Gender differences in age and BMI distributions in partial upper airway obstruction during sleep

Gender medicine and sleep disorders: from basic science to clinical research

Several pivotal differences in sleep and sleep disorders are recognized between women and men. This is not only due to changes in hormonal balance during women's reproductive life, such as in pregnancy and menopause. Women are more likely to report insomnia and non-specific symptoms of apneas, such as fatigue or mood disturbance, compared to men. Thus, it is important for clinicians and researchers to take sex and gender differences into account when addressing sleep disorders in order to acknowledge the biology unique to women. We present a narrative review that delves into the primary sleep disorders, starting from basic science, to explore the impact of gender differences on sleep and the current status of research on women's sleep health.

Evolution of sleep-disordered breathing and blood pressure during menopausal transition

The purpose of this study was to investigate how the blood pressure increase observed during menopausal transition is affected by sleep-disordered breathing and the menopause itself. Further, we aimed to find new sleep-disordered breathing related markers that would predict the development of hypertension. Sixty-four community-dwelling premenopausal women aged 45-47 years were studied. Polysomnography, serum follicle stimulating hormone, forced expiratory volume in 1 s, and a physical examination were performed at baseline and again after 10 years of follow-up. Indices for sleep apnea/hypopnea and inspiratory flow-limitation were determined. Regression models were used to study the relationships between variables. Changes in the apnea-hypopnea index or serum follicle stimulating hormone were not significant for blood pressure change. An increase in morning blood pressure during the follow-up period was associated with a body mass-index increase. An increase in evening blood pressure was associated with an increase in inspiratory flow-limitation during non-rapid eye movement sleep. Incident hypertension during the follow-up was associated with hypopnea (median hypopnea index 7.6/h, p = 0.048) during rapid eye movement sleep at baseline. Users of menopausal hormone therapy had a lower rapid eye movement sleep apnea-hypopnea index (1.6/h vs. 6.9/h, p = 0.026) at baseline whereas at follow-up users and non-users did not differ in any way. The progression of menopause or the use of menopausal hormone therapy had a minimal effect on blood pressure in our population. The effects of inspiratory flow-limitation on blood pressure profile should be studied further.

Co-exposure to multiple air pollutants and sleep disordered breathing in patients with or without obstructive sleep apnea: A cross-sectional study

BACKGROUND

Air pollution may be a contributing risk factor for obstructive sleep apnea (OSA). However, the health effects of co-exposure to multiple air pollutants on OSA patients remain unclear.

OBJECTIVES

To assess the joint effect of multi-pollutant on sleep disordered breathing (SDB) parameters in patients with or without OSA and identify the dominant pollutants.

METHODS

A total of 2524 outpatients from April 2020 to May 2021 were recruited in this cross-sectional study. Ambient air pollutant data were obtained from the nearest central monitoring stations to participants' residential address. SDB parameters were measured by the ApneaLink devices, including apnea-hypopnea index (AHI), hypopnea index (HI), oxygen desaturation index (ODI), average oxygen saturation (SpO₂), percentage sleep time with <90% saturation (T90), and desaturation. Bayesian kernel machine regression (BKMR) was applied to evaluate the effects of multiple pollutants.

RESULTS

Significant associations were observed between air pollutants and SDB parameters (including increases in AHI, HI, ODI, and desaturation) among patients with OSA. Co-exposure to air pollutants was positively correlated with AHI, HI, and ODI. PM₁₀ and O₃ dominated the effects of pollutant mixtures on OSA, with the highest posterior inclusion probability (PIP) values of 0.592 and 0.640, respectively. Stratified analysis showed that, compared to male patients with OSA, stronger effects on the SDB parameters were observed in female patients. Stronger associations were also found in the warm season than those in the cold season.

CONCLUSION

Co-exposure to air pollutants was associated with SDB parameters among patients with OSA, PM₁₀ and O₃ might play the dominant roles.

Sleep during menopausal transition: a 10-year follow-up

Study Objectives

A 10-year observational follow-up study to evaluate the changes in sleep architecture during the menopausal transition.

