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/m2), overweight (BMI of 25 to 30 kg/m2) and obese (BMI > 30 kg/m2).

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.

[Effects of dose of erythropoiesis stimulating agents on cardiovascular outcomes, quality of life and costs of haemodialysis. the clinical evaluation of the DOSe of erythropoietins (C.E. DOSE) Trial]

BACKGROUND

Anaemia is a risk factor for death, adverse cardiovascular outcomes and poor quality of life in patients with chronic kidney disease (CKD). Erythropoietin Stimulating Agents (ESA) are the most used treatment option. In observational studies, higher haemoglobin (Hb) levels (around 11-13 g/dL) are associated with improved survival and quality of life compared to Hb levels around 9-10 g/dL. Randomized studies found that targeting higher Hb levels with ESA causes an increased risk of death, mainly due to adverse cardiovascular outcomes. It is possible that this is mediated by ESA dose rather than haemoglobin concentration, although this hypothesis has never been formally tested.

METHODS

We present the protocol of the Clinical Evaluation of the Dose of Erythropoietins (C.E. DOSE) trial, which will assess the benefits and harms of a high versus a low ESA dose therapeutic strategy for the management of anaemia of end stage kidney disease (ESKD). This is a randomized, prospective open label blinded end-point (PROBE) design trial due to enroll 900 haemodialysis patients. Patients will be randomized 1:1 to 4000 UI/week i. v. versus 18000 UI/week i. v. of epoetin alfa, beta or any other epoetin in equivalent doses. The primary outcome of the trial is a composite of cardiovascular events. In addition, quality of life and costs of these two strategies will be assessed. The study has been approved and funded by the Italian Agency of Drugs (Agenzia Italiana del Farmaco (AIFA)) within the 2006 funding plan for independent research on drugs (registered at www.clinicaltrials.gov (NCT00827021)).