Background/objectives: Some studies document relationships of the incidence of gestational diabetes mellitus (GDM) with individual components of the diet, but studies exploring relationships with patterns of eating are lacking. This observational study aimed to explore a possible relationship between the incidence of GDM and the Mediterranean diet (MedDiet) pattern of eating.
Subjects/methods: In 10 Mediterranean countries, 1076 consecutive pregnant women underwent a 75-g OGTT at the 24th-32nd week of gestation, interpreted both by the ADA_2010 and the International Association of the Diabetes and Pregnancy Study Groups (IADPSG)_2012 criteria. The dietary habits were assessed by a previously validated questionnaire and a Mediterranean Diet Index (MDI) was computed, reflecting the degree of adherence to the MedDiet pattern of eating: a higher MDI denoting better adherence.
Results: After adjustment for age, BMI, diabetes in the family, weight gain and energy intake, subjects with GDM, by either criterion, had lower MDI (ADA_2010, 5.8 vs 6.3, P=0.028; IADPSG_2012, 5.9 vs 6.4, P<0.001). Moreover, the incidence of GDM was lower in subjects with better adherence to the MedDiet (higher tertile of MDI distribution), 8.0% vs 12.3%, OR=0.618, P=0.030 by ADA_2010 and 24.3% vs 32.8%, OR=0.655, P=0.004 by IADPSG_2012 criteria. In subjects without GDM, MDI was negatively correlated with both fasting plasma glucose and AUC glucose, P<0.001 for both.
Conclusions: Adherence to a MedDiet pattern of eating is associated with lower incidence of GDM and better degree of glucose tolerance, even in women without GDM. The possibility to use MedDiet for the prevention of GDM deserves further testing with intervention studies.