To examine the changes in bladder function after renal transplantation by comparing lower urinary tract symptoms in the first and third years after transplantation in a group of renal transplant recipients.

The long-term changes in bladder function after transplantation were studied using a longitudinal study design. The study group consisted of 53 patients who underwent renal transplantation in 1998 at the University Medical Centre Nijmegen and who returned a completed questionnaire about their micturition pattern in the first and third year after transplantation. The data on symptoms of lower urinary tract dysfunction were collected using the International Continence Society (male) and Bristol Female Lower Urinary Tract Symptoms questionnaires. The control group consisted of 74 patients who visited the Outpatient Clinic of Otorhinolaryngology at year 1. In our analyses, we compared the micturition behavior of the transplant group at year 3 with the control group and with their own micturition behavior at year 1.

The results of our study showed that 3 to 4 years after transplantation, the renal transplant group still urinated significantly more often during the day and during the night than did the control patients. Furthermore, among most (63% to 68%) of the patients who showed these symptoms in the first year after transplantation, the symptoms were still present 2 to 3 years later.

The frequency and incidence of nocturia among renal transplant patients are fairly persistent phenomena.