Body mass index (BMI) is a calculation that uses a person’s height and weight. While it fails to consider a person’s body type, it is one factor that healthcare professionals use to determine a patient’s overall health. 

Previous research shows variations in BMI are associated with a higher risk for heart disease. Could BMI variation also affect kidney health? Investigators in South Korea examined whether BMI could affect the prognoses of patients with kidney dysfunction. Learn more about what they did, what they found, and what their findings can mean.* 

Researching BMI Variations

This observational study analyzed data from 84,636 chronic kidney disease (CKD) patients listed in the national health screening database. Data analyzed included BMI and age, as well as other factors, such as: 

• Sex
• Waist circumference 
• Smoking history
• Alcohol consumption 
• Physical activity 
• Diabetes mellitus
• Income status

Patients had a median age of 68, and all had a baseline diagnosis of predialysis CKD. 

What they Found

After a median (average) follow-up of four years, the researchers found those with greater BMI variability had:

• A 66% higher risk of mortality
• A 20% higher risk for kidney replacement therapy
• A 19% higher risk for myocardial infarction (MI) or stroke

What it Means

The negative consequences of BMI variability mean physicians and medical professionals should be tracking and monitoring weight changes.

Dr. Holly Kramer, a professor of public health sciences and medicine at Loyola University in Maywood, Illinois, is not surprised by the findings and believes they may also indicate mental health concerns of which physicians should be mindful. “If you are seeing large fluctuations in their body weight, that may mean something is not stable in their life, and it could be social problems and not medical problems. Looking at trajectories of body weight can give you information and lead to queries about issues.” 

*Schieszer, J. (2021, August 24). BMI Fluctuations May Predict Poor Outcomes in CKD. Renal and Urology News. https://www.renalandurologynews.com/home/news/nephrology/chronic-kidney-disease-ckd/body-mass-index-fluctuations-in-chronic-kidney-disease-influence-death-cardiovascular-risks/