Oxygen deteriorates arterial function in type 1 diabetes - Gordin et al. (2016)
Key Points
Oxygen administration increases blood pressure in type-1 diabetics
Oxygen administration deteriorates arterial function by increasing arterial stiffness in type-1 diabetics
Activation of the parasympathetic nervous system by oxygen administration might actually be a defense mechanism
The Breathing Diabetic Summary
Oxygen treatment (hyperbaric oxygen, oxygen bars, etc.) gets a great deal of attention for its seemingly positive benefits. However, although somewhat unknown to most, oxygen treatment also has negative side effects, such as increasing blood pressure and increasing arterial stiffness. Because arterial stiffness is particularly important in diabetes, this paper set out to see how oxygen administration impacts type-1 diabetics.
The study had 98 type-1 diabetics and 49 healthy controls. They monitored several hemodynamic parameters (for example, blood pressure) in these patients during 10 minutes of spontaneous breathing, followed by 15 minutes of spontaneous breathing with oxygen added at 5 liter/min. Recordings were not taken during the first 5 minutes of oxygen inhalation to allow things to stabilize.
The results revealed that oxygen administration increased blood pressure in the diabetics but not in the controls. Moreover, blood pressure increased more in patients with higher HbA1c. Interestingly, even with the increase in blood pressure, heart rate decreased in all of the subjects. Finally, arterial stiffness increased significantly in the diabetic group and only slightly in the healthy controls.
We know from previous studies that oxygen administration leads to acute improvements in baroreflex sensitivity, an overall marker of cardiovascular and autonomic function, which seems counter to these results. However, it appears that the transient worsening of arterial function due to oxygen administration triggers a parasympathetic response (seen in the reduced heart rate) in an attempt to compensate. This response could be interpreted as a transient improvement in autonomic function, but it might actually be a defense mechanism. The parasympathetic response is not due to the oxygen, but a reaction to the increased blood pressure caused by the oxygen.
However, we do know that oxygen therapy has benefits in certain diseases. The authors cite research showing that oxygen therapy might be more beneficial in patients with severe tissue hypoxia, whereas it might actually be harmful in populations with no hypoxia or moderate hypoxia (such as diabetics). The results of this study fall in line with that theory.
Overall, this paper shows that oxygen administration negatively impacts arterial function in type-1 diabetics. Because arterial function is critical for avoiding diabetic complications, these results are clinically important. To improve autonomic function, slow breathing might be a better route, which offers many of the same benefits of oxygen administration, without the negative side effects. In fact, these results motivated one of my favorite papers ever, which concluded that “Slow breathing could be a simple beneficial intervention in diabetes.”
Abstract from Paper
AIMS: Although oxygen is commonly used to treat various medical conditions, it has recently been shown to worsen vascular function (arterial stiffness) in healthy volunteers and even more in patients in whom vascular function might already be impaired. The effects of oxygen on arterial function in patients with type 1 diabetes (T1D) are unknown, although such patients display disturbed vascular function already at rest. Therefore, we tested whether short-term oxygen administration may alter the arterial function in patients with T1D.
METHODS: We estimated arterial stiffness by augmentation index (AIx) and the pulse wave velocity equivalent (SI-DVP) in 98 patients with T1D and 49 age- and sex-matched controls at baseline and during hyperoxia by obtaining continuous noninvasive finger pressure waveforms using a recently validated method.
RESULTS: AIx and SI-DVP increased in patients (P < 0.05) but not in controls in response to hyperoxia. The increase in AIx (P = 0.05), systolic (P < 0.05), and diastolic (P < 0.05) blood pressure was higher in the patients than in the controls.
CONCLUSIONS: Short-term oxygen administration deteriorates arterial function in patients with T1D compared to non-diabetic control subjects. Since disturbed arterial function plays a major role in the development of diabetic complications, these findings may be of clinical relevance.
Journal Reference:
Gordin D., Bernardi L., Rosengård-Bärlund M., Mäkinen V.P., Soro-Paavonen A., Forsblom C., Sandelin A., and P.H. Groop (2016), Oxygen deteriorates arterial function in type 1 diabetes, Acta Diabetologica, 53 (3), 349 – 357, doi: 10.1007/s00592-015-0775-3.