The Obesity Paradox Reconsidered: Evidence from a Multicenter Romanian Hemodialysis Cohort

Area of Science:

• Nephrology
• Epidemiology
• Gerontology

Background:

• The obesity paradox in maintenance hemodialysis (MHD) patients, where higher BMI is linked to better survival, remains controversial.
• Limited data exist on body weight status and mortality in Eastern European hemodialysis populations, particularly the elderly.

Purpose of the Study:

• To describe body weight distribution and cardiometabolic comorbidities in a Romanian MHD cohort.
• To evaluate the association between BMI categories and all-cause mortality in this population.

Main Methods:

• Retrospective cohort study of 679 MHD patients across eight Romanian centers.
• Analysis included demographic, clinical, laboratory, and echocardiographic data.
• Kaplan-Meier curves and Cox proportional hazards models assessed survival and mortality predictors.

Main Results:

• Obesity (BMI ≥ 30 kg/m²) was independently associated with increased all-cause mortality (HR 1.411, p=0.045) in multivariable analysis.
• Median survival was significantly lower with increasing BMI (normal weight: 7.56 years; overweight: 4.56 years; obese: 3.92 years).
• Overweight status did not show a survival advantage over normal weight.

Conclusions:

• Obesity, by BMI, is associated with increased mortality in Romanian MHD patients, contradicting the traditional obesity paradox.
• These findings suggest a need for a more nuanced interpretation of BMI's role in MHD patient outcomes.
• Further research is warranted to explore the complex relationship between adiposity and survival in dialysis populations.