In adults ≥80 years with TSH 6–10 mIU/L and minimal symptoms, do you initiate levothyroxine, monitor, or avoid treatment entirely?

I tend to check free T4 in this situation. Aging is associated with some elevation in TSH value up to 10 mIU/L with normal free T4, and in those patients, levothyroxine is not needed. In some patients, I have seen it rise above 10 with normal free T4. Supplementing levothyroxine to lower serum TSH would increase free T4 and the risk of atrial fibrillation and osteoporosis.

As always, we do want to provide an individualized approch. Based on the extent of frailty and severity of symptoms, I do offer watchful waiting as an option during the shared decision conversation. TRUST (Thyroid Hormone Replacement for Untreated Older Adults with Subclinical Hypothyroidism) trial has shown no significant improvement in hypothyroid or fatigue symptoms in older adults treated with levothyroxine compared to placebo. This suggests that the non-specific symptoms often present in this age group, such as fatigue and weakness, are more likely related to multiple comorbidities, not just hypothyroidism. While subclinical hypothyroidism is associated with increased cardiovascular mortality in individuals under 65, this risk does not...