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January2014 Vol.51 Issue:      1 Table of Contents
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Insomnia and Obstructive Sleep Apnea among Egyptians: A Hospital-Based Study

Mohammed El Sayed El Awady, Kamel Hammouda, Amr Hassan, Al Shaimaa Abo El Fotouh

Department of Neurology, Cairo University; Egypt



ABSTRACT

Background: Insomnia, the most prevalent sleep disorder, affects 10–15% of the general population. Sleep questionnaires are easily administered measure that provides a clinically relevant screening guide for sleep disorders. Sleep disorders are under-estimated in the general population studies. The Insomnia symptom questionnaire (ISQ) has 13 self-rated questions. Only questions 1, 2, 5 are used to determine the presence, frequency and the duration of sleep symptom criteria, questions 6, 13 are used to identify significant day time consequences of the sleep complaint. Approximately 2% to 5% of the population meets the diagnostic criteria for obstructive Sleep apnea (OSA) in the general population, reported to be as high as 24% in men and 9% in women. Screening tools such as the Sleep Apnea scale of Sleep Disorders Questionnaire (SA-SDQ) are gaining increasing importance because of the high prevalence of OSA in the population coupled with the high cost of PSG. Objective: To screen the presence of undiagnosed insomnia and obstructive sleep apnea in asymptomatic healthy adults Egyptians. Methods: Two thousand healthy adults Egyptians recruited from El-Kasr El-Aini hospital neurology outpatient clinics completed the Insomnia Symptom Questionnaire (ISQ) and SA-SDQ. Results:  Of the 2000 participants, 602 (30.1%) had sleep apnea, 601 (30.1%) had insomnia; female patients were more prone to experience insomnia. (P-value 0.047). Conclusion: Sleep disorders such as insomnia and sleep apnea syndrome are common problems that are under-reported in apparently healthy adult Egyptians. [Egypt J Neurol Psychiat Neurosurg.  2014; 51(1): 89-95]

 Key Words: Insomnia; Epidemiology; Insomnia, Sleep apnea.

Correspondence to Amr Hassan El Sayed Mohammed, Neurology Department - Cairo University; Egypt.

Tel.: +201006060809     Email: amrhasanneuro@kasralainy.edu.eg





Introduction

 

Over the past decade, researchers have learned much about the science of sleep, the importance of studying sleep; sleep related problems and their impact on daily living1. Sleep questionnaires are easily administered and scored self-report measure that provides a clinically relevant screening guide for sleep disorders.2

Insomnia, the most prevalent sleep disorder, affects 10–15% of the general population3. Insomnia affects up to 30% of the adult population4. It is the second most frequent health complaint after pain5. Women are 1.4 times as likely as men to complain of insomnia symptoms6.

Absence of airflow for at least 10 seconds defines an obstructive sleep apnea7. The definition of apneas occur with an EEG arousal and are accompanied by an oxygen de-saturation, often at least 2% to 4% while the definition of an obstructive hypopnea is recognized as a reduction in airflow, typically in the range of 30% to 50%, with duration of at least 10 seconds8.

 

Population-based studies suggest that men experience OSA at two to three times the rate of women9. OSAS occurs in all age groups, from infancy to adulthood and beyond, but the peak age of presentation is 2 to 6 years of age10. Poor-quality sleep due to obstructive sleep apnea is present in approximately 40% of obese individuals, and about 70% of obstructive sleep apnea patients are obese11.

The aim of this study is to Screen the presence of undiagnosed insomnia and obstructive sleep apnea in asymptomatic healthy adults Egyptians.

 

Subjects and Methods

 

Study Design and Participants’ Selection

This cross­-sectional study was conducted on 2000 healthy Egyptian individuals. Our sample consisted of healthy attendants and patients' healthy companions who visited Neurology Outpatient Clinic and Neurology department, Kasr Al-Aini hospital. They were enrolled from November 2011 till November 2012. Their age at the time of assessment ranged from 20 years to 60 years.

