A: Schematic diagram of mechanism for protection from diabetes tested under question 2. Curved line is hyperbolic relationship
between insulin output and SI at baseline. Arrow no. 1 represents an intervention-induced increase in SI. Arrow no. 2 represents a reciprocal reduction in total insulin output, as seen in a previous short-term study of women with
recent GDM (11). B: SI and total insulin output (IVGTT insulin area) at baseline in each of 73 troglitazone-treated women who increased SI into the protective range after 3 months on trial. •, women destined to have a small decrease in IVGTT insulin area 3 months
after randomization (i.e., women in tertiles 1 and 2 for change in insulin area, Table 3). ○, women destined to have a large decrease in insulin area (women in tertile 3 for change in insulin area). ——, hyperbola
y = k/x, where “k” is the mean of the products of SI and insulin area for each of the 73 women (11,18,19). ——, 95% CIs. C and D: Means of SI and IVGTT insulin area at baseline and 3 months later in each of the two subgroups.