Obesity in renal transplantation: analysis of 2691 patients

Obesity is a cardiovascular risk factor in renal transplantation (RT). The objective of this study was to analyze the prevalence of post-RT obesity and risk factors associated with its development.

The study included all patients with a functioning renal transplant on December 31, 2003, who were residents of Catalonia, aged older than 14 years and who underwent transplantation between 1990 and 2003 (n = 2793); 102 patients (3.7%) were excluded due to lack of data for 1 or more study variables. Mean age was 53 +/- 14 years (range, 15-83) (61% men). Mean transplant duration was 63.0 +/- 44.5 months (range, 0-168). The chi-square test was used to compare proportions, analysis of variance (ANOVA) to compare mean values, and logistic regression to study risk factors for post-RT obesity. All data were taken from the Renal Registry of Catalonia (RMRC).

Among RT patients, 38% were overweight (body mass index [BMI], 25-29.9 kg/m(2)) and 16% were obese (BMI >30). Prevalence of obesity was higher in women (21% vs 13%; P < .0001). Age was associated with obesity in RT patients aged 45-64 (20%) and 65-74 (18%) with respect to the group aged 15-44 years (9%) or >74 years (13%) (P < .0001). A total of 26% of patients who were normal weight before RT (BMI, 20-24.9) became overweight post-RT and 6% developed obesity (P < .0001). Among patients who were overweight pre-RT, 68% persisted with post-RT excess weight and 16% progressed to obesity (P < .0001). In the multivariate study, significant risk factors for developing post-RT obesity included the following: female (relative risk [RR], 2.46; P < .0001), age (45-64 years; RR, 2.36; P < .0001; and 65-74 years; RR, 2.23; P = .002), high blood pressure (RR, 1.44; P = .03), duration of transplant (RR, 1.06; P < .0001), cardiomyopathy (RR, 1.51; P = .007), and, particularly, the presence of excess weight (RR, 2.69; P < .0001) and pre-RT obesity (RR, 59.02; P < .0001).

There is a high prevalence of post-RT excess weight and obesity. Adequate control of cardiovascular risk in renal transplant recipients should also include strict measures to prevent and treat obesity.