Ashry Gad1*, Joharah Al-Quaiz1, Tawfik Khoja2, Abdullah As-Sharif 3, Hamad Al-Manea 3, Abdullah Al-Edriss3, Sheikh Shafi1
1Department of Family and Community Medicine, College of Medicine, King Saud University, 2 Director Executive Board Council for Gulf cooperation States, 3Ministry of Health, Riyadh, Saudi Arabia.
*Corresponding Author: Professor Ashry Gad Mohamed. Email: [email protected]
DOI: http://dx.doi.org/10.14206/canad.j.clin.nutr.2013.01.04
ABSTRACT
Background: Anemia among school aged children is known to be an important global public health problem in both developing and developed countries. It affects the physical and intellectual functions of the affected children. School years are ideal opportune time to intervene to prevent and control anemia. Objectives: The objective of the study is to investigate the frequency of anemia and the associated dietary and medical risk factors in school aged children in Riyadh region. Subject and Methods: A cross sectional survey was carried out in Riyadh region. The study sample was selected using the two stages of cluster sampling technique. Standardized Arabic questionnaire was completed by parents of school aged children by two well trained nurses. Dietary frequency was requested for the last week prior to the interview. A venous blood sample was taken for hemoglobin estimation. Anemia in school aged children was defined according to the WHO definition. Results: The total sample was 1117 children, 49.9% males and 50.1% females. Prevalence of anemia was 22.3% (22.4% in males & 22.2% in females). Frequent eating of red meat reduced the risk of anemia (OR=0.8). Frequent drinking of cola or sour milk (Laban) with lunch meal significantly increased the risk of anemia (OR=1.52, 1.06-2.16 and OR=1.55, 1.07-2.25 respectively). Family history of hereditary blood disorders or iron deficiency anemia increased the risk of anemia in school aged children (OR=5.48, 1.02-31.21 and OR= 3.38, 1.74-6.54 respectively). Conclusions: Anemia in school children is a moderate public health problem in Riyadh region. Drinking sour milk with lunch and positive family history increases the risk of anemia in school children.
Full Text
INTRODUCTION
Anemia prevalence rate in pediatric population can be an important indicator of nutritional status (1). Iron deficiency is the main cause of anemia; therefore anemia prevalence can be used as a proxy for prevalence of iron deficiency anemia (2).Anemia among school-aged children is known to be a significant global public health problem affecting 305 million people around the world. In developing countries its prevalence ranges from 29.2% to 79.6% (3).Even in USA as many as 20% of children are assumed to become anemic at some point by the age of 18 years (4). It can cause many adverse effects on child health, including delayed psychomotor development, impaired cognitive function, IQ loss and increased susceptibility to lead toxicity (5, 6). Correction of iron deficiency at this age group enhances children’s learning potential in schools, increases their fitness and work capacity. In addition improvement of girls’ iron status may help to prevent anemia during the reproductive years (7-10).
The prevalence of anemia as a public health problem is categorized as follows: <5% no public health problem; 5-19.9% mild public health problem; 20-39.9% moderate public health problem and ≥40% severe public health problem (8-11). Only two countries among 192 WHO member states anemia is not a public health problem. It is mild in 40, moderate in 81 and severe in 69 states (11). The school years are an opportune time to intervene, and indeed the school setting offers an ideal distribution system, and interventions must be based on sound epidemiological understanding of the problem at this age group (11). Nutritive status of school aged children is vulnerable (3); we therefore conducted this cross sectional survey to investigate the frequency of anemia and the associated dietary and medical risk factors in school aged children in Riyadh.
SUJECTS AND METHODS
Study design and setting
A Community based household cross sectional survey was conducted over a period of 4 months. Saudi subjects from Riyadh region, older than one year, were recruited on voluntary basis as a reference population for this study. Riyadh region, with a population amounted to 3.726.523 Saudi persons (Ministry of Planning, preliminary results of 1425 (2004 G) census. The study was approved by Ministry of Health.
Sampling
The sample size was calculated on the assumption of 30% prevalence of IDA in Riyadh (5). At 95% confidence level and acceptance of 2% as degree of precision, the sample size was 2016 persons if the simple random method was used. Due to the large reference population, cluster sampling technique was applied and a design effect of 2 was used. The sample size increased to 4032. A response rate for blood extraction was assumed to be 60-70% and accordingly the final sample size was calculated to include 6204 participants. Out of these 1117 school aged children were included in this study. Two stage cluster sampling technique was used to accomplish the study. In the first stage 36 clusters were selected proportionally allocated with the number of population in each PHCC catchments area. In the second stage a constant number was selected per cluster. Assuming that the average Saudi family in Riyadh region is 7 persons, 25 households were included in each cluster.