Methods

Fifty-seven premenopausal women (mean age 46 years, SD 0.9) were studied at baseline and after a 10-year follow-up. At both time points, polysomnography (PSG) was performed, and the serum follicle-stimulating hormone (S-FSH) concentration was measured. Linear regression models were used to study the effects of aging and menopause (assessed as change in S-FSH) on sleep.

Results

After controlling for body mass index, vasomotor, and depressive symptoms, higher S-FSH level was associated with longer sleep latency (B 0.45, 95% confidence interval [CI]: 0.07 to 0.83). Aging of 10 years was associated with shorter sleep latency (B −46.8, 95% CI: −77.2 to −16.4), shorter latency to stage 2 sleep (B −50.6, 95% CI: −85.3 to −15.9), decreased stage 2 sleep (B −12.4, 95% CI: −21.4 to −3.4), and increased slow-wave sleep (B 12.8, 95% CI: 2.32 to 23.3) after controlling for confounding factors.

Conclusions

This study suggests that PSG measured sleep of middle-aged women does not worsen over a 10-year time span due to the menopausal transition. The observed changes seem to be rather age- than menopause-dependent.

Cardiovascular and somatic comorbidities and sleep measures using three hypopnea criteria in mild obstructive sleep-disordered breathing: sex, age, and body mass index differences in a retrospective sleep clinic cohort

STUDY OBJECTIVES

To describe sex, age, and body mass index (BMI) differences in comorbidities and polysomnography measures, categorized using 3 different apnea-hypopnea index (AHI) criteria in sleep clinic patients with mild obstructive sleep-disordered breathing.

METHODS

A retrospective cohort of 305 (64% female) adult sleep clinic patients who underwent full-night in-laboratory polysomnography having been diagnosed with mild sleep-disordered breathing and prescribed positive airway pressure. Effects of sex, age, and BMI on comorbidities and polysomnography measures, including rates of AHI defined by ≥ 3% desaturations (AHI_3%), with arousals (AHI_3%A), by ≥ 4% desaturations (AHI_4%), and by respiratory disturbance index, were evaluated.

RESULTS

Sixty-nine (23%), 116 (38%), 258 (85%), and 267 (88%) patients had AHI_4%, AHI_3%, AHI_3%A, and respiratory disturbance index ≥ 5 events/h, respectively. Ninety-day positive airway pressure adherence rates were 45.9% overall and higher in women > 50-years-old (51.2%, P = 0.013) and men (54.5%, P = 0.024) with no difference whether AHI_4% or AHI_3%A was < 5 or ≥ 5 events/h. Men and women had similar rates of daytime sleepiness (43.3%), anxiety (44.9%), and hypertension (44.9%). Women were more likely to have obesity, anemia, asthma, depression, diabetes, fibromyalgia, hypothyroidism, migraine, and lower rates of coronary artery disease. More patients with AHI_4% < 5 events/h had depression, migraines, and anemia, and more patients with AHI_4% ≥ 5 events/h had congestive heart failure. Women were more likely to have higher sleep maintenance and efficiency, shorter average obstructive apnea and hypopnea durations, and less supine-dominant pattern. Average obstructive apnea and hypopnea duration decreased with increasing BMI, and average hypopnea duration increased with age. Obstructive apnea duration and obstructive hypopnea with arousal duration decreased with increasing BMI. More women had AHI_4% < 5 (81.5% vs 69.1%), AHI_3% < 5 (68.7% vs 49.1%), and AHI_3%A < 5 events/h (18.5% vs 10.0%). Greater age and higher BMI were associated with higher AHI.

CONCLUSIONS

Current AHI criteria do not predict comorbidities or adherence in mild sleep-disordered breathing patients. In this hypothesis-generating descriptive analysis, sex, BMI, and age may all be factors that should be accounted for in future research of mild sleep-disordered breathing patients. Different sleep study measures may weigh differently in calculations of risk for cardiovascular versus somatic comorbidities.

