Non-alcoholic fatty liver disease; a part of the metabolic syndrome in the renal transplant recipient and possible cause of an allograft dysfunction

Abstract

Despite all improvements in transplant medicine, renal transplant recipients have a high risk for cardiovascular mortality. A high prevalence of cardiovascular complications in renal transplant recipients (RTR) is explained by cardiovascular risk factors present before transplantation, in addition to the development of new risk factors as well as worsening of preexisting risk factors after transplantation. A majority ot these patients develop metabolic syndrome within a year after the transplantation. The metabolic syndrome (MS) is associated with impaired renal allograft function and increased insulin resistance. Non alcoholic fatty liver disease (NAFLD) represents a liver manifestation of metabolic syndrome and it development is strongly associated with all components of MS in general population. The current importance of NAFLD and its link to the MS has encouraged an interest in its possible role in the development of atherosclerosis in recent years. Considering the fact that all components of MS are more common among renal transplant recipients compared to general population, it would be expected that RTR may have a much higher incidence of NAFLD compared to general population. We propose that the presence of NAFLD in RTR could be a strong predictor in cardiovascular morbidity and mortality. Also, according to the recent investigations about the possible link between NAFLD and chronic kidney disease, we hypothesis that NAFLD may be associated with deteriorating graft function, causing a chronic allograft nephropathy and graft loss. Common factors underlying the pathogenesis of NAFLD and chronic allograft dysfunction may be insulin resistance, oxidative stress, activation of rennin-angiotensin system, and inappropriate secretion of inflammatory cytokines by steatotic and inflamed liver.