We therefore hypothesized that longer cumulative duration of lactation among women with past GDM is associated with healthier levels of cardiometabolic biomarkers (including measures of glucose/insulin metabolism, fasting lipids, inflammation, and anthropometrics), as well as with lower risk of clinical metabolic outcomes (including hypertriglyceridemia, prediabetes, T2D, and obesity). This evidence concerns the gene INS and prediabetes syndrome.