Prevalence of iron deficiency and iron deficiency anaemia among children with congenital heart defects at tertiary hospitals in Dar es Salaam, Tanzania: a cross-sectional study

Abstract

Introduction: iron deficiency (ID) is the most prevalent nutritional problem worldwide with children being the most vulnerable. In children with congenital heart defect (CHD), ID may lead to iron deficiency anaemia (IDA) which carries a poor prognosis due to exacerbation of left ventricular dysfunction and heart failure. This study assessed the prevalence and factors associated with ID and IDA among children with CHD at Muhimbili National Hospital (MNH) and Jakaya Kikwete Cardiac Institute (JKCI) in Tanzania.

Methods: a descriptive hospital-based cross-sectional study was conducted among 238 participants with echocardiography confirmed CHD presenting at MNH and JKCI. A structured questionnaire was used to collect demographic data and medical history. Anthropometric measurements were done and blood samples for evaluation of complete blood count, serum ferritin and C-reactive protein were collected. Descriptive statistics such as frequencies, percentages, median with interquartile range, were used to describe study participants. Comparison of continuous variables was performed using Student's t-test or Mann-Whitney U-test as appropriate and Chi-square (x2) test or Fisher's exact test for categorical variables to determine associations. Odds ratio (OR) with 95% confidence intervals (CI) were estimated to determine risk factors for iron deficiency and iron deficiency anaemia. All analyses were conducted using SPSS version 20 and p-value ≤0.05 was considered statistically significant.

Results: characteristic of study participant majority 66.4% (n 158) were less than 60 month of age with nearly equal number of male 51.3%(122) to female 48.7% (n 116). The overall prevalence of anaemia among study participants was 47.5% (n 238) with mild, moderate and severe anaemia being 21.4%, 21.4% and 4.6% respectively. The prevalence of iron deficiency was 26.9% (n 64) and that of iron deficiency anaemia was 20.2% (n 48). Age below 5 years, cyanotic CHD, history of recent illness and less consumption of red meat were significantly associated with iron deficiency (ID) and iron deficiency anaemia (IDA). After controlling for independent variables, history of recent illness aOR 0.46, 95% CI 0.22-0.98 P 0.045 less frequent consumption of red meat aOR 0.11 95% CI 0.04-0.32 P <0.001 and cyanotic CHD aOR: 0.40, 95% CI 0.18-0.87; p 0.021, were associated with of iron deficiency similarly age below 5 years aOR 0.33 0, 95% CI 14-0.89 P 0.02 early weaning practices aOR 0.50 95% CI 0.23-0.97 P 0.050 less frequent consumption of red meat aOR 0.07 CI (0.02-0.24 p <0.01 were significantly associated with iron deficiency anaemia.

Conclusion: nearly half of the children with CHD in this study had anaemia, more than a quarter had ID and one-fifth had IDA. Routine screening and management of both ID and IDA in children with CHD should be practised during weaning and throughout the childhood to prevent ventricular dysfunction further heart failure.

Keywords: Iron deficiency; Tanzania; children; congenital heart defects; iron deficiency anaemia.