Pattern of bone mineral density in sickle cell disease patients with the high-Hb F phenotype

Low bone mineral density (BMD) is common in sickle cell disease (SCD) patients of all ages due to erythropoietic stress and consequent bone marrow hyperplasia. Kuwaiti SCD patients have a mild clinical phenotype because of their high Hb F level. There has been no previous documentation of BMD in this population of patients. SCD patients (n = 81) and controls (n = 67) were recruited from hematology clinics of Mubarak Hospital, Kuwait. BMD was measured using dual X-ray absorptiometry (Hologic) in the lumbar spine and the hip (left femoral neck). Among the 53 adult patients, the prevalence of low BMD was 67.4% in the spine and 33.3% in the hip while among controls, the figures were 23.1 and 11.3%, respectively. These differences are significant (p < 0.01). In SCD children, the figures were 17.9% (in the lumbar spine) and 3.6% (in the hip), while in controls the figures were 13.3 and 0%, respectively. The differences are not significant (p > 0.05). Patients with frequent vaso-occlusive crisis had significantly lower mean BMD, but those with MRI evidence of avascular necrosis of the femoral head were more likely to have normal or osteosclerotic BMD. Our study showed that osteopenia/osteoporosis is uncommon among Kuwaiti children with SCD but quite common in adults.