Therapeutic Approaches for the Management of Sleep Disorders in Geriatric Population

OBJECTIVE

Aging is a natural biological phenomenon that occurs in human beings. With increasing of age, there is an appearance of deleterious changes related to progression onto pathological conditions, including hypertension, heart disease, diabetes, hearing and vision impairments, as well as sleep disorders. It is important to recognize that some sleep disturbances reported by aged subjects include insomnia, obstructive sleep apnea, restless legs syndrome, among others. Moreover, accumulating evidence indicates that coexistence of medical issues with sleep disorders constitutes clinical challenges for treatment of comorbidities in elderly. Here, we have attempted to review and summarize the available literature that assesses the sleep disturbances in aging. In addition, we highlight the management of sleep disorders associated with aging. Due to the particular health condition of aged adults, the development of effective pharmacological interventions for sleep disorders treatment in aging is warranted.

METHODS

Review of studies retrieved from the PubMed.

RESULTS

The sleep-wake cycle includes abnormalities classified as sleep disorders. Comorbidity between sleep disturbances and aging-related health issues will represent a public health challenge to be addressed in the near future. Moreover, this scenario will suggest an area that requires further drug investigation and design of new pharmacological and pharmaceutical strategies to treat sleep disorders in the elderly population.

CONCLUSION

The review highlights the sleep disturbances in aging. We focus on current knowledge in medicinal chemistry and further design of new treatments tools for managing sleep disturbances in the aged population.

Flow limitation/obstruction with recovery breath (FLOW) event for improved scoring of mild obstructive sleep apnea without electroencephalography

OBJECTIVE

Apnea/hypopnea index (AHI), especially without arousal criteria, does not adequately risk stratify patients with mild obstructive sleep apnea (OSA). We describe and test scoring reliability of an event, Flow Limitation/Obstruction With recovery breath (FLOW), representing obstructive airflow disruptions using only pressure transducer and snore signals available without electroencephalography.

METHODS

The following process was used (i) Development of FLOW event definition, (ii) Training period and definition refinement, and (iii) Reliability testing on 10 100-epoch polysomnography (PSG) samples and two 100-sample tests. Twenty full-night in-laboratory baseline PSGs in OSA patients with AHI with ≥4% desaturations <15 were rescored for FLOW events, traditional hypopneas with desaturations, respiratory-related arousal (RRA) events (hypopneas with arousals and respiratory-effort related arousals) and non-respiratory arousals (NRA).

RESULTS

Scoring of FLOW events in 100-epoch samples had good reliability with intraclass correlation (ICC) of 0.91. The overall kappa for presence of events on two sets of 100 sample events was 0.84 and 0.87 demonstrating good agreement. Moreover, 80% of RRA and 8% of NRA were concurrent with FLOW events. Furthermore, 56% of FLOW events were independent of RRA events. FLOW stratifies patients in traditional AHI categories with 50%/8% of AHI with ≥3% desaturations (AHI3) <5 and 12%/63% of AHI3 >5 in lowest/highest tertiles of AHI3 plus FLOW index.

CONCLUSIONS

Scoring of FLOW after training is reliable. FLOW scores a high proportion of RRA and many currently unrepresented obstructive airflow disruptions. FLOW allows for stratification within the current normal-mild OSA category, which may better identify patients who will benefit from treatment.

Prolonged partial upper airway obstruction during sleep - an underdiagnosed phenotype of sleep-disordered breathing

Obstructive sleep apnea syndrome (OSAS) is a well-recognized disorder conventionally diagnosed with an elevated apnea-hypopnea index. Prolonged partial upper airway obstruction is a common phenotype of sleep-disordered breathing (SDB), which however is still largely underreported. The major reasons for this are that cyclic breathing pattern coupled with arousals and arterial oxyhemoglobin saturation are easy to detect and considered more important than prolonged episodes of increased respiratory effort with increased levels of carbon dioxide in the absence of cycling breathing pattern and repetitive arousals. There is also a growing body of evidence that prolonged partial obstruction is a clinically significant form of SDB, which is associated with symptoms and co-morbidities which may partially differ from those associated with OSAS. Partial upper airway obstruction is most prevalent in women, and it is treatable with the nasal continuous positive pressure device with good adherence to therapy. This review describes the characteristics of prolonged partial upper airway obstruction during sleep in terms of diagnostics, pathophysiology, clinical presentation, and comorbidity to improve recognition of this phenotype and its timely and appropriate treatment.