 

Translation and preparation of item pool:

We used a method that has been used in many countries and for many self-reported scales. The process includes translation from the source language (i.e., forward translation), translation from the target language backs into the source language (i.e., back translation) so the developer of the source-language version can participate fully and examination of translation quality. Translation was done by Center for Foreign Language and Professional Translation, Cairo University.

Inclusion criteria: we included night sleepers whose age ranged from 20-60 years.

 

Exclusion Criteria: we excluded

1.                Night shift workers.

2.        Individuals with neurological disease, diagnosed sleep disorder, chronic or current medical illness especially ENT diseases, chronic chest diseases, thyroid troubles and obesity.

3.        Drug abusers and patients receiving psychotropic drugs.

 

Ethical committee approval:

The participants agree with the terms of the informed consent, and the study was approved by the local ethics committee.

 

Clinical evaluation:

1.        Meticulous history taking and thorough Neurological examination.

2.        Body mass index (BMI) was calculated as follows:

BMI = body weight in kilograms/ square height in meters.

 

Sleep questionnaires:

All participants were contacted and systematically interviewed regarding the following demographic and clinical parameters including:

A.       Insomnia Symptom Questionnaire (ISQ)12, a validated scale was used to screen the presence of undiagnosed insomnia. The Insomnia symptom questionnaire (ISQ) has 13 self-rated questions. Only questions 1, 2, 5 are used to determine the presence, frequency and the duration of sleep symptom criteria, questions 6, 13 are used to identify significant day time consequences of the sleep complaint.

B.       Sleep Apnea scale of Sleep Disorders Questionnaire (SA-SDQ), a validated 12-items scale used to screen the presence of undiagnosed sleep apnea, total scores range from 0 to 60. SA-SDQ consists of eight questions and four other items related to weight, smoking status, age and body mass index which are calculated to generate a raw score with cut-off points for OSA were 32 for women and 36 for men (at that score or above the diagnosis of sleep apnea is considered)13.

Statistical Analysis

Descriptive statistics were carried out using the mean and standard deviation for quantitative data and the frequency distribution for qualitative data. Student t-test was used to compare between quantitative data. The qualitative data statistical differences and potential relations were assessed using Chi-Square test. P<0.05 is considered to be statistically significant. 

P value less than 0.001 was considered highly significant. The statistical analysis was done using SPSS (Statistical Package for Social Science; SPSS Inc., Chicago, IL, USA) version 12 Windows 7.

 

ResultS

 

In this study, participants were 2000 healthy individuals with the following demographic data:

-        There were 1283 male (64.2%) and 717 females (35.9%).

-        There were 266 (13.3%) participants between age (20-30 years), 325 (16.25%) between age (30-40 years), 905 (45.25%) between age (40-50 years) and 504 (25.2%) between age (50-60 years).

-        The participants with BMI < 25 were 1195 (59.75%) & 805 (40.25%) were with BMI (25-30).

 

Insomnia:

On assessment of the participants using insomnia scale, 1399 participant out of 2000 (69.9%) had no insomnia while 601 participant out of 2000 (30.05%) had insomnia.

 

Insomnia and age:

Out of 266 participants in age range (20-30 years) 77 participant had insomnia (28.9%), 94 out of 325 participants in age range (30-40 years) had insomnia (28.9%), 272 out of 905 participants in age range (40-50 years) had insomnia (30.1%)  and 158 out of 504 participants in age range (50-60 years) had insomnia (31.3%).

This difference did not reach statistical significant difference with P value (0.413), as shown in Table (1).

 

Insomnia and gender:

Out of 601 participants who had insomnia using Insomnia Symptom Questionnaire (ISQ), 366 participants were males (28.5%) & 235 were females (32.8%),while out of 1399 participants who had no insomnia using ISQ, 917 participants were males (71.5%) and 482 (67.2%) were females. This difference reached statistical significant difference with P value (0.047). These data are shown in Table (2).

Insomnia and BMI:

On assessment of the participants using ISQ in relation to BMI, it was found that 366 participants