How to prevent the Big O: osteoporosis

Q: I have been an avid (some would say excessive) exerciser and have kept my weight down. I thought this would keep me healthy. But now that I am in my early 50s, I worry whether my bones are as strong as the rest of me. How can I make sure they are?

A: I am going to wax personal in my answer to your question. I, too, have exercised a lot. In fact, in my childhood I was an aspiring dancer. Hours of grueling ballet classes kept me classically thin (or, to be more precise, downright skinny).

But, as my height surpassed my talent and I met with rejection in the dance world, I figured I wasn’t destined to be a ballerina. And, when I reached my 50s, my skeletal past began to haunt me.

Had my bones, like those of many dancers, been weakened by excessive exercise and weight loss? Had I consumed enough calcium? Probably not. In my teens, Coke and coffee were the beverages of choice.

Many women these days are wondering whether their bones are strong enough to withstand the onslaught of menopause, and they are right to be concerned. Osteoporosis is not just a disease of “little old ladies.” A survey of more than 160,000 women ages 50 to 65 found that fully one-third had bone mass low enough to triple their risk of fracture.

And fracture they do. Within a year of testing, 2,440 of these younger women had osteoporotic fractures, and an astounding 20 percent of those were the ones we all worry about — those that occur in the hip.

Bone is a living tissue that is constantly being built up and broken down by two types of cells. Bone-drilling cells called osteoclasts help reshape and build the bone by creating microcavities, which are then filled by bone-building cells called osteoblasts. It takes just three weeks to drill and fill those holes. As long as the filling surpasses the drilling, our bodies can build bones.

We accumulate most of our bone mass in childhood and adolescence, but can continue to improve on its density until our early 30s. Calcium intake is critical to this process. During this time we need 1,000 mg a day, either through food or calcium supplements.

We also need estrogen to perform this architectural feat. Without this hormone, our bone-drilling cells go a little berserk, chopping away at our skeletons faster than the bone-filling cells can keep up.

If you had inadequate estrogen levels because of low weight or excessive exercise (especially if you skipped or stopped your periods for any length of time), you will likely begin menopause with a low bone density. During the following seven years, you can lose as much as 3 percent of your bone mass annually. This adds up to a whopping 21 percent.

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The osteoclasts do eventually settle down, but they never cease their excavations. We continue to have an annual bone loss of 1/2 percent to 1 percent for the rest of our lives.

According to the National Osteoporosis Foundation, osteoporosis and osteopenia (low bone density) are major health concerns for all women over 50. Half of these women will experience an osteoporotic fracture — a fracture due to low bone density, where the bone needs only minimal trauma to break.

Many of these broken bones will be in places where they can’t be fixed by slings or casts. Twenty-five percent of postmenopausal women will fracture the vertebrae in their spine; 15 percent will break a hip. The former makes you shorter and causes those characteristic dowager’s humps, and can also cause severe back pain. Hip fractures usually require extensive surgery and can be fatal. (Twenty percent of women die as a result of surgical and bed-rest complications.) Fifty percent will never walk again without assistance and 25 percent will need long-term care.

So, give your bone-building cells the calcium they need to do their job — 1,200 mg a day if you take hormone-replacement therapy and 1,500 mg if you don’t. Bone is also strengthened by pulling and pushing the muscles that surround it; so get some weight-bearing exercise (walking or jogging). Swimming and biking won’t work. You should also work out with weights for 15 minutes, two to three times a week.

If you do develop significant menopausal symptoms, talk to your doctor about the pros and cons of hormone therapy. Hormones decrease fracture rate and help prevent further bone loss. There is also a new, very low-dose estrogen delivered through a skin patch, Menostar, that has just been approved to help prevent bone loss.

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I am particularly concerned about women who have stopped hormone therapy. Once menopausal women discontinue hormone therapy, they will, like women in the throes of menopause, experience rapid bone loss. These women often need additional medication to maintain or build bones.

Drugs for treating osteoporosis stop the bone-drilling cells from creating microcavities. I often prescribe low-dose Fosomax for patients with worrisome osteopenia, and use a higher dose of this or Actonel for osteoporosis. Both drugs can be taken in once-weekly tablets. For patients with breast-cancer risk, I may prescribe Evista. Like estrogen, this helps prevent bone loss, but won’t relieve other menopausal symptoms.

Many insurance companies will not cover the cost of a full bone-density scan for women under 65. That may be too late. Women with risk factors for osteoporosis (thinness, previous athletic behavior, smoking, taking steroids, a family history of osteoporosis) should get a bone-density scan as soon as they are menopausal, or even before. A scan will diagnose osteoporosis or osteopenia.

Dr. Reichman’s Bottom Line: Bone problems are surprisingly common in women. Assess your risk for osteoporosis early enough to keep your bones healthy in the future.

Dr. Judith Reichman, the “Today” show's medical contributor on women's health, has practiced obstetrics and gynecology for more than 20 years. You will find many answers to your questions in her latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," published by William Morrow, a division of HarperCollins.

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