The study looked at how thyroid levels and fasting affect the production of a protein called apoA-I in the liver. They found that being hyperthyroid increased the production of apoA-I, while being hypothyroid decreased it. However, over time, the increased production in hyperthyroid rats normalized. Fasting did not seem to have an effect on apoA-I production. This suggests that the liver can control the production of apoA-I independently of other proteins, and that thyroid levels play a role in regulating this process.