High BMI Increases IgA Nephropathy Renal Risks
Patients who are overweight or obese when they are diagnosed with IgA nephropathy (IgAN) have more renal risk factors than normal-weight patients, and these risk factors translate into a worse prognosis, according to researchers.
Overweight or obesity increased hypertension frequency, proteinuria level, and severity of some renal lesions at diagnosis, which placed patients at higher risk for stage 3 or higher chronic kidney disease (CKD) and dialysis or death when compared with normal-weight patients, investigators reported online ahead of print in Nephrology Dialysis Transplantation.
Francois Berthoux, MD, and colleagues at University Hospital of Saint-Etienne in Saint-Etienne, France, prospectively studied data from 331 IgAN patients. At diagnosis, 195 patients had a normal body mass index (BMI), defined as less than 25 kg/m2, and 136 had an elevated BMI (25 or higher). The elevated-BMI group included 102 patients with a BMI of 25-29.9 (overweight) and 34 had a BMI of 30 or higher (obese).
At diagnosis, 52.9% of overweight/obese patients had hypertension compared with only 24.6% of normal-BMI patients, and 39.7% of overweight/obese patients had proteinuria of 1 g/day or more compared with 22.1% of normal-BMI patients. The overweight/obese group also had worse histopathologic lesion scores and worse estimated glomerular filtration rate (eGFR) than the normal-BMI group (69.1 vs. 80.2 mL/min/1.73 m2).
The primary composite endpoint of dialysis or death was reached by 21.3% of overweight/obese patients compared with only 13.9% of normal-BMI patients, the researchers reported. At last follow-up, the proportion of patients with CKD stage 3 or higher was 43.4% in the overweight/obese group compared with 21% of normal-BMI patients. The final eGFR was 59.3 in overweight/obese patients versus 73.4 in normal-BMI patients.
Obesity was more prevalent in the women than men (15.3% vs.8.2%), and overweight/obese patients were about 10 years older at diagnosis (46.6 vs. 37 years).