Like Mother, Like Daughter

October 14, 2011
Ronald Barentsen, MD, PhD

During a gynecologic consultation my patient, Mrs. Andersen age 48 years was distraught and asked me for advice. She was worried about her mother, but also about herself. She was very concerned and proceeded to explain in detail the current situation.

Case history

During a gynecologic consultation my patient, Mrs. Andersen age 48 years was distraught and asked me for advice. She was worried about her mother, but also about herself. She was very concerned and proceeded to explain in detail the current situation.

She believes her mother is probably suffering from osteoporosis. Mother had experienced a forearm fracture more than 10 years ago, at the age of 63, and recently she suffered a hip fracture. She had been operated on for the fracture and was recovering very well. Her mother’s physician had told her that at her age (75), there is no way to prevent more fractures other than take measures to diminish the risk of falling. My patient, Mrs. Andersen has heard from her friends that osteoporosis has strong genetic influences and she is also worried that she will have fractures in the future too. Her question is, "What can I do to prevent what happened to Mother from happening to me?"

Questions like this are not uncommon in daily practice. With Ms. Andersen a generally accepted risk factor was involved (the genetic factor), but sometimes the same question arises just because a woman is concerned about her health. For a proper answer, you need more information about her fracture risk, so an inventory of risk factors is the first step.

Mrs. Andersen. is a Caucasian woman and her mother has had multiple fractures. She has a dietary intake of calcium with 2 portions of milk each day. She is non-smoking with average exercise. Her menarche was at 14 years, she has 3 children, and she was usually regular menstruating until recently. During the last year, her periods became more irregular and her last menstrual period was 3 months ago.

Weight 148 lbs. (67 kg). Height 5’5" (1.68 m). No disease, no drug therapy.

The history reveals no risk factors other than the genetic one and perhaps a smaller intake of calcium than advised.

What to advise her? Two important measures serve general health and can always be advised to women: to increase the daily intake of calcium to at least 4 portions of dairy products (eventually as calcium supplements) and somewhat more exercise. You can advise women who are at very high risk to start hormone replacement therapy or bisphosphonates, but when available, measurement of bone mass is the best next step.

Indications for bone mass measurement

  • Complaints/symptoms of possible osteoporosis
  • Presence of risk factors
  • Impression of osteopenia at a X-ray investigation
  • Follow-up with therapy
  • Screening

Bone mass measurement

Bone mass measurement was subsequently done on Mrs. Andersen both at the lumbar spine and at the proximal femur with DXA.

Result: Bone mass - L1-L4: 0,83 g/cm2: T: -1.7

Collum femoris: 0,68 g/cm2: T: -1.4

Interpretation of results:

As it turns out Mrs. Andersen has osteopenia. This is a clinical definition. But her personal concern is what can she expect in terms of fractures? There is a strong relationship between bone mass and fracture rate. It has been calculated that the fracture risk doubles with every standard deviation below the mean. So a woman with a bone mass of T=-1 has twice the risk of a woman with a bone mass T=0. And the lifetime risk of a woman at the age 50 for one or more fractures is nearly 40%. With a T-score of -1.7, her risk will be increased substantially.

Mrs. Andersen is still premenopausal, perhaps perimenopausal. After menopause one can expect that her bone mass will decrease within 3-5 years by about 15%. This amount is about 1 standard deviation. Her bone mass will decrease within a few years to a level of T –2.7 in the lumbar spine and a level of -2.4 in the proximal femur. After that first few years the decrease in bone mass will continue at the rate of 0.5% each year. Mrs. Andersen will certainly suffer from osteoporosis in about 5-10 years unless action is taken.

Options

There are several options available nowadays.

Prevention of bone loss is achieved with adequate hormone supplementation from the moment that the ovaries cease their activity, so during perimenopause or shortly after menopause. With an adequate amount of estrogen, bone mass will remain unchanged and consequently fracture risk remains the same. For optimal results, one has to continue the hormone supplementation for at least 5-7 years. It is proven that with such therapy the number of fractures decreases significantly.

Recently bisphosphonates have been introduced in the prevention of osteoporosis. Before, these substances were used only in established osteoporosis after the occurrence of fractures. With the bisphosphonates, bone mass can be maintained for many years and we can expect that the number of fractures will decrease subsequently, but this outcome (less fractures) has yet to be proven.

In some countries the new "selective estrogen receptor modulator", raloxifene has been introduced recently for the prevention of osteoporosis. The experience is limited, but the expectation is that the effect on bone mass will be the same as that of estrogen.

Advice

First of all, we have to counsel Mrs. Andersen about the natural course of her bone mass and the risk of fractures. It is always difficult to speak in terms of risk. With severe osteoporosis, it is possible that no fracture will occur and with normal bone mass, a fracture is not impossible, but Mrs. Andersen has a substantial risk to suffer from one or more fractures in the future. She can diminish her risk. First of all, with some general measures: a change of her lifestyle with more physical exercise, preferably in the open air (vitamin D!) and increased intake of calcium to 4-5 portions of dairy products every day (or calcium supplements of about 1000 mg).

Secondly, medication has to be offered: estrogen/progestagen supplementation or bisphosphonates. For the definite choice, one has to consider the other benefits of hormone supplementation, such as the decrease of cardiovascular disease and the effect on dementia, but also the possible increase in risk of breast cancer, especially in long-term users. In addition, side effects such as withdrawal bleeding should be discussed. The most important point in this decision process has to be the proven effect of HRT on the number of fractures. On the other hand, with bisphosphonates, the side effects are rarely seen. But the ultimate proof of benefit after many years has yet to be found.

Decision

After counseling, Mrs. Andersen decided to start with HRT at least during the first few years. Her opinion was that she could always change to bisphosphonates if the treatment with HRT becomes problematic and she has no risk factors for breast cancer.

She will start therapy soon because we considered her already perimenopausal. A simple urine test that measures bone breakdown (resorption) can be done as soon as three months after the commencement of her treatment to make sure it is working. Then, after 2-3 years of treatment, bone mass measurement will be repeated to monitor the treatment.

Mrs. Anderson is satisfied with this course of action but still concerned for her mother’s prognosis. She comments on the fact that the type of information and treatment options offered to her were not available 30 years ago to her mother. "If they had been", she muses, "Perhaps Mother would be out enjoying herself instead of recovering from hip surgery." She is more than likely correct. 

Clinical Definition of Osteoporosis

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