Sleep disordered breathing: is it different for females?

Obstructive sleep apnoea (OSA) is no longer considered to be a disease of males only. The latest prevalence estimates of moderate-to-severe OSA in women range from 6% to 20% [1, 2], resulting in male/female ratio from 3/1 to 2/1 [1]. These figures may still underestimate the prevalence of sleep disordered breathing (SDB) in women, in whom the upper airway obstruction often manifests as noncountable, nonapnoeic respiratory events (snoring, flow limitation or partial upper airway obstruction) [3–6]. Failure to recognise the distinct clinical presentation and partial obstruction in sleep studies may lead to under-recognition of SDB in females [7, 8]. For instance, prior to diagnosing OSA, women are twice as likely as men to be treated for depression [7].

Predominance of low AHI and partial upper airway obstruction may lead to undertreatment of female SDBhttp://ow.ly/TKN7d

Evaluation of the different sleep-disordered breathing patterns of the compressed tracheal sound

OBJECTIVE

Suitability of the compressed tracheal sound signal for screening different sleep-disordered breathing patterns was evaluated. The previous results suggest that the plain pattern in the compressed sound signal represents mostly normal, unobstructed breathing, the thick pattern consists of periodic apneas/hypopneas and during the thin pattern, flow limitation in the nasal cannula signal is abundant.

METHODS

Twenty-seven patients underwent a polysomnography with a tracheal sound and oesophageal pressure monitoring. The tracheal sound data was compressed and scored visually into three different breathing patterns. The percentage of oesophageal pressure values under -8cm H2O, the minimum pressure value and the average duration of the breathing cycles were extracted from 10-min episodes of those plain, thick and thin patterns. In addition, the spectral contents of the tracheal sound during the different breathing patterns were evaluated.

RESULTS

The percentage of time when the oesophageal pressure negativity increased was highest during the thin pattern and lowest during the plain pattern. In addition, the thin pattern presented most high frequency components in the 1001-2000Hz frequency band of the tracheal sound.

CONCLUSIONS

The results confirmed our previous findings that both the thick and thin patterns seem to consist of obstructed breathing, whereas during the plain pattern the breathing is normal, unobstructed.

SIGNIFICANCE

Most screening methods for sleep-disordered breathing reveal only periodic apneas/hypopneas, but with the compressed sound signal the sustained partial obstruction can be estimated as well.

Diagnosis and treatment of sleep apnoea in women with schizophrenia

BACKGROUND

Obstructive sleep apnoea (OSA) is often overlooked in the context of schizophrenia because its hallmark, daytime sleepiness, is so easily attributable to antipsychotic drugs. This is a special problem for women.

AIMS

To underscore the importance of diagnosing and treating OSA in women with schizophrenia.

METHODS

A review of the recent literature (search terms: Obstructive Sleep Apnoea; Schizophrenia; Women (or Gender); Obesity; Antipsychotics; Continuous Positive Airway Pressure (CPAP)) as it applies to a composite case vignette taken from the files of a specialty clinic that treats women with psychosis.

RESULTS

The rate of OSA in women who are both obese and postmenopausal is very similar to that of men. Family history, smoking, and the use of tobacco, alcohol and of antipsychotic medication increase the risk. Despite reluctance, patients with schizophrenia generally agree to undergo sleep studies. Compliance with CPAP is difficult, but can be aided by the physician and is, on the whole, relatively high in women. CPAP improves sleep parameters and may also improve cardiometabolic and cognitive indices, although this still needs to be more fully researched.

CONCLUSION

Schizophrenia and untreated OSA are both associated with high mortality rates in women as well as men.

