|Year : 2017 | Volume
| Issue : 1 | Page : 14-18
Hemoglobin level and iron profile as risk factors for lower respiratory tract infections among children
Osama N.E. Saleh1, Manal M Ismail2, Marwa H Abdel Hamed MD 1, Mai E.M.A. Bassiony3
1 Department of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt
2 Department of Clinical Pathology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
3 Department of Pediatrics, Ain Shams University, Cairo, Egypt
|Date of Submission||18-Nov-2016|
|Date of Acceptance||22-Dec-2016|
|Date of Web Publication||18-May-2017|
Marwa H Abdel Hamed
Department of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, 1156
Source of Support: None, Conflict of Interest: None
Context Acute lower respiratory tract infection is a major cause of death under 5 years of age, and anemia is the commonest cofactor in pediatric patients seeking medical advice, especially in developing countries.
Aim The aim of this study was to evaluate the role of anemia as a risk factor for lower respiratory tract infections in infants and children.
Setting and design A case–control study was conducted in Children’s Hospital, Ain Shams University.
Patients and methods This study was conducted on a total of 80 infants and children aged 6 months to 6 years − 40 cases hospitalized for lower respiratory tract infections, with a mean age of 13.2±9.3 months, and 40 age and sex-matched healthy controls without any respiratory problems, with a mean age of 14.8±10.09 months.
Results There was a statistically higher percentage of iron deficiency anemia among cases (55%) than among controls (27.5%), with a significantly lower mean hemoglobin level among anemic cases than among anemic controls. There was a significantly lower mean serum iron in anemic cases than in anemic controls. Recurrent chest infection was statistically significantly more common in anemic cases (93%) than in nonanemic cases (8%).
Conclusion The present work concluded that anemia, especially iron deficiency anemia, may play a role in the development of acute lower respiratory tract infections among Egyptian children.
Keywords: hemoglobin, iron profile, lower respiratory tract infections
|How to cite this article:|
Saleh ON, Ismail MM, Abdel Hamed MH, Bassiony ME. Hemoglobin level and iron profile as risk factors for lower respiratory tract infections among children. Egypt J Haematol 2017;42:14-8
|How to cite this URL:|
Saleh ON, Ismail MM, Abdel Hamed MH, Bassiony ME. Hemoglobin level and iron profile as risk factors for lower respiratory tract infections among children. Egypt J Haematol [serial online] 2017 [cited 2017 Jun 25];42:14-8. Available from: http://www.ehj.eg.net/text.asp?2017/42/1/14/206434
| Introduction|| |
Children below 5 years of age suffer from about five to six episodes of acute lower respiratory tract infections (LRTIs) per year, which continues to be a burden later on. Most deaths from ALRIs are caused through severe pneumonia .
Anemia is one of the most common nutritional problems in the world. It is associated with increased risk for morbidity and mortality, especially in young children under the age of 5 years. Iron deficiency is considered as the most common cause of anemia in developing countries .
Iron deficiency exerts adverse effects on the immune response, low hemoglobin (Hb) level, and impaired tissue oxygenation, and acts as an independent risk factor in developing lower respiratory tract infection in children .
| Aim|| |
The aim of this study was to evaluate the role of anemia as a risk factor for LRTIs in infants and children.
| Patients and methods|| |
This case-controlled study was conducted on a total of 80 infants and children aged 6 months to 6 years − 40 cases hospitalized for lower respiratory tract infections in the Children’s Hospital, Ain Shams University (26 boys and 14 girls) with a mean age of 13.2±9.3 months; and 40 age and sex-matched healthy controls without any respiratory problems attending the outpatient clinic (24 boys and 16 girls) with a mean age of 14.8±10.09 months.
The two main groups (case and control groups) were further subdivided into the anemic group (n=43) and the nonanemic group (n=37).
All hospitalized cases aged between 6 months and 6 years with a diagnosis of LRTI, fever, cough, tachypnea, chest retractions, and rhonchi or crackles up on chest auscultation, according to WHO criteria, were included in the study .
Premature children or children with congenital chest wall malformations, severe systemic illness as congenital heart disease, chronic diseases, or children with history of intake of iron supplements were all excluded from the study.
