Stress Reduction Lowers Glucose Levels in Obese Women

Mindfulness-based stress reduction (MBSR) not only significantly reduces stress in overweight or obese women, it also lowers their blood glucose levels, according to a new study.¹

Mindfulness-based interventions have shown preliminary effects in lowering glucose levels and blood pressure in patients with diabetes. Researchers at Penn State College of Medicine in Hershey, PA, conducted a randomized clinical trial to evaluate the feasibility of MBSR in overweight or obese women and to determine the cardiometabolic effects of the intervention.

The study included 86 women with a body mass index of 25 kg/m² or higher who were randomized to 8 weeks of MBSR or health education. The participants were followed up for 16 weeks.

Women in the MBSR group demonstrated significantly improved mindfulness at 8 weeks and significantly decreased perceived stress at 16 weeks compared with those in the health education group. What’s more, the MBSR group had significant reductions in fasting glucose at 8 weeks (−8.9 mg/dL) and at 16 weeks (−9.3 mg/dL) compared with baseline. Fasting glucose levels did not significantly improve in the health education group.

The between-group difference in fasting glucose did not reach statistical significance, the researchers noted, possibly because the study was not powered to detect a difference in glucose. There were no significant changes in blood pressure, weight, or insulin resistance in the MBSR group.

“If, as our study suggests, MBSR lowers glucose in people with overweight or obesity, then it could be an effective tool for preventing or treating type 2 diabetes,” the researchers stated.

Why fasting glucose levels decreased in the MBSR group remains unclear, particularly with no changes in weight, cortisol levels, or insulin resistance. One possible explanation, the researchers suggested, is that increased mindfulness made it easier for women in the MBSR group to adhere to the diet and exercise guidelines they had received.

Other studies show mindfulness per se may improve metabolic parameters. One study of obese adults found no change in fasting glucose levels in a mindfulness plus a diet-exercise group in contrast to increased fasting glucose in a diet-exercise alone group. Another study of overweight or obese women found no differences in fasting glucose between a mindfulness group and a waitlist control group, but this may have been due to differences in the type or duration of the mindfulness intervention, and whether the mindfulness intervention included diet-exercise components, the researchers noted.

They suggested the hypothalamic-pituitary-adrenal axis, particularly cortisol levels, may be a potential mechanism to explain how MBSR reduces glucose. “It may be important to evaluate effects on more integrated measures of cortisol, such as 24-hour urine free cortisol,” the researchers stated.

Another potential mechanism is through the sympathetic nervous system. A previous study showed MBSR significantly reduced catecholamine levels at 1 year. Catecholamine was not measured in this study.

The researchers concluded: “Future studies are needed to determine whether a sustained increase in mindfulness with a longer mindfulness-based intervention would result in even greater and more long-term benefits.”

References:

1. Raja-Khan N, Agito K, Shah J, et al. Mindfulness-based stress reduction in women with overweight or obesity: a randomized clinical trial. Obesity. 2017;25:1349-1359