BMI and Liver Stiffness in Older Adults

by | Sep 8, 2025 | Uncategorized | 0 comments

Consider the article “A U-shaped relationship between body mass index and the risk of elevated liver stiffness in older people: evidence from the 5-year retrospective cohort study”, published September 8, 2025 in International Journal of Obesity.

Overview

Background
The research investigates how body mass index (BMI) correlates with the risk of elevated liver stiffness in older adults. Liver stiffness serves as a non-invasive indicator of liver fibrosis and overall liver health.

Methods

  • Population: 2,736 older adults from the West China Health and Aging Cohort Study (WCHAC).
  • Measurements: Liver stiffness was assessed via transient elastography (TE). Average BMI over five years was analyzed.
  • Analysis Techniques:
    • Multinomial logistic regression to estimate risk associations.
    • Group-based trajectory modeling to identify BMI patterns over time.
    • Restricted cubic spline analysis to explore dose–response relationships.

Key Findings

  1. Risk by BMI Quartiles
    • The second BMI quartile exhibited the lowest prevalence of elevated liver stiffness.
    • Higher quartiles had significantly increased risk compared to Q2:
      • Q4 vs Q2: Odds Ratio (OR) = 2.05 (95% CI: 1.37–3.11)
      • Q5 vs Q2: OR = 2.82 (95% CI: 1.78–4.39)
  2. BMI Trajectories Over 5 Years
    Five distinct patterns emerged:
    • Low-normal-weight stable (7.42%)
    • Moderate-normal-weight stable (29.10%)
    • Low-level overweight stable (36.22%)
    • High-level overweight stable (20.32%)
    • Stable obesity (6.94%)
      The moderate-normal-weight stable group again had the lowest prevalence of elevated liver stiffness, while individuals in high-level overweight stable and stable obesity groups had significantly higher odds:
    • High-level overweight stable: OR = 2.02 (95% CI: 1.39–2.97)
    • Stable obesity: OR = 2.83 (95% CI: 1.72–4.64)
  3. Dose–Response Relationship
    • A U-shaped association was confirmed between average BMI and liver stiffness risk.
    • The optimal BMI range for minimizing elevated liver stiffness in older adults is in the Normal range in green above (Underweight: <18.5 Normal weight: 18.5–24.9 Overweight: 25–29.9 Obese: ≥30).

Conclusions
This study identifies a U-shaped relationship in older adults: both lower and higher BMI levels are associated with increased liver stiffness, while a middle range carries the lowest risk. Maintaining BMI in that optimal range may help reduce risk of liver fibrosis in this population.

The Net Net

These results can inform guidelines for weight management in older adults, with a view toward preserving liver health.

Precision in BMI recommendations: Rather than suggesting “lower is always better,” this study adds color—highlighting that in older adults, being underweight or overweight may both elevate liver risk.

Trajectory Nuance: The findings reinforce that consistently normal weight over time matters more than short-term weight dips or gains.