Study of the Effect of Once a Week Risedronate on the Microstructure of Tibia and Radius Using a New Scanning Method

A Non-Invasive Evaluation of Bone Microarchitecture Modification in Osteopenic Postmenopausal Women by 3D-Peripheral Quantitative Computed Tomography (3D-pQCT)

The primary purpose of the protocol is to evaluate the sensitivity of 3D-pQCT (3D-Peripheral Quantitative Computed Tomography) technology to detect minute changes in bone microarchitecture.

The 3D-pQCT equipment allows the evaluation of changes occurring within the bone at "microarchitecture" level, without the need for invasive bone biopsies. The primary objective is to evaluate the sensitivity of the technology to detect a difference between those treated with risedronate 35mg OAW (once a week) or placebo. Early phase postmenopausal women with osteopenia have been chosen because they have a more rapid and higher level of bone loss during the first few years of the menopause.

Inclusion Criteria:

• cessation of menstruation (surgical or natural) between 6 and 36 months prior to study enrollment;
• osteopenic
• must have at least 1 evaluable radius and tibia, without history of fracture (traumatic or atraumatic)
• BMI (body mass index) between 18 and 28 kg/m2 inclusive;

Exclusion Criteria:

• history of any generalized bone disease, including hyperparathyroidism, Paget's disease of bone, renal osteodystrophy, or any other acquired or congenital bone disease; or any known condition that would interfere with the assessment of DXA (dual-energy X-ray absorptiometry) at either the lumbar spine (3 non-evaluable lumbar vertebrae at lumbar spine L1 - L4) or the femoral neck.
• clinical or radiological evidence of osteoporosis, such as atraumatic vertebral compression fracture (* 20% reduction in anterior-to-posterior or middle-to-posterior height ratio; or 20% reduction of the anterior, middle, and/or posterior height as compared with the adjacent vertebrae) documented by spinal X ray or a history of osteoporosis-related atraumatic fracture of the hip or of the wrist;
• glucocorticoid-induced osteopenia;
• previous bisphosphonate therapy;