Accelerated
coronary artery disease develops in most if not all heart transplant recipients within the first year after
transplantation. Increased lipid peroxidation seems to be involved in
atherogenesis. In these patients we have investigated whether there is an association between lipid peroxidation, reduced
antioxidant defenses, and some conventional coronary risk factors.
Lipid peroxides,
lipids,
uric acid,
albumin,
antioxidant enzymes and their cofactors (the
trace elements selenium,
iron,
copper, and
zinc) have been determined in heart transplant recipients compared with nonrecipients with
coronary artery disease.
Lipid peroxides (p = 0.002) and
uric acid (p = 0.01) were higher and
zinc (p = 0.001) was lower in heart transplant recipients. Thirteen of 30 transplant recipients compared with one of 30 nonrecipients (p < 0.001) had very low (less than 10 mumol/L)
zinc levels.
Antioxidant enzymes and other
trace elements were not significantly different. In univariate regression analysis,
zinc correlated positively with
albumin (p = 0.02) and negatively with
lipid peroxides (p < 0.05). Uricemia had a strongly positive correlation with hydroperoxides (r = 0.45; p = 0.0001). In stepwise multivariate regression analysis,
lipids, uricemia,
creatinine, and
zinc were significant (p < or = 0.004) predictors of the
lipid peroxide level.
Cyclosporine and
corticosteroid dosages were significant (p = 0.01) determinants of
zinc concentration in the transplant recipients. Although a causal relationship between increased lipid peroxidation and accelerated
arteriosclerosis is not definitely demonstrated, the results of this analysis suggest new insights into conventional
coronary disease risk factors and possible therapeutic interventions; further controlled trials are needed.