Emfit movement sensor in evaluating nocturnal breathing

Obstructive sleep apnea (OSA) diagnostics by the movement sensors static charge-sensitive bed (SCSB) and electromechanical film transducer (Emfit) is based on dividing the signal into different breathing patterns. The usage of non-invasive mattress sensors in diagnosing OSA is particularly tempting if patient has many other non sleep-related monitoring sensors. However, a systematic comparison of the apnea-hypopnea index (AHI) with Emfit-parameters is lacking. In addition to periodic breathing, SCSB and Emfit visualize episodes of sustained negative increases in intrathoracic pressure (increased respiratory resistance, IRR), of which relevance is still ambiguous. Our aim is to compare Emfit-parameters with the AHI and to provide a description of the patients suffering from IRR. Time percentage with all obstructive periodic Emfit breathing patterns (OPTotal%) showed the best correlation with the AHI. The OPTotal percentage of 21 yielded to excellent accuracy in detecting subjects with an AHI of 15/h or more. Patients with IRR received high scores in GHQ-12-questionnaire. An Emfit movement sensor might offer additional information in OSA diagnostics especially if nasal pressure transducer cannot be used.

LUPP relieves partial upper airway obstruction during sleep in patients with velopharyngeal narrowing

CONCLUSION

Patients with upper airway narrowing at the soft palate level and partial upper airway obstruction during sleep seem to benefit from laser-assisted uvulopalatoplasty (LUPP) in terms of decreased velopharyngeal collapsibility and improved nocturnal breathing.

OBJECTIVES

The current operative treatments for obstructive sleep apnea syndrome (OSAS) are not very effective compared with continuous positive airway pressure (CPAP). It has been suggested that active treatment should be performed earlier, when sleep apnea is present in a milder form. The main problem is identifying progressive sleep apnea. The present study assessed the efficacy of LUPP in patients with partial upper airway obstruction during sleep diagnosed by means of a static charge-sensitive bed (SCSB) combined with oxyhemoglobin desaturation recording and digital fluoroscopy-based collapsibility estimation.

METHODS

LUPP was carried out in 27 patients under local anesthesia as day surgery. Digital fluoroscopy and SCSB were recorded preoperatively and 6 months after LUPP.

RESULTS

Partial upper airway obstruction events and arterial oxyhemoglobin desaturations during sleep decreased significantly. Digital fluoroscopy revealed that the minimal anteroposterior dimension increased and collapsibility decreased at the level where velopharyngeal obstruction occurred, the soft palate.

Risk factors and treatment for obstructive sleep apnea amongst obese children and adults

PURPOSE OF REVIEW

The purpose of this review is to summarize the evidence for the association between obesity and obstructive sleep apnea (OSA), as well as predisposing risk factors and treatment strategies for OSA amongst obese patients.

RECENT FINDINGS

Recent findings highlight a number of factors including sex, age, upper airway structure and ethnicity, which may predispose patients to OSA when obese. Both invasive and noninvasive weight-reduction strategies also show positive signs of being an effective means to reduce or remediate OSA amongst obese adults and children.

SUMMARY

In view of recent findings, a direct association between body mass and upper airway obstruction should be viewed with caution. Obesity may play a more significant role in the predisposition to OSA amongst particular subgroups of the population, such as adults, and those with particular craniofacial and upper airway morphology. Healthcare prioritization and requirements may be more substantial for such groups. Further, commonly used treatment methods for OSA (such as adenotonsillectomy for children and continuous positive airway pressure for adults) may be less effective for obese individuals. Weight-reduction strategies appear important for an optimal outcome, and such strategies may be more or less invasive depending on the severity of obesity, OSA or both, and other patient complications.

Nocturnal transcutaneous carbon dioxide tension in postmenopausal estrogen users and non-users

Objective

The effect of menopause on breathing is not fully understood. We have previously shown that postmenopausal women have a higher sleep-induced increase in transcutaneously measured carbon dioxide tension (TcCO2) than premenopausal women. Therefore, we hypothesized that estrogen therapy (ET) would normalize this sleep-induced TcCO2 increase.

