|Year : 2019 | Volume
| Issue : 10 | Page : 3276-3281
Diagnosis of obstructive sleep apnea in women: Is there any difference?- Experience from a tertiary care hospital of North India
Zia Hashim1, Alok Nath1, Mansi Gupta1, Ajmal Khan1, Ravi Mishra1, Shivani Srivastava1, Surya Kant Tripathi2
1 Department of Pulmonary Medicine, SGPGIMS, Lucknow, Uttar Pradesh, India
2 Department of Respiratory Medicine, KGMU, Lucknow, Uttar Pradesh, India
|Date of Submission||04-Aug-2019|
|Date of Decision||21-Aug-2019|
|Date of Acceptance||10-Sep-2019|
|Date of Web Publication||31-Oct-2019|
Dr. Mansi Gupta
IVth Floor, PMSSY Block, SGPGIMS, Lucknow, Uttar Pradesh - 226 014
Source of Support: None, Conflict of Interest: None
Context: Obstructive sleep apnea (OSA) considered classically to be a male-dominant disease, may have significant gender-based differences in clinical presentation and diagnosis. Aims: To evaluate gender-based differences in the clinical profile and polysomnographic features of Indian patients with OSA. Settings and Design: A prospective observational study was conducted over a period of 12 months involving adult ambulatory patients, referred for evaluation of OSA. Methods and Materials: Enrolled patients underwent detailed clinical evaluation followed by supervised polysomnography. Sleep studies were manually validated and analyzed. Statistical Analysis Used: Continuous variables were compared using two-tailed independent- sample t-test. For the univariate analysis, the Chi-square test was used. Results: Out of 150 enrolled patients, 94 (62.7%) were males (male-to-female: 1.7:1; age: 51.85 ± 12.60 years; BMI: 32.09 ± 5.53 kg/m2). Most common presenting features were excessive daytime somnolence, snoring, and easy fatiguability. Women with OSA were older than men. Insomnia and anxiety were significantly higher among females. Parameters defining sleep architecture were similar in both groups. Although obstructive apneas and hypopneas were similar, mean apnea hypopnea index was significantly higher (P < 0.05) in males compared to females with higher titratable continuous positive airway pressure. Conclusions: There are gender-specific differences in the clinical presentation of OSA due to various anatomical, physiological, and psychosocial factors. Their potential influence on the clinical features, natural history, and implications on treatment need further evaluation on a larger scale.
Keywords: Apnea hypopnea index, diagnosis, gender differences, Obstructive sleep apnea, polysomnography features
|How to cite this article:|
Hashim Z, Nath A, Gupta M, Khan A, Mishra R, Srivastava S, Tripathi SK. Diagnosis of obstructive sleep apnea in women: Is there any difference?- Experience from a tertiary care hospital of North India. J Family Med Prim Care 2019;8:3276-81
|How to cite this URL:|
Hashim Z, Nath A, Gupta M, Khan A, Mishra R, Srivastava S, Tripathi SK. Diagnosis of obstructive sleep apnea in women: Is there any difference?- Experience from a tertiary care hospital of North India. J Family Med Prim Care [serial online] 2019 [cited 2020 Mar 30];8:3276-81. Available from: http://www.jfmpc.com/text.asp?2019/8/10/3276/269999
| Introduction|| |
Obstructive sleep apnea (OSA), a syndrome characterized by repeated episodes of upper airway obstruction during sleep, is a common disorder with significant morbidity and mortality., It is not only associated with disabling symptoms but also long-term health consequences requiring life-long care.,, In addition to excessive daytime somnolence (EDS) and chronic fatigue, OSA is a harbinger of aggravation or onset of heart diseases, neuropsychiatric manifestations, and related mortality.,,
Much of our knowledge about OSA comes from studies with largely male populations.,,,,, With most studies showing a higher prevalence of OSA in men, the gender-based discrepancy is more often evident in the clinical settings., Young et al. estimated the prevalence of OSA in women, at 9% (using the data from the Wisconsin Sleep Cohort Study), while the prevalence in men was estimated at 24%. Interestingly, the under-recognition of OSA in women was highlighted due to marked differences in disease prevalence in clinical settings (male-to-female ratio of 8-10:1) compared to an expected male-to-female ratio of 2-4:1 in the general population from epidemiological studies.,, In 1997, 93% of women with moderate-to-severe OSA were thought to remain undiagnosed when comparing positive screening questionnaires against the known diagnosis of OSA. Prevalence rates have continued to rise,, with recent HypnoLaus study, a population-based study estimating the prevalence of moderate-to-severe OSA in women at 23.4%.