After taking an oral consent from parents, all infants and children in the study were subjected to the following:
Full history taking
It included personal history; present history, stressing on fever, cough, dyspnea, grunting, cyanosis, and refusal of feeding; and past history of similar attacks.
Full clinical examination:
- General examination including anthropometric measurements, temperature, heart rate, respiratory rate: thresholds for fast breathing depend on the child’s age; for children aged 2–12 months, the breath rate will be 50 or more breaths/min, whereas for children aged 12–60 months, the breath rate will be 40 or more breaths/min ,.
- Local chest examination for retractions, chest movements, localized bulge or localized retraction, and signs of respiratory distress, tracheal shift, palpable bronchi, breath sounds, and adventious sounds.
All cases and controls were subjected to the following:
- Complete blood count by Sysmex containing Hb concentration. Anemia is considered when Hb is below 11 g/dl according to WHO . Moreover, mean corpuscular volume (MCV), mean corpuscular Hb, and mean corpuscular Hb concentration were determined.
- Capsular reactive protein and chest radiography showing opacity, hyperinflation, exaggerated bronchovascular markings, etc., were carried out for cases only.
- Iron profile, which included serum ferritin, total iron binding capacity, and serum iron for anemic children.
Serum iron and total iron binding capacity
These were determined using the Beckman Synchron CX Systems (California, USA).
Interpretation of the results
The reference value for serum iron for infants is 40–100 μg/dl, whereas for children it is 50–120 μg/dl. The reference value for total iron binding capacity (TIBC) for infants is 100–140 μg/dl and 250–400 μg/dl in children. Therefore, a child was considered as iron deficient if his serum iron was lower than 50 μg/dl or his serum TIBC was higher than 400 μg/dl .
It was determined using the Immulite/1000 Ferritin (Siemens, Los Angeles, California, USA).
For diagnosis of iron deficiency anemia (IDA), the cutoff value was set at less than 10 ng/ml .
- Mentzer index was calculated by using the following formula: MCV/red blood cell count.
- The transferrin saturation was calculated by using the following formula: iron level/TIBC×100 (normal values: 20–45%) .
- IDA was diagnosed in the control group by serum ferritin of less than 10 ng/ml , or serum iron lower than 50 μg/dl and serum TIBC higher than 400 μg/dl .
- Considering the fact that infection can affect iron panel studies by increasing the ferritin level (usually by >50 µg/l if iron deficiency is absent) and decreasing the iron level and TIBC, the diagnosis of IDA was established in cases when at least three of the below parameters were present:
- Low MCV level with specificity around 96% (not affected by infections).
- Smear showing hypochromic microcytic anemia.
- Red cell distribution width more than 14.5 with a sensitivity of 92.1% and specificity of 90.9% in detecting IDA.
- Mentzer index more than 13.5 (with around 85% specificity and sensitivity).
- Transferrin saturation less than 10% (with a specificity of 85% if <15% and sensitivity around 80%) .
Data analysis was carried out by using an IBM computer with statistical program for the social science (SPSS, version 12; SPSS V.20 using SPSS inc., Chicago, Illinois, USA), using mean±SD, number, and percentage, the χ2-test, unpaired t-test, and the correlation coefficient test.
P-value greater than 0.05 were considered statistically insignificant.
P-values less than 0.05 were considered statistically significant.
And P-values less than 0.01 were considered statistically highly significant.
| Results|| |
Of 80 infants and children aged between 6 months and 6 years enrolled in the study, 40 had LRTI according to the above-mentioned inclusion criteria; 65% were boys and 35% were girls. Overall, 67.5% were diagnosed with bronchopneumonia, 25% with bronchiolitis, and 7.5% with lobar pneumonia ([Table 1]).
|Table 1 Classification of lower respiratory tract infections among cases|
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Furthermore, 40 healthy controls were studied in the outpatient department − 60% boys and 40% women.
