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 possibly 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.
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
“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.
How can healthcare providers assess the need for levothyroxine therapy in elderly patients?
Interview: Exploring the Impacts of Levothyroxine in Older adults
Editor (Time.news): Thank you for joining us today, Dr. Elena Ghotbi. As the lead author of a recent study presented at the Radiological Society of North America meeting, you’ve brought crucial insights to the table regarding levothyroxine, particularly in older adults. Can we start with a brief overview? What prompted the focus on levothyroxine and its effects on bone health?
Dr. Elena Ghotbi: thank you for having me. Levothyroxine is a synthetic version of thyroxine, or T4, and it’s one of the most commonly prescribed medications for older adults in the United States, especially for managing hypothyroidism. The growing population of elderly patients taking this medication, combined with emerging evidence of potential side effects like increased bone loss, warranted a more in-depth examination.
Editor: That’s quite a meaningful concern.For our readers unfamiliar with hypothyroidism,could you explain how this condition affects the body and why levothyroxine is prescribed?
Dr. Ghotbi: Certainly! Hypothyroidism occurs when the thyroid gland does not produce enough thyroxine. this can lead to various symptoms such as fatigue, weight gain, and hair loss.If untreated, it can result in serious health complications. Levothyroxine aims to replace the missing hormone, helping to alleviate these symptoms and restore hormone levels to normal.
editor: You mentioned that around 23 million Americans are on levothyroxine. That’s an astounding number. How do you assess the accuracy of the prescriptions given, especially for older adults who may not have a current need for this medication?
Dr. Ghotbi: Yes, the statistics are concerning. Our data indicate that a significant number of older adults might be receiving these prescriptions without having hypothyroidism. This raises the question of whether lifelong treatment is appropriate for everyone, particularly if they are experiencing wellness and normal thyroid-stimulating hormone (TSH) levels. Regular monitoring and re-evaluation of the need for levothyroxine are critical.
editor: So, what did your research find regarding the relationship between levothyroxine and bone health in this demographic?
Dr. Ghotbi: Our findings highlight that even when TSH levels are normal, levothyroxine use may still lead to increased bone loss in older adults. It underscores the importance of individualized treatment plans. Each patient’s situation should be carefully balanced between the benefits of managing hypothyroidism and the potential risks, such as osteoporosis.
Editor: This certainly calls for more attention on the management of thyroid conditions in older adults. what recommendations can you provide to healthcare providers based on your study?
Dr. Ghotbi: Regular monitoring of patients on levothyroxine, especially older adults, is crucial. Healthcare providers should periodically reassess the necessity of ongoing therapy and bone health.Collaborating with patients about the potential risks while ensuring they understand the importance of thyroid health is also key to effective treatment.
Editor: Thank you for those valuable insights, Dr. Ghotbi. Before we conclude, are there any final thoughts you would like to share with our readers?
Dr. Ghotbi: Yes, I encourage anyone taking levothyroxine, especially older adults, to have open discussions with their healthcare providers about their treatment plan. Being informed can help ensure that they are receiving the most appropriate care for their health needs. It’s critically important to remember that treatment should always be personalized and closely monitored.
Editor: Thank you so much for your time and expertise,Dr. Ghotbi. This is an essential conversation for many families and healthcare providers alike.
Dr. Ghotbi: Thank you for the possibility to discuss this pressing issue. it’s my hope that we can improve the safety and effectiveness of thyroid treatments for older adults.