Mediterranean Type Diet is Associated with Low Risk of New-Onset Diabetes and Mortality after Renal Transplantation

Background: The incidence of new-onset diabetes after transplantation (NODAT) and cardiovascular events leading to premature mortality is high in renal transplant recipients (RTR). We hypothesized that a Mediterranean type diet protects against development of NODAT and premature mortality in RTR. Methods: In a prospective cohort study consisting of 707 adult stable RTR with a functioning graft for > 1 year, dietary intake at baseline was assessed with a 177 item validated food frequency questionnaire. Patients were divided into two categories, low resemblance (0-4 points) and high resemblance (5-9 points), based on a 9-point score according to the degree that their dietary pattern resembles that of a Mediterranean type diet. RTR with missing dietary data, diabetes mellitus at baseline or who underwent combined pancreas-kidney transplantation were excluded from analyses, leaving 474 RTR. Cox multivariable regression analyses were used to study the association of the Mediterranean diet with the development of NODAT and mortality. Results: In total 474 RTR (56,8% men) were included with a mean ± SD age of 51.5 ± 13.2 years. At baseline, 256 (54%) had a high resemblance to that of a Mediterranean type diet. During median follow-up of 3.8 (interquartile range [IQR], 3.0-4.6) years from baseline, 28 (6%) developed NODAT and 52 (11%) patients died. RTR with ≥ 5 points were both significantly associated with a lower risk of developing NODAT (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.20-0.94; P=0.04) and mortality (HR, 0.54; 95% CI, 0.31-0.95, P=0.03), both adjusted for age and sex. The results of multivariable analyses, in which we adjusted for potential confounders including total energy intake, physical activity and smoking status, did not materially change the results of the analyses adjusted for age and sex. Conclusions: Dietary habits that resemble the Mediterranean type diet may protect against NODAT and mortality after kidney transplantation. More attention should be directed to the nutritional habits of renal transplant recipients.