Zoledronic Acid for Osteoporotic Fracture Prevention (ZEST II)

Although close to 85% of frail women in long-term care (LTC) facilities have osteoporosis and the risk of osteoporotic fractures is nearly 10 times that of community dwelling elderly, few are treated and studies are scarce. It is postulated that in frail, LTC women an annual infusion of zoledronic acid, an antiresorptive therapy for osteoporosis, will:

• be effective demonstrated by fracture reduction;
• be safe.

To address these hypotheses, up to 1000 female LTC residents age 65 and older will be screened in order to enroll 310 eligible for randomization in a 3 year, randomized, double-blind, calcium and vitamin D controlled trial with the antiresorptive agent zoledronic acid. Use of an intravenous, once yearly agent avoids concerns of oral bisphosphonate side effects, poor absorption and burden on staff. Participants will reside in the long-term care settings associated with the Division of Geriatric Medicine, University of Pittsburgh and will include women with multiple comorbid conditions, functional and cognitive impairment, and limited mobility.

Inclusion criteria

• women age ≥65 years including those using assistive devices to maximize generalizability if they:

• Reside in long-term care (LTC);
• Have:

• osteoporosis by axial bone density (spine, hip or forearm bone mineral density (BMD) T-score ≤ -2.5 SD); or
• a previous adult fragility fracture of the spine or hip; or,
• would be treated based on FRAX National Osteoporosis Foundation (NOF) treatment thresholds of a 10 year risk of ≥ 20% for a major osteoporotic fracture or ≥ 3% for hip fracture using femoral neck BMD.

Exclusion criteria

• Men because osteoporosis is less common in men and our initial ZEST 1 study only included women.
• Institutionalized women with subacute illnesses surviving or discharged in < 3 years.
• Women currently on bisphosphonate, denosumab, or teriparatide therapy or who have been on a bisphosphonate for greater than 1 year during the previous 2 years because bisphosphonates are long acting.
• Patients with a calculated creatinine clearance < 35 ml/min or who have a contraindication for bisphosphonates (allergy, hypocalcemia).