Prevalence of anemia and its associated factors in patients with chronic kidney disease at Muhimbili national hospital Dar es Salaam

Abstract

Background: Chronic Kidney Disease (CKD) is a worldwide public health problem, the incidence and prevalence of which has increased in recent years in both developed and developing countries including Tanzania. Anemia, being a major health problem in Tanzania, is also a major co-morbidity of CKD patients and is common in all stages but becomes more pronounced at the latter stages of kidney failure. The causes of anemia are multifactorial ranging from erythropoietin deficiency to nutritional anemia due to iron deficiency, vitamin B12 and folate deficiency. However, erythropoietin deficiency is the most significant cause of anemia in CKD. Anemia has direct adverse effects on cardiovascular disease (CVD) consequences, such as left ventricular hypertrophy (LVH), and accelerates progression of CKD. As a result, patients with anemia due to CKD are at increased risk of hospitalization with increased length of hospital stay, reduced quality of life and increased mortality. Objective: To determine the prevalence of anemia and its associated factors among CKD patients attending at MNH Nephrology unit in Dar-es-Salaam. Methodology: A hospital based cross sectional study was carried out among CKD patients aged 18 years and above at Muhimbili National Hospital. Consecutive recruitment was adopted and 100 CKD patients were recruited out of 1476 patients with different renal diseases who were attended from May, 2011 to October 2012 at Nephrology unit. MDRD equation was used to determine GFR and abdominal ultrasound was used to determine evidence of Kidneys damage. Endogenous Erythropoietin (EPO) measurement was determined in serum using an Enzyme linked immunosorbent assay EPO ELISA EIA-3646 (DRG Diagnostic GmbH Germany) and Iron status was established using transferrin concentration, serum iron and serum ferritin levels . A questionnaire with structured interviews was used during data collection. Pre-coded data were entered into computer using Epi Info software version 3.5.1 and then data were transferred to SPSS (Statistical Package for Social Sciences) version 17.0 for further cleaning, categorizing of continuous variables and eventually analysis.Results: One hundred (100) patients with chronic kidney disease were consecutively sampled from a total of 1476 of patients with various forms of Kidney diseases who attended at the Nephrology unit during the period of data collection. All were of African origin with mean age 44.4+14.6 years and 61% were males. Majority of study subjects (91%) were in advanced CKD stages (stage 4 and 5) and overall prevalence of anemia was (97%) defined using WHO criteria. Of 82 study participants who were evaluated for EPO level, (87.8%) had low EPO production as response to a given hemoglobin level and there was no correlation between EPO level and hemoglobin value (r=0.012, p value=0.913) Fifty four (54%) study participants had iron deficiency whereby majority (37%) had functional iron deficiency and (17%) had absolute iron deficiency. Conclusion: Prevalence of anemia among CKD patients attending at Nephrology unit at MNH is high. Most of CKD patients showed evidence of inadequate endogenous EPO production and defective iron supply for erythropoiesis.