Research has documented gender-based differences in the upper airway, fat distribution, respiratory stability, and sleep physiology., However, only a few dedicated studies have investigated the gender differences in the clinical aspects of OSA., There is no study to our knowledge reporting the gender differences in clinical presentation and diagnosis of OSA in Indian sub-population. In our study, we aimed to specifically evaluate the gender differences in the clinical profile of patients with OSA diagnosed at our centre. The study also assessed the clinical presentation and polysomnographic data of patients suspected of having OSA.
| Subjects and Methods|| |
Study design and subjects
We conducted a prospective observational study in our department at a tertiary-care hospital in India, after approval from the Institutional Ethics Committee (The date of approval is 27-08-2019). All adult, ambulatory, and cooperative patients (age ≥18 years) referred during the study period (12 months) to our sleep clinic for evaluation of suspected OSA were assessed for suitability on the outpatient (OPD) basis. Patients with a pre-existing diagnosis of OSA or ongoing treatment with continuous positive airway pressure (CPAP) device and those having clinical features of other sleep disorders like restless leg symptoms, chronic insomnia, cataplexy, etc., were excluded. Pregnant women and patients with advanced respiratory failure requiring long-term oxygen therapy (LTOT), active infections, substance abuse, neuromuscular diseases, malignancies, and neuropsychiatric illnesses were also excluded from the study. Those fulfilling the inclusion criteria were prospectively enrolled after obtaining informed consent from all the patients.
At the baseline study visit, details of their symptoms and comorbidities were recorded. All participants had their sleep and medical history information collected along with the use of regular medications. A thorough physical examination, including measurement of the vital signs, height, weight, body mass index (BMI), was performed. The probability of OSA was assessed using the STOP-BANG questionnaire in all the patients. Epworth Sleepiness Scale (ESS) was calculated for each patient. Patients also underwent the routine as well as the specific investigations to rule out various comorbidities like diabetes mellitus, hypertension, dyslipidemia, hypothyroidism, etc.
Eligible patients were assigned dates for their sleep studies as per their convenience within 2 weeks of their assessment in the sleep clinic. The study was carried out in a specially designated, quiet, and comfortable sleep laboratory with the temperature maintained around 25--28°C. Patients underwent a full-night type-I sleep study in the dedicated sleep laboratory at SGPGIMS, Lucknow, (using the Alice 6 Diagnostic Sleep System, Respironics, USA) according to the American Academy of Sleep Medicine Task Force (AASM) standard methodology.,, Sixty-eight channels were used to document the following parameters: sleep stages (four-channel electroencephalogram, electrooculogram, chin-electromyogram), electrocardiogram channel, airflow at nose and mouth (thermistors, nasal flow cannula), chest and abdominal respiratory movement bands (respiratory impedance), oxygen saturation (pulse oximetry), snoring (microphone), and body position. All the polysomnographic (PSG) studies were supervised and attended by an experienced sleep technician.
