Opposite bone remodeling effects of teriparatide and alendronate in increasing bone mass

Arch Intern Med. 2005 Aug 8-22;165(15):1762-8. doi: 10.1001/archinte.165.15.1762.


Background: Antiresorptive agents for the treatment of osteoporosis suppress bone remodeling and reestablish bone turnover at a lower rate to reduce bone loss. Recombinant teriparatide (human parathyroid hormone 1-34) stimulates bone formation, increases bone mass, and improves bone microarchitecture. We contrasted the effects of once-daily doses of 20 mug of teriparatide and 10 mg of alendronate sodium on bone mineral density (BMD) and markers of bone turnover.

Methods: Markers of bone turnover and areal BMD were assessed in 203 postmenopausal women with osteoporosis in an 18-month randomized parallel double-blind study; volumetric BMD was measured in a subset of women.

Results: Teriparatide significantly increased markers of bone turnover that peaked at 6 months (serum procollagen type I N-terminal propeptide, 218%, and urinary N-telopeptide corrected for creatinine, 58%; P<.001); alendronate significantly decreased the markers at 6 months (-67% and -72%, respectively; P<.001). At 18 months, areal and volumetric spine BMDs were significantly higher with teriparatide than with alendronate (10.3% vs 5.5% [P<.001] and 19.0% vs 3.8% [P<.01], respectively). Areal femoral neck BMD was significantly higher than baseline in the teriparatide and alendronate groups (3.9% and 3.5%, respectively). There were no significant differences in trabecular femoral neck BMD between the teriparatide and alendronate groups (4.9% and 2.2%, respectively). Cortical volumetric femoral neck BMD was significantly different between the teriparatide and alendronate groups (-1.2% and 7.7%, respectively; P = .05).

Conclusion: Two distinct options for the management of osteoporosis lead to increases in BMD by opposite mechanisms of action on bone remodeling.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alendronate / pharmacology*
  • Bone Density / drug effects
  • Bone Remodeling / drug effects*
  • Collagen / urine
  • Collagen Type I
  • Female
  • Humans
  • Middle Aged
  • Peptide Fragments / blood
  • Peptides / urine
  • Procollagen / blood
  • Teriparatide / pharmacology*


  • Collagen Type I
  • Peptide Fragments
  • Peptides
  • Procollagen
  • collagen type I trimeric cross-linked peptide
  • procollagen type I carboxy terminal peptide
  • Teriparatide
  • Collagen
  • Alendronate