NEW research from the Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD) challenges conventional assumptions about body weight and cardiovascular risk in patients with chronic kidney disease (CKD). The study indicates that maintaining a consistently higher body mass index (BMI) over time may be associated with a lower risk of adverse cardiovascular events (CVEs).
The relationship between BMI and outcomes in CKD has long been debated, particularly due to the so-called “obesity paradox,” where overweight or obese individuals appear to have better survival outcomes than those with lower BMI. However, most previous studies have relied on single time-point measurements, limiting understanding of how weight changes over time influence risk.
To address this gap, researchers analysed longitudinal data from 1,061 CKD patients over a seven-year period. BMI was assessed at three intervals and categorised as high (≥23 kg/m²) or low (<23 kg/m²). Advanced statistical approaches, including targeted maximum likelihood estimation (TMLE) and marginal structural models, were used to account for time-varying clinical factors such as kidney function, blood pressure, inflammation, and nutritional status.
Sustained Higher BMI Associated with Fewer Cardiovascular Events
The findings revealed that patients with persistently high BMI had a significantly lower risk of cardiovascular events compared with those who maintained a consistently low BMI. Specifically, sustained higher BMI was associated with a 72% reduction in CVE risk. In contrast, patients whose BMI fluctuated, either increasing or decreasing over time, did not experience the same protective effect.
These results suggest that long-term weight stability at a higher BMI may confer cardiovascular benefits in CKD, potentially reflecting better nutritional reserves or resilience against disease-related stressors. The authors caution, however, that the findings do not necessarily endorse weight gain as a universal strategy but rather highlight the importance of considering individual patient trajectories.
Researchers Call for Individualised Risk Assessment in CKD
The study raises important questions about current weight management guidelines in CKD populations, which often prioritise weight reduction. Instead, a more personalised approach that accounts for long-term BMI patterns and overall health status may be warranted.
Further research is needed to confirm these findings and to explore the underlying mechanisms, but the study adds to growing evidence that “one-size-fits-all” recommendations may not be appropriate in complex chronic conditions like CKD.
Reference
Oh YJ et al. Long-term dynamic effect of body mass index on adverse cardiovascular outcomes with targeted maximum likelihood estimation method: result from the KNOW-CKD study. Sci Rep. 2026; DOI: 10.1038/s41598-026-45135-7.
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