The PSG data was reviewed at the laboratory by an experienced sleep specialist and results were recorded for subsequent analyses. Recordings were validated manually as well as using the software-assisted scoring method. The sleep stages were scored according to the updated AASM Manual of Scoring of Sleep and Associated Events (version 2.4).,, Abnormal breathing events included apneas and hypopneas. Apnea was defined as the cessation of airflow ≥90% compared to baseline for ≥10 s. Hypopnea was defined as either a reduction in airflow ≥30% compared to baseline for ≥10 s accompanied by a ≥3% desaturation or arousal, or alternatively, a reduction in airflow ≥30% compared to baseline for ≥10 s accompanied by a ≥4% desaturation. Apnea hypopnea index (AHI) was the average number of apnea and hypopnea events per sleep hour. The events were further categorized into obstructive apneas (OAs) (cessation of airflow in the presence of respiratory effort), central apneas (CAs) (cessation of airflow with absence of respiratory effort), mixed apneas (MAs) (a respiratory event during which a central apnea is followed by an obstructive component), and hypopnea (Hs). OSA was diagnosed when a patient had AHI ≥15 or if a patient with symptoms suggesting OSA had AHI ≥5/h of total sleep time.
All statistical analyses were performed using the SPSS statistical software, version 22.0 (SPSS Inc., Chicago, IL, USA). Demographic and clinical (continuous) variables have been presented with descriptive statistics (mean ± standard deviation). Proportional data were expressed in terms of percentages. Continuous variables were compared using a two-tailed independent sample t-test. Categorical variables were compared using the Chi-square test when needed. For the univariate analysis, the Chi-square test was used. A P value <0.05 was taken as significant.
| Results|| |
A total of 150 patients referred to our sleep clinic for evaluation of OSA were enrolled in the study. Out of these, 94 (62.7%) were males with a male-to-female ratio of 1.7:1 and a mean age of 51.85 ± 12.60 years. Most of our patients were obese, with an average BMI of 32.09 ± 5.53 kg/m2. Most common presenting features were EDS, snoring, and easy fatiguability. The clinical probability of OSA was high, with an average STOP-BANG score of 4.2 ± 1.9. Summary of the important clinical and PSG data of all patients is described in [Table 1]. The average age of the females with a diagnosis of OSA was significantly higher than that of males. EDS was the most common symptom observed in 80.6% of patients, followed by loud snoring, which was observed in 68% of patients. However, the difference in these symptoms was not statistically significant between the two groups. Insomnia and anxiety were significantly higher among females. ESS was not significantly different between the two groups. Hypertension was the most common comorbidity in our cohort as a total of 60.67% were hypertensive. Diabetes and hypothyroidism were observed in 50.6 and 33.34% patients, respectively. However, these comorbidities were similar in both groups. Univariate analysis of clinico-demographic characteristics is presented in [Table 2].
Univariate analysis of PSG data of the two groups is presented in [Table 3]. Total recording time, total sleep time, sleep efficiency was found to be similar in both groups. Similarly, stages of sleep and sleep latency were also similar in both groups. The incidence of OAs and Hs were similar, but CAs and MAs were significantly higher in males. Time spent with saturation below 90% was statistically similar in both the groups. Mean AHI was significantly higher in males compared to females. The proportion of males having more severe OSA was also higher in males. After the diagnosis, CPAP prescription was similar in both groups. However, the highest titrable pressure was higher for males as compared to females.
| Discussion|| |
OSA has emerged as a major public health problem with large community-based studies confirming prevalence as high as 15-17% in middle-aged adults, primarily obese males.,,,,, Despite the growing awareness regarding the disease, it is estimated that most patients are under-diagnosed, suggesting the inadequacy of current resources in meeting the growing demands. One of the major factors associated with under-diagnosis is the lack of awareness about this clinical entity among the primary care and family physicians in general, who are the first point of contact between patients and the healthcare facilities. Many cases are missed either due to under-reporting of symptoms by the patients or due to the ignorance of the clinicians regarding the appropriate screening for OSA in patients presenting with a multitude of symptoms. In addition, an often-neglected concern in its under-recognition remains the fact that there are significantly different gender-related aspects in the clinical presentation of OSA. The difference can be observed in all aspects of the presentation of OSA right from symptoms, PSG features, to the treatment with CPAP.