There was a significantly higher percentage of anemia among cases (72.5%) than among controls (35%) (P=0.001), with a statistically higher percentage of IDA among cases (55%) than among controls (27.5%) (P=0.03) ([Table 2] and [Figure 1]). In addition, this study showed that the mean Hb level among anemic cases was 9.42±0.79 g/dl, which was statistically significantly lower than that of anemic controls (10.0±0.43 g/dl) (P=0.03).
|Figure 1 Distribution of iron deficiency anemia among cases and controls. IDA, iron deficiency anemia.|
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There was a significantly lower mean serum iron in anemic cases (31.4±19.0) than in anemic controls (40.6±12.8) (P=0.013) and significantly higher serum ferritin in anemic cases (48.1±41.6) than in anemic controls (14.6±15) (P=0.000), but there was no statistically significant difference concerning TIBC and transferrin saturation ([Table 3] and [Figure 2]). There was a statistically significant difference between anemic and nonanemic cases regarding degree of respiratory distress, with grade 3 more common among anemic cases whereas grade 2 more common among nonanemic cases ([Table 4]). History of recurrent chest infection was statistically significantly more common in anemic cases (93%) than in nonanemic cases (8%) (P=0.000). [Figure 3]
|Figure 2 Iron profile in anemic cases and control. TIBC, total iron binding capacity.|
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|Figure 3 Percentage of anemic and non anemic children among cases and control.|
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| Discussion|| |
IDA is considered to be among the most important contributing factors to the global burden of anemia. IDA is the most common cause of anemia in the world. It is a worldwide nutritional problem, affecting all age groups and all socioeconomic levels of society . It is a common disease in Egypt, with a very high prevalence. Egypt Demographic Health Survey (2005) reported a 48.5% prevalence of iron deficiency anemia among Egyptian children and 26.6% among Egyptian adults .
Acute respiratory infection (ARI) is one of the leading causes of illness and death in children under 5 years of age (under-5 s). According to WHO estimates, nearly 2 million under-5 s die from ARI every year, corresponding to about 19% of all deaths in this age group. Pneumonia and bronchiolitis are considered to be the leading contributors to the global burden of ARI in young children and are responsible for the greater part of these deaths, of which the vast majority occurs in the developing world .
Identification of modifiable risk factors for LRTI may help in reducing the burden of disease and preventing deaths from ALRTI. Along with many risk factors like low birth weight, lack of breast feeding, severe malnutrition, and smoking, low Hb may also be a risk factor .
The percentage of IDA was 80% in anemic cases and 82% in anemic controls, and this may be attributed to the relationship between iron deficiency and infection susceptibility, as experimental evidence shows that iron is a fundamental element for normal development of the immune system. Its deficiency affects the capacity to have an adequate immune response. The role of iron in immunity is necessary for immune cell proliferation and maturation, particularly lymphocytes associated with the generation of a specific response to infection .
In this study, out of 43 anemic infants, 40 (93%) had history of recurrent chest infection and three (7%) has no history of recurrent chest infection, whereas out of 37 infants in the nonanemic group, three (8%) has history and 34 (92%) has no history of recurrent chest infection. This percentage is higher than that reported by Mourad et al. , which was 37.5% in the anemic group and 14.5% in the nonanemic group; this may be attributed to living in a developing country as Egypt and the presence of other risk factors such as living in rural areas, ignorance, overcrowding, poor sewages, pollution, etc.
Concerning serum iron, there was a statistically significantly lower value among anemic cases than controls (P=0.013), and a statistically significantly higher ferritin value (P=0.000), but there was no statistically significant difference concerning TIBC and transferrin saturation and this can be explained by the fact that infection can affect iron panel studies by increasing the ferritin level as an acute phase reactant, and decreasing the iron and TIBC levels .
This study revealed a strong corelation between anemia and degree of respiratory distress as a manifestation of LRTI, and this may be explained by the fact that the normal function of Hb is to facilitate oxygen and carbon-dioxide transport; it carries and inactivates nitric oxide and also plays the role of a buffer. Hb in the blood is mainly responsible for stabilizing the oxygen pressure in the tissues. Therefore, quantitative and/or qualitative reduction in Hb may adversely affect the normal functions. Probably, it may be the reason for low Hb level found to be as a serious risk factor for developing ALRTI .
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]