Primary hypoparathyroidism is common in adult patients with b-thalassemia and protect patients from osteoporosis.

Introduction b-thalassemia (bT) is associated to several endocrine abnormalities mainly due to iron overload. With the increase in bT-patients life expectancy, due to progresses in iron chelation therapy, more patients enter into adulthood than in the past and the prevalence of endocrine diseases is being reconsidered. The aim of the study is to investigate the prevalence of primary hypoparathyroidism (pHPT) in adult bT-patients and to characterize the relative clinical phenotype with particular regard to bone health. Methods We enrolled 26 adult patients with major or intermedia bT (12M and 14F; mean ageGS.D. of 38.1G7.5 years). Serum PTH, 25-hydroxyvitamin D (25OHD), calcium, phosphorous, albumin, bone turnover markers, and bone mineral density (BMD) by dual-energy X-ray absorptiometry (Hologic) at lumbar and femoral site were measured. Results pHPT (PTH !15 pg/ml) was found in seven of the 26 patients (27%). Of them, four patients (57%) had hypocalcemia and two were on chronic calcium therapy. Lumbar BMD was significantly higher in patients with pHPT (0.884G 0.189 g/cm2) than in patients without pHPT (0.731G0.124 g/cm2) (PZ0.023). No significant difference was found in femoral BMD, even though a trend for higher BMD was present in pHPT (0.704G0.117 vs 0.670G0.143 g/cm2 in pHPT and no-pHPT respectively) (PZ0.578). The prevalence of osteoporosis was higher in patients without pHPT (68%) than in patients with pHPT (29%). Two patients had a history of bone osteoporotic fractures and both of them did not present pHPT. Bone turnover markers were no different in the two groups. Conclusions The prevalence of pHPT in adult bT-patients is higher if compared to that observed in pediatric bT-patients, the latter ranging from 8 to 11%. Moreover we found an higher prevalence of pHPT compared to that reported in literature on adult bT patients. As expected, pHPT seems to exert a protective role on the development of osteoporosis in these patients.