Prevalence of low bone mass and vitamin D deficiency in β-thalassemia major.

Low bone mass, a major cause of morbidity in patients with β-thalassemia major (β-TM), is multifactorial. There is lack of data about the current prevalence of low bone mass in patients with β-TM. The aims of this study are to examine the current prevalence of low bone mass in β-TM patients and the association between demographic characteristics, markers of iron overload, endocrinopathies, glycemic status and bone mineral density (BMD) as well as to study the 25-OH-vitamin D status of the patients and its relationship with BMD. Our institution serves the largest cohort of β-TM patients in the UK. From 99 patients (49 males, 50 females) with a mean ± standard deviation (SD) age of 36 ± 9 years, 55.5% had low BMD for their age as defined by Z-score BMD <-2.0 either at the lumbar spine (43.9%) or at the hip (25.5%). The only statistically significant association on the multivariate analysis was between hypogonadism and low BMD at the lumbar spine. In our study, 29.9% of patients had vitamin D deficiency, 65.7% had vitamin D insufficiency and 12.4% had optimal levels. No association between vitamin D status and low bone mass was found. Our study demonstrated a much lower prevalence of low bone mass in adults with β-TM compared to previous studies. Further studies are needed to examine whether this suggests a widespread improvement across patients with β-TM possibly due to advances in therapeutics. Most patients had suboptimal 25-OH-vitamin D levels, but no association between vitamin D status and bone mass was demonstrated.