OSA seen traditionally as a disease of males can longer be ignored as significant morbidity affecting females. The latest prevalence estimates of moderate-to-severe OSA in women from various studies range from 6 to 25%,,, resulting in male-to-female ratio from 45:1 to 2-3:1. In our study, the difference further narrowed down to a ratio of 1.7:1. As pointed out in a study on 1,166 patients, it is likely that women with OSA may be under-diagnosed due to circumstances related to their families, lifestyle, and sociocultural factors, with lesser women reaching healthcare facilities and seeking medical opinion for their symptoms related to OSA.
Hormones have been majorly implicated in the gender-related variations, with male hormones like testosterone tending to increase obesity and severity of OSA several mechanisms, while female hormones are promoting airway and ventilatory stabilization., This difference continues up to the postmenopausal period, where female tend to catch up with their male counterparts. In consistence with the findings of previous studies,, in women from different ethnicities, our study also suggests that the differences between men and women in the prevalence of OSA decrease as age increases. However, our findings are in contrast to a large series from North America in which females were much heavier and were about the same age as males. It is also noteworthy that approximately 50% of our female patients were post-menopausal with a median age of 54.9 years. Although hormonal influences in females could also affect the manifestation of comorbidities (hypertension, diabetes, hypothyroidism), our study failed to demonstrate any such differences.
Another reason for the gender disparity in the diagnosis of OSA could be the possibility that healthcare providers disregard the atypical symptoms at clinical presentation in women.,,, One of the earlier studies had shown that regardless of the severity level, women with OSA did not report their symptoms that differed significantly from men with the same level of sleep apnea. A population-based sample found that up to 40% of women with AHI >15/h did not report any of the classic OSA symptoms (snoring, witnessed apneas, and daytime sleepiness). Our study has not only emphasized upon Indian women failing to acknowledge their OSA symptoms and seeking late medical help but also on reporting of atypical symptoms such as depression, anxiety, and insomnia more commonly than men. This could further manifest as non-restorative sleep, easy fatiguability, lack of energy, morning headaches, mood disturbances, and a poor quality of life., In a recent study, waist circumference and waist-to-height ratio were better predictors for OSA in females. While in men, waist-to-height ratio and neck circumferences were associated with mild OSA and BMI was more closely associated with severe OSA.
We also analyzed the gender differences in the PSG features in our group of 150 patients. As opposed to previous studies,,,, showing differences in the sleep architecture and sleep-related respiratory events, we have not found any difference in the sleep architecture (TST, sleep latency, NREM sleep, and REM sleep) of female patients as compared to males. One of the main findings in our study is that women with OSA have significantly milder disease than men. This difference was maintained even on sub-classifying the OSA based on its severity. However, the difference between REM-AHI and NREM-AHI in females could not be appreciated, unlike previous studies,,, showing shorter apnea duration with lesser NREM-AHI in women. There may also be gender differences in the arousal response patients have to apneas. In a study conducted in 3,234 Japanese patients, it was found that female sex is an important risk factor for REM-related OSA and women aged over 50 years were at a greater risk than those aged under 50 years.
Interestingly, women in our study were typically as symptomatic as men, despite having less severe disease. This could be related to women, in general, having more episodes of upper airway resistance (without frank apneas) during sleep and non-restorative sleep, causing uncommon clinical manifestations like insomnia and other neuropsychiatric features. Having lower AHI in females also translated into our finding of having lower CPAP titration pressures in women as compared to men. Recently, in an Italian cohort of 1,082 patients, it was shown that with CPAP therapy, males had better perceived health-related quality of life (HRQoL) at first visit.
