I agree with you that it is wonderful that younger CAH people have  been commenced and maintained on a better regime of corticosteroids, by virtue of smaller doses. That is a huge step.

However more subtly one problem I see is that although endogenous cortisol (that which is produced by the body naturally in a healthy person) is produced/secreted in the exact amounts needed at exactly the times needed this can never/rarely happen with exogenous steroid treatment. So herein lies a problem. 

Because of dosing times and because of varying and unpredicted events that happen throughout each day to every different person, there will be throughout the period of any day, times of undersuppression (undersupply) and times of oversuppression (oversupply). Multiply this by 365 days for each year and then year in and year out for a CAH patient...I think we can see the possibilities of what could happen.

Considering the catabolic effects of corticosteroids these repeated episodes of oversuppression (albeit small) theoretically could over time have deleterious effects on the individual to whom this has been happening. It is well known and well documented the negative effects of excessive endogenous cortisol production in a person with Cushing disease.  While this is an example of a dramatic oversupply of cortisol, once a cause is found and treatment implemented the levels often stabilize and the disease process is hopefully over. In the case of a person having ‘replacement corticosteroids for life’, although the times of oversupply may not be as dramatic as mentioned for Cushings, it is more subtle and long, long term.

There is not a lot of literature from the western medical genre exploring this possibility. There is on the other hand quite a lot of comment about the catabolic effects of therapeutic corticosteroids in alternative medical literature. So in theory, there is the possibility of catabolic effects happening every time that an oversupply occurs or a dose is given when the body does not need it. Scary thought! But what the heck, we just have to inbuild as healthy a lifestyle as we possibly can to help counteract some of these yucky possibilities. Fortunately there is more information around now to help us do this.