Serum magnesium levels of children living with sickle cell anaemia at the Lagos University Teaching Hospital: a comparative cross-sectional study.

BACKGROUND: Sickle cell anaemia (SCA) is a lifelong, chronic haemolytic disorder with episodic vaso-occlusive crises (VOC) and chronic end-organ damage. Red cell dehydration during a VOC changes permeability with loss of potassium and magnesium. Magnesium has been found to act via both Gardos and K-Cl channels, preventing red cell dehydration and reducing the propensity for sickling. This study assessed serum magnesium levels in children living with SCA in steady state and crisis, and the relationship between serum magnesium levels and severity of pain in VOC. METHODS: A comparative cross-sectional study involving age- and gender-matched 180 children living with SCA aged 1-18 years (90 in VOC and steady state, respectively). The severity of pain was assessed using standard pain tools (FLACC and Wong-Baker FACES Pain scale), and a blood sample was taken for magnesium assay using the colorimetry method of analysis. Categorical variables were presented as frequencies and percentages. Comparison of means between the two groups and according to magnesium status was carried out using an independent Student's t-test. RESULTS: The mean age of participants in VOC and steady state was 8.49 ± 2.4 years and 8.62 ± 2.0 years, respectively. The mean serum magnesium of subjects in VOC was significantly higher compared to the steady state (0.85 ± 0.1 vs 0.83 ± 0.1 mmol/l, p = 0.032). The moderate to severe pain was the most common pain (63.3%), and the average serum magnesium was higher in the group with moderate to severe pain, but the difference was not statistically significant across the three groups (p = 0.315). CONCLUSION: VOC maybe associated with elevated serum magnesium in SCA.