Although there are well-known gender differences, there are only a few dedicated studies investigating the effect of gender on the clinical aspects of OSA. To our knowledge, this is the first and only study in the Indian population, highlighting the gender-based differences in clinical characteristics in OSA. This study carries special importance for family physicians and physicians working at primary care level, as it not only highlights the most significant clinical features to look for in patients suspected of having OSA but also brings out the differences in clinical manifestations of OSA in males and females. This could potentially lead to more efficient screening of OSA at primary care level and reduce under-reporting of the disease burden in specific population subsets. Moreover, the gender-based differences in the PSG features of patients with OSA suggested through our study may help the physicians in providing a patient-tailored treatment and follow-up.
There are a few limitations to our study. Our sample size was relatively small for the disease burden in the community that could have affected our findings. Secondly, there is a potential weakness due to the referral bias, as the study population was selected from our sleep clinic, which may not be a representative sample for the community. Another pitfall is the lack of inclusion of a normal healthy control group of adults for comparison. Comparing females to males with OSA, rather than matched controls meant having no data on differences between female patients with OSA and the general female population, where insomnia, mood disturbances, and certain specific morbidities like hypothyroidism can be common.
In conclusion, there are significant gender-related differences in clinical presentation as well as PSG features in patients with OSA that need to be considered while screening and managing patients at healthcare facilities. Although our study manages to highlight various gender-based aspects in OSA, larger community-based studies are required to further substantiate the findings of our study.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Strohl KP, Redline S. Recognition of obstructive sleep apnea. Am J Respir Crit Care Med 1996;154:279-89.
Punjabi NM, Caffo BS, Goodwin JL, Gottlieb DJ, Newman AB, O'Connor GT, et al
. Sleep-disordered breathing and mortality: A prospective cohort study. PLoS Med 2009;6:e1000132.
Baldwin CM, Griffith KA, Nieto FJ, O'Connor GT, Walsleben JA, Redline S. The association of sleep-disordered breathing and sleep symptoms with quality of life in the sleep heart health study. Sleep 2001;24:96-105.
Pinto JA, Ribeiro DK, Cavallini AF, Duarte C, Freitas GS. Comorbidities associated with obstructive sleep apnea: A retrospective study. Int Arch Otorhinolaryngol 2016;20:145-50.
Veasey SC, Rosen IM. Obstructive Sleep Apnea in Adults. New Engl J Med 2019;380:1442-9.
Duran J, Esnaola S, Rubio R, Iztueta A. Obstructive sleep apnea-hypopnea and related clinical features in a population-based sample of subjects aged 30 to 70 yr. Am J Respir Crit Care Med 2001;163:685-9.
Nieto FJ, Young TB, Lind BK, Shahar E, Samet JM, Redline S, et al
. Association of sleep-disordered breathing, sleep apnea, and hypertension in a large community-based study. Sleep heart health study. JAMA 2000;283:1829-36.
Palomaki H, Partinen M, Juvela S, Kaste M. Snoring as a risk factor for sleep-related brain infarction. Stroke 1989;20:1311-5.
Stradling JR, Crosby JH. Predictors and prevalence of obstructive sleep apnoea and snoring in 1001 middle aged men. Thorax 1991;46:85-90.
Bixler EO, Vgontzas AN, Ten Have T, Tyson K, Kales A. Effects of age on sleep apnea in men: I. Prevalence and severity. Am J Respir Crit Care Med 1998;157:144-8.
Ip MS, Lam B, Lauder IJ, Tsang KW, Chung KF, Mok YW, et al
. A community study of sleep-disordered breathing in middle-aged Chinese men in Hong Kong. Chest 2001;119:62-9.
Udwadia ZF, Doshi AV, Lonkar SG, Singh CI. Prevalence of sleep-disordered breathing and sleep apnea in middle-aged urban Indian men. Am J Respir Crit Care Med 2004;169:168-73.
