Cardiovascular risk factors in renal transplant recipients attending nephrology clinics in Nairobi, Kenya

Abstract

BACKGROUND: Cardiovascular disease (CVD) is recognized as the leading cause of morbidity and mortality amongst patients with chronic kidney disease (CKD). Currently, 50-60% of deaths in renal transplant recipients are directly attributable to CVD. No dataeexisted on the prevalence of cardiovascular risk factors in renal transplant recipients (RTR) in Kenya. OBJECTIVE: The aim of the study was to determine the prevalence of established cardiovascular risk factors and to analyze for associations of these risk factors with age, gender, duration of dialysis pre-transplant, medications including immunosuppressant use, cause of CKD, pre-existent diabetes or hypertension, and type and number of renal allograft in RTR in Nairobi, Kenya. SETTING: The Renal Unit Transplant Clinic at Kenyatta National Hospital (KNH) and nephrology clinics at KNH Doctors Plaza, Nairobi Hospital Doctors Plaza and Parklands Nephrology Centre. STUDY POPULATION: Renal allograft recipients attending nephrology clinics in Nairobi METHODS: This study was conducted as a cross-sectional prevalence design. 91 renal allograft recipients underwent consecutive sampling and were evaluated for selected CVD risk factors including hypertension, obesity, decreased GFR, cigarette smoking, hypertension, diabetes mellitus, impaired glucose tolerance, anemia, dyslipidemia and proteinuria. DATA COLLECTION AND ANALYSIS:. Continuous variables were expressed as means and standard deviations, prevalence expressed as percentages with 95% Confidence Intervals and associations between CVD risk factors and patient variables or immunosuppressant drugs evaluated by Chi-square test. A P value less than or equal to 0.05 was considered statistically significant. RESULTS: In the study, 91 renal transplant recipients were enrolled between 151 August 2011 and 151 February 2012 with a male to female ratio of2.1 to 1 anti mean age of 44.2 years (SD12.44). Hypertension, dyslipidemia and abdominal obesity by waist-hip ratio were the most prevalent risk factors among the study population at 95.6%, 73.6% and 68.1 % respectively. Statistically significant associations were found between the presence of a second renal allograft and NODAT (P = 0.011) as well as history of pre-transplant diabetes mellitus and use of insulin with impaired graft function (P = 0.026 and P = 0.004 respectively). Most allograft recipients were on Prednisolone, Cyclosporine and Mycophenolate mofetil combination therapy with those on Azathioprine having the longest duration of exposure (142.0 months) while those on Everolimus had the shortest duration (7.5 months). No statistically significant associations were found between any of the immunosuppressant agents and the cardiovascular risk factors. LIMITATIONS: Recall bias in past medical history. Misclassification bias in use of a single occasion blood pressure reading for hypertension and single urine sample for microalbuminuria. Overestimation bias in use of estimated GFR equation. Misclassification bias in use of Caucasian cutoffs values for BMI and waist circumference in Africans.

CONCLUSIONS: There is a high magnitude of cardiovascular risk factors in the renal transplant population especially hypertension, abdominal obesity and hyperlipidemia. Statistically significant associations were described between presence of a second renal allograft and development of NOD AT as well as between both history of pre-transplant diabetes mellitus and the use of insulin by renal transplant recipients with impaired graft function. The most common immunosuppressants used by the transplant recipients were Prednisolone, Mycophenolate mofetil and Cyclosporine with no statistically significant associati9ns were found between immunbsuppressant agents and the cardiovascular risk factors.

RECOMMENDATIONS: Renal transplant recipients should be prioritized as a population at . high risk for cardiovascular mortality in health policy formulation for interventional measures with local adaptation and implementation of guidelines on cardiovascular risk factors, Long term prospective studies should be carried out to characterize post-transplantation anemia, control of diabetes mellitus and associations between immunosuppressive agents, drug dosages and duration of use in renal transplant recipients with cardiovascular risk factors using larger sample Sizes.