Effect of Physical Activity and/or Healthy Eating on GDM Risk: The DALI Lifestyle Study.

CONTEXT: Lifestyle approaches for preventing gestational diabetes mellitus (GDM) have produced mixed results.

OBJECTIVE

The aim of the present study was to compare the effectiveness of 3 lifestyle interventions [healthy eating (HE), physical activity (PA), and both HE and PA (HE+PA)] with usual care (UC) in reducing GDM risk.

DESIGN

The present study was a multicenter randomized controlled trial conducted from 2012 to 2014 [the DALI (vitamin D and lifestyle intervention for GDM prevention) lifestyle study].

SETTING

The study occurred at antenatal clinics across 11 centers in 9 European countries.

PATIENTS: Consecutive pregnant women at <20 weeks of gestation with a body mass index (BMI) of ≥29 kg/m2 and without GDM using the International Association of Diabetes and Pregnancy Study Group criteria (n = 436). For the intervention, women were randomized, stratified by site, to UC, HE, PA, or HE+PA. The women received 5 face-to-face and ≤4 telephone coaching sessions using the principles of motivational interviewing. A gestational weight gain (GWG) <5 kg was targeted. The coaches received standardized training and an intervention toolkit tailored to their culture and language.

MAIN OUTCOME MEASURES: The endpoints were the GWG at 35 to 37 weeks and the fasting glucose and insulin sensitivity [homeostasis model assessment insulin resistance (HOMA-IR)] at 24 to 28 weeks.

RESULTS

We randomized 108 women to HE+PA, 113 to HE, 110 to PA, and 105 to UC. In the HE+PA group, but not HE or PA alone, women achieved substantially less GWG than did the controls (UC) by 35 to 37 weeks (-2.02; 95% confidence interval, -3.58 to -0.46 kg). Despite this reduction, no improvements were seen in fasting or postload glucose levels, insulin concentrations, or HOMA-IR. The birthweights and large and small for gestational age rates were similar.

CONCLUSIONS

The combined HE+PA intervention was able to limit GWG but did not reduce fasting glycemia. Thus, lifestyle changes alone are unlikely to prevent GDM among women with a BMI of ≥29 kg/m2.