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 (non-diabetic; 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 vs Neoral 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.