Effects of Respiratory Yoga Training on Heart Rate Variability and Baroreflex of Healthy Elderly Subjects
Condition: Elderly Subjects; Respiration Exercises
Study type: Interventional
Phase: Phase 3

Summary: 
      The decreases of physiological capacities which take place with senescence include
      diminishing respiratory capacity as well as a reduction of heart rate variability and
      baroreflex sensibility. Altogether, these alterations increase elderly people's frailty and
      have a negative impact over quality of life. Since Yoga (Indian auto-discipline) has a wide
      range of respiratory exercises already investigated as components for non-pharmacological
      treatments for hypertension (situation in which heart rate variability is also diminished),
      the investigators hypothesis is that the training of respiratory exercises of Yoga may have a
      significant positive effect on heart rate variability and baroreflex of health elderly
      subjects, increasing quality of life and reducing frailty.

      We included 30 health elderly subjects (both sexes, from 60 years-old onwards) divided into 2
      randomized experimental groups: control (C) and respiration (R). Each group underwent an
      entry evaluation, followed by a 4-months training period, after which they were re-evaluated.
      Control consisted of 2 stretching classes per week, and respiration consisted of 2
      respiratory exercises classes a week. Both groups were instructed to perform the exercises at
      home twice a day, and to keep a record of each session in a log sheet. Evaluations were:
      WHOQOL-OLD questionnaire for quality of life, 20 minutes of seated rest with heart rate,
      respiration and blood pressure acquired continuously for further spectral analysis.
    

Detailed description: 
      Heart rate variability was performed using the autoregressive model, and the baroreflex was
      calculated with the spontaneous approach, both with the softwares developed in Milan by
      Alberto Porta in a non-invasive way.

      The frequency domain analysis of heart rate, respiration and systolic blood pressure were
      conducted, consisting of calculating the power spectral density with the minimum error
      predicted by Akaike's algorithm. Spectral power was then subdivided into two bands of
      physiological interest: low - (LF 0.03-0.15 Hz) indicating predominant sympathetic
      modulation, and high - (HF 0.15-0.5 Hz) frequency, indicating parasympathetic modulation of
      the heart. The fraction calculated dividing LF by HF (LF/HF ratio) provided information of
      sympathovagal balance to the heart. The spectral analysis of Systolic Blood Pressure provided
      information of the vasomotor tone, and the integration of heart rate information with these
      data also provided information about the spontaneous baroreflex gain.

      Other questionnaires used were: Pittsburgh Quality of Sleep Questionnaire, Stress Symptoms
      Questionnaire by Marilda Lipp - validated in Brazil, and Beck's anxiety and depression
      inventories.
    

Intervention name(s): Stretching Exercises; Respiratory Exercises conducted twice a day for 10 minutes
Intervention type(s): Other; Other
Intervention description(s): Conducted twice a week, with instructions for home exercises twice a day, and registering each session on a log sheet.; Conducted twice a week, with instructions for home exercises twice a day, and registering each session on a log sheet.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Healthy Elderly Subjects; Respiratory Yoga Exercises; Heart Rate Variability; Baroreflex; Quality of Life