Aerobic Exercise in Women With Gestational Diabetes (GDM-FIT)

A few, small randomized controlled trials have investigated the effects of exercise on blood glucose levels in women with gestational diabetes (GDM), with inconsistent results. To assess the effects of supervised exercise in women with GDM, 48 women with gestational diabetes, diagnosed between the 18th and 28th week of gestation, will be recruited, after exclusion of subjects with contraindications to exercise. These subjects will be randomly assigned to two groups: structured exercise intervention or standard care. Women in the intervention group will perform low intensity aerobic exercise three times per week at 30% HRR (heart rate reserve), under continuous heart rate monitoring. Duration of each session will progress from 26 minutes the first week to 40 minutes (increasing 2 min/week). Women in the control group will receive standard diet and physical exercise recommendations. In all women, clinical, metabolic and anthropometric features will be assessed before, during and at the end of the study. Newborn data will also be collected.

Women in the intervention group will perform low intensity aerobic exercise three times per week at 30% HRR (Heart Rate Reserve), under continuous heart rate monitoring. Duration of each session will progress from 26 minutes the first week to 40 minutes (by increasing 2 min/week).

Throughout the intervention period, an average of 3-5 months according to the gestational week of inclusion in the study

A non-invasive assessment of arterial stiffness (in the carotid-radial and carotid-femoral parts of the arterial tree) by the technique of applanation tonometry

A continuous glucose monitoring system (CGMS) will be applied at 32-34 week of gestation, and blood glucose will be recorded every 5 min over the following five days. Glucose concentrations during the 40-min exercise session, the subsequent night, and the 24-h period following exercise, as well as during the corresponding periods of a non-exercise day will be recorded, and glucose variability and time spent in hypoglycemia or hyperglycemia will be calculated

Inclusion Criteria: Singleton pregnancy, Gestational diabetes diagnosis between 18th and 28th week of gestation, Caucasian. Exclusion Criteria: Hemodynamically significant heart disease, Restricted lung disease, Incompetent cervix/cerclage, Persistent second or third trimester bleeding, Placenta previa, Threatened preterm labor, Ruptured membranes, Preeclampsia, Hypertension, Severe anemia, Cardiac arrhythmias, History of epilepsy, Chronic bronchitis, Orthopedic limitations, Overt hyperthyroidism/ hypothyroidism, Type 1 diabetes mellitus, Drugs that interfere with metabolic control (such as cortisone)

Endocrinology, Diabetes and Metabolism Section, Department of Medicine, University of Verona and Azienda Ospedaliera Universitaria Integrata of Verona