Data Collection
A Standardized Arabic questionnaire-interview was designed to satisfy the study objectives. It investigated about socio-demographic characteristics, dietary, medical history of each child 5-12 years old within the family. Data were collected by two well trained nurses. For nutritional status assessment the dietary frequency was requested for the last week prior to interview. A venous blood sample was taken for hemoglobin estimation. Anemia was defined according to WHO hemoglobin level in Children 5-11.99 years (< 11.5 g/dl) (12).
Statistical Analysis
The data was entered and analyzed, using SPSS PC version 17.0 statistical software. The outcome variable was dichotomized as anemia (presence or absence). The study variables related to socio-demographic, medical history and dietary assessments were used to observe and quantify the statistical association. Odds ratio (OR) was used to measure an association between the two categorical variables. To adjust odds ratios of the variables that proved to be statistically associated with the occurrence of anemia in the bivariate, analysis were entered into multivariate logistic regression model. The 95% confidence intervals for adjusted odds ratios were calculated. A p-value of <0.05 was considered as statistically significant.
RESULTS
Total 1117 school aged children were included for this study. Out of this 557 (49.9%) were males and 560 (50.1%) were females. Only 753 (67.4%) parents gave consent for blood sampling. Prevalence of anemia was 168 (22.3%), with no statistically significant difference between males and females (P>0.05).Table 1 shows that frequent eating of red meat reduced the risk of anemia (OR=0.8), however this risk reduction was not statistically significant (CI=0.56 -1.14). Frequent drinking of cola or sour milk (Laban) with lunch meal significantly increased the risk of anemia (OR=1.52, 1.06-2.16 and OR=1.55, 1.07-2.25 respectively).
Blood related disorders in the child and/or his family are shown in Table 2. Family history of hereditary blood disorders or iron deficiency anemia increased the risk of anemia in school aged children (OR=5.48, 1.02-31.21 and OR= 3.38, 1.74-6.54 respectively). Personal history of blood transfusion and IDA were risk factors for anemia in the studied children (OR=11.48, 1.06-288.4 and OR=3.11, 1.57-6.17 in order).
Table 3 displays results of multivariate logistic regression analysis and revealed that drinking sour milk (Laban) with lunch and family history of anemia were independent risk factors for developing anemia in school aged children in Riyadh region.
DISCUSSION
The present study revealed that anemia is a moderate public health problem among school aged children in Riyadh region (22.3%). A national study conducted eleven years ago reported prevalence of anemia of similar figure of 24.8% among Saudi children younger than 14 years with the highest prevalence being in the Eastern region (41.3%) (13). The former study used hemoglobin level of 11.2 gm/dl as a threshold for anemia which is lower than the current WHO (11.5 gm/dl) used in the current study. Also another study in Jeddah that included 2000 school children found that 20.5% of them were anemic (14). The low prevalence of anemia in North America may be attributed to the fortification of iron in most of the available foods there (15).
Al-Othaimeen et al., conducted a study among 1210 school girls aged 7-14 years old in Riyadh city and found that 30% had hemoglobin level <11 gm/dl. Prevalence rate of the latter study is higher than the present work (22.2%) (16), this may be attributed to the inclusion of girls aged 12-14 years where most of them were menstruating. Higher rate was also reported by Rasheed et al., who investigated 285 primary school girls in urban area of Al-Khober in the Eastern province of Saudi Arabia. They found that 26.4% of girls had anemia (hemoglobin level <11 gm/dl) (17).
Haemoglobin level was used in this study as an indicator for Iron status in the body. Kihli-Kumar recommended the assessment of hemoglobin as the most common method of assessing anemia (3, 18). School children were chosen for the study as rapid growth in school aged children increases the demand for iron (19) and anemia is estimated to affect one half of school age children in developing countries (20). The school years are an opportune time to intervene, and interventions must be based on sound epidemiologic understanding of the problem in this age group (2). It has been suggested that when anemia prevalence is 20%, iron deficiency exists in 50% of the population and when anemia prevalence is greater than 40% the entire population suffers from some degree of iron deficiency.
Several dietary factors can influence iron absorption. Enhancing factors are ascorbic acid which is found in citric fruits, meat, fish and poultry. Inhibitory factors include tannic acid which is found in tea, coffee and chocolate, and calcium which is present in milk and dairy products (21, 22).Cross sectional surveys revealed that the frequency of meat and dairy consumption determines hemoglobin values in school age children (23). In the present work meat was a protective factor in bivariate analysis (OR=0.8). Sour milk called Laban by the Saudi public was approved to be a risk factor for anemia in school aged children (OR=1.48). Its high contents of calcium may explain this finding particularly as it is used during or just after lunch meal which is the main meal of the Saudi population, thus inhibiting the absorption of iron.
