Sleep disordered breathing in renal transplant patients

Sleep disordered breathing (SDB) is a prevalent, important nontraditional cardiovascular (CV) risk factor in end-stage renal disease patients. The prevalence of SDB in renal transplant patients is unknown. We compared polysomnographic studies in 163 transplant patients with matched samples in the general population and explored longitudinally the effect of return to dialysis after graft failure on SDB in three consecutive cases. Episodes of nocturnal hypoxemia, average and minimal O(2) saturation overnight in transplant patients did not differ from those in individuals in the general population matched for age, gender and body mass index (BMI). The prevalence of moderate-to-severe SBD in these patients did not exceed the estimated prevalence of the same disturbance in the general population. The respiratory disturbance index in transplant patients was directly associated with BMI (p < 0.001). In the longitudinal study all indicators of SDB coherently increased after transplant failure. The prevalence of SDB in transplant patients does not differ from that in well-matched individuals in the general population. The favorable effect of renal transplantation on CV risk may be at least partially explained by the lack of risk excess for SDB in this population. Longitudinal observations after transplant failure are compatible with the hypothesis that renal transplantation reverses SDB.