fruity........I have just had a thought.
50 or 60 yrs ago before modern thyroid tests (T3 T4 TSH) were available, people who were taking thyroxine for under active thyroid were monitored by taking their blood cholesterol levels (there was nothing else)
Now if someone who had normal thyroid function took thyroxine today ( perhaps for weight loss etc) then indeed that might give inaccurate cholesterol readings.