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Indian Pediatr 2010;47: 437-439 |
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Iron Deficiency as a Risk Factor for First
Febrile Seizure |
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Rajwanti K Vaswani, Praveen G Dharaskar, Swati Kulkarni and K Ghosh
From Department of Pediatrics, King Edward Memorial
Hospital, Parel, Mumbai, India.
Correspondence to: Dr Rajwanti K Vaswani, Bungalow no -
1, Gulab Park, Opposite Hong Kong Bank, Near Basant Cinema, Chembur,
Mumbai 400 074, India.
Email: [email protected]
Received: January 21, 2008;
Initial review: February 27, 2008;
Accepted: April 15, 2009.
Published online: May 10, 2009.
PII: S097475590900035-2 |
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Abstract
We conducted this study to determine the role of iron
deficiency as a risk factor for first febrile seizure in children. Fifty
children between 6 months to 6 years with first febrile seizure (Cases)
and 50 children with febrile illness but without convulsions (Controls)
were enrolled from the pediatric ward of a tertiary care hospital. Iron
deficiency was determined by estimation of hemoglobin, red blood cell
indices and serum ferritin. The mean serum ferritin level (µg/L) was
significantly low in Cases (31.9 ± 31.0) as compared to Controls (53.9 ±
56.5) with P = 0.003. Iron deficiency could be a potential risk
factor for febrile seizure in children.
Key words: Febrile seizure, Serum ferritin, Iron deficiency.
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Febrile
seizures are the most common type of seizures, occurring in 3 to 4 % of
children(1). Owing to their association with epilepsy in future, various
studies have attempted to identify the risk factors associated with them
viz, family history of febrile seizures, epilepsy, perinatal factors
and temperature peak. Pisacane, et al.(2) reported that low
iron level is associated with febrile seizure, whereas Kobrinsky, et
al.(3) reported that iron deficiency raises the threshold for
seizures. As iron is important for function of neuro-transmitters and
various enzymes, low level of serum ferritin may lower the seizure
threshold(4). Fever can worsen the negative effects of low serum ferritin
on the brain and trigger seizure(2). We conducted this study to determine
any association between iron deficiency and first febrile seizure.
Methods
A case-control study was conducted from August 2005 to
July 2006 following approval from Institutional Ethics Committee. Fifty
consecutive children aged 6 months to 6 years, admitted to the Pediatric
ward with first episode of febrile seizure were enrolled as cases. Febrile
seizure was defined as a seizure occurring in association with a febrile
illness, in the absence of CNS infection or any other defined causes of
seizure(1). Children with previous febrile/afebrile seizures, neurological
infections, developmental delay, or on iron therapy were excluded. A
control group was selected from age and sex matched children admitted with
febrile illness including respiratory infections or acute gastroenteritis
but without seizures and without iron supplements.
Demographic data, seizure details, nature of febrile
illness, family history of epilepsy / febrile seizures, temperature at
admission, and nutritional status were recorded. IAP weight for age
classification was used to grade protein energy malnutrition(5).
Estimation of hemoglobin, red blood cell indices (MCV and MCH) and serum
ferritin (Microwell Elisa) was done.
Iron deficiency anemia was defined as hemoglobin <11g /dL,
MCV <70 fl, MCH <27 pg and serum ferritin <12 µg/dL(6). In presence of
fever, a higher cut -off value of serum ferritin (25-50 µg/L) was
considered(7). Cases and Controls were compared with respect to blood
indices and serum ferritin. Chi–square and ANOVA tests for discontinuous
variables and unpaired t test for continuous variable at 5%
significance (P< 0.05) level were used for statistical analysis.
Results
Fifty Cases and 50 Controls were enrolled. Their
demographic characteristics and hematological parameters are depicted (Table
I). The proportion of children with low ferritin (<25µg/L) was
significantly higher (P< 0.0001) in Cases (34, 68%) than in
Controls (15, 30%). With serum ferritin <12 µg/L, the proportion of
children with low ferritin was comparable in Cases (6,12%) vs
Controls (2,4%) (P=0.14). Thirty four cases and 15 controls had a
low ferritin value ( Ł25
µg/L). It was observed that amongst Cases, 77% had no PEM, 15% grade I PEM
and 8% grade II PEM whereas within Controls, 60% had no PEM and 40% had
grade I PEM.
TABLE I
Demographic Data and Hematological Parameters of Cases and Controls
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Parameters |
Cases |
Controls |
P value |
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( n = 50) |
( n = 50) |
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| Age (years) |
1.73 ± 0.94 |
1.75 ±0.91 |
0.91 |
| Temperature at admission (°C) |
38.6 ± 0.36 |
38.5 ± 0.29 |
0.13 |
| Height (cm) |
80.9 ± 9.3 |
81.3 ± 9.1 |
0.85 |
| Weight (Kg) |
9.9 ± 2.1 |
10.0 ± 2.1 |
0.88 |
| Hemoglobin (g/dL) |
9.4 ± 1.2 |
9.5 ± 1.0 |
0.70 |
| MCV (fL) |
73.4 ± 9.5 |
73.6 ± 8.3 |
0.89 |
| MCH (pg) |
21.4 ± 3.1 |
21.7 ± 2.9 |
0.71 |
| Serum ferritin (µg/L) |
31.9 ± 31.0 |
53.9 ± 50.5 |
0.003 |
Discussion
We observed significantly low serum ferritin levels in
children with first febrile seizure than in controls. Similar results were
observed by Pisacane, et al.(2). Daoud, et al.(8) reported
that mean serum ferritin was significantly low in children with first
febrile seizure and also proportion of children with low ferritin was
significantly higher in febrile seizure group than in controls. Previous
studies have reported an association between iron deficiency and breath
holding spells and improvement with iron therapy(9).
The study does have some limitations. Serum ferritin, a
nonspecific acute phase reactant can rise in any inflammatory disease.
Iron deficiency and convulsions may be seen in lead poisoning but lead
levels could not be determined in our subjects. Larger studies are needed
to confirm our findings.
Acknowledgment
Dr M E Yeolekar, Director (M E & H) and Dean of Seth GS
Medical College and KEM Hospital for granting permission to publish the
paper.
Contributors: RKV: concept and design; revising the
article critically for important intellectual content and will act as the
guarantor of the manuscript; PGD: Acquisition, analysis and interpretation
of data, and drafting the article; SK: analysis and interpretation of data
and drafting the article; KG: analysis and interpretation of data and
revising the article critically for important intellectual content. All
the authors approved the version to be published.
Funding: Grant from Diamond Jubilee Society Trust,
Seth GS Medical College and KEM Hospital, Mumbai.
Competing interests: None stated.
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What This Study Adds?
• Serum ferritin level is significantly low in children with
first episode of febrile seizure.
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References
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