A bonus for bone-density researchers
Osteoporosis drug study turns up unexpected health benefits
Rarely in the field of medical research do you set out to confirm one thing and stumble on something that may be of even greater benefit.
But that may be the case for a group of University of Auckland scientists who spent years examining the benefits of a drug that helps improve bone density, only to discover it also appears to greatly reduce heart disease and cancer.
The drug, zoledronate, is commonly prescribed for osteoporosis.
The team at Auckland Medical School set out to test their assumption that it would also help the much larger group of women with osteopenia, a less severe form of bone loss.
The study confirmed what they expected. Depending on the type of break, it reduces fractures by from 35 per cent to 50 per cent, according to the study’s report in the New England Journal of Medicine.
The bonus finding from the six-year project, which involved 2000 New Zealand women, is that the drug also appears to reduce, by about a third, the chance of heart attack or cancer.
Confirmation that the drug works for people with osteopenia has already prompted a global rethink of how best to limit fractures in older women, an increasing problem in New Zealand because of our ageing population.
By age 55, one in six women will have osteopenia. By age 75, half of all women will.
“Fifty per cent of women have a fracture between menopause and the time of death, and 80 per cent occur in women with osteopenia,” says Professor Ian Reid, who led the research team.
“Giving zoledronate to this group of women every 18 months to two years could be a game-changer and significantly reduce New Zealand’s total fracture burden.”
The clinical side of the study was led by Dr Anne Horne. “I saw all these 2000 ladies, five visits each. It was eight years of my life.”
Half the women received four infusions of zoledronate at 18-month intervals and the others received inactive infusions.
Horne told the Weekend Herald that they knew zoledronate was a good drug and expected it to work for those with less serious bone loss even though it had not been proven. It’s gratifying for the team that it has received a lot of attention overseas, says Horne.
“To do a study from one university in little New Zealand . . . it’s quite nice to have led the way.”
It means GPs will now know that women over the age of 65 who are even in the normal range of bone density can benefit from the drug.
Horne suggests women over that age ask their doctor for a bone-density scan.
The unexpected finding from the trial — that the drug appeared to reduce the incidence of cancer and heart attacks — is “exciting and interesting”, says Horne.
“We know some cancers spread to bone early in their course, so having zoledronate coating the bones may prevent these cancer cells attaching to bone and establishing themselves there.
“We also think that zoledronate may bind to the calcium in the walls of blood vessels, stabilising them and preventing the progression of arterial wall damage so people suffer fewer heart attacks.”
Studies specifically designed to test those outcomes are now needed.
If they are confirmed, the Auckland scientists will have stumbled upon an added benefit that Reid said could be “as great, or even greater” than the impact on fracture prevention in older women.
The drug is inexpensive and is infused by a doctor in a process that takes about 15 minutes.
The main side effect noted in the trial was that the first time the drug was administered, about a third developed flu-like symptoms that cleared after a few days.
It was a thrill to be part of a study that has made a contribution to medical knowledge, not to mention won a medal for the scientists involved, says Jackie Archer.
After seeing a flier on the notice board of the Orewa retirement village where she lives and works, Archer became one of the 2000 women who volunteered to take part in the study to test whether the drug would benefit women with less serious bone density loss.
“It’s a terrific outcome,” says Archer, a sprightly 83-year-old.
“In the past if someone broke a hip, we just didn’t know much about it. It was just, ‘oh dear’.”
She signed up because she was in the study’s age range and wasn’t told until afterwards that she was in the half that was given zoledronate rather than a placebo.
“It certainly has improved my bone density.”
News that the drug may help guard against heart attacks and cancer is the icing on the cake.
“I felt privileged to be part of the study and it was a thrill that it was so successful.”
The Auckland Medical School research team were presented with the Health Research Council’s Liley Medal for their work.
After her husband died when she was aged in her 70s, Archer toured the South Island solo in her motorhome.
Though her road trips are shorter these days, she continues to live an active life.
She works part-time at the retirement village where she lives, goes to the movies and the library and regularly drives her motorhome to visit family in Northland. “I’ve actually got the perfect life,” she says.