Incidence of cardiovascular risk factors and complications before and after kidney transplantation

Cardiovascular disease is a leading cause of death after renal transplantation with an incidence considerably higher than that in the general population. The aim of this study was to evaluate the association of atherosclerotic cardiovascular complications and the prevalence of cardiovascular risk factors prior to and following transplantation.

Atherosclerotic cardiovascular diseases including coronary artery disease, as well as cerebral and peripheral vascular disease, and cardiovascular risk factors pre- and posttransplantation were analyzed in 500 renal transplant recipients between 1988 and 1992. The mean recipient age at transplantation was 45 +/- 12 years, with 58% men and 7% diabetics.

Following transplantation 11.7% developed atherosclerotic cardiovascular diseases, the majority being coronary artery disease (9.8%). Comparison of the risk factors before and after transplantation showed the increased prevalence of systemic hypertension to be 67% to 86%, of diabetes mellitus, 7% to 16%, and obesity, with a body mass index > 25 kg/m2 from 26% to 48%, whereas the number of smokers was halved to 20%. The triglycerides decreased significantly (from 235 +/- 144 mg/dL to 217 +/- 122 mg/dL) but the total and high-density lipoprotein (HDL) cholesterol rose significantly (from 232 +/- 65 mg/dL to 273 +/- 62 mg/dL and from 47 +/- 29 mg/dL to 56 +/- 21 mg/dL, respectively). The low-density lipoprotein (LDL) cholesterol increase was insignificant (from 180 +/- 62 mg/dL to 189 +/- 53 mg/dL). Upon univariate analysis, cardiovascular diseases were significantly associated with male gender; age over 50 years; diabetes mellitus (DM); smoking; total cholesterol > 200 mg/dL; LDL cholesterol > 180 mg/dL; HDL cholesterol < 55 mg/dL; fibrinogen > 350 mg/dL; body mass index > 25 kg/m2; and 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); and LDL cholesterol > 180 mg/dL (RR = 2.3) as independent risk factors.

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. The treatment of risk factors must be introduced early in the course of renal failure and continued following transplantation. Future prospective studies should evaluate the success of treatment regarding reduction of cardiovascular morbidity and mortality in this high-risk population.