Methods

Nine postmenopausal ET users and nine non-users went through an overnight polygraphic sleep study including continuous monitoring of TcCO2.

Results

TcCO2 levels were higher during sleep than evening wakefulness (awake median 6.55 kPa versus sleep median 6.90 kPa, P = 0.001). ET users had a greater sleep-induced increase in TcCO2 than non-users when comparing the difference between wakefulness and slow-wave sleep (0.85 kPa versus 0.28 kPa, P = 0.004). Lower sleep efficiency was associated with higher sleep-induced increase in TcCO2.

Conclusions

In contrast to our initial hypothesis, postmenopausal ET users have a higher sleep-induced increase in TcCO2 than women without ET. Thus, TcCO2 may be sensitive in measuring the peripheral estrogen effect. These findings warrant placebo-controlled intervention studies to confirm the effects of ET on TcCO2 measurements.

Reimbursed drugs in patients with sleep-disordered breathing: A static-charge-sensitive bed study

BACKGROUND

Co-morbidities in men and women with sleep-disordered breathing (SDB) were compared retrospectively to an age-standardized, general Finnish population. The prevalence of diseases was based on the reimbursement refunds of medications.

METHODS

Two hundred thirty-three age- and BMI-matched male-female pairs and 368 consecutive women identified from our sleep recording database were included. Data on medication were gathered from the National Agency for Medicines and Social Insurance Institution database.

RESULTS

Men with SDB had three-fold prevalence of reimbursed medication for diabetes and two-fold prevalence of reimbursed medication for chronic arrhythmia. Women with SDB had three-fold prevalence of reimbursed medication for thyroid insufficiency, and postmenopausal women had two-fold prevalence of reimbursed medication for psychosis. BMI and age did not explain prevalence of reimbursed medications for chronic arrhythmia or psychosis. In both genders with SDB, prevalence of reimbursed medications compared to the general population was two-fold for hypertension and seven-fold for asthma and/or chronic obstructive pulmonary disease (COPD). Partial upper airway obstruction was associated with three-fold prevalence of reimbursed medication for asthma and/or COPD in both genders and 60% reduced prevalence of reimbursed medication for hypertension in females matched for age and BMI.

CONCLUSIONS

Co-morbidity profile differed between genders. Our results emphasize the importance of diagnosis and treatment of co-morbidities and partial upper airway obstruction.

Investigation of obstructive sleep apnea using nonlinear mode interactions in nonstationary snore signals

Acoustic studies on snoring sounds have recently drawn attention as a potential alternative to polysomnography in the diagnosis of obstructive sleep apnea (OSA). This paper investigates the feasibility of using nonlinear coupling between frequency modes in snore signals via wavelet bicoherence (WBC) analysis for screening of OSA. Two novel markers (PF1 and PSF), which are frequency modes with high nonlinear coupling strength in their respective WBC spectrum, are proposed to differentiate between apneic and benign snores in same- or both-gender snorers. Snoring sounds were recorded from 40 subjects (30 apneic and 10 benign) by a hanging microphone, and subsequently preprocessed within a wavelet transform domain. Forty inspiratory snores (30 as training and 10 as test data) from each subject were examined. Results demonstrate that nonlinear mode interactions in apneic snores are less self-coupled and usually occupy higher and wider frequency ranges than that of benign snores. PF1 and PSF are indicative of apneic and benign snores (p < 0.0001), with optimal thresholds of PF1 = 285 Hz and PSF = 492 Hz (for both genders combined), as well as sensitivity and specificity values between 85.0 and 90.7%, respectively, outperforming the conventional diagnostic indicator (spectral peak frequency, PF = 243-275 Hz, sensitivity = 77.7-79.7%, specificity = 72.0-78.0%, p < 0.0001). Relationships between apnea-hypopnea index and the proposed markers could likely take the functional form of exponential or power. Perspectives on nonlinear dynamics analysis of snore signals are promising for further research and development of a reliable and inexpensive diagnostic tool for OSA.