INTRODUCTION
Gestational diabetes mellitus (GDM) is the most common pregnancy
complication which impacts at least 14% of pregnancies globally
[1–3]. GDM is a form of diabetes that occurs in pregnancy and
although usually subsides following delivery it can have lasting
implications for mother and child [4, 5]. GDM is associated with an
increased risk of pregnancy complications such as macrosomia, caesarean
sections, and a higher risk of developing type 2 diabetes and
cardiovascular disease in the future compared to women with pregnancies
without GDM [6–8]. Given the increased risk for complications such
as macrosomia with increasing postprandial glucose concentrations
[9], therapies that aim to specifically address postprandial
hyperglycaemic excursions could play a vital role in the frontline
treatment of GDM.
Postmeal walking, or walking after three main meals, has been proposed
as a potential strategy to target postprandial hyperglycaemia in
populations with diabetes [10–15]. Postmeal walking has been shown
to reduce hyperglycaemia in people with type 2 diabetes and women at
risk of GDM [12, 13, 16, 17], however the available research on
women with GDM have presented varied responses [10, 11, 18]. Here,
one bout of postprandial walking [18] or three bouts of postmeal
walking [10] lowers postprandial glucose compared to sitting.
Whereas, compared to usual care (i.e., not sitting, in a free-living non
laboratory environments) three 10-min postmeal bouts were similar to
30-min of continuous walking for glycaemic control [11]. Given the
need for more therapeutic options that are translatable and effective
for the management of GDM a longer-term intervention from diagnosis to
delivery, in a free-living environment, that compares postmeal walking
against the current standard care from diagnosis through to delivery is
warranted.
During pregnancy, women are recommended to perform at least 150 minutes
of moderate physical activity per week [19], however, only one in
six women meet these recommendations [20]. Barriers to physical
activity include lack of motivation, tiredness, pregnancy-related
symptoms, and a lack of education regarding the guidelines [21].
Breaking up activity into shorter bouts is one strategy to reduce
barriers of fatigue and lack of time. In addition, accumulating activity
in three short bouts has shown similar health benefits for fitness,
blood pressure, lipids, insulin and glucose, to one continuous bout in a
systematic review and meta-analysis of 19 studies involving over 1000
community dwelling adults [22]. Therefore, a strategy to encourage
women to overcome barriers to physical activity is necessary to ensure
women with GDM are able to reach their standard-care guidelines.
In a randomised controlled trial, we examined the effect of a 7-week
intervention of three daily 10-minute bouts of postprandial walking
compared to standard-care guidelines on postprandial hyperglycaemia,
fasting blood glucose, mean 24-h blood glucose, physical activity, and
sedentary time. It was hypothesised that 10 minutes of postprandial
walking three times daily would improve postprandial hyperglycaemia,
fasting blood glucose, mean 24-h blood glucose, physical activity, and
sedentary time in women with GDM compared to control standard guidelines
which include recommendations to perform 30 minutes of continuous
physical activity on most days.