Bone mineral density findings in patients with sickle cell disease

Abstract Background: Individuals with sickle cell disease (SCD) are at an increased risk of low bone mineral density (BMD), including osteoporosis and osteopenia. This study aimed to investigate status of bone health by BMD among adults with SCD and explore associations with clinical and laboratory factors. Methods: A retrospective analysis of 52 adult patients (age range 19 to 72) with SCD who had completed Dual-Energy X-ray Absorptiometry (DEXA) was performed. Clinical variables including age, sex, weight, fracture history, vitamin D, ferritin, chronic kidney disease, liver disease, and chronic pain were recorded. Patients were categorized as having normal BMD, osteopenia, or osteoporosis based on World Health Organization criteria. Welch's t-tests compared mean BMD between men and women at the lumbar spine, total hip, and femoral neck. Mann-Whitney testing was used for non-normally distributed vitamin D levels. Pearson correlations assessed relationships between BMD and age, vitamin D, and weight. Results: Of the 52 patients, 18 (34.6%) had normal BMD, 18 (34.6%) had osteopenia, and 16 (30.8%) had osteoporosis. 30 of the participants were female and 22 were male. Mean age did not differ significantly between women (44.4 ± 14.4) and men (43.3 ± 12.8, p = 0.76). Age was not significantly associated with BMD at the lumbar spine (p = 0.41), total hip (p = 0.20), or femoral neck (p = 0.29). Lumbar spine BMD (0.996 vs. 1.019 g/cm², p = 0.70) and femoral neck BMD (0.846 vs. 0.935 g/cm², p = 0.16) were not significantly different between sexes. Total hip BMD was significantly lower in women than in men (0.968 vs. 1.098 g/cm², p = 0.035). Vitamin D levels did not significantly differ by sex (p = 0.25) and showed no correlation with BMD at any site. There was no significant correlation between weight and BMD at the lumbar spine (p = 0.28), total hip (p = 0.43), or femoral neck (p = 0.66). Fracture history was not associated with BMD. Conclusions: In adults with SCD, this study found no significant differences in lumbar spine and femoral neck BMD between men and women. There was a significant difference in total hip BMD between men and women (p= 0.035). Vitamin D deficiency was common, but it was not associated with BMD. There were no associations between BMD and fracture history, age, or weight. This study did not demonstrate that low bone density is associated with traditional osteoporosis risk factors suggesting that BMD as measured by DXA may not accurately reflect bone loss in individuals with SCD. Future studies should further investigate whether reduced peak bone mass contributes to reduced BMD in SCD and whether optimizing vitamin D during the growth period can improve peak bone mass in SCD.