Data on treatment of glucocorticoid-induced osteoporosis (GIO) in men
are scarce. We performed a randomized, open-label trial in men who have
taken glucocorticoids (GC) for 3 months, and had an areal bone mineral
density (aBMD) T-score 1.5 standard deviations. Subjects received 20g/d
teriparatide (n=45) or 35mg/week risedronate (n=47) for 18 months.
Primary objective was to compare lumbar spine (L1L3) BMD measured by
quantitative computed tomography (QCT). Secondary outcomes included BMD
and microstructure measured by high-resolution QCT (HRQCT) at the 12th
thoracic vertebra, biomechanical effects for axial compression, anterior
bending, and axial torsion evaluated by finite element (FE) analysis
from HRQCT data, aBMD by dual X-ray absorptiometry, biochemical markers,
and safety. Computed tomography scans were performed at 0, 6, and 18
months. A mixed model repeated measures analysis was performed to
compare changes from baseline between groups. Mean age was 56.3 years.
Median GC dose and duration were 8.8mg/d and 6.4 years, respectively;
39.1% of subjects had a prevalent fracture, and 32.6% received prior
bisphosphonate treatment. At 18 months, trabecular BMD had significantly
increased for both treatments, with significantly greater increases with
teriparatide (16.3% versus 3.8%; p=0.004). HRQCT trabecular and
cortical variables significantly increased for both treatments with
significantly larger improvements for teriparatide for integral and
trabecular BMD and bone surface to volume ratio (BS/BV) as a
microstructural measure. Vertebral strength increases at 18 months were
significant in both groups (teriparatide: 26.0% to 34.0%; risedronate:
4.2% to 6.7%), with significantly higher increases in the teriparatide
group for all loading modes (0.005
between groups. None of the patients on teriparatide but five (10.6%)
on risedronate developed new clinical fractures (p=0.056). In
conclusion, in this 18-month trial in men with GIO, teriparatide showed
larger improvements in spinal BMD, microstructure, and FE-derived
strength than risedronate.