Deep breathing improves blunted baroreflex sensitivity even after 30 years of type 1 diabetes - Rosengard-Barlund et al. (2011)

Key Points

  • Diabetics generally suffer from a reduced baroreflex sensitivity (BRS), which is an early indicator of autonomic dysfunction

  • Reduced BRS can be restored with slow breathing, even in patients who have had diabetes for greater than 30 years

The Breathing Diabetic Summary

The aim of this study was to determine whether slow breathing could restore the baroreflex sensitivity (BRS) of patients who have had diabetes for a long duration (>30 years).  The BRS is important because it measures your body’s ability to quickly adjust your blood pressure to changing conditions.  An abnormal BRS also is considered an early indicator of autonomic dysfunction.  Also note that “long duration” here is defined as having diabetes more than 30 years.  So, any positive effects of breathing seen in this paper will be good news for those of us who have had diabetes a long time (I’m at 20 years now).

Their procedure used device-guided breathing and a technician who also monitored the each patient’s breathing using a stopwatch.  We can easily do this ourselves using a breathing app.  Moreover, they only have the subjects perform the slow breathing rate (six breaths per minute) for 1 minute, a very short amount of time.  Yet, as we will see, they still saw some pretty amazing results.

The experiment showed that slow breathing significantly increased BRS in diabetic patients.  In fact, by breathing slowly, the BRS of the diabetics was almost as high as control subjects breathing spontaneously.  Thus, slow breathing was able to reverse the blunted BRS we experience as diabetics.  This means that breathing slowly (for 1 minute!) was able to reverse a key indicator of autonomic dysfunction.  We can only imagine what would happen if a diabetic were to breathe lightly and slowly all the time…

The authors showed that the mechanism behind the increased BRS was (1) an increased heart rate variability (HRV; another key marker of overall health) and (2) an increased parasympathetic tone.  This paper, just like others, found that diabetics spend more time in a sympathetic state; therefore, this last mechanism of increasing parasympathetic tone was extremely important.

To summarize, this paper shows that slow breathing can reverse BRS in diabetics, regardless of disease duration.  For us, this paper motivates the use of Principle 1 and Principle 2 to slow our breathing 24/7 (remember, they only breathed slowly for 1 min here and still saw remarkable results) and reap the benefits of these results to reverse long-term complications associated diabetes.

Abstract from Paper

Aims/hypotheses Cardiovascular autonomic neuropathy is associated with increased morbidity in patients with type 1 diabetes. Although it is conventionally considered to be an organic, irreversible disorder, we previously demonstrated in patients with short-duration type 1 diabetes that reduced baroreflex sensitivity (BRS) could be corrected by slow, deep breathing, indicating a functional component to the disorder. We have now tested whether autonomic abnormalities in long-term diabetes progress to a stage that cannot be modified by functional manoeuvres, indicating a switch towards predominantly organic dysfunction.

Methods We studied 117 patients with a short duration (8.9± 0.1 years) and 37 patients with a long duration (33.7± 0.5 years) of type 1 diabetes, 73 healthy controls and 12 heart transplanted participants (surgical heart denervation). An autonomic score was calculated from autonomic function tests. Spectral analysis of heart rate and blood pressure variability, and BRS, were obtained from recordings during normal (15 breaths per min) and slow, deep (six breaths per min) controlled breathing.

Results BRS was reduced in all patients, but more in patients with a long duration of diabetes or with increasing autonomic involvement, although the effect of duration disappeared after adjustment for age. Slow breathing increased the BRS to the level of the control participants at a normal rate of breathing (15 per min) in all patients except those with an abnormal autonomic score.

Conclusions/interpretation Patients with type 1 diabetes have a blunted BRS that in the majority of patients can be restored by slow breathing, irrespective of disease duration. Even after a long duration of diabetes, the abnormal BRS is at least in part of functional origin.

Journal Reference:

M. Rosengård-Bärlund, L. Bernardi, J. Holmqvist, G. Debarbieri, M. Mäntysaari, C.-G. af Björkesten, C. Forsblom, P.-H. Groop, and the FinnDiane Study Group, (2011) Deep breathing improves blunted baroreflex sensitivity even after 30 years of type 1 diabetes, Diabetologia, 54, 1862–1870, DOI:10.1007/s00125-011-2164-y.