During this 30-min period, the subjects were required to avoid eating, drinking (other than water for taking risedronate) or taking any other medications. Supplementary calcium lactate (containing 200 mg Ca2 +) was administered orally once daily after dinner from the registration date until the end of the

study. Concomitant use of any drug considered to affect bone metabolism, including vitamin D, was prohibited during the study. The study comprised a screening phase followed by a 12-month double-blind treatment phase, and each subject was required to visit the study site on Day 15 after the first dose of the study drug (with Day 1 being the first treatment day) and then monthly for a total of 12 months. Lumbar spine (L2–L4) Metabolism inhibitor BMD was measured at baseline, and after 6 and 12 months (or upon discontinuation) by dual energy X-ray absorptiometry (DXA) using a QDR system (model: Hologic QDR-4500 or higher). At each study site, investigators Epigenetic signaling pathway inhibitor carried out “accuracy control calibration” using a lumbar standard phantom attached to the equipment

before the first measurement on the subjects at each measurement date, and checked that BMD was within acceptable limits (± 1.5% of phantom values). X-ray images of thoracic vertebra and lumbar spine were taken at baseline and after 12 months (or upon discontinuation). Two central independent committees were established for DXA assessment and for X-ray assessment. The central committee for DXA assessment confirmed whether subjects fulfilled inclusion/exclusion criteria and whether Y-27632 2HCl BMD measurement results were eligible. The central committee for X-ray assessment confirmed fragility fracture and evaluated vertebral

fracture. The assessment of prevalent fracture was made if the ratio of the central vertebral height to the anterior (C/A) or posterior vertebral body height (C/P) was less than 0.8, or the ratio of the anterior to posterior vertebral body height (A/P) was less than 0.75, or if the anterior, central, and posterior vertebral heights were decreased by more than 20% compared with those of the adjacent vertebral body in Th4 to L4. A new or worsening vertebral fracture was judged if any one of the three vertebral heights (A, C, or P), had decreased by at least 20% and by 4 mm in a vertebra diagnosed grade progression by semiquantitative assessment [22]. Compliance with treatment was determined by returned tablet counts and interviews with subjects at each clinic visit. DXA and X-ray were not required in subjects who discontinued treatment within 84 days after the first dose of the study drug. Biochemical markers of bone metabolism were measured at baseline, and after 1, 3, 6, 9, and 12 months (or upon study discontinuation).