Short-term efficacy of home-based heart rate variability biofeedback on sleep disturbance in patients with incurable cancer: a randomised open-label study

An Estimation Formula for Resonance Frequency Using Sex and Height for Healthy Individuals and Patients with Incurable Cancers

Resonance frequency breathing is a technique that involves breathing that maximizes heart rate variability. It is specific to individuals and is determined through a procedure taking approximately 30 min, using a procedure that is often best carried out at specialized medical institutions. This is a physical and time-consuming burden because of hospital visits and measurements, particularly for patients with cancer. Therefore it would be beneficial if a procedure can be found to determine resonance frequency from the patient's physical characteristics, without the need for special assessment procedures. This exploratory cross-sectional study examined the correlation between individual characteristics and resonance frequency in healthy volunteers. Multiple regression analysis was performed with the measured resonance frequency as the target variable and individual characteristic parameters as explanatory variables. The study aims to build an estimation formula for resonance frequency with some of these parameters and assess its validity. In addition, the validity of the formula's applicability to patients with incurable cancers is assessed. A total of 122 healthy volunteers and 32 patients with incurable cancers were recruited as participants. The median resonance frequency of 154 participants was six breaths per min. Sex and height were selected as explanatory variables associated with the measured resonance frequency in the volunteers. The estimation formula for resonance frequency using individual characteristics was 17.90-0.07 × height for men and 15.88-0.06 × height for women. Adjusted R-squared values were 0.55 for men and 0.47 for women. When the measured resonance frequency in patients with incurable cancers was six breaths per minute or less, the resonance frequency estimated by this formula was slightly larger than the measured ones. Information on individual characteristics, such as sex and height, which can be easily obtained, was useful to construct an estimation formula for resonance frequency.

Effects of heart rate variability biofeedback (HRVBFB) on sleep quality and depression among methamphetamine users

Methamphetamine is garnering concern due to its increasing use worldwide. Depression and sleep quality are major mental health issues in substance users. Heart rate variability biofeedback (HRVBFB) has shown promising results in terms of reducing depression and increasing sleep quality. The present study aimed to explore the effects of HRVBFB on these two issues in methamphetamine users. Sixty-one methamphetamine users were enrolled and allocated randomly into a treatment as usual (TAU) group and a HRVBFB plus TAU group. The levels of depressive symptoms and sleep quality were assessed at intake, end of the intervention, and end of follow-up. Compared with baseline, the levels of depressive symptoms and poor sleep quality were decreased at the end of the intervention and follow-up in the HRVBFB group. The HRVBFB group exhibited a greater decrease in depressive symptoms and a better improvement in sleep quality than the TAU group. The associations of HRV indices with levels of depressive symptoms and poor sleep quality were different in the two groups. Our results showed that HRVBFB is a promising intervention for reducing depressive symptoms and improving sleep quality in methamphetamine users. The benefits with respect to depressive symptoms and poor sleep quality can extend beyond the end of HRVBFB intervention.

Biofeedback as an Adjunct or Alternative Intervention to Cognitive Behavioral Therapy for Insomnia

Insomnia is highly prevalent and comorbid with many disorders. However, insomnia is underdiagnosed and undertreated in many populations. Cognitive behavioral therapy for insomnia (CBT-I) is not appropriate or sufficient for some individuals. Biofeedback has demonstrated efficacy in a range of disorders, including insomnia. The authors discuss the history and rationale for the use of biofeedback in the treatment of insomnia and other comorbid disorders. The article also presents current research on biofeedback for insomnia and comorbid disorders with recommendations for using biofeedback as an adjunct or alternative intervention to CBT-I.

Relationship between the number of breaths that maximizes heart rate variability and height in patients with incurable cancers

INTRODUCTION

Resonant frequency breathing is a coping skill used for relaxation. A resonant frequency varies from person to person and is only investigated by specialized medical institutions.

METHODS

The relationships between patients' resonant frequencies and age, sex, height, and body weight were assessed using an analysis of variance.

RESULTS

The average resonant frequency among the 50 patients with incurable cancers was 6.05 breaths per minute. There was a significant difference in height between the resonant frequencies of 5, 5.5, 6, 6.5, and 7 breaths per minute (p < 0.001).

CONCLUSION

Resonant frequency may be correlated with height in patients with incurable cancers.

TRIAL REGISTRATION

UMIN000029820. Registered on November 4, 2017.