SERUM ZINC LEVELS IN CHILDREN WITH SICKLE CELL ANAEMIA ATTENDING LAGOS UNIVERSITY TEACHING HOSPITAL LAGOS

Abstract

Sickle cell anaemia is a common haemoglobinopathy affecting black people. It has multi-systemic
manifestations and is associated with severe morbidity and mortality. There are clinical similarities
between sickle cell anaemia patients and those with zinc deficiency, which suggests that there is an
association between zinc deficiency and sickle cell anaemia. In view of this, a cross sectional study
was done to evaluate the level of zinc in children with sickle cell anaemia in a steady state and those
in bone pain crisis aged 1-10 years attending the Lagos University Teaching Hospital and compare
them with controls. Seventy-one children in steady state and 71 in vaso-occlusive bone pain crisis
were studied. These were compared with Seventy -one controls whose haemoglobin genotype was
AA. Due to unequal loss of patients in some groups, matching of patients for age was not optimal.
Serum zinc was assayed by means of the atomic absorption spectrophotometer. Haemoglobin
concentration was determined by using haemoglobinometer and PCV determined using haematocrit
reader. Serum zinc and haemoglobin concentrations were compared in both study and control
groups.

There were 82 boys and 60 girls with SCA giving a male to female ratio 1.3:1 while in the control
group there were 41 boys and 30 girls, giving a male: female ratio of 1.3:1. The mean ages for both
the study and control groups were 6.08 ± 2.56 years and 5.95 ± 2.83 years respectively and this was
not statistically significantly different (p> 0.05). The mean serum zinc concentration for the controls
was 43.02 ± 14.16 µg/dl and was significantly higher than that of sickle cell anaemia subjects
(32.33 ± 13.95 µg/dl) p=0.001. The mean serum zinc level in sickle cell anaemia subjects in steady
state was 38.41 ± 13.80 µg/dl this was lower than the control, but was not statistically significant
(p=>0.05). The mean serum zinc in sickle cell anaemia subjects in bone pain crisis was 26.25 ±
11.27 µg/dl which was significantly lower than those of control and sickle cell anaemia subjects in
steady state (p<0.001).

The children with haemoglobin genotype AA had a mean PCV of 33.11 ± 5.56 % and mean
haemoglobin of 11.29 ± 1.97 g/dl which were significantly higher than the study group with a mean
PCV of 20.90 ± 3.41 %, haemoglobin of 7.12 ± 1.13 g/dl for HbS anaemia subjects in steady state
and mean PCV of 22.32 ± 4.83 % and 7.59 ± 1.57 g/dl haemoglobin in vaso-occlusive crisis (
p=0.001). The haemoglobin concentration of subjects in bone pain crisis was higher than those in
steady state, but the difference was not statistically significant. (p>0.05). There was a positive
correlation (r=0.4138; p= 0.001) between serum zinc, haemoglobin and packed cell volume in the
control but this was not observed in the study subjects. In the control subjects, the higher the
education and the social class of the mother the higher the serum zinc level. In the SCA group, this
relationship was demonstrated only with the educational level of the mother.

This study shows that SCA subjects in bone pain crisis have significantly low zinc levels than those
in steady state and control subjects. A double blind study with zinc supplementation should be
conducted to observe its effect in painful crisis and other symptomatology in SCA.

SERUM ZINC LEVELS IN CHILDREN WITH SICKLE CELL ANAEMIA ATTENDING LAGOS UNIVERSITY TEACHING HOSPITAL LAGOS