Norman Swan: And another story which actually hasn't had much coverage in the news, I think it's very much worth our talking about, is a really important and interesting paper on hormone replacement therapy for women who are peri and menopausal.
Tegan Taylor: Yeah, and some pretty gnarly sounding side effects. I'm quite keen for you to put this into context for us, Norman.
Norman Swan: So the context here is hormone replacement therapy has been around for a long time, estrogen only, estrogen plus progesterone, a drug called tibolone, and, more recently, transdermal patches for hormone replacement therapy. So, there's been controversy. The early studies, which were observational, not clinical trials, suggested it protected against heart disease, dementia, breast cancer. And then they say, well, we need to do clinical trials to find out whether this is true. And two clinical trials have shown an increased risk of coronary heart disease, stroke, heart attacks and thrombosis, risking pulmonary embolism, a clot in the lung.
One of those trials was heavily criticised because it had older women, not the typical population of women who are on hormone replacement therapy. So now, to try and answer these questions, a massive study out of Sweden where they've looked at 900,000-odd women, where they know what drugs they've taken and they know what diseases or problems they've got down the line. And what they've done is called an emulator trial, so they weren't actually on a clinical trial, but they organised this population of women because they knew they weren't on hormone replacement therapy, then they went on various kinds, so you could have a group that weren't on treatment versus treatment and various types of treatment, and then follow them through over the years to see what happened to them in terms of their cardiovascular system.
Long story short, tibolone increased the risk of coronary heart disease, heart attacks, stroke, not necessarily of clots. Oral (and I say this; oral) combined estrogen and progesterone increased the risk of coronary heart disease, and estrogen alone orally probably did too. But for the reassurance of a lot of women, transdermal (in other words, skin patches) did not seem to increase the risk of coronary heart disease, and luckily over the last few years that's where the market has gone. Most women who start hormone replacement therapy these days are on the transdermal patches and probably don't need to worry about heart disease, apart from the usual risk factors.
Tegan Taylor: So for someone listening to this, what kind of questions should they be asking their doctor? You know, you hear hormone replacement therapy, increased risk of coronary heart disease, even with all of the context you've just given us, what should they be asking about?
Norman Swan: Well, if the doctor is recommending an oral version of hormone replacement therapy, give them the link to the show, we've got the link to the British Medical Journal paper, and say, 'Why can't I have a skin patch?' Because it looks as though skin patches are fine.
Tegan Taylor: A good chat to have with your doctor, put them on the spot, tell them Norman sent ya.