Drinking tea or coffee in the current work did not influence the prevalence of anemia (p>0.05). On the same line Temme and Van Hoydonck conducted a PubMed search and reported that tea consumption does not influence iron status in Western countries in which people have adequate iron stores. Only in populations with marginal iron status there seems to be a negative association between tea consumption and iron status (24). Poulter J and Nelson M reviewed 35 references investigating the impact of drinking tea on iron status and reported that according to the available evidence restriction of drinking tea is advised only to groups at risk of iron deficiency. It is advised to drink tea between meals or to wait at least one hour after eating before drinking tea (25).
Presence of positive family history of anemia is an independent risk factor for occurrence of anemia in school aged children in the current work (OR=2.42, 1.18-4.94). This may be due to common exposure to iron deficient diets by the family or presence of hereditary blood diseases within the family. In addition, this diagnosis of IDA in Saudi Arabia is more complicated with the high incidence of hemoglobin disorders such as sickle cell and thalassemia traits (26, 27).
CONCLUSION
Anemia is a moderate public health problem among school aged children in Riyadh region. Iron fortification is highly recommended. Health education programs should be conducted in schools to highlight the risk factors of anemia particularly drinking sour milk with meals. Children with family history of anemia should be screened for anemia and treated if indicated.
Conflicts of Interest
The authors indicated no potential or actual conflict of interest pertaining to this study.
Authors’ Contributions
All authors made full contribution to data acquisition, interpretation of results, drafting and revising the final manuscript. All authors read and approved the final manuscript.
Limitation of the Study
The limitations of the present study are the relatively low response rate due to fear of children and their parents from blood extraction, and the lack of classification of nutritional anemia into IDA and non-iron deficiency anemia as ferritin level estimation was not done.
Acknowledgements
We would like to thank all nurses, technicians and physicians for their kind support in data collection and laboratory analysis. We also thank the children and their parents for contribution in the study. This study was funded by Saudi Ministry of Health.
Table 1: Dietary factors and anemia in school children, Riyadh, Saudi Arabia
| Food | Intake |
Status |
Odds Ratio |
95% Conf. Interval |
P |
|
|
Anemic |
healthy |
|||||
| Frequent eating of red meat | YesNo |
93 83 |
341 243 |
0.8 |
0.56 -1.14 |
0.19 |
| Frequent eating of vegetable | YesNo |
115 60 |
358 223
|
1.19 |
0.83 – 1.73 |
0.33 |
| Frequent drinking of Tea & coffee | YesNo |
34 141 |
145 435 |
0.72 |
0.47 – 1.12 |
0.13 |
| Frequent drinking of Cola | YesNo |
86 86 |
229 347 |
1.52 |
1.06 – 2.16 |
0.017 |
| Frequent drinking of sour milk (Laban) with lunch | YesNo |
115 57 |
328 252 |
1.55 |
1.07 – 2.25 |
0.016 |
| Frequent drinking of juice | YesNo |
49 123 |
133 442 |
1.32 |
0.89 – 1.98 |
0.15 |
Table 2: Blood related disorders and anemia in school children, Riyadh, Saudi Arabia
| Health problem | presence |
Status |
Odds Ratio | 95% Conf. Interval | P | |
| Anemic | Healthy | |||||
| Personal history of hereditary blood disorder | YesNo |
8 143 |
14 558 |
2.23 |
0.84 – 5.8 |
0.10 |
| Family history of hereditary blood disorder | YesNo |
4 128 |
3 526 |
5.48 |
1.02 – 31.21 |
0.01 |
| History of blood transfusion | YesNo |
3 151 |
1 578 |
11.48 |
1.06 – 288.4 |
0.008 |
| Current blood disorder | YesNo |
6 156 |
2 592 |
11.38 |
2.00 – 115.9 |
0.002 |
| Past history of IDA | YesNo |
18 131 |
24 544 |
3.11 |
1.57 – 6.17 |
0.0005 |
| Family history of IDA | YesNo |
20 129 |
25 545 |
3.38 |
1.74 – 6.54 |
0.00005 |
Table 3: Results of logistic regression analysis
| Variable |
Adjusted Odds Ratio |
95% Conf. Interval |
P |
| Drinking cola with lunch |
1.36 |
0.94 – 1.99 |
0.108 |
| Drinking sour milk ( laban) with lunch |
1.48 |
1.00 – 2.19 |
0.050 |
| Family history of anemia |
2.42 |
1.18 – 4.94 |
0.015 |
NB. The model explains 79.2% of occurrence of anemia.
REFERENCES
1. Oken E, Rifas-Shiman SL, Kleinman KP, Scanlon KS, Edwards JWR, Gillman MW. Trends in childhood anemia in a Massachusetts Health Maintenance organization, 1987-2001. Med Gen Med 2006; 8(3):58-63.
2. Dallman PR, Yip R, Johnson C. Prevalence and causes of anemia in the United States, 1976 to 1980. Am J Clin Nutr 1984; 39:437–445.
