BACKGROUND: Cardiovascular disease is both a major threat to the life expectancy of kidney transplant recipients and an important determinant of late allograft loss. Obesity is an important risk factor for cardiovascular disease.
METHODS: We investigated the relation between both pretransplant and 1-year posttransplant body mass index (BMI) with patient and renal graft survival in a cohort of 1810 adult patients. Sixty-one percent of all patients were men; median age (interquartile range [IQR]) was 46 years (35-56 years); median (IQR) pretransplant BMI was 23.0 kg/m (20.8-25.6 kg/m); 1 year after transplantation, the median (IQR) BMI had increased 1.6 kg/m (0.3-3.2 kg/m) and median (IQR) follow-up time was 8.3 years (5.3-12.0 years). We categorized BMI as follows: ≤ 20, more than 20 to ≤ 25 (normal), more than 25 to ≤ 30, and more than 30 (obesity) kg/m.
RESULTS: Using a Cox proportional hazards model, after adjustment for cardiovascular risk factors, the relative risks (95% confidence intervals) of death and death-censored graft failure during all follow-up for pretransplant obesity compared with normal BMI were 1.22 (0.86-1.74) and 1.34 (1.02-1.77), respectively; for obesity 1 year after transplantation compared with normal BMI, it was 1.39 (1.05-1.86) and 1.39 (1.10-1.74), respectively; and for change in BMI (per 5 kg/m increment) during the first year after transplantation, it was 1.23 (1.01-1.50) and 1.18 (1.01-1.38), respectively.
CONCLUSIONS: One year posttransplant BMI and BMI increment are more strongly related to death and graft failure than pretransplant BMI among kidney transplant recipients. Patients with BMI more than 30 kg/m compared with a normal BMI have approximately 20% to 40% higher risk for death and graft failure. © 2011 by Lippincott Williams & Wilkins
