Serum Calcium-to-Magnesium Ratio and Mineral Dysregulation in Sickle Cell Anaemia: A Comparative Study in Zaria, Nigeria

Abstract

Context

Sickle cell anaemia (SCA) is a genetic disorder characterized by chronic haemolysis, vaso-occlusion, and multisystem complications. Disturbances in mineral metabolism—particularly calcium and magnesium—have been linked to the pathophysiology of SCA through effects on vascular function, oxidative stress, red cell dehydration, and bone health. Understanding these mineral alterations may provide insights into disease severity and crisis triggers.

Aim

To evaluate serum calcium, magnesium, and the calcium-to-magnesium ratio in adult SCA patients during steady state and vaso-occlusive crisis (VOC), compared with healthy HbAA controls, and to explore the clinical implications of these biochemical changes.

Settings and Design

A cross-sectional comparative study involving 180 adult participants, consisting of:

• 60 SCA patients in steady state

• 60 SCA patients during vaso-occlusive crisis

• 60 age- and sex-matched apparently healthy HbAA controls

Methods and Materials

Demographic and clinical data were obtained from consenting participants who met the inclusion criteria. Blood samples were collected for biochemical analysis.

• Serum calcium and magnesium were measured using a Selectra Chemistry Auto-Analyzer.

• The calcium-to-magnesium ratio was computed for each participant.

Statistical Analysis

Data were analyzed using SPSS Version 25.

• One-way ANOVA was used to compare biochemical parameters across study groups.

• Pearson’s correlation analysis assessed relationships between variables.

• ROC curve analysis evaluated the discriminatory power of calcium, magnesium, and their ratio.

Results

• Serum calcium and magnesium levels were significantly reduced in SCA patients compared to HbAA controls (p < 0.001).

• The lowest levels of both minerals were recorded in patients experiencing vaso-occlusive crisis.

• The calcium-to-magnesium ratio was significantly elevated during VOC (p < 0.001), indicating a mineral imbalance that may worsen disease pathophysiology.

• ROC analysis showed that calcium, magnesium, and particularly the Ca/Mg ratio demonstrated strong discriminatory ability for identifying crisis states in SCA.

Conclusion

SCA patients exhibit marked abnormalities in calcium and magnesium homeostasis, with further deterioration during vaso-occlusive crises. The elevated calcium-to-magnesium ratio during crisis may serve as a potential biochemical marker for disease severity and crisis prediction. Routine evaluation of these minerals may improve clinical monitoring, early intervention, and overall patient management.