Dietary, physical activity counselling does not confer benefits for gestational diabetes
A lifestyle intervention combining dietary and physical activity counselling initiated during early pregnancy does not appear to effectively improve dietary intake, physical activity, or obstetric and perinatal outcomes in pregnant women at high risk of gestational diabetes mellitus (GDM), according to data from the RADIEL trial.
RADIEL randomized 492 women with obesity and/or prior GDM to undergo four sessions of lifestyle counseling (n=249) or usual care (controls; n=243) before 20 weeks’ gestation. Overall, 470 women completed the study and were included in the final analysis.
A total of 167 women (35.5 percent) had prior GDM treated with diet (dGDM), 25 (5.3 percent) had prior GDM treated with medication (mGDM), and 278 (59.2 percent) were either nulliparous or had no history of GDM, with obesity being the only criteria for inclusion. In the group of women with prior GDM, 38.5 percent were obese.
Lifestyle indicators, gestational weight gain, or obstetric and perinatal outcomes did not differ between the lifestyle intervention and control groups.
Results of oral glucose tolerance test in the first half of pregnancy showed that incident early GDM occurred in 87 women who underwent lifestyle counselling and in 72 who received usual care (37.7 percent vs 36.5 percent; p=0.81). The total incidence of GDM diagnosed in the first or second half of pregnancy was 44.8 percent and 48.1 percent (p=0.48), respectively.
Total energy intake between baseline and the third-trimester visit increased by 231 kJ/day in the intervention group and by 104 kJ/day in the control group (p=0.56). Intakes (percent of total energy intake) of fat, protein, carbohydrate or dietary fibre did not significantly differ between the two groups.
Finally, median weekly leisure-time physical activity from the baseline to the third-trimester visit decreased by 15 minutes in the intervention group vs 22 minutes in the control group (p=0.65). In the third trimester, only 15.3 percent and 13.7 percent of women in the respective groups met the physical activity goal of ≥150 minutes/week (p=0.53).
Researchers postulated that the intensity of the given intervention in the RADIEL trial (maximum of four study visits, including a group session with a dietitian) was probably not high enough to yield extra benefits, considering the high standard of usual care (ie, recommendations on diet and physical activity for all women and treatment for women with both early and later GDM).