BLOOD LEAD LEVELS IN CHILDREN WITH CHRONIC NEUROLOGICAL DISORDERS SEEN AT THE UNIVERSITY OF BENIN TEACHING HOSPITAL, BENIN CITY. NIGERIA

Abstract

There is paucity of studies in Nigeria that have evaluated blood lead levels in children with
CND. Therefore, this descriptive cross sectional study was carried out to determine the
prevalence of elevated blood lead levels in children with CND (epilepsy, cerebral palsy,
attention deficit hyperactivity disorder, mental retardation), determine their mean blood lead
levels compared to age and sex matched control and ascertain the risk factors predisposing
these children to elevated blood lead levels.
One hundred and thirty nine children with CND aged 1-15 years (89 or 64.0 % males and 50
or 36.0 % females) presenting in the child neurology clinic at the University of Benin
Teaching Hospital were recruited and compared with age and sex matched clinically non
anemic, well nourished children without neurological disorders who presented with minor
ailments such as upper respiratory tract infection and uncomplicated malaria at the GOPC of
the University of Benin Teaching Hospital from march 2011 to march 2012.Venous whole
blood lead levels was measured using Atomic absorption spectrophotometer.
The prevalence of elevated blood lead levels was alarmingly high in children with CND
(72.7%) and even in controls without CND (79.9%). The mean blood lead level of 25.05±
16.65 µg/dL was significantly higher in children with CND compared to mean blood lead
level of 19.24 ± 10.17 µg/dL in the controls (t =3.51, p=0.00). The blood lead level of
children with CND increased with increasing age. Adolescents aged 11 to 15 years with CND
had significantly higher mean blood lead levels of 36.36 ± 18.56 µg/dL than other age group
categories (t = 4.01, p = 0.00). Subjects with CND from the upper socio economic class had
significantly higher mean blood lead levels of 24.67 ± 17.12µg/dL compared to controls
(18.12 ± 9.17µg/dL) (t =3.42, p = 0.00). Subjects with mixed disorders and epilepsy had
significantly higher mean blood levels than other forms of CNDs (F = 2.75, p = 0.03).
Subjects with “adequate” and “moderately high” adaptive levels as measured with the
Vineland Adaptive Behaviour Scale had significantly higher mean blood lead levels of 26.05
± 15.51µg/dL and 29.60 ± 20.23µg/dL compared to controls with 19.11± 11.31µg/dL and
20.26 ± 9.92 µg/dL (t = 2.84, p = 0.01) (t = 2.41, p = 0.02) respectively. Mean blood lead
levels of subjects with normal nutritional status (25.17 ± 16.43) was significantly higher
compared to controls with normal nutritional status (19.50 ± 10.43) (t =3.12, p= 0.00)
Finger sucking was an important risk factor in predicting elevated blood lead level in children
with CND (OR = 2.56, p = 0.04), there is a two and half fold increased risk of elevated blood
lead level in children with CND who sucked their fingers and those who live in homes that
use generators (p= 0.13, OR= 2.64).
The blood lead levels of children in Benin and environs is generally high due to exposure to
a highly lead- laden environment. It is therefore recommended that blood lead level screening
should be incorporated in the evaluation of children with CND in the neurology clinic

BLOOD LEAD LEVELS IN CHILDREN WITH CHRONIC NEUROLOGICAL DISORDERS SEEN AT THE UNIVERSITY OF BENIN TEACHING HOSPITAL, BENIN CITY. NIGERIA