Levothyroxine use in older adults may increase bone loss even with normal TSH levels, highlighting the need for regular monitoring and individualized treatment to balance benefits and risks.
Levothyroxine, the second most frequently prescribed medication for older adults in the U.S., might be linked to bone loss, according to findings presented at the recent annual meeting of the Radiological Society of North America (RSNA).
Levothyroxine, marketed under multiple brand names including Synthroid, is a synthetic version of a hormone called thyroxine and is commonly prescribed to treat the condition hypothyroidism, or underactive thyroid. In people with hypothyroidism, the thyroid gland does not produce enough thyroxine on its own, often resulting in fatigue, weight gain, hair loss, and other symptoms. If left untreated, hypothyroidism can lead to serious and potentially fatal complications.
Approximately 23 million Americans—about 7% of the U.S. population—take levothyroxine daily. Sometimes, patients have been taking levothyroxine for many years, but it is not clear why it was initially prescribed or if it is still required.
“Data indicates that a significant proportion of thyroid hormone prescriptions may be given to older adults without hypothyroidism, raising concerns about subsequent relative excess of thyroid hormone even when treatment is targeted to reference range goals,” said the study’s lead author Elena Ghotbi, M.D., postdoctoral research fellow at Johns Hopkins University School of Medicine in Baltimore, Maryland.
Though there are some variables, a normal reference range for thyroid-stimulating hormone (TSH) is typically around 0.4 – 5.0 microunits per milliliter. Excess thyroid hormone has been associated with increased bone fracture risk.
Study Details and Methods
For this study—a multidisciplinary collaboration between the Russell H. Morgan Department of Radiology and Radiological Science and Endocrinology Department at Johns Hopkins Medical Institutions, Dr. Ghotbi and colleagues aimed to determine whether levothyroxine use and higher thyroid hormone levels within the reference range are associated with higher bone loss over time in older “euthyroid” adults, meaning adults with normal thyroid function.
The researchers used the Baltimore Longitudinal Study of Aging (BLSA), a prospective observational cohort study of community-dwelling older adults. Participants aged 65 and older who had at least two visits and thyroid function tests consistently within the reference ranges were included in Dr. Ghotbi’s study.
“This research is a collaboration between Johns Hopkins and the BLSA, the longest-running study on aging conducted by the Intramural Research Program of the National Institute on Aging,” said co-author Eleanor Simonsick, Ph.D., epidemiologist and BLSA co-director. “The BLSA’s extensive data include repeated DEXA measurements at each study visit, which provides valuable insight into the progression of bone density and bone mass changes over time, offering a more comprehensive understanding of aging-related osteoporosis.”
The study group included 81 euthyroid levothyroxine users (32 men, 49 women) and 364 non-users (148 men, 216 women), with a median age of 73 and TSH levels of 2.35 at the initial visit. Other risk factors like age, gender, height, weight, race, medications, smoking history and alcohol use were considered in propensity score matching of levothyroxine users versus non-users.
Findings: Levothyroxine and Bone Loss
The results showed that levothyroxine use was associated with greater loss of total body bone mass and bone density—even in participants whose TSH levels were within the normal range—over a median follow-up of 6.3 years. This remained true when taking into account baseline TSH and other risk factors.
“Our study suggests that even when following current guidelines, levothyroxine use appears to be associated with greater bone loss in older adults,” said Shadpour Demehri, M.D., co-senior author and professor of radiology at Johns Hopkins.
Jennifer Mammen, M.D., Ph.D., co-senior author and associate professor of endocrinology at Johns Hopkins, advises that adults taking levothyroxine should discuss their treatment with their health care provider and regularly monitor their thyroid function tests. “A risk-benefit assessment should be conducted, weighing the strength of the indications for treatment against the potential adverse effects of levothyroxine in this population,” she said.
Meeting: 110th Scientific Assembly and Annual Meeting of the Radiological Society of North America
Other co-authors are Hamsa Ibad, M.B.B.S., and Qian-Li Xue, Ph.D.
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6 Comments
So, even after years of testing and use, adverse side effects can still end up being detected for medical products. Yet they rushed those COVID vaccines out on the market on the shortest notice, with a bare minimum of testing…
They were tested concurrently not in the usual sequenced way. and their use saved millions of lives.
That’s some PR crap you just said. “Concurrent” means nothing. Every medicine needs to be tested for long-term side effects before being unleashed on the general public. And now we see the long-term side effects and someone should be held accountable for them.
And those vaccines didn’t save anybody. When it turned out that they didn’t even stop the spread, the powers that be sold them as “something that will alleviate the symptoms”. That’s not what vaccines are supposed to do. In the end there were more vaxxed than unvaxxed people hospitalized for covid, even though the vaccination in the population never even exceeded 50%.
You’d have to have a really short memory span not to know that.
Lol!!!!!!!¡
Correlation does not mean causation.
Before quitting your levothyroxine you might remember the problems caused by hypothyroidism.
Symptoms of an underactive thyroid, also known as hypothyroidism, include:
Fatigue: Feeling tired all the time
Sensitivity to cold: Feeling uncomfortable in cold temperatures
Weight gain: Unexplained weight gain
Constipation: Having difficulty passing stool
Dry skin: Skin that feels dry, coarse, or itchy
Puffy face: A puffy appearance around the eyes
Hoarse voice: A hoarse voice
Muscle aches and weakness: Feeling achy or weak in your muscles
Menstrual changes: Having heavier or irregular menstrual periods
Thinning hair: Losing hair from your scalp, eyebrows, legs, or other parts of your body
Slowed heart rate: Also known as bradycardia
Depression: Feeling depressed
Memory problems: Having difficulty concentrating or remembering things
Numbness or tingling: Feeling numbness or tingling in your hands
Drooping eyelids: Having drooping eyelids
Elevated cholesterol: Having high levels of cholesterol in your blood
And you can take medicine for osteoporosis that works. I have been on it for levothyroxine for 20 years and now at age 78 my latest bone density scan shows normal — but I also took fosamax for a few years along the way. And the thyroid replacement did immediately improve my life and continues to help.
And that’s what medicines should do – cause more good than harm. No medicine is perfect and never will be. But they should never be imposed nor denied and the recipient should always be well informed about potential harmful side effects, just like you are.