Impact of diabetes mellitus on kidney transplant recipients in Spain

Background. The increasing prevalence of pre-existing diabetes mellitus (DM) and especially the incidence of post-transplant diabetes mellitus (PTDM) is a disturbing tendency with far-reaching health and cost implications. We assessed the factors associated with PTDM and the impact of either condition on death-censored graft and patient survival. Methods. We studied 3365 adult kidney allograft recipients transplanted in 1990, 1994 and 1998, whose graft was functioning after 1 year of follow-up. Three groups were considered: Group I (DM; N = 156), Group II (PTDM; N = 251) and Group III (nondiabetic; N = 2958). Results. Group I patients had been dialysed for shorter periods and received angiotensin-converting enzyme inhibitor (ACEI) or angiotensin-receptor blockers (ARB) therapy more frequently during follow-up than the other groups (P < 0.001). Mean age, body weight and body mass index (BMI) were greater in Group II patients than the other groups (P < 0.001). Group II showed lower rejection rates than Group III (P < 0.01). Risk factors for developing PTDM were recipient age >60 years (OR = 2.24; P < 0.001), female recipient (OR = 1.5; P < 0.005), recipient weight >65 kg (OR = 1.77; P < 0.002), BMI >25 kg/m(2) (OR = 1.6; P < 0.04) or >30 kg/m(2) (OR = 2.92; P < 0.005), and tacrolimus-based therapy (OR= 1.48; P < 0.05). Of note, the use of Sandimmune(R) vs Neoral(R) had a protective effect (OR = 0.7; P < 0.01). Using Cox's proportional hazards analysis, DM correlated with reduced death-censored graft survival (RR = 1.68; 95% CI=1.14-2.47; P < 0.008), while PTDM correlated with reduced patient survival (RR = 1.55; 95% CI = 1.05-2.27; P < 0.02). Conclusions. One year after transplantation, DM was associated with a decrease in death-censored graft survival, while PTDM was an independent negative predictor of patient survival after kidney transplantation. New strategies to improve outcome are needed.