Osteopenia and Osteoporosis: Bone-Mineral Density Loss in Anorexia Nervosa

By: Carrie Brown, MD

Monday, April 18, 2016

300300p27278EDNmainMedical Monday Brown 600From the ACUTE team: To offer our readers a more comprehensive look into the various aspects of eating disorders and treatment, Medical Mondays will periodically be penned by team physicians at the ACUTE Center for Eating Disorder.

This week’s Medical Monday is written by Carrie Brown, MD.

Hi everyone, I’m here today to tell you about conditions known as osteopenia and osteoporosis, otherwise known as bone-mineral density loss, or simply “weak bones”. Osteopenia and osteoporosis are two conditions on the same spectrum. Mild bone density loss is called osteopenia and severe bone density loss is called osteoporosis.

Bone-mineral density loss is common in older women after menopause, and is also found in men and women with anorexia nervosa. Osteoporosis is usually to blame when someone has suffered a broken hip after a fall, or compression fractures in the spine.

Why, you may ask, is the condition common in people with anorexia? One of the most important reasons has to do with hormones. During adolescence, when our bodies are growing the most, we typically experience a surge in hormones (estrogen in girls and testosterone in boys). These hormones are critical for building up bone strength. Bone mass usually peaks between ages 25 and 30, but bone buildup is the greatest during the teen years. Therefore, for men and women whose eating disorder started in the teen years, osteoporosis is an especially big concern. A fourteen-year-old young woman who has lost her menstrual periods due to losing weight from her eating disorder has seen her hormonal system go into hibernation and certainly does not have enough estrogen circulating in the body to promote normal, healthy bone strength. We also know that being underweight, even with normal menstrual periods, can cause bone mineral density loss.

So, how do we evaluate bone health? The test for osteopenia is called a DEXA scan, which is a quick, painless, and safe test that involves lying on a table while your body is scanned. The DEXA scan takes a close look at the bone mass in your hips and spine. Once the test is complete, the results are sent to your doctor who can explain them to you.

It can be saddening and frustrating to receive a diagnosis of bone density loss, as it is often a sign that one’s eating disorder is undeniably affecting one’s health. The good news is that if your doctor diagnoses osteopenia or osteoporosis, you have a chance to take action so that your bones get stronger. To improve bone strength, weight restoration for both men and women is critical since weight restoration turns hormones back on. For women, re-starting regular menstrual periods can be a sign that estrogen levels are getting back to normal and protecting bones again. It is very important to understand that re-starting menstruation by going on birth control is absolutely not a solution to this problem.

Aside from weight restoration, your doctor may offer a medication to help rebuild bone strength. Men with bone density loss should have their testosterone level checked, and if low, start testosterone replacement therapy which has been proven to rebuild bones in scientific studies. Several other medications are available in pill, injection, and IV form that have been proven in scientific studies to rebuild bones in patients with anorexia nervosa. If you have been diagnosed with bone density loss, I recommend you see a medical doctor with expertise in eating disorders to discuss the option of treating bone density loss with medicine, so that you can make an informed decision regarding how to address the condition.

You might ask, is this diagnosis really a big deal? Absolutely. Once osteopenia or osteoporosis is diagnosed, it usually worsens without medical treatment and/or lifestyle changes. Continued low weight leads to continued bone loss. Osteoporosis dramatically increases the risk of spinal fractures which cause height loss and hip fractures which usually require surgery. Once bone density loss is diagnosed, it is important to have a DEXA scan every year to track changes over time.

Best wishes to you all in your journeys toward recovery,
Dr. Carrie Brown