Weight change in chronic kidney disease: Association with mortality and kidney function

Area of Science:

• Nephrology
• Internal Medicine
• Clinical Research

Background:

• Excess body weight is a known risk factor for chronic kidney disease (CKD) progression.
• Weight loss in CKD patients is paradoxically linked to increased mortality, making universal weight loss recommendations controversial.
• Limited data exists on weight change patterns in CKD populations.

Purpose of the Study:

• To describe weight changes in patients with moderate to severe CKD.
• To explore the association between weight changes and mortality or renal endpoints in overweight/obese CKD patients.

Main Methods:

• Followed non-dialysis patients with estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² and body mass index (BMI) ≥ 25 kg/m² for up to 5.5 years.
• Defined clinically significant weight change as ≥ 5% and renal endpoint as dialysis, transplant, or a ≥ 40% fall in eGFR.
• Used Cox-regression to assess relationships between first-year weight change and subsequent mortality or renal endpoints.

Main Results:

• 310 patients (median age 75, median BMI 31 kg/m²) were studied; 68% had Stage 4 CKD.
• Over 4.4 years, 128 patients died and 140 had significant weight change (42 lost ≥ 5% weight, 23 gained ≥ 5% weight).
• Significant weight loss or gain in the first year was associated with increased hazard of death and renal endpoints, with few cases of intentional weight loss.

Conclusions:

• Moderate to severe CKD patients experience significant weight changes unrelated to baseline kidney function.
• Significant weight changes are associated with increased mortality and kidney function loss.
• The observed associations are likely influenced by confounding factors.