The incidence of hip fracture has decreased steadily over the past 40 years, but a new analysis suggests that new osteoporosis drugs have made only a small contribution to the trend.
The report, published in JAMA Internal Medicine, included 10,552 men and women and their offspring followed since 1970. Every five years through 2010, the researchers recorded the number of hip fractures in people over 60. They found that the incidence of hip fractures decreased by 67 percent over those years, and rates were lower in people born later.
The bone-strengthening bisphosphonates, like Fosamax (introduced in 1995) and Boniva (introduced in 2003), cut the fracture incidence by about 4.8 percent, the researchers estimate.
But smoking decreased to 15 percent of participants in 2010, from 38 percent in 1970, and heavy drinking declined to 4.5 percent, from 7 percent. Both are significant risk factors for fracture. Other risk factors, like being underweight and early menopause, were stable over the years.
“Smoking cessation accounts for about 90 percent of the decline in the age-adjusted decrease,” said the lead author, Dr. Timothy Bhattacharyya, an orthopedic surgeon with the National Institutes of Health.
Other factors that may have played a role included estrogens, which were approved for osteoporosis treatment in 1988, and bone mineral density testing, which first became available in the 1990s. But “we didn’t observe any effect from estrogens or bone mineral density testing,” Dr. Bhattacharyya said.
Still, he said, “Bone mineral tests are the best objective test of bone density in determining treatment, and bisphosphonates are an effective preventive method. If you’re taking them, you should continue to do so.”