Oxygen-induced impairment in arterial function is corrected by slow breathing in patients with type 1 diabetes - Bernardi et al. (2017)

Key Points

  • Slow breathing increased autonomic function, arterial function, and blood oxygen saturation in type 1 diabetic patients

  • Slow breathing stimulates the parasympathetic nervous system and suppresses the sympathetic nervous system, providing an antioxidant effect

  • “Slow breathing could be a simple beneficial intervention in diabetes.”

The Breathing Diabetic Summary

The last key point above, taken directly from the abstract, says it all. This paper was published in Nature, one of the most prestigious scientific journals around, and they are highlighting the usefulness of slow breathing for diabetes.  Pretty awesome.

The introduction points out many of the negative side effects of diabetes, such as enhanced risk for cardiovascular disease.  These negative side effects are associated with autonomic nervous system abnormalities commonly seen in many diabetics.  However, the authors have previously found that slow breathing can reverse some of these problems, suggesting that the autonomic issues might be reversible. 

For this study, they had participants perform 5 minutes of spontaneous breathing, followed by 2 minutes of slow breathing at 6 breaths per minute.  That is a very short amount of time yet, as we will see, they still got remarkable results. 

During spontaneous breathing, they found that diabetics had worse baseline data than controls.  For example, diabetics had a lower resting blood oxygen saturation and higher blood pressure.  One of the main markers they measured was the baroreflex sensitivity (BRS), which measures your body’s ability to quickly adjust your blood pressure to match the current circumstances.  At baseline, the diabetics’ had a lower BRS score, something found in previous studies.

However, after just 2 minutes of slow breathing, their BRS increased to values similar to those of the controls during spontaneous breathing.  Thus, by simply breathing slowly, we can improve this important marker of autonomic function.  Slow breathing also improved the arterial function and blood oxygen saturation of the diabetics.

How did this happen?  They authors suspect the improvements in oxygen saturation were due to improved ventilation perfusion (i.e., better matching of air and blood flow in the lungs).  As for the arterial and autonomic function, they believe this occurred due to a reduction in sympathetic nervous system activity and an increase in parasympathetic nervous system activity.  They provide evidence that this mechanism also provides a direct antioxidant effect.  Because diabetics suffer from excess oxidative stress and free radicals (something they also discuss in this paper), this aspect of slow breathing is extremely important for improving our overall health.

In summary, this paper provides practical evidence that slow breathing can improve the overall health of diabetics. By performing only 2 minutes of slow breathing, these patients were able to improve key autonomic markers, improve blood oxygen saturation, and improve their arterial function. Pretty amazing!

Abstract from Paper

Hyperoxia and slow breathing acutely improve autonomic function in type-1 diabetes. However, their effects on arterial function may reveal different mechanisms, perhaps potentially useful. To test the effects of oxygen and slow breathing we measured arterial function (augmentation index, pulse wave velocity), baroreflex sensitivity (BRS) and oxygen saturation (SAT), during spontaneous and slow breathing (6 breaths/min), in normoxia and hyperoxia (5 L/min oxygen) in 91 type-1 diabetic and 40 age-matched control participants. During normoxic spontaneous breathing diabetic subjects had lower BRS and SAT, and worse arterial function. Hyperoxia and slow breathing increased BRS and SAT. Hyperoxia increased blood pressure and worsened arterial function. Slow breathing improved arterial function and diastolic blood pressure. Combined administration prevented the hyperoxia-induced arterial pressure and function worsening. Control subjects showed a similar pattern, but with lesser or no statistical significance. Oxygen-driven autonomic improvement could depend on transient arterial stiffening and hypertension (well-known irritative effect of free-radicals on endothelium), inducing reflex increase in BRS. Slow breathing-induced improvement in BRS may result from improved SAT, reduced sympathetic activity and improved vascular function, and/or parasympathetic-driven antioxidant effect. Lower oxidative stress could explain blunted effects in controls. Slow breathing could be a simple beneficial intervention in diabetes.

Journal Reference:

Luciano Bernardi, Daniel Gordin, Marco Bordino, Milla Rosengård-Bärlund, Anna Sandelin, Carol Forsblom, & Per-Henrik Groop, (2017) Oxygen-induced impairment in arterial function is corrected by slow breathing in patients with type 1 diabetes, Nature Scientific Reports, DOI:10.1038/s41598-017-04947-4.