Prevalence of vitamin D deficiency in patients with sickle cell disease in Bahrain

Abstract

Background: Patients with sickle cell disease (SCD) had a low serum level of vitamin D. The prevalence and the impact of this observation in SCD patient's in Bahrain is not clear. Aim: To assess the prevalence of vitamin D deficiency (VDD) in homozygous patients with SCD, and to evaluate the clinical and biochemical predictors of occurrence of VDD in such patients. Methods: We evaluated the vitamin D status in 70 patients with confirmed diagnosis of SCD and compared them with an age matched control group. Serum level of vitamin D, parathormone (PTH), calcium, phosphate, alkaline phosphatase, haemoglobin (Hb), and uric acid were measured. Linear regression analysis was performed to assess the relation between PTH and vitamin D level. Multiple regression analysis was performed to assess the predictive value of gender, body mass index (BMI) >24, serum level of uric acid>400 umol/Land estimated glomerular filtration rate (eGFR) <60, for occurrence of vitamin D deficiency in patients with SCD. Results: The mean age of the study group was 28.85 ±7.21 years compared with the control of 29.91 ±4.3 years, p=0.23. There were 40 (57%) female SCD patients compared with 39 (55%) in the control. In patients with SCD, the serum level of vitamin D was sufficient, >50 nmol/L in 4 (5%) patients, insufficient > 27.5 -≤50 nmol/L in 21 (30%) patients, deficient >12.5 -≤27.5 nmol/L 35 (50%) and profoundly deficient ≤12.5 nmol/L in 10(15%). In the control group, those with sufficient level of vitamin D were 53 (75%), insufficient 21(30%) deficient of 10 (15%) and none with profound deficiency, respectively. The serum level of PTH and alkaline phospahtase were significantly higher in the SCD group compared with control group. The eGFR, Hb and were significantly lower, serum level of uric acid was significantly higher (p < 0.05 but no significant difference between serum level of calcium or phosphate. Linear regression analysis showed inverse relation between VDD (<25 nmol/L) and PTH (r = -0.34, P<0.001). Multiple regression analysis showed female gender, BMI>24, hyperurecemia and low eGFR were positive predictor of VDD in patients with SCD. Conclusion:The risk of vitamin D deficiency among subjects with SCD-SS was 3.8 folds greater than control subjects; the prevalence of VDD in SCD was 95% and 25% in the control patients without SCD. On linear regression analysis, there is a significant inverse relation between serum levels of vitamin D and PTH in SCD patients. The female gender, BMI>24, hyperurecemia>400 umol/L and low eGFR<60 were positive predictor of VDD in patients with SCD.

A Meta-analysis on Vitamin D Deficiency in Patients with Sickle Cell Disease

“…Full texts of 40 studies were screened, and 15 studies were subsequently excluded because of insufficient data to estimate the outcomes of interest (Figure 1). A total of 25 studies published from 1993 to 2019 that met the eligibility for data were used for qualitative and quantitative syntheses: 10 studies from the Americas [12,[28][29][30][31][32][33][34][35][36]; six studies from Asia [37][38][39][40][41][42]; five studies from Europe [43][44][45][46][47]; two studies from Africa [48,49], one study that used samples from both Jamaica and West Africa [50], and one study that used samples from both Brazil and Nigeria [51].…”