Lancet Sub-Journal: This common thyroid problem, the vast majority of elderly people do not need immediate treatment!

▎ WuXi AppTec content team editor

Subclinical hypothyroidism (hypothyroidism) is one of the most common endocrine disorders in the clinic, manifested by a significant increase in serum thyrotropin levels (usually ≥ 4.5 mIU/L) and normal free thyroxine levels.

Methylenexia is more common in the elderly population, and its main harm is the development of clinical hypothyroidism and the increase in blood lipids, leading to atherosclerosis and coronary heart disease. Current international guidelines have different recommendations for the treatment of hypothyroidism in the elderly population. Recently, The Lancet Diabetes & Endocrinology published a review that comprehensively summarized important data from clinical studies conducted in patients over the age of 65 with hypothyroidism over the past decade.

The results of the analysis showed that the incidence of cardiovascular, musculoskeletal, and cognitively impaired prognostic events in older patients with serum thyrotropin levels of 4.5 to 7.0 mIU/L was not significantly increased compared with the control group with normal thyroid function. In addition, studies suggest that when thyrotropin levels are below 7.0 mIU/L (clinically accounting for about 75%), older patients may not need to start levothyroxine treatment immediately, and the dose of levothyroxine should also be individualized according to the patient's age, comorbidities, etc.

Screenshot source: The Lancet Diabetes & Endocrinology

The pathogenesis of hypothyroidism is complex and can usually be caused by structural abnormalities in the thyroid gland itself or outside the thyroid gland. Serum thyrotropin levels are a key indicator of the diagnosis of methyroidism, with clinical levels of 4.5 to 6.9 mIU/L in about 75% of patients with hypothyroidism, 7.0 to 9.9 mIU/L in 20%, and 10 mIU/L and above in 5% of patients. Levothyroxine is one of the most important drugs used to treat methylene.

It should be noted that there is currently a lack of uniform standards for the treatment of methylene methoxide in different guidelines. In addition, some elevated thyrotropin levels also return to normal without intervention, and thyrotropin levels in healthy older adults can also rise spontaneously under normal circumstances. Therefore, it is likely that there is a case of overtreatment with levothyroxine in elderly patients clinically.

Based on authoritative published data from the past 10 years (January 1, 2010 to July 31, 2021), including meta-analyses, randomized clinical trials, and cohort studies, the researchers assessed the benefits and safety of drug therapy in elderly patients with methyroidosis (65 years and older) with different thyrotropin levels.

The results of the analysis suggest that the symptoms of thyroxine deficiency are usually not obvious in most elderly patients with methyroidism, and that the symptoms associated with hypothyroidism and cardiovascular/bone-related indicators in elderly patients with methyroidism are not improved after levothyroxine therapy.

Thyrotropin level: 4.5 to 6.9 mIU/L

In older patients (65 years and older) with thyrotropin levels of 4.5 to 6.9 mIU/L, thyrotropin levels were not associated with mood/cognitive alteration, weakness, and bone loss/fracture. After levothyroxine treatment, the risk of cardiovascular, musculoskeletal, and cognitive-related adverse events in these patients did not improve significantly. The results of observational studies and randomized controlled trials only support effective monitoring of this subset of patients first, rather than immediate initiation of treatment.

Thyrotropin level: 7.0 to 9.9 mIU/L

For elderly patients with thyrotropin levels of 7.0 to 9.9 mIU/L: elderly patients aged 65 to 84 years, whose hypothyroidism status is associated with an increased risk of cardiovascular events (coronary heart disease, stroke), these patients can consider drug therapy, but need to avoid overtreatment; for elderly patients aged ≥ 80 years, there is no significant association between the hypothyroidism status and poor prognosis at the same level of thyrotropin, and the clinical caution can be selected "Wait-and-see (waiting to see)" In addition, some studies suggest that hypothyroidism can even provide some survival benefit for older patients aged 85 years and older.

Thyrotropin level: 10.0 to 19.9 mIU/L

In older patients (65 years and older) with thyrotropin levels of 10.0 to 19.9 mIU/L, their hypothyroidism is also associated with an increased risk of cardiovascular events (heart failure, coronary heart disease) and may be considered for pharmacotherapy, although continuous evaluation based on patient follow-up results is required to avoid overtreatment.

▲ Elderly patients are recommended for treatment based on different thyrotropin levels (Image source: Reference [1])

The goal of hypothyroidism is primarily to prevent the progression of Methylene methia to clinical hypothyroidism, in addition to alleviating symptoms associated with hypothyroidism or preventing the occurrence of associated adverse events. The current paper confirms that older patients with hypothyroidism may be overdiagnosed and overtreated, while increased risk of drug interactions and adverse events with medications may lead to higher health care spending.

The researchers believe that elderly patients aged 65 years and older should only be considered for levothyroxine if thyrotropin levels are consistently above 7 mIU/L, and if it is below 7 mIU/L, immediate treatment may not be considered. Older patients are most susceptible to overtreatment, so levothyroxine therapy in older patients with methylene depletion should be more individualized.