Kim J, In K, Kim J, You S, Kang K, Shim J, et al
. Prevalence of sleep-disordered breathing in middle-aged Korean men and women. Am J Respir Crit Care Med 2004;170:1108-13.
Peppard PE, Young T, Barnet JH, Palta M, Hagen EW, Hla KM. Increased prevalence of sleep-disordered breathing in adults. Am J Epidemiol 2013;177:1006-14.
Lin CM, Davidson TM, Ancoli-Israel S. Gender differences in obstructive sleep apnea and treatment implications. Sleep Med Rev 2008;12:481-96.
Ralls FM, Grigg-Damberger M. Roles of gender, age, race/ethnicity, and residential socioeconomics in obstructive sleep apnea syndromes. Curr Opin Pulm Med 2012;18:568-73.
Franklin KA, Lindberg E. Obstructive sleep apnea is a common disorder in the population-a review on the epidemiology of sleep apnea. J Thorac Dis 2015;7:1311-22.
Senaratna CV, Perret JL, Lodge CJ, Lowe AJ, Campbell BE, Matheson MC, et al
. Prevalence of obstructive sleep apnea in the general population: A systematic review. Sleep Med Rev 2017;34:70-81.
Quintana-Gallego E, Carmona-Bernal C, Capote F, Sánchez-Armengol A, Botebol-Benhamou G, Polo-Padillo J, et al
. Gender differences in obstructive sleep apnea syndrome: A clinical study of 1166 patients. Respir Med 2004;98:984-9.
Young T, Evans L, Finn L, Palta M. Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle-aged men and women. Sleep 1997;20:705-6.
Bixler EO, Vgontzas AN, Lin HM, Ten Have T, Rein J, Vela-Bueno A, et al
. Prevalence of sleep-disordered breathing in women: Effects of gender. Am J Respir Crit Care Med 2001;163:608-13.
Ip MS, Lam B, Tang LC, Lauder IJ, Ip TY, Lam WK. A community study of sleep-disordered breathing in middle-aged Chinese women in Hong Kong: Prevalence and gender differences. Chest 2004;125:127-34.
Heinzer R, Vat S, Marques-Vidal P, Marti-Soler H, Andries D, Tobback N, et al
. Prevalence of sleep-disordered breathing in the general population: The HypnoLaus study. Lancet Respir Med 2015;3:310-8.
Thurnheer R, Wraith PK, Douglas NJ. Influence of age and gender on upper airway resistance in NREM and REM sleep. J Appl Physiol (Bethesda, Md: 1985) 2001;90:981-8.
Jordan AS, Wellman A, Edwards JK, Schory K, Dover L, MacDonald M, et al
. Respiratory control stability and upper airway collapsibility in men and women with obstructive sleep apnea. J Appl Physiol (Bethesda, Md: 1985) 2005;99:2020-7.
Shepertycky MR, Banno K, Kryger MH. Differences between men and women in the clinical presentation of patients diagnosed with obstructive sleep apnea syndrome. Sleep 2005;28:309-14.
Valipour A, Lothaller H, Rauscher H, Zwick H, Burghuber OC, Lavie P. Gender-related differences in symptoms of patients with suspected breathing disorders in sleep: A clinical population study using the sleep disorders questionnaire. Sleep 2007;30:312-9.
Nagappa M, Liao P, Wong J, Auckley D, Ramachandran SK, Memtsoudis S, et al
. Validation of the STOP-Bang questionnaire as a screening tool for obstructive sleep apnea among different populations: A systematic review and meta-analysis. PLoS One 2015;10:e0143697.
Johns MW. Sensitivity and specificity of the multiple sleep latency test (MSLT), the maintenance of wakefulness test and the epworth sleepiness scale: Failure of the MSLT as a gold standard. J Sleep Res 2000;9:5-11.
Ruehland WR, Rochford PD, O'Donoghue FJ, Pierce RJ, Singh P, Thornton AT. The new AASM criteria for scoring hypopneas: Impact on the apnea hypopnea index. Sleep 2009;32:150-7.
