BOSTON — Obese living kidney donors may have an increased risk of hypertension, but not renal insufficiency or proteinuria, many years after donation, Dr. Mehdi Tavakol said at the 2006 World Transplant Congress.
In some reports, a high body mass index has been strongly associated with an increased risk of developing end-stage renal disease, whereas other studies have found that obese patients who underwent a unilateral nephrectomy for reasons other than donation had a higher risk of proteinuria and renal disease, said Dr. Tavakol of the division of transplant surgery at the University of California, San Francisco.
Dr. Tavakol and his associates located individuals who had donated a kidney at the university during 1969–2002 to determine if obesity at the time of the donation (BMI higher than 30 kg/m
When the patients were broken into subgroups based on quartiles of BMI (less than 25, 25–29.9, 30–34.9, and 35 or higher), the investigators found no significant differences in the incidence of renal insufficiency (glomerular filtration rate less than 60 mL/min), proteinuria (greater than 150 mg/day), or microalbuminuria (greater than 30 mg/day). All of the BMI subgroups had a 70%–75% lower glomerular filtration rate at the time of follow-up than at the time of their predonation measurement.
But almost 50% of obese donors had hypertension at follow-up, compared with 30% of nonobese donors. The incidence of hypertension also rose significantly with increasing obesity. Univariate and multivariate analyses confirmed that obesity was a significant risk factor for developing hypertension.
These results “should be taken into consideration in the preoperative evaluation, counseling, and postoperative follow-up of these patients,” he said.