Eating Disorders and Bone Density: What’s the connection?
Eating Disorders and Bone Density: What’s the connection?
Eating disorders are often associated with the fear of gaining weight. The strong desire to be thin can be incredibly dangerous and have long-lasting health consequences. Malnutrition is one of the consequences. Malnutrition and starvation often go hand in hand. As the body enters starvation, it displays many warning signs and symptoms such as fatigue, dizziness, vitamin deficiencies, slow heart rate, ketones in the urine, elevated liver tests, and constipation. It can also cause an increased risk for infection, slow wound healing, anxiety, and poor concentration during school or work. Malnutrition can occur at any body size. It occurs when the body is deprived of vitamins, minerals, and other nutrients necessary for the muscles, bones, organs, and tissues to function properly. When a person severely restricts their intake or has inconsistencies in how they eat, they often suffer from malnutrition. Malnutrition occurs when the diet does not provide the body with adequate calories, protein, and nutrients to be sufficiently sustained. Did you know malnutrition can exacerbate poor body image? The regions of the brain that are involved with judgment and cognition are directly impacted by starvation.
Eating disorders can cause osteoporosis and osteopenia
Osteoporosis is a condition in which the bones become brittle and fragile from tissue loss. This can be caused by restriction and starvation associated with an eating disorder. Osteopenia is a condition that occurs when the body reabsorbs old bone at a faster rate than it produces new bone. Once a decrease in bone mineral density is discovered, it is imperative that treatment is sought. The quicker intervention occurs, the less likely it is that the damage becomes irreversible or progresses. Weight restoration, resumption of a regular menstrual period in women, and ensuring adequate vitamin D and calcium levels are vital in preventing or reducing bone density loss.
Measuring bone density
Bone density is often measured using a DXA scan or Dual-energy X-ray absorptiometry. The scan uses low-dose X-rays to see how dense or strong your bones are. The scan results provide details about the risk for osteoporosis and fractures. It can also measure body composition, including body fat and muscle mass. The DXA scan is often performed by a member of the hospital's radiology or nuclear medicine department and usually takes 10- 20 minutesWhen should you have a DXA scan done?
A DXA scan should be performed if you have been without a menstrual period for 6 or more months or if a low (underweight) body weight is maintained for 6 months or more. It is essential to consider bone density, as individuals with anorexia are 3x more likely to develop a long-term fracture. There is also a high prevalence of reduced bone mineral density in individuals with anorexia. On a bone density scan, between 25% and 40% of people with anorexia will have osteopenia.
Are there warning signs for osteopenia and osteoporosis?
Experiencing localized pain and weakness in an area could be considered a warning sign. However, osteopenia and osteoporosis are silent diseases in their early stages. Since you can’t feel your bones shrink, a DXA scan is vital. Having a low BMI is a strong predictor of lower bone mineral density. Low bone mineral density can affect the body long after restoring weight. The length of time an individual suffers from an active eating disorder has been thought to correlate directly with the degree of low bone mineral density seen on a DXA scan.
What are the consequences of low bone density?
There are devastating consequences to low bone density, including loss of height, a lifelong risk of fragility fractures, and osteoporosis. Having an eating disorder makes you 7X more likely to have bone fractures. Anorexia can also change shoe size. Fat is stored in all areas of the body, including the feet. Not having adequate fat stores on the feet can lead to a decrease in shoe size. Shoe size could also increase due to edema or swelling in the ankles and feet. This is caused by hormonal changes brought on by starvation or by purging. Individuals with anorexia are also shorter than their peers due to growth stunting from lack of nutrition.
The role of Vitamin D and Calcium in bone mineral deficiency
There is a high incidence of vitamin D deficiency in patients with osteopenia. When body weight decreases, it reduces estrogen, which causes menstrual periods to cease. Loss of a period, the length of period loss, and low BMI are all linked to low bone mineral density. These factors go hand in hand with low vitamin D and calcium levels, also predictors of bone loss.
Why early intervention is important
Osteoporosis can develop quickly in individuals with anorexia. Around 40% of individuals with anorexia have osteoporosis at one or more skeletal sites, and about 90% have osteopenia.
Bone loss leads to increased risk of fracture. Since osteoporosis develops over time, it often isn’t detected until a fracture occurs. While osteoporosis can be prevented by building strong bones early in life, it can be difficult or impossible to reverse the longer the condition lasts.
Your DXA results are back. Now what?
Many treatments can help encourage the return of bone health. Nutrition is a key to bone health. It is encouraged that those with eating disorders work with a dietitian to restore weight and include adequate vitamin D and calcium in the diet. There are also medications that can be used to treat and manage osteoporosis. Oral contraceptives use estrogen replacement which can improve and preserve bone mineral density. Estrogen plays a pivotal role in bone metabolism, improving bone formation and inhibiting bone resorption. A 6% increase in bone density can translate to a doubling of bone strength. Regular DXA scans are also recommended for people with anorexia to determine levels of bone loss and risk of fracture. The return of menstruation is also imperative in preserving bone mineral density.
The importance of weight gain/weight restoration
Weight restoration and the resumption of menses have been shown to increase bone density. Weight gain is associated with a preferential increase in bone density at the total hip, and menstrual recovery is related to the increased bone density at the spine. Increases in lean body mass during weight recovery can increase bone density. Exercise in patients with anorexia should be avoided until weight restoration is complete and a doctor has cleared you for exercise. Even then, caution should be given to exercise.
Who is your team?
As you embark on your journey to recover from disordered eating or an eating disorder, it is important you have a support team. Your treatment team should include a therapist or psychiatrist, a doctor (or PA or NP), and a dietitian to manage your eating disorder and low bone density. The primary goal of medical therapy for individuals with anorexia is weight gain and, in females, the return of normal menstrual periods. Depending on your low bone density severity, a Rheumatologist or Endocrinologist may also be recommended. A rheumatologist can diagnose and treat osteoporosis. Endocrinologists see patients with hormone-related issues and can manage the treatment of metabolic disorders such as osteoporosis. Having a support system of family and friends is also important. Remember, nutritional rehabilitation and weight regain are the mainstays of treatment and bone health.
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