In middle-aged adults with TSH 5–10 mIU/L and no symptoms, would you start levothyroxine or monitor, and does your threshold change with cardiovascular risk factors?  

In a middle-aged patient with a TSH between 5-10 and no symptoms, I would initially monitor their thyroid levels. I would consider checking a TPO antibody titer; if positive, the rate of transition to overt hypothyroidism is greater. I would also screen for other medical issues that could be impacte...