Background: The autonomic nervous system plays a crucial role in the brain’s communication with
metabolically important peripheral organs, modulating insulin sensitivity and secretion.
Increased sympathetic tone is a common feature in prediabetes and diabetes. The parasympathetic
nervous system activity might be improvable through resonance frequency breathing
(RFB) with heart rate variability-biofeedback (HRV-BF) training.
Methods: We here investigated the effect of a four-week mobile RFB-HRV-BF intervention on
glucose metabolism and HRV of 30 healthy adults (17 females; mean age: 25.77±3.64
years; mean body mass index: 22.65±2.95 kg/m2). Before and after the intervention, glucose metabolism was assessed by 75 g oral
glucose tolerance tests (with blood sampling every 30 minutes over 2 hours) and HRV
was measured through electrocardiography.
Results: RFB-HRV-BF training did not influence glucose metabolism in healthy adults but reduced
fasting as well as 2-h-post-load glucose in participants categorized as more insulin
resistant before the intervention. In addition, RFB-HRV-BF training was associated
with an increase in the time and frequency domain HRV parameters SDNN, RMSSD, HRV-HF
and HRV-LF after four weeks of intervention.
Conclusions: Our findings introduce RFB-HRV-BF training as an effective tool to modulate the
autonomic nervous system with a shift towards the parasympathetic tone. Along with
the observed decrease in glycemia in those with lower insulin sensitivity, RFB-HRV-BF
training emerges as a promising non-pharmacological approach to improve glucose metabolism
which has to be further investigated in prediabetes and diabetes.