A role for testosterone?
Since a daily dose of more than 5 to 7.5 mg of prednisone increases the risk of gonadotropin and testosterone suppression, 24 testosterone replacement therapy has been used to treat glucocorticoid-induced osteoporosis in men.
In two placebo-controlled trials in men receiving glucocorticoid therapy for bronchial asthma or chronic obstructive pulmonary disease, testosterone therapy was associated with a significant 4% increase (95% CI 2–7) in bone mineral density in the lumbar spine. 25,26
While these studies cannot be considered conclusive in view of their small size and the lack of fracture data, the Endocrine Society currently recommends that men with chronic obstructive pulmonary disease who are receiving glucocorticoids, are hypogonadal, and have no contraindications to androgen replacement therapy (eg, prostate cancer) be offered testosterone therapy to preserve lean body mass and bone mineral density. 27
Calcitonin is not a first-line therapy
Neither the ACR nor the UK guidelines recommended calcitonin as first-line therapy.
A Cochrane systematic review 28 evaluated the data on the use of calcitonin to prevent and treat glucocorticoid-induced osteoporosis. Nine trials met the inclusion criteria, and included 221 patients randomized to receive calcitonin and 220 patients who received placebo. Calcitonin was more effective than placebo in preserving bone density in the lumbar spine, with a weighted mean difference of 2.8% (95% CI 1.4–4.3) at 6 months and 3.2% (95% CI 0.3–6.1) at 12 months. However, at 24 months, the lumbar spine bone mineral density was not statistically different between groups, nor was the relative risk of fractures. Calcitonin was given subcutaneously in one trial, in which it showed a substantially greater degree of prevention of bone loss than in the other trials, in which it was given nasally.
NEWLY APPROVED AND INVESTIGATIONAL AGENTS
Zoledronic acid once a year
Zoledronic acid (Reclast), a bisphosphonate given intravenously once a year, was approved for glucocorticoid-induced osteoporosis after the ACR and UK guidelines were published.
Zoledronic acid underwent a randomized multicenter, double-blind, active control trial 29 in 833 men and women, age range 18 to 85 years, who had glucocorticoid-induced osteoporosis (they had been treated with 7.5 mg per day or more of prednisone or its equivalent). Of these patients, 416 received a single infusion of 5 mg of zoledronic acid and daily oral placebo, and 417 received a single placebo infusion and daily oral risedronate 5 mg as an active control. All patients also received 1,000 mg of calcium and 400 to 1,000 IU of vitamin D per day. The study duration was 1 year.
Of those who had received a glucocorticoid for more than 3 months, those who received zoledronic acid had a significantly greater mean increase in lumbar spine bone mineral density compared with those in the oral risedronate group: 4.1% vs 2.7%, an absolute difference of 1.4% ( P < .0001).
In those who had received a glucocorticoid for 3 months or less, those who received zoledronic acid also had a significantly greater mean increase in lumbar spine bone mineral density compared with those in the risedronate group at 1 year: 2.6% vs 0.6%, a treatment difference of 2% ( P < .0001).