3. Djokic D, Drakulovic MB, Radojicic Z, Radovic LC, Rakic L, Kocic S, Davidovic G. Risk factors associated with anemia among Serbian school age children 7-14 years old: results of the first national health survey. Hippokratia 2010; 14(4):252-260.
4. Irwin JJ, Kirchner JT. Anemia in children. American family Physician 2001;64(8):1379-1386.
5. Lozoff B, De Andraca I, Castillo M, Smith JB, Walter T, Pino P. Behavioral and developmental effects of preventing iron-deficiency anemia in healthy full term infants. Pediatrics 2003;112: 846-854.
6. Grantham-Mcregor S, Ani C. A review of studies on the effect of iron deficiency on cognitive development in children. J nutr 2001;131:649S-666S.
7. DeMaeyer EM, Adiels-Tegman M. The prevalence of anemia in the world. Rapp Trimest Stat Sanit Mond 1985;38:302-3l6.
8. Ham ID, Fairchild MW. Summary and conclusions of the International Conference on Iron Deficiency and Behavioral Development. Am J Clin Nutr l989;50:703-705.
9. Stephenson LS, Latham MC, Adams El, Kinoti SN, Pertet A. Physical fitness, growth and appetite of Kenyan school boys with hookworm, Trichuris trichiura and Ascaris lumbricoides infections are improved four months after a single dose of Albendazole. J Nutr 1993;123: 1036-1046.
10. Savioli L, Bundy DAP, Tomkins A. Intestinal parasitic infections: a soluble public health problem. Trans R Soc Trop Med Hyg 1992; 86:353-359.
11. Maclean M, Egli CI, Wajdyla D, Benoist B. Worldwide prevalence of anemia. In: Nutritional anemia. Edited by Kraemer K & Zimmermann MB. Sight and Life Press. pp: 3- 12., 1st, 2007.
12. Benoist BD, Mclean E, Egli I, Cogswell M. Worldwide prevalence of anemia 1993-2005. WHO 2008. Spain.
13. El-Hazmi MA, Warsy AS. The pattern of common anemia among Saudi children. J Trop Pediatric 1999; 45(4):221-225.
14. Abalkhail B, Shawky S. Prevalence of daily breakfast intake, iron deficiency anemia and awareness of being anemic among Saudi school students. Int J Food Sci Nutr 2002; 53(6): 519-528.
15. Hurrell RF, Jacob S. Role of the food industry in iron nutrition: iron intake from industrial food products. In: Hallberg L, Asp NG, eds. Iron nutrition in health and disease. London: John Libbey & Co., 1996 pp. 339–347.
16. Al-Othaimeen A, Osman AK, Al-Orf S. Prevalence of nutritional anemia among school girls in Riyadh city, Saudi Arabia. Int J Food Sc Nutr 1999;50:237-243.
17. Rasheed P, Al-Yousef N, Al-Dabal B. Nutritional profile of Saudi primary school girls in an urban region. Ann Saudi Med 1989;9:371-377.
18. Kihli-Kumar M. Screening for anemia in children: AAP recommendations: a critique. Pediatrics 2001;108:1-2.
19. Brabin L, Brabin BJ. The cost of successful adolescent growth and development in girls in relation to iron and vitamin A status. Am J Clin Nutr 1992; 55:955-958.
20. Stoltzfus RJ, Chwaya HM, Tielsch JM, Schulze KJ, Albonico M, Savioli L. Epidemiology of iron deficiency anemia in Zanzibari schoolchildren: the importance of hookworms. Am J Clin Nutr 1997;65(1):153-159.
21. Zijp IM, Korver O, Tijburg LB. Effect of tea and other dietary factors on iron absorption. Crit Rev Food Sci Nutr 2000;40(5): 371-398.
22. Coutinho GGPL, Bertollo EMG, Bertelli ECP. Iron deficiency anemia in children: a challenge for public health and for society. Sao Paulo Med J 2005; 123(2):11-22.
23. Khatib IM, Elmadf I. Poor nutritional health of Bedouin preschool children in Jordon: the irony of urbanization. Ann Nutr Metab 2009; 54:301-309.
24. Temme Eh, Van Hoydonck PG. Tea consumption and iron status. Eur J Clin Nutr 2007; 56(5): 379-386.
25. Nelson M, Poulter J. Impact of tea drinking on iron status in the Uk: a review. J Hum Nutr Diet 2004; 17(1):43-54.
26. Al-Hazmi MA, Jabbar FA, Al-Faleh FZ, et al. Patterns of sickle cell thalassemia and glucose-6 phosphate dehydrogenase deficiency gene in north-western Saudi Arabia. Hum Hered 1991;4:26-34.
27. Warsy AS, El-Hazmi MA. Glucose-6 phosphate dehydrogenase deficiency in Saudi Arabia- a review. Saudi Med J 1987;8:12-20.