We've seen the Carr study about three or four times today, and I think there's some points in that article that need to come on the table for consideration.
First of all, TSH is not a blood pressure. Blood pressure is a surrogate endpoint for clinical effectiveness and blood pressure has been correlated with mortality and morbidity. TSH has not been correlated in any prospective study that I'm aware of with clinical symptomatology of thyroid disease.
If you look at the Carr paper very carefully, it's probably the lowest evidence of clinical studies that we would consider; that is to say, it's not a randomized, double-blind study. It's not even a randomized study. It's a case-control study and certainly that has merit, but it also has many limitations and weaknesses.
It's also an artificial study in that optimal doses were obtained after thyrotropin-releasing hormone injection. In other words, it was a simulated TSH response to an exogenous injection of TRH.
But as I read through that, there were a couple of points that the authors made that I thought were interesting. An optimal dose was determined for each