Researchers discover that obesity hinders kidney donation

Morbidly obese patients are generally excluded as organ donors given their increased risk for complications during operation and the development of chronic conditions linked to obesity (i.e., type 2 diabetes, heart disease, etc.). Researchers conducted this study to determine how often obesity is the reason for unsuccessful donation of organs, and further analyze how often morbidly obese patients successfully lose weight and are able to be donors.

"This study suggests that morbid obesity is a barrier to kidney donation, and even though morbidly obese patients reported that they were trying to lose weight through diet and lifestyle modifications, they were largely unsuccessful at losing the weight and becoming donation candidates," said Mala Sachdeva, MD, assistant professor of medicine at the Hofstra North Shore-LIJ School of Medicine and researcher at the Feinstein Institute for Medical Research. "As a next step, we must conduct larger studies that assess how vast a problem this is on a national level and determine how best to expand our living donor pool for kidney transplantation. Due to kidney shortages, there must be tangible efforts made to increase the donor pool. Perhaps potential donors who are excluded from donation due to their high BMI should participate in more stringent weight loss programs, check in much more regularly at their transplant center for follow ups, and even join social support groups as a means of motivation. Something needs to be done to increase the number of live donors but also to make it as safe as possible for them to donate."

This study was a single-center, retrospective analysis of 104 potential living kidney donors between 2008 and 2011 who were grouped according to their body mass index (BMI). Those who had a BMI higher than 35 kg/m2 (which classifies them as morbidly obese) were excluded from donation. After exclusion, the morbidly obese participants were referred to a nutritionist, who created an individualized diet and lifestyle modification regimen and then followed up with them throughout the study period.

Of the 104 donors, 19 (18 percent) had a normal BMI of less than 25. Eighty five of the 104 (82 percent) donors spanned the overweight to morbidly obese classifications. Thirty eight (37 percent) were overweight (BMI 25-29.9). Twenty four (23 percent) were categorized as class I obesity (BMI 30-34.9), 17 (16%) as class II obesity (BMI 35-39.9), and six (six percent) as class III obesity (BMI greater than 40). Of the total of 23 (22 percent) who were considered morbidly obese (BMI greater than 35), only three (13 percent) succeeded at losing weight and donating. Seven (30 percent) were unable to lose weight but were trying, six (26 percent) changed their minds to donate, three (13 percent) were lost to follow up, two (nine percent) were declined for medical reasons, one declined for social reasons, and one declined due to recipient death.

Provided by North Shore-Long Island Jewish Health System