Effect of Zoledronic Acid on Skeletal Muscle After Bariatric Surgery: A Secondary Analysis From a Randomized Controlled Trial.

OBJECTIVE: This study aimed to investigate whether a single infusion of 5 mg zoledronic acid, given before bariatric surgery to prevent bone loss, could also hinder the loss of muscle mass, strength, and physical function. METHODS: In this double-blinded study, patients referred for bariatric surgery were randomized 1:1 to either intervention (INT: single dose zoledronic acid 5 mg) or placebo (CON). Assessments were conducted at baseline and 12 months postoperatively. The outcomes were body composition (DXA), muscle strength for knee extensor (KE) and knee flexor (KF), and physical function. RESULTS: Fifty-nine patients (age: 48.9 ± 6.3 years, BMI: 42.3 ± 5.3 kg/m2) were allocated to INT (n = 31) or CON (n = 28). At 12 months, no between-group differences were observed in body weight, fat mass, or lean body mass. Both groups experienced ~14% loss of lean body mass. No between-group differences were observed for absolute or relative muscle strength. Absolute strength declined by 11%-18%, while relative strength improved by 10%-22%. No between-group differences were found in physical function measures, all of which improved by 5%-18%. CONCLUSIONS: A single infusion of 5 mg zoledronic acid did not prevent the loss of muscle mass or strength or improve physical function. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04742010; EudraCT number: 2019-001650-26.