Effects of autonomic nervous system modulation by heart rate variability biofeedback training with resonant frequency breathing on glucose metabolism in individuals with prediabetes

• Applicants: Professor Dr. Martin Heni; Dr. Benedict Herhaus, Ph.D.
• Subject Area: Endocrinology, Diabetology, Metabolism
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 540546352

Approximately 20% of adults have prediabetes in Germany. Prediabetes is defined as a condition with glucose levels outside the normal range but not yet meeting the criteria for type 2 diabetes. The pathogenesis of prediabetes involves (as well as of type 2 diabetes) whole-body insulin resistance associated with inadequate insulin secretion. These two central processes of glucose regulation are modulated by the brain. Here, the brain communicates via the autonomic nervous system (ANS) with metabolically important organs in the periphery to modulate insulin sensitivity and insulin secretion. These processes are impaired in people with prediabetes and diabetes. An ANS sympathovagal imbalance was also observed in individuals with prediabetes. There are no specific therapeutic approaches to improve the ANS sympathovagal imbalance. It is assumed that resonant frequency breathing (RFB) maximizes HRV through rhythmization of breathing, heartbeat, and blood pressure. Through this state of coherence, the activity of the parasympathetic nervous system is upregulated and the activity of the sympathetic nervous system is suppressed, leading to an increase in modulation of ANS activity. Several studies have demonstrated that heart rate variability-biofeedback (HRV-BF) interventions improve HRV, reduce stress/anxiety and alleviate symptoms in patients with various medical conditions. To the best of our knowledge, no study has investigated the effect of HRV-BF-RFB on the glucose metabolism. Therefore, the proposed randomized controlled non-blinded trial aims to gain evidence about the effect of HRV-BF-RFB compared to an anti-stress program on glucose metabolism in individuals with prediabetes. Glucose metabolism is characterized using the 75 g oral glucose tolerance test. There are two potential mechanisms by which HRV-BF-RFB may improve the glucose metabolism in individuals with prediabetes: (a) 0°-phase relationship between heart oscillations and breathing maximizing the amplitude of respiratory sinus arrhythmia (RSA) and (b) activation of the cholinergic anti-inflammatory pathway. We hypothesize that in individuals with prediabetes HRV-BF-RFA intervention will improve glucose metabolism and glucose variability.

• DFG Programme: Research Grants