Body mass index and metabolic syndrome impact differently on major clinical events in renal transplant patients

OBJECTIVE: Kidney transplant recipients (KTRs) are bound to develop cardiovascular disease (CVD), and obesity represents a well-known risk factor for CVD. It has been reported that the metabolic syndrome (MetS) is a frequent finding in KTRs, and MetS could develop even if body mass index (BMI) is only mildly increased. We compared the impact of BMI and MetS on the development of major clinical events (MCEs) in a cohort of 107 KTRs during a follow-up of 63 +/- 31 months. PATIENTS AND METHODS: Clinical characteristics were recorded at the time of enrollment and patients were classified on the basis of MCEs development. In a Cox model, MCEs were the dependent variable while age, sex, history of CVD, glomerular filtration rate, length of dialysis pre-transplantation, BMI classes and diagnosis of MetS were independent variables. Patients were classified into 3 groups: normal (BMI < 25 kg/m(2)), overweight (BMI of 25 to 30 kg/m(2)) and obese (BMI > 30 kg/m(2)). RESULTS: During follow-up, 55 MCEs were recorded: 16 patients died (15%), 19 (18%) had major cardiovascular events (CVEs), and 20 (19%) started dialysis due to graft failure. KTRs who had MCEs (n = 42) were older, had a lower renal function, longer dialysis vintage pre-transplantation, higher prevalence of history of CVD and higher BMI than those without MCEs. Cox regression analysis showed that length of dialysis pre-transplantation, renal function, previous CVD, and BMI classes (overweight and obesity) were related to MCEs. CONCLUSIONS: BMI, but not MetS, predicted MCEs in KTRs as well as non-traditional CVD risk factors such as length of dialysis pre-transplantation and graft function. Thus, a simple evaluation during clinic visits could identify KTRs at high risk for MCEs.