Nutritional and metabolic issues in solid organ transplantation: targets for future research

Cardiovascular morbidity and mortality complicates the course of a significant proportion of renal transplant recipients and is increasingly prevalent among recipients of other solid organ transplants, such as heart or liver transplant patients. A posttransplant metabolic syndrome comprised of hypertension, dyslipidemia, increased fat mass/obesity, and glucose intolerance, combined with other metabolic side effects derived from glucocorticoid and calcineurin inhibitor immunosuppression, attenuates allograft and patient survival. After the early posttransplant years, infection and rejection are the major risks that recipients face, whereas metabolic and cardiovascular disease become the most serious long term risk factors impacting patient survival. While significant advances in immunosuppressive therapy have prolonged the allograft and patient survival in solid organ transplant recipients, little has been done in the way of controlled interventional trials utilizing nutritional, dietary, or biobehavioral modification, especially when combined with drug treatment to reduce the effects of the posttransplant metabolic syndrome. In addition to cardiovascular morbidity, metabolic bone disease, osteopenia, and impaired growth in children pose significant challenges in posttransplant management. In this review, the data from some of the known observational dietary trials in solid organ transplant recipients and prior evidence obtained from studies in chronic kidney disease and the general population is considered in formulating new targets for future research to deal with this ever-increasing population of high risk patients.