Grigg-Damberger MM. The AASM scoring manual four years later. J Clin Sleep Med 2012;8:323-32.
Malhotra RK, Kirsch DB, Kristo DA, Olson EJ, Aurora RN, Carden KA, et al
. Polysomnography for obstructive sleep apnea should include arousal-based scoring: An American academy of sleep medicine position statement. J Clin Sleep Med 2018;14:1245-7.
Franklin KA, Sahlin C, Stenlund H, Lindberg E. Sleep apnoea is a common occurrence in females. Eur Respir J 2013;41:610-5.
Mohsenin V. Effects of gender on upper airway collapsibility and severity of obstructive sleep apnea. Sleep Med 2003;4:523-9.
Vagiakis E, Kapsimalis F, Lagogianni I, Perraki H, Minaritzoglou A, Alexandropoulou K, et al
. Gender differences on polysomnographic findings in Greek subjects with obstructive sleep apnea syndrome. Sleep Med 2006;7:424-30.
Yukawa K, Inoue Y, Yagyu H, Hasegawa T, Komada Y, Namba K, et al
. Gender differences in the clinical characteristics among Japanese patients with obstructive sleep apnea syndrome. Chest 2009;135:337-43.
Mohsenin V. Gender differences in the expression of sleep-disordered breathing: Role of upper airway dimensions. Chest 2001;120:1442-7.
Mohsenin V, Yaggi HK, Shah N, Dziura J. The effect of gender on the prevalence of hypertension in obstructive sleep apnea. Sleep Med 2009;10:759-62.
Chang ET, Wang HM, Lai HL. Gender differences in obstructive sleep apnea syndrome. Eur J Intern Med 2016;33:e9-10.
Young T, Hutton R, Finn L, Badr S, Palta M. The gender bias in sleep apnea diagnosis. Are women missed because they have different symptoms? Arch Intern Med 1996;156:2445-51.
Lee MH, Lee SA, Lee GH, Ryu HS, Chung S, Chung YS, et al
. Gender differences in the effect of comorbid insomnia symptom on depression, anxiety, fatigue, and daytime sleepiness in patients with obstructive sleep apnea. Sleep Breath 2014;18:111-7.
Wimms A, Woehrle H, Ketheeswaran S, Ramanan D, Armitstead J. Obstructive sleep apnea in women: Specific issues and interventions. Biomed Res Int 2016;2016:1764837.
Polesel DN, Nozoe KT, Tufik SB, Bezerra AG, Fernandes MTB, Bittencourt L, et al
. Gender differences in the application of anthropometric measures for evaluation of obstructive sleep apnea. Sleep Sci (Sao Paulo, Brazil) 2019;12:2-9.
Subramanian S, Guntupalli B, Murugan T, Bopparaju S, Chanamolu S, Casturi L, et al
. Gender and ethnic differences in prevalence of self-reported insomnia among patients with obstructive sleep apnea. Sleep Breath 2011;15:711-5.
O'Connor C, Thornley KS, Hanly PJ. Gender differences in the polysomnographic features of obstructive sleep apnea. Am J Respir Crit Care Med 2000;161:1465-72.
Ware JC, McBrayer RH, Scott JA. Influence of sex and age on duration and frequency of sleep apnea events. Sleep 2000;23:165-70.
Mano M, Hoshino T, Sasanabe R. Impact of gender and age on rapid eye movement-related obstructive sleep apnea: A clinical study of 3234 Japanese OSA patients. Int J Environ Res Public Health 2019;16.
Lo Bue A, Salvaggio A, Iacono Isidoro S, Romano S, Insalaco G. OSA and CPAP therapy: Effect of gender, somnolence, and treatment adherence on health-related quality of life. Sleep Breath 2019. doi: 10.1007/s11325-019-01895-3.
[Table 1], [Table 2], [Table 3]