New research from Korea has shown that weight fluctuations or body mass index variability are linked to increased risk of cardiovascular-related problems and early death in adults with chronic kidney disease (CKD).

The observational study included 84,636 patients with predialysis CKD, with eGFR <60 ml/min per 1.73 m2 or dipstick albuminuria ≥1, from South Korea’s national health screening database. These patients were followed for a median of 4 years. In this study, the researchers examined the association between variability of BMI or various metabolic parameters and risks of all-cause mortality and incident myocardial infarction, stroke and requirement for kidney replacement therapy (KRT). 

Mortality risk was found to be 66% higher in patients with the highest body mass index variability and they were also 20% more likely to require kidney replacement therapy. The risk of experiencing a heart attack or stroke each was 19% higher in these patients. At 4 years, 2% of the study participants suffered a heart attack, 3% had a stroke, 4% needed kidney replacement therapy such as dialysis, while the mortality was 6%.

Not just a fluctuating body weight, variability in some components of the metabolic syndrome such as fasting blood glucose also showed a significant association with prognosis. Higher the number of metabolic syndrome components with high variability, worse was the prognosis.

This study has clinical implications and suggests that while it is important for clinicians managing these patients to assess BMI and metabolic parameters, it is equally important or perhaps more important to look for any variability in these numbers for their potential prognostic significance. Any change in trend should raise an alert.

The study is published August 12, 2021 in JASN, the Journal of the American Society of Nephrology.