Cardiovascular risk factors and diseases after renal transplantation

Abstract

Cardiovascular disease is a leading cause of death after renal transplantation (tpx), and the incidence is considerably higher than in the general population.

Objective: To evaluate the incidence of atherosclerotic cardiovascular complications after tpx, the prevalence of cardiovascular risk factors, prior to and following tpx, and the association between the risk factors and complications.

Patients and methods: Analysis of atherosclerotic cardiovascular diseases (coronary artery disease, cerebral and peripheral vascular disease) and cardiovascular risk factors before and after transplantation in 427 renal transplant recipients between 1987 and 1992 (mean age at transplantation 45+/-12 years, 58% male, 7% diabetics) with a mean post-transplant follow-up of 29+/-20 months.

Results: Following tpx 11.7% developed atherosclerotic cardiovascular diseases, the majority coronary artery disease (9.8%). The comparison of risk factors 12 months before and 24 months following transplantation showed: prevalence of systemic hypertension (from 73% to 85%), diabetes mellitus (from 7% to 16%) and obesity with a body mass index >25 kg/m2 (from 26% to 48%) had increased significantly whereas the number of smokers halved to 20%. Triglycerides decreased significantly (from 235 mg/dl to 217 mg/dl). Total and HDL cholesterol rose significantly (from 232 mg/dl to 273 mg/dl and from 47 mg/dl to 56 mg/dl, respectively). LDL cholesterol increase was significant (from 180 mg/dl to 189 mg/dl). In the univariate analysis, cardiovascular diseases were significantly associated with male gender, age over 50 years, diabetes mellitus (DM), smoking, total cholesterol > or=200 mg/dl, LDL cholesterol >180 mg/dl, HDL cholesterol < or =55 mg/dl, fibrinogen > or =350 mg/dl, body mass index >25 kg/m2, serum uric acid >6.5 mg/dl and with more than two antihypertensive agents per day. The Cox proportional hazards model revealed DM with a relative risk (RR) of 4.3, age >50 years (RR=2.7), body mass index >25 kg/m2 (RR=2.6), smoking (RR=2.5), LDL cholesterol >180 mg/dl (RR=2.3) and uric acid >6.5 mg/dl as independent risk factors.

Conclusions: The high incidence of cardiovascular disease following renal transplantation is mainly due to a high prevalence and accumulation of classical risk factors before and following transplantation. Future prospective studies should evaluate the success of treatment regarding reduction of cardiovascular morbidity and mortality in this high risk population.