Effect of an Intermittent Weekly Dose of Human Parathyroid Hormone (1-34) on Osteoporosis: A Randomized Double-Masked Prospective Study Using Three Dose Levels

To test the effect of amino-terminal peptide 1–34 of human parathyroid hormone (hPTH (1–34)) as a possible bone anabolic agent in the treatment of osteoporosis, weekly subcutaneous injection of 50 units (L group), 100 units (M group) or 200 units (H group) of hPTH (1–34) was started in 220 patients with osteoporosis at 71 institutions randomly divided into three groups in a double-masked system. Lumbar spine bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) increased by 0.6%, 3.6% and 8.1% after 48 weeks in groups L, M and H respectively, responses in groups M and H being significantly higher than in L (p<0.05, Mann–Whitney U-test). Since the coefficient of variation for lumbar spine measurement stayed at 1–2.5%, increases of 3.6% and 8.1% appeared significant. Metacarpal BMD and cortical thickness measured by radiogrammetry did not change significantly. Serum calcium decreased in each group and serum phosphorus decreased in groups M and H. Urinary calcium/creatinine decreased at the 12th week in group H and at the 24th and 48th weeks in groups M and L. Serum 25(OH) vitamin D and 1,25(OH)₂ vitamin D decreased in each group at the 48th week (p<0.05). Serum bone-type alkaline phosphatase was increased at the fourth week in groups H and M and decreased at the 48th week in group H. Urinary hydroxyproline, pyridinoline and deoxypyridinoline declined significantly in each group. Backache improved in 30–40% of each group. No serious adverse effects were found during the test period. Intermittent weekly injection of hPTH (1–34) increased lumbar BMD in osteoporosis, suggesting usefulness in the treatment of osteoporosis. Received: 2 February 1998 / Accepted: 3 August 1998