What is the effect of alendronate verses vitamin D on selected bone turnover markers in women with postmenopausal osteoporosis and a high fracture risk?

1. Post-menopausal women will be recruited from Bope-Poddala MOH area in Galle using latest electoral registers.

2. Participants who fulfill the eligibility criteria with high fracture risk will be randomly assigned into two groups (Treatment group and Control group) by block randomization method (one block will consist of two participants)

3. Treatment group will receive oral alendronate (70 mg/week) with oral vitamin D3 (800IU/day) for 6 months.

4. Control group will receive a placebo prepared similar to the alendronate tablet along with vitamin D3 (800IU/day) for 6 months.

5. Study participants, clinicians and data collectors/analysts will be blinded to the intervention

1. Newly diagnosed post-menopausal females with high fracture risk. Fracture risk assessment: The fracture risk will be assessed based on FRAX algorithm using clinical risk factors and bone mineral density values. Women with major fracture risk >10% and/or hip fracture risk >3% will be considered to have a high fracture risk. Lekamwasam S, (2013), Sri Lankan FRAX model and country-specific intervention thresholds. Arch Osteoporos;8:148.

1. Females with a history of significant neuroendocrine disorder that affect the BTMs (disorders of thyroid gland like hyperthyroidism and disorders of parathyroid glands such as hyperparathyroidism and hypoparathyroidism)
2. Treatment with anticonvulsant, thyroxin and hydrochlorothiazide that affect the vitamin D and calcium metabolism
3. Chronic kidney disease stage 4 or 5 (when eGFR is less than <30 mL min-1 per 1.73 m2)
4. Chronic liver disease (clinically evident)
5. Other metabolic or inherited bone diseases other than postmenopausal bone loss including Paget’s disease and osteomalacia
6. Rheumatoid arthritis or collagen disease
7. Subjects with malignancies
8. Immobilized or disabled subjects due to cerebrovascular disease
9. Gastric surgery, major gastrointestinal disease that causes significant malabsorption,
10. Use of any systemic steroid (prednisolone, dexamethasone or equivalent),
11. Use of bisphosphonates within the year directly preceding the study
12. Other anti-osteoporotic drugs (selective oestrogen receptor modulators and calcitonin) and calcium, vitamin supplement during the last three months
13. Women who have experienced early menopause (before 45 years of age)
14. Women who have undergone any therapy which can affect the bone metabolism (hormone replacement therapy andandrogen-stimulating therapy)
15. Women who are known to take antipsychotics and antiepileptic sodium valproate
16. Fracture during the last one year
17. Acute illness at the time of recruitment or during last 3 months
18. Allergy for bisphosphonates