Kidney transplant recipients who consume moderate amounts of alcohol have lower mortality rates by 44% and lower levels of diabetes than transplant recipients who are abstainers or heavy drinkers, according to new research….
The study of 600 kidney transplant recipients found that patients who had moderate alcohol intake were 44% less likely to die in an average follow-up of 7 years than those who consumed more or less alcohol, and they were as much as 67% less likely to develop diabetes than other drinkers or nondrinkers.
The participants, evaluated by researchers at the University Medical Center Groningen in the Netherlands, were evaluated from 2001 to 2003. Their alcohol consumption was self-reported, and their mortality was recorded until May 2009. The average age of the participants was 51 years, 55% were men, and they participated at a median time of 5.9 years post-transplant.
Among the recipients, 288 (48%) reported abstaining from alcohol consumption; 94 (16%) reported sporadic alcohol use, defined as less than 1 unit per week; 210 (35%) reported moderate use, defined as more than 1 unit per week and up to 3 units per day; and 8 (1%) reported heavy use, defined as more than 4 units per day. The total prevalence of post-transplant diabetes was 12% (78 patients).
During a median follow-up period of 7 years, 15.7% (33 subjects) moderate drinkers died, as did 26.0% (75 subjects) of abstainers, 24.5% (23 subjects) of sporadic drinkers, and 25% (2 subjects) of heavy drinkers (P = .01).
In univariate Cox-regression analyses, moderate alcohol intake was associated with reduced risk for mortality (hazard ratio, 0.56; 95% confidence interval [CI], 0.4 – 0.8; P = .005). The association did not change after adjustment for potential confounders, including diabetes and smoking. Moderate alcohol consumption was also associated with a low prevalence of post-transplant diabetes (odds ratio, 0.33; 95% CI, 0.2 – 0.6; P < .002).
Dorien M. Zelle, MSc, from the University Medical Center Groningen, stated that, “An improvement in mortality rates for kidney transplant patients has particular relevance because their rates of death increase after transplant; 1 recent study showed 5-year survival rates among kidney recipients to be much lower than in the general population.”
“While their quality of life increases following a successful transplant, patients still have lower survival rates than the general public, with 5-year survival rates of only about 85%, compared with nearly 100% in the general public,” she said.
One of the leading causes of premature death in kidney transplant patients is cardiovascular disease, and cardiovascular mortality is increased by as much as 4 to 6 times, compared with the general population, after transplantation.
Although studies of the general public have shown that moderate alcohol use causes reductions in the risk for cardiovascular disease, the risk for premature death, and the development of diabetes, the recommendations on alcohol consumption for kidney transplant recipients are spotty at best, Ms. Zelle said.
“The [Kidney Disease: Improving Global Outcomes] practice guidelines for the care of kidney transplant patients do not mention specific alcohol restrictions for these patients; however, patients who turn to the Internet will find various different recommendations,” she said.
“Advice on the Internet ranges from, ‘You should not drink alcohol for 1 year after your transplant,’ to ‘It is best not to drink alcohol at all,’ and ‘Avoid drinking alcohol unless your doctor gives you permission’.”
The study did not differentiate between types of alcohol consumed, but Ms. Zelle said that previous studies have shown that alcohol, in general, appears to be beneficial.
“We know from previous studies in the general population that it’s not only wine that’s good, but the alcohol appears to be doing the trick,” she said. “Studies on alcohol show a lowering of insulin resistance, thereby giving a lower risk for diabetes and cardiovascular diseases.”
Although the findings suggest promising benefits of moderate alcohol use, a variety of other factors are needed for further support, said Frank C. Brosius, MD, professor of internal medicine in the Department of Molecular and Integrative Physiology, University of Michigan, in Ann Arbor.
“It is important to recognize that this is an outcomes study, so although the investigators try to correct for all confounding variables, there still may be some that … skew the data,” he said.
“A prospective [randomized controlled trial] would have to be done to corroborate these findings, but this will never happen, given the expense. The best that can and should happen will likely be other observational cohort outcomes studies in other populations of transplant patients.
“I think the correct conclusion from this single study is that moderate alcohol intake is not harmful to transplant patients, and may be helpful, as it is in other populations,” Dr. Brosius said. “There does not seem to be any reason to recommend abstinence in transplant patients.”