AimsPrevious gestational diabetes mellitus (GDM) entails increased risk of future diabetes. We describe the characteristics of women with previous GDM and compare with no previous GDM from the cohort Diabetes in Kalmar and Kronoberg (DKK) of 1248 adults, 40% women, with new diabetes, and factors affecting age and C-peptide levels at diagnosis of diabetes.MethodsAge-at-diagnosis of diabetes, BMI, hypertension, hyperlipidemia, smoking, physical activity, and pre-existing myocardial infarction, stroke, or peripheral arterial insufficiency were registered at ordinary care visits close to diagnosis of diabetes, for the 43 women (9.4% of 456 from DKK with complete data for this analysis) with self-reported previous GDM (yes/no) and 86 controls without it, matched for date of diagnosis of diabetes. Blood samples were centrally analyzed for GADA and C-peptide for classification of diabetes.ResultsWomen with previous GDM had lower mean age-at-diagnosis of diabetes, 53.4 vs 65.0 years, lower systolic blood pressure (SBP), 131.2 vs 137.5 mmHg, and fewer had pre-existing hypertension than without previous GDM (p < 0.001-0.05). Among antibody negative women with previous GDM, BMI (p = 0.024), hypertension (p = 0.023) and hyperlipidemia (p < 0.001) were associated with higher levels of C-peptide, while physical activity was inversely associated (p = 0.035), and SBP (p = 0.02) and hypertension (p = 0.016) were associated with age-at-diagnosis of diabetes.ConclusionsWomen with previous GDM were a decade younger and had lower prevalence of hypertension at diagnosis of diabetes; C-peptide levels were associated with BMI, hypertension, and hyperlipidemia and showed a tendency to be lower, possibly indicating a phenotype with higher risk of overt cardiovascular disease later in life.