Calcium–Phosphorus Metabolism in Patients with Sickle Cell Disease: A Study from Yaoundé, Cameroon

Background Calcium-phosphorus disorders are an underestimated source of morbidity in sickle cell patients in sub-Saharan Africa. This study aimed to evaluate the biological parameters of calcium-phosphorus metabolism in sickle cell patients treated in Yaoundé, Cameroon. Objective: To evaluate the biological parameters of calcium-phosphorus metabolism in homozygous sickle cell patients monitored in Yaoundé. Methodology: We conducted a cross-sectional analytical study from November 2023 to August 2024 among patients monitored in Yaoundé. We measured and confirmed the haemoglobin phenotype and measured parathyroid hormone (unfractionated) and total serum vitamin D, calcium, phosphorus and serum albumin. Associations between variables were sought using linear regression and odds ratio (OR) calculations with a 95% confidence interval (95% CI). The significance threshold was set at 5%, and a p-value of less than 0.05 was therefore considered statistically significant. Results: Of the 86 participants, the median age was 16 years [9;20], 46% were aged between 15 and 29, 65% (n=54) were male, with a male-to-female ratio of 1.2. The majority (66, 76.74%) had high ALP and hyperphosphataemia, i.e. 61 (70.9%) with moderate vitamin D deficiency in 73% (n=63). We found that being under 16 years of age was significantly associated (p=0.026) with a 72% reduction in the risk of hypercalcaemia. No factors were associated with hypocalcaemia, hyperphosphataemia, hypophosphataemia or vitamin D deficiency. A statistically significant positive correlation was found between serum phosphorus levels and bone remodelling (p = 0.00; Rho = 0.48) and a significant negative correlation between age and bone remodelling (p = 0.01; Rho = -0.26). Conclusion: This preliminary study shows that subjects with homozygous sickle cell disease had hyperphosphataemia, hypovitaminosis D and elevated alkaline phosphatase levels, the early detection of which could reduce the frequency and severity of complications. morbidity and mortality. This study illustrates the need for regular monitoring of these biochemical parameters in individuals with sickle cell disease.