Incidence and factors associated with uncontrolled hypertension at 12 months after kidney transplantation in Saudi Arabia

Introduction: Uncontrolled hypertension after kidney transplantation (KTx) is very common and is associated with significant morbidity. However, studies that assess its incidence and risk factors are limited and outdated in the Middle East.Methods: This is a single-center retrospective study of KTx recipients (KTRs) in our center between January 2017 and May 2020 with a 12-month follow-up period. The target of hypertension treatment during the time of this study was <140/90 mmHg, according to the published guidelines. We divided patients according to their blood pressure (BP) control at one year into two groups: controlled blood pressure (cBP) (<140/90) and uncontrolled blood pressure (uBP) ( & GE; 140/90). We studied the association between cBP and patients' demographics, baseline cardiovascular risk factors, and changes in their metabolic and cardiovascular profile during the first 12 months after KTx.Results: A total of 254 KTRs were included. 79.2% developed post-KTx hypertension, 74% were & GE; 30 years, 58% were men, and 80% were living-donor KTRs. The renal replacement modality among our patients/sample before KT was hemodialysis in 78.4%, peritoneal dialysis in 11.5%, and 10.1% underwent pre-emptive transplantation. At one year, 76 (29.9%) KTRs did not attain the target BP goal. Systolic BP decreased from baseline to 12 months by 13 & PLUSMN;24 mmHg in the cBP group and increased by 8.7 & PLUSMN;21 mmHg in the uBP group (p<0.001). Additionally, diastolic BP decreased by 8.5 & PLUSMN;16.9 mmHg in the cBP group and increased by 2.3 & PLUSMN;18.8 mmHg in the uBP group (p<0.001). Factors associated with uBP included age (47 vs 41 years, p=0.008) and diabetes mellitus (p=0.012). Contrarily, gender, dialysis vintage, preemptive transplantation, type of dialysis (hemodialysis vs peritoneal dialysis), type of transplant (living donor kidney transplant vs deceased donor kidney transplant), and smoking were not different among the two groups. There were no significant differences between the two groups in regard to creatinine change from baseline, rate of rejection, weight change, A1C change, new onset diabetes post-transplant, LDL change, PTH change from baseline, and persistent hyperthyroidism. However, higher BMI at 12 months was associated with a higher incidence of uBP (27.2 & PLUSMN;5.9 vs 29.2 & PLUSMN;5.4, p=0.013). Using multivariate analysis, we found that serum creatinine at 12 months was the only predictor of uBP (OR=1.005 (1-1.011), p=0.036).Conclusion: At one-year post renal transplantation, about one-third of KTRs had uBP despite multiple antihypertensive medications. SBP and DBP significantly trended upwards after transplantation in uBP patients, whereas SBP and DBP significantly trended downwards after transplantation in cBP patients. Further controlled, prospective studies in the Saudi population are needed to confirm these findings.