However, later in adulthood, both in vivo and ex vivo islet insulin secretion were suppressed with concomitant impaired glucose tolerance in the GDM offspring, suggesting beta-cell exhaustion from early beta-cell hyperplasia and function (Bihoreau et al. 1986b, Aerts et al. 1988, Gauguier et al. 1991). This evidence concerns the gene INS and Impaired glucose tolerance.