As this study has demonstrated, markers are simply not a valid way to determine effectiveness of a treatment. In type 2 diabetes, the problem isn't a lack of ability to produce insulin; neither is it high blood glucose. The problem is the cells' ability to utilize insulin to transport glucose from blood into cells.
The problem is that cells' ability to use insulin has deteriorated. So, how can it be beneficial to give more insulin when cells are unable to utilize what's already there? Clearly, that's counterproductive.
Yet, that's precisely what doctors do! They give insulin to replace insulin, when a lack of insulin isn't the problem! It should come as no surprise that the real concerns of anyone being treated for diabetes are not answered by insulin treatment.
There's one lesson to be learned here: Health isn't found in pharmaceutical drugs, not even old tried-and-true drugs.