Stress can affect people with Type 2 Diabetes by raising stress-associated cortisol levels that stimulate greater production of blood sugar (glucose). Aerobic exercise can improve health in persons with diabetes by improving insulin sensitivity, lowering glycated hemoglobin (HbA1c) levels, and promoting cardiovascular fitness. Intentional slow breathing and mindfulness meditation may offer additional benefit to persons with diabetes by reducing stress-related cortisol levels that show an association with glucose levels. 

Obaya et al. [Frontiers of Physiology] conducted a study to compare the effects of aerobics exercise alone versus aerobics exercise combined with intentional slow breathing and mindfulness meditation on cortisol and glucose levels in women with Type 2 Diabetes.

The researchers randomly assigned 58 Middle-Eastern women (average age = 46 years) to either an aerobics training group (AT) or an aerobics training group that also included slow, deep breathing and mindfulness meditation (AT+DMM). All participants met the following criteria: 1) diagnosed with Type 2 Diabetes, 2) experiencing moderate-to-high stress levels, and 3) engaging in low levels of physical activity. Both groups met for three sessions per week for six weeks with sessions lasting 40 minutes for the AT group and 60 minutes for the AT+DMM group. 

Aerobics training involved using a treadmill at an intensity of 60-75% of each participant’s maximum heart rate. Following aerobics training, the AT+DMM group added 10 minutes of slow and deep abdominal breathing, followed by 10 minutes of mindfulness meditation.

During mindfulness practice, participants sat upright while attending to their breath and listening to relaxing music. Blood draws were collected at pre- and post-intervention at 8:00AM to quantify serum cortisol and fasting blood glucose.

The results revealed that both study groups significantly reduced their blood serum cortisol and fasting blood glucose after the intervention. The AT+DMM group had significantly larger decreases in blood serum cortisol (d=0.69) and fasting blood glucose (d=0.94) than the AT group, achieving a 30% decrease in serum cortisol and a 15% reduction in fasting blood glucose compared to baseline levels.

The study shows that intentional slow breathing and mindfulness meditation adds to the benefits of aerobic exercise in reducing cortisol and glucose levels in a sample of stressed women with Type 2 Diabetes. These findings suggests that slow breathing and breath-focused meditation may be a useful adjunctive treatment in managing high blood sugar when combined with exercise for people experiencing heightened levels of stress.

The study is limited by its not exploring the differential effects of slow breathing and meditation and by the brief duration of the intervention which prevented it from yielding interpretable change in HbA1c given that HbA1c provides a measure of the average blood sugar level over the preceding three months.

Reference:

Obaya, H. E., Abdeen, H. A., Salem, A. A., Shehata, M. A., Aldhahi, M. I., Muka, T., Marques-Sule, E., Taha, M. M., Gaber, M., & Atef, H. (2023). Effect of aerobic exercise, slow deep breathing and mindfulness meditation on cortisol and glucose levels in women with type 2 diabetes mellitus: A randomized controlled trial. Frontiers in Physiology. 

Link to study