From the Guidelines
A higher than normal TSH in a 70-year-old likely indicates hypothyroidism, which should be treated with levothyroxine (synthetic thyroid hormone) if the TSH level is above 10.0 mIU/L, as this is generally considered the threshold for initiation of treatment 1.
Treatment Considerations
When treating hypothyroidism in elderly patients, it's essential to consider the potential risks and benefits. The typical starting dose for elderly patients is lower than for younger adults, usually 25-50 mcg daily, taken in the morning on an empty stomach 30-60 minutes before breakfast. The dose may need adjustment based on follow-up TSH tests, which should be performed every 6-8 weeks until levels normalize, then annually thereafter.
Monitoring and Adjustments
Treatment aims to normalize TSH levels, typically to a target of 1-4 mIU/L for most elderly patients, though a slightly higher target (4-6 mIU/L) may be appropriate for the very elderly or those with cardiac conditions. Overtreatment can cause cardiac arrhythmias or osteoporosis, so careful monitoring is essential. Certain medications can interfere with levothyroxine absorption, including calcium supplements, iron, and antacids, so these should be taken at least 4 hours apart from thyroid medication.
Key Points to Consider
- The decision to start therapy in patients with TSH levels between 4.5 and 10.0 mIU/L is more controversial, and careful consideration of the individual patient's risk factors and symptoms is necessary 1.
- Subclinical hypothyroidism is associated with poor obstetric outcomes and poor cognitive development in children, but evidence for dyslipidemia, atherosclerosis, and decreased quality of life in adults with subclinical hypothyroidism is inconsistent and less convincing 1.
- Clinicians should be aware of subtle signs of thyroid dysfunction, particularly among those at high risk, including the elderly, postpartum women, those with high levels of radiation exposure, and patients with Down syndrome 1.
From the Research
Higher than Normal TSH in 70-Year-Olds
- A higher than normal Thyroid-Stimulating Hormone (TSH) level in a 70-year-old may indicate hypothyroidism, a common disorder characterized by inadequate thyroid hormone secretion 2, 3.
- The symptoms of hypothyroidism can range from minimal to life-threatening and include cold intolerance, fatigue, weight gain, dry skin, constipation, and voice changes 2.
- The diagnosis of hypothyroidism is based on blood levels of TSH and free thyroxine, and treatment typically involves levothyroxine replacement therapy 2, 3.
- For patients over 60 years old, levothyroxine therapy should be started at a lower dosage (12.5 to 50 mcg per day) to avoid adverse effects such as osteoporotic fractures and atrial fibrillation 2, 3.
- The decision to treat subclinical hypothyroidism (elevated TSH with normal free T4 levels) should be based on the patient's symptoms and TSH level, with treatment generally recommended only if the TSH level exceeds 10 mIU/L 3, 4.
- TSH goals are age-dependent, with a higher upper limit of normal for older patients (7.5 mIU/L for patients over 80 years old) 4.
- Regular assessment of TSH levels and symptom relief is necessary to adjust levothyroxine dosage and ensure optimal treatment 2, 5.