Background: Hypertension persists in many patients with diabetes mellitus after kidney transplantation. However, the impact of control of diabetes as well as kidney failure on hypertension by combined kidney and pancreas transplantation has not been studied.
Methods and results: Between March 1993 and August 1998, 111 patients with type 1 diabetes mellitus underwent successful pancreas transplantation (108 kidney/pancreas transplantation) and another 28 patients with type 1 diabetes mellitus underwent isolated kidney transplantation. Blood pressure measurements and all antihypertensive medications were determined for both groups before transplantation and at 1, 3, 6, and 12 months and at the most recent outpatient evaluation after transplantation. At baseline, the mean blood pressure was 151/88 and 151/83 mm Hg for the kidney/pancreas and isolated kidney transplant patients, respectively. The mean blood pressure decreased to 134/77 mm Hg 1 month after kidney/pancreas transplantation (P<0.001) and decreased further to 126/70 mm Hg (P<0.001) at a mean follow-up of 18 months. This reduction in blood pressure after transplantation occurred despite a decrease in antihypertensive medications and the institution of immunosuppressive agents. At 1 month after kidney/pancreas transplantation, the average number of antihypertensive medications per patient was 0.9+/-1.0, compared with 2.5+/-1.1 before surgery (P<0.001). At 18 months after transplantation, 34% of patients were both normotensive (blood pressure </=130/85 mm Hg) and receiving no antihypertensive medications. In contrast, there was no significant decrease in systolic blood pressure or antihypertensive medication use in the patients receiving an isolated kidney transplant.
Conclusions: Successful kidney/pancreas transplantation results in a marked improvement in hypertension treatment that is not observed in patients undergoing isolated kidney transplantation. These data underscore the importance of diabetes in the pathogenesis of hypertension in patients with diabetes and kidney failure.