Osteoporosis and thyroid disease can occur together, in part because of how important thyroid hormones are to your bone density and structure.
Osteoporosis is a bone disease that affects bone mineral density and bone strength. It occurs when your balance of bone resorption and formation is disrupted, and more bone is lost than is replaced.
While older age is a factor associated with osteoporosis, it’s not considered a routine or typical part of getting older. Not everyone will develop osteoporosis, and age isn’t the only reason your bone health may be affected.
The systems in your body are interconnected, and bones are no exception. Research shows dysfunction in other areas, like in the thyroid, can also lead to bone fragility.
Thyroid dysfunction can cause bone mineral density loss and diminished bone strength that may lead to osteoporosis.
Your thyroid, an endocrine gland that produces hormones and regulates iodine in the body, is important to bone health. Its hormones are used in skeletal development and the balance of bone resorption and remodeling.
When your thyroid isn’t working as it should, it can create a chain reaction that ultimately disrupts bone tissue function.
Not everyone living with thyroid dysfunction develops osteoporosis, however, and the exact way these conditions are connected is still unclear.
Overactive thyroid (hyperthyroidism)
Hyperthyroidism occurs when your thyroid produces excess thyroid hormones (T3 or T4 hormones or both). Overt hyperthyroidism, the severe form of hyperthyroidism, is the presence of low T3, T4, or both as well as low levels of thyroid-stimulating hormone (TSH).
Overt hyperthyroidism affects your bones by causing a shortened bone remodeling cycle, which leads to higher bone turnover and calcium loss.
Subclinical hyperthyroidism, defined as normal-range T3 and T4 but abnormal TSH, often lacks obvious symptoms and is considered a milder type of hyperthyroidism. Its relationship to osteoporosis is less clear than in the overt type, but
Underactive thyroid (hypothyroidism)
Having high levels of TSH and low levels of T3 and T4 is known as overt hypothyroidism.
Its relationship to osteoporosis is contentious. Some evidence indicates it’s a condition linked to reduced bone turnover but not reduced bone density, while other data indicates bone density is affected.
Authors of a 2020 research review suggest hypothyroidism should be included as an osteoporosis risk factor because most studies show that out-of-range TSH does compromise bone density.
The same cannot be said for subclinical hypothyroidism, or the milder version of hypothyroidism with normal T4 levels. The review’s authors note that recent data doesn’t support a link between subclinical hypothyroidism and osteoporosis risk.
When should I get a bone density scan?
Bone density scans measure your bone mineral concentrations along certain points on the body in order to gain an overall idea of your bone health.
Dual-energy X-ray absorptiometry (DXA) is the
Bone density scans are generally recommended for female adults over age 65 and male adults over age 70. Intersex individuals and transgender people using HRT should check in with their doctor at age 65 to discuss the best schedule for their routine scans.
You may benefit from a bone density scan if you:
The relationship between your thyroid function and bone health is complex. It involves not just your thyroid, but the hypothalamic-pituitary-thyroid (HPT) axis, a circular process made up of three self-regulating body functions.
While thyroid hormones T3 and T4 are specifically indicated in bone functions, they are regulated by TSH from the pituitary gland, which is stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus.
TSH, T3, and T4 may all influence bone structure and formation.
TSH also stimulates T3 and T4, thyroid hormones that play their own role in bone health.
T3 and T4 are metabolized in skeletal cells. They are part of a cascade of biological processes essential for skeletal development, proper bone tissue function, and your linear bone growth and maturity from childhood.
When any part of the HPT axis goes awry, the delicate hormone balance that helps ensure your bones remain strong can be disrupted.
If you’ve received a thyroid condition and osteoporosis diagnosis, both conditions can be treated at the same time.
Treating thyroid conditions may be beneficial to bone health, but
Hyperthyroidism and hypothyroidism are indications of how your thyroid is working. They can have many different underlying causes that influence your treatment plan. Causes range from:
In hyperthyroidism and hypothyroidism, thyroid medication is often the first step in regulating your hormones before they cause body-wide complications.
Medication is also the first-line treatment for osteoporosis. This includes medications that directly work to preserve bone density and strength, like bisphosphonates and sclerostin inhibitors, as well as medications to regulate hormones like estrogen when osteoporosis is linked to menopause.
Other treatments for osteoporosis include lifestyle changes, physical activity, and dietary management.
Overall, treating osteoporosis and thyroid dysfunction comes down to your circumstances. Not all medications used to treat these conditions should be used for everyone or in every co-occurring diagnosis. Talk with your doctor to determine the best course of treatment for you.
Osteoporosis and thyroid dysfunction can go hand in hand due to how important thyroid hormones are for bone development and longevity.
Not everyone living with a thyroid condition will experience complications with bone health, however, and some forms of thyroid dysfunction aren’t yet linked to bone changes.
You can treat both osteoporosis and thyroid conditions at the same time, but treating your thyroid doesn’t guarantee an improvement in bone health. Some hypothyroid medications may even contribute to bone density loss. Your doctor can talk you through the pros and cons of each treatment before you start.