Study design and participants
thalassemia, vertebral fracture, osteoporosis
OTHER HEMOGLOBINOPATHIES, SYNDROME, TAO, THALASSEMIA, OSTEOPOROSIS
We conducted a double-blind, randomized controlled trial to evaluate the efficacy of alendronate, compared with placebo, in patients with TAO. Eligible participants were ambulatory thalassemia patients aged 18–50 years (males) or more than 18 years (premenopausal females). Other hemoglobinopathies were allowed in case of compound heterozygosity with α- or β-thalassemia leading to clinically significant thalassemia syndrome. Patients had to be diagnosed with thalassemia-associated osteoporosis as defined by one of the following criteria, (i) a bone mineral density (BMD) Z-score of less than -2.0 SD at either the L1-L4 spine or the femoral neck on either side, measured by dual-energy X-ray absorptiometry (DXA; Hologic Discovery A, Hologic Company, Marlborough, MA, USA); or (ii) presence of vertebral deformity detected by vertebral fracture analysis (VFA; obtained in the supine position from T4 to L4 using the same machine as DXA). Key exclusion criteria were an estimated glomerular filtration rate of less than 30 ml per minute per 1.73 m