Teriparatide increases vertebral density and decreases the risk of spinal fractures in postmenopausal women regardless of their age, fracture history, or bone mineral density at baseline, reported Dr. Robert Marcus and his associates at Eli Lilly & Co., Indianapolis.
In a study funded by Lilly, which markets teriparatide as Forteo, the authors observed a dose-dependent increase in vertebral bone mineral density (BMD) after 3 months of treatment with teriparatide, compared with placebo. There also was a corresponding reduction in the incidence of new vertebral fractures.
Women who entered the study with the lowest BMD experienced the greatest percentage increase in BMD, but the absolute changes in BMD (as measured in grams per square centimeter) were similar m all of the treatment groups.
The study participants were 1,637 white women with a mean age of approximately 70 years. They had at least one moderate or two mild atraumatic vertebral fractures and a minimum of seven evaluable nonfractured vertebrae. Women with a hip or vertebral T score < -1 also were included, even if they had no evidence of vertebral fractures. Overall, the mean T score of all study participants was -2.6, and they had a mean of 2.3 prevalent fractures.
The women were divided into three groups: 541 self-administered an injection of teriparatide in a dose of 20 [micro]g/day; 552 took 40 [micro]g teriparatide/day, and 544 injected a placebo. All of the women also took 1,000 mg/day of calcium and 400-1,200 IU vitamin D/day for the length of the study, the duration of which was 19 months. Compared with the placebo group, women in the 20 [micro]g and 40 [micro]g of teriparatide groups experienced a 10% and 14% increase in vertebral BMD, respectively. The increased bone density was associated with a reduction of 65% and 69%, respectively in the incidence of new vertebral fractures.
To evaluate the relationship between teriparatide treatment and age, the investigators divided the women into three age groups: younger than 65; from 65 to less than 75 years; and 75 or older. Teriparatide significantly increased BMD across all age groups, although the percentage increase was greatest in the oldest women, perhaps because the study was overpowered with respect to analysis of BMD (J. Bone Miner. Res. 18:18-23, 2003).
Older women in the placebo group experienced an increase in BMD, compared with younger women over the course of the study, possibly because they were more deficient in calcium and vitamin D and benefited more from those supplements, Dr. Marcus and his associates said.
COPYRIGHT 2003 International Medical News Group
COPYRIGHT 2003 Gale Group