title: Effects of guided breathing on blood pressure and heart rate variability in hypertensive diabetic patients.
abstract: OBJECTIVE
  Our aim was to investigate medium-term effects of device-guided breathing on blood pressure (BP) and its capacity to improve the cardiovascular autonomic balance in hypertensive diabetic patients. This feasibility study was conceived as a proof-of-concept trial under real life conditions for justification of further investigations.
  
  
  METHODS
  A randomized, controlled study (RCT) of the effects of device-guided slow breathing on top of usual care against usual care alone (including non-pharmacological and pharmacological treatment). The intervention included 12-min sessions of guided breathing performed daily for 8 weeks. Treatment effects were assessed with ambulatory blood pressure monitoring (24h ABPM) and with spectral analysis of short-term heart rate variability (HRV) obtained during standardized modified orthostatic load. Thirty-two subjects with diabetes and antihypertensive therapy were randomly assigned to both study groups.
  
  
  RESULTS
  After 8 weeks of guided breathing, significant reductions were demonstrated in 24 h systolic BP (x±SEM: 126.1±3.0 vs 123.2±2.7 mmHg, p=0.01), and in 24 h pulse pressure (PP, 53.6±2.6 vs. 51.3±2.5 mmHg, p=0.01), whereas no significant impact in the control group was shown. The differences in treatment effects (delta mmHg, RESPeRATE® vs control) were significant only for PP (-2.3±0.8 vs +0.2±1.2 mmHg, p<0.05). Strong baseline dependence of treatment effects (delta systolic BP) was observed (p<0.01). Guided breathing showed a stronger treatment effect in terms of an increase in HRV, predominantly in low frequency band (p<0.03 vs. usual care).
  
  
  CONCLUSIONS
  Even in well controlled hypertensive diabetic patients, guided breathing induced relevant effects on BP and HRV, finding which should be investigated further.
authors.affiliation: Research Group Functional Rehabilitation and Group Education, Vienna, Austria; Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Austria; Principal Investigator´s Clinical Office, Internal Medicine and Diabetology, Vienna, Austria. Electronic address: kinga.howorka@meduniwien.ac.at.
authors.forename: Kinga
authors.initials: K
authors.lastname: Howorka
authors.forename: Jiri
authors.initials: J
authors.lastname: Pumprla
authors.forename: Jennifer
authors.initials: J
authors.lastname: Tamm
authors.forename: Alfred
authors.initials: A
authors.lastname: Schabmann
authors.forename: Sophie
authors.initials: S
authors.lastname: Klomfar
authors.forename: Elysee
authors.initials: E
authors.lastname: Kostineak
authors.forename: Nora
authors.initials: N
authors.lastname: Howorka
authors.forename: Eliska
authors.initials: E
authors.lastname: Sovova
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory; D001945:Breathing Exercises / Q000295:instrumentation / Q000379:methods*; D048909:Diabetes Complications / Q000628:therapy*; D003920:Diabetes Mellitus; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012119:Respiration
keywords: Ambulatory blood pressure monitoring; Device guided breathing; Diabetes; Heart rate variability; Hypertension; RESPeRATE®; Randomized controlled study; Spectral analysis