Predictors of Hypertension Following Successful Renal Transplantation: A Population-Based Study

Factors Associated with Uncontrolled Hypertension among Renal Transplant Recipients Attending Nephrology Clinics in Nairobi, Kenya

Objective. To determine the factors associated with poor blood pressure control among renal transplant recipients in a resource-limited setting. Methods. A cross-sectional study was carried out on renal transplant recipients at the Kenyatta National Hospital. Sociodemographic details, blood pressure, urine albumin : creatinine ratio, and adherence using the MMAS-8 questionnaire were noted. Independent factors associated with uncontrolled hypertension were determined using logistic regression analysis. Results. 85 subjects were evaluated. Mean age was 42.4 (SD ± 12.2) years, with a male : female ratio of 1.9 : 1. Fifty-five patients (64.7%) had uncontrolled hypertension (BP ≥ 130/80 mmHg). On univariate analysis, male sex (OR 3.7, 95% CI 1.4-9.5, p = 0.006), higher levels of proteinuria (p = 0.042), and nonadherence to antihypertensives (OR 18, 95% CI 5.2-65.7, p < 0.001) were associated with uncontrolled hypertension. On logistic regression analysis, male sex (adjusted OR 4.6, 95% CI 1.1-19.0, p = 0.034) and nonadherence (adjusted OR 33.8, 95% CI 8.6-73.0, p < 0.001) were independently associated with uncontrolled hypertension. Conclusion. Factors associated with poor blood pressure control in this cohort were male sex and nonadherence to antihypertensives. Emphasis on adherence to antihypertensive therapy must be pursued within this population.

Blood pressure control according to the prevalence of diabetes in renal transplant recipients

Hypertension is one of the most frequent complications of renal transplantation. About 70% to 90% of this population display either high blood pressure (BP) or require antihypertensive therapy. Diabetes mellitus is also a common finding among kidney transplant recipients. The aim of the study was to assess the BP control among kidney transplant recipients according to the prevalence of diabetes. This retrospective analysis included 172 renal transplant recipients of overall mean age 50 years and 51% males. Hypertension was present in 79% of patients. About one-third of the studied population showed abnormal blood pressures based on office measurements. The cohort was divided into two groups according to the presence of diabetes: group 1, diabetic patients (n = 14) versus group 2, nondiabetics (n = 158). Nondiabetic patients were significantly older than diabetic ones (61.5 versus 49 years; P < .05) and their time after renal transplantation was longer (98.83 versus 67.33 months, P < .05). There was no difference in regard to hypertension prevalence, mean BP value, percentage of abnormal (≥ 140/90 mm Hg) BP values or glomerular filtration rate. Diabetic patients were prescribed less steroid. The main hypotensive drug used in whole cohort and in no-diabetic patients was a beta-blocker (n = 64, 37%; n = 4, 28%), patients with diabetes used beta-blockers and angiotensin-converting enzyme inhibitors at the same frequency (n = 60, 37%). The main causative factor for hypertension appeared to be the calcineurin inhibitor. More aggressive antihypertensive treatment using combined drugs, including RAS blockers, might provide adequate BP control among renal transplant subjects with high cardiovascular risk.

Hypertension: The Neglected Complication of Transplantation

Arterial hypertension and transplantation are closely linked, and its association may promote impaired graft and overall survival. Since the introduction of calcineurin inhibitors, it is observed in 50–80% of transplanted patients. However, many pathophysiological mechanisms are involved in its genesis. In this review, we intend to provide an updated overview of these mechanisms, dealing with the causes common to all kinds of transplantation and emphasizing special cases with distinct features, and to give a perspective on the pharmacological approach, in order to help clinicians in the management of this frequent complication.

The influence of low donor age, living related donation and pre-emptive transplantation on end-organ damage based on arterial hypertension after paediatric kidney transplantation

BACKGROUND

To date, no study has described the pre-transplant and transplant risk factors for end-organ damage based on arterial hypertension in children after kidney transplantation (KTX).

METHODS

A retrospective chart review was performed of 206 children with KTX between 1991 and 2007. Patients<120 cm were excluded as no validated percentiles for 24-h ambulant blood pressure monitoring (ABPM) exist. Complete data sets were available for 116 patients. Data were recorded at 12, 24 and 36 months post- KTX. We analysed the influence of donor age, age at transplantation, pre-emptive transplantation, living or deceased transplantation and glomerular filtration rate (GFR) on the presence of end-organ damage, ABPM, ABPM standard deviation score and the numbers of anti-hypertensives used.

RESULTS

Lower donor age and the decade of transplantation were associated with less detection of end-organ damage (P=0.001). A lower need for anti-hypertensive medication (P=0.001) was detected in children who received organs from living donors and from deceased donors with a donor age<35 years and who were transplanted pre-emptively. Low recipient age was the only factor associated with lower ABPM (P=0.001). In our study, the type of immunosuppressive regimen and the GFR had no influence on the blood pressure.

CONCLUSIONS

It may be speculated that the risk of arterial hypertension and associated end-organ damage in children after KTX could be reduced by using organs from young donors with an advantage for living related and pre-emptive donation.