Effect of overweight on kidney transplantation outcome

Obesity is a prevalent problem in renal transplant recipients that is followed by reduced graft and patient survivals. Because the prevalence of overweight (OW) is increasing in the renal transplant population, we studied the influence of OW on graft and recipient evolution.

We analyzed a series of 337 patients with renal allografts having a mean follow-up of 53.4 +/- 30.6 months. We excluded 39 patients obese at transplantation. We compared the evolution of 134 OW patients (45.5%), and 160 patients (54.4%) with a body mass index <25 (NW group).

OW patients were older (P = .000) with a higher prevalence of hypertension (P = .028), left ventricular hypertrophy (P = .014), and dyslipidemia (P = .001). They had received kidneys from older donors (P = .019). OW patients showed a higher incidence of acute tubular necrosis (ATN) (P = .006), without a higher incidence of acute rejection episodes (P = .756). Postransplant diabetes mellitus was more frequent (P = .000), and systolic blood pressure (P < .05), total cholesterol (P < .05), and tryglicerides were higher (P < .05) in the OW group. Serum creatinine at 6 months (P = .007) and proteinuria >0.5 g/24 hours, (P = .023) were higher among the OW group. Graft survival was not different between groups, but patient survival was lower in the OW group (P = .002). A logistic regression analysis showed that the recipient age (RR: 5.243) and the presence of OW (RR: 1.100) were independent prognostic factors for patient death.

OW was a common situation among renal transplant candidates. It was associated with worse cardiovascular and metabolic profiles. OW patients showed worse allograft function and lower patient survival. A major effort must be exerted to avoid excessive weight gain, particularly among those OW at transplantation.