These researchers investigated the progression to type 2 diabetes among Māori women with previous gestational diabetes mellitus (GDM). The study recruited 2786 Māori women aged 28–86 years without previously diagnosed diabetes between 2004 and 2006 and residing permanently in the Waikato and Southern Lakes areas. All were invited to participate in an oral glucose tolerance test. Fifty (1.8%) women reported previous GDM. The prevalence decreased significantly with age (p=0.009). Women aged <50 years with previous GDM had higher body mass index (mean, 35.6 kg/m2 vs 32.4 kg/m2; p<0.01), waist circumference (mean, 105.3 cm vs 96.9 cm; p<0.01), fasting blood glucose (mean, 5.5 mmol/L vs 5.1 mmol/L; p≤0.01), 2-hour post-prandial blood glucose (mean, 6.6 mmol/L vs 5.6 mmol/L; p<0.01) and HbA1c (mean, 6.0% vs 5.8%; p<0.05) than women without previous GDM. In analyses standardised for age, previous GDM (age <70 years, above which no women had prior GDM) was a significant risk factor for newly detected diabetes (OR 4.0; 95% CI, 1.67 to 9.71). Women aged <40 years with prior GDM were significantly more likely to have undiagnosed diabetes than women without previous GDM (20.0% vs 1.5%; p<0.001).
