR], 1.79; 95% CI, 1.10-2.89) and a markedly higher risk for cardiovascular mortality (HR, 3.49; 95% CI, 1.83-6.63); the rapid increase in BMI trajectory also had a higher risk for all-cause mortality.
• Pre-diagnostic BMI showed a U-shaped association with the risk for all-cause mortality, with the risk increasing once BMI exceeded 30. The relationship between pre-diagnostic BMI and the risk for cancer-specific mortality was J-shaped, with the lowest risk near a BMI of 30 and a clearer rise in the risk at higher BMI values.

IN PRACTICE:

“By integrating BMI data across adulthood and disease stages, this study demonstrates a time-dependent association between obesity and MASLD outcomes, underscoring the clinical importance of lifetime weight history,” the authors of the study wrote.

SOURCE:

The study was led by Zhen Sun, Shanghai Jiao Tong University School of Medicine, Shanghai, China. It was published online in Clinical Gastroenterology and Hepatology.

LIMITATIONS:

Determining the exact timing of the onset of MASLD is difficult. The use of self-reported historical BMI introduced potential recall bias. In addition, as an observational study, residual confounding could not be completely eliminated.

DISCLOSURES:

The study was funded by the National Key R&D Program of China, the National Natural Science Foundation of China, and the Shanghai Municipal Health Commission. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.