Sleep Apnea: What Causes It? Weak Diaphragm Muscles May Be A Huge Factor

Research on the respiratory system being conducted at UB may shed new light on the causes of sleep apnea, brief episodes during the night when breathing ceases, depriving the brain of oxygen.

Sleep apnea occurs most often among people aged 30 to 40 who are overweight. It can cause excessive sleepiness during the day, which can disrupt work and social life.

Using rats as an animal model, Gaspar Farkas, UB associate professor of physical therapy and exercise science, and colleagues showed that weakened diaphragm muscles, the muscles most responsible for breathing, may be one of the factors contributing to the condition.

The researchers measured diaphragm function in lean and obese rats over a normal 18-month lifetime, testing them when they were young (6-8 weeks), mature (10-12 months) and old (17-18 months). They found that diaphragm muscles in the obese animals lost their ability to respond forcefully as the animals aged. Diaphragm response in the obese young animals was not compromised.

"The diaphragm is the only respiratory muscle that is active during REM sleep, and in obese people it is already overloaded," Farkas said. "We have shown that these muscles become weakened with age, at a time when load and stress on these muscles are already great, so it's a double deficit.

"This finding helps to explain why an obese person may not have problems with sleep apnea at 20, but may have problems at 50," he added.

Researchers from the University of Florida at Gainesville and the University of South Dakota also participated in the study.

From Mike: No doubt in mind that weak diaphragms are a major aspect of OSA More about

The Effect of Cervical Circumference, Lingual Height and Lingual Width on the Obstructive Sleep Apnea-Hypopnea Syndrome
Chen H, Zhang X.

Department of Otolaryngology, Haidian Hospital, Beijing, 100080, China. chenhanent@tom.com

OBJECTIVE: To investigate the relation between the obstructive sleep apnea syndrome and the metrical value of the patient's cervical circumference, lingual height and lingual width. 

METHOD: The clinical and radiographic data of 33 (OSAHS) patients were retrospectively analyzed, the value of cervical circumference was direct manual measurement, the value of lingual height, lingual width was indirect measured through X-ray radiography of Iodic oil, and selected 33 normal adult as control group. 

RESULT: The mean of cervical circumference, lingual height and lingual width of OSAHS group have significant difference to normal control group respectively, the value of OSAHS group remarkably higher than control group. 

CONCLUSION: Cervical circumference, lingual height and lingual width make important effect on pathogenesis of OSAHS.

PMID: 16375110 [PubMed - in process]
From Mike:
Makes good sense and is a reason why we work with the tongue and cervical spine a lot but that is only part of the whole picture. More about

Manual Abdominal Compression for the Detection of Expiratory Flow Limitation

Abdel Kafi S, Leduc D, Sergysels R, Ninane V.

Service de Pneumologie et de Soins Intensifs, CHU Saint-Pierre, Bruxelles, Belgique. sophia_abdelkafi@stpierre-bru.be

INTRODUCTION: Expiratory flow limitation (EFL) is a characteristic feature of chronic obstructive pulmonary disease (COPD) and leads to dynamic hyperinflation (DH) which is a major source of dyspnoea, particularly during exercise. 

STATE OF THE ART: A new technique for the detection of EFL, based on manual compression of the abdomen (MCA), was assessed both in normal subjects and patients with COPD. MCA was always associated with a moderate increase in pleural pressure and allowed the detection of EFL in a reproducible manner, in both the seated and supine postures. The technique was well tolerated.

It was also a reliable method for the detection of EFL during exercise since EFL detection was effectively associated with the development of DH. Finally, MCA was also compared to NEP in patients with obstructive sleep apnea syndrome (OSAS) and in these patients, MCA invariably increased expiratory flow whereas the NEP method produced flow limitation in some cases because of upper airway collapse. 

PERSPECTIVES: EFL detection with MCA may be clinically useful since EFL is a determinant of dyspnoea, affects ventilatory response to exercise as well as maximum exercise capacity. 

CONCLUSIONS: MCA is a reliable technique for the detection of EFL in different positions, during resting breathing or exercise, requiring neither special equipment nor patient cooperation.

PMID: 15968762 [PubMed - indexed for MEDLINE]

From Mike:
Helpful but so much more is needed. More about

Mathematical Models of Periodic Breathing and Their Usefulness in Understanding Cardiovascular and Respiratory Disorders

Neil S. Cherniack and Guy S. Longobardo 

Experimental physiology, 91(2), 295–305.

https://doi.org/10.1113/expphysiol.2005.032268 

Periodic breathing is an unusual form of breathing with oscillations in minute ventilations and with repetitive apnoeas or near apnoeas. Reported initially in patients with heart failure or stroke, it was later recognized to occur especially during sleep.

The recurrent hypoxia and surges of sympathetic activity that often occur during the apnoeas have serious health consequences. Mathematical models have helped greatly in the understanding of the causes of recurrent apnoeas.

It is unlikely that every instance of periodic breathing has the same cause, but many result from instability in the feedback control involved in the chemical regulation of breathing caused by increased controller and plant gains and delays in information transfer. Even when it is not the main cause of the periodic breathing, unstable control modifies the ventilatory pattern and sometimes intensifies the recurrent apnoeas.

The characteristics of disturbances to breathing and their interaction with the control system can be critical in determining ventilation responses and the occurrence of periodic breathing. Large abrupt changes in ventilation produced, for example, in the transition from waking to sleep and vice versa, or in the transition from breathing to apnoea, are potent factors causing periodic breathing.

Mathematical models show that periodic breathing is a 'systems disorder' produced by the interplay of multiple factors. Multiple factors contribute to the occurrence of periodic breathing in congestive heart failure and cerebrovascular disease, increasing treatment options.

From Mike: Clearly one major factor is UDB

WHERE THEY WENT WRONG I BELIEVE?

The Effect of Treatment on Diaphragm Contractility in Obstructive Sleep Apnea Syndrome.

El-Kabir DR, Polkey MI, Lyall RA, Williams AJ, Moxham J.

Lane Fox Respiratory Unit and Sleep Disorders Centre, St Thomas' Hospital, Guy's King's and St Thomas' School of Medicine, Lambeth Palace Road, London SE1 7EH, UK. desielk@cwcom.net

In untreated obstructive sleep apnea syndrome (OSAS) inspiratory efforts are made against an occluded airway and diaphragm fatigue might therefore complicate OSAS.

To test this hypothesis we measured twitch transdiaphragmatic pressure (Tw Pdi) in response to bilateral cervical magnetic stimulation of the phrenic nerve roots in nine patients with OSAS before and one month after successful therapy with nasal continuous positive airways pressure (nCPAP).

The mean Tw Pdi before therapy was 23.2cm H2O and after therapy was 22.8cm H2O (P = 0.59); the mean change after initiation of nCPAP was 0.4cm H2O with 95% confidence intervals of -1.3cm H2O and +2.1 cm H2O. We conclude that low frequency diaphragm fatigue does not complicate untreated OSAS

Diaphragm strength and sleep.
If you're like most people, you know that one of the biggest dangers of snoring and untreated sleep apnea is a reduction in the body's intake of oxygen. It's a little known fact that your diaphragm muscles can be a HUGE help in reducing sleep apnea and breathing volume. 
The diaphragm muscles are responsible for breathing – weak muscles mean your breathing isn't as strong or as easily deepened as it should be. 

But there is hope!
There are a few key breathing development techniques and exercises that are meant to strengthen the diaphragm and increase lung volume and oxygen intake. 

Without the right amount of oxygen, we experience fatigue and depression, and low oxygen levels can also lead to serious health conditions such as heart failure. 

By following our program in our Sleep program you'll be well on your way to a stronger diaphragm, greater lung volume and more oxygen. In our Sleep program you'll be well on your way to a stronger diaphragm - and much better oxygen intake.

From Mike: My theory is that properly developing the diaphragm as well as the vocal tract will eliminate most OSA. Some may need dental work and/or weight loss as well. Begin here  or  Consult.