Fig 1. Hypothesized disease progression.

Time course of parameters indicative of peripheral insulin sensitivity, hepatic insulin sensitivity and insulin secretory ability over the lifetime of a representative DPP study subject, as determined by genetic factors, alimentary habits and other life conditions. Black refers to the natural course of the disease, blue to intervention with Placebo, green to intervention with Intensive Life-Style modification, red to intervention with Metformin. In panel (a) the Metformin curve is identical with Placebo; the four forecasts are identical for insulin secretory ability in panel (c).