Comparison of biochemical markers of bone remodelling in the assessment of the effects of alendronate on bone in postmenopausal osteoporosis

The effects of alendronate treatment on biochemical markers of bone remodelling and bone mineral density (BMD) were studied in 30 Caucasian women (postmenopausal for at least 3 years, age 42–76 years, with BMD of the lumbar spine at least 2 S.D. below the mean for mature, premenopausal women). The patients were randomly assigned to receive alendronate (10 mg/day) or placebo for 12 months (double blind). The study was subsequently extended to a second year of open alendronate treatment. The treatment with alendronate resulted in a significant and progressive increase in BMD of the lumbar spine and femoral neck. Under the treatment, the maximal decrease of biochemical markers of bone remodelling (osteocalcin in plasma, bone-specific alkaline phosphatase, N-terminal propeptide of type I procollagen and C-terminal telopeptide of type I collagen in serum, and cross-linked amino-terminal N-telopeptide and total hydroxyproline in urine) was observed at 6 months with no further change during the 2-year period. There were no significant differences in discriminating between patients treated for 1 year with alendronate or placebo using either the percentage change in spine BMD at month 12, or a single measurement of the marker at month 6, or log (percent of baseline at month 6 of value of the marker). In this respect, the power of all the biochemical markers were comparable. The markers are a valuable adjunct to the measurements of BMD, especially in the patients not showing an increase of 3% or more at the lumbar spine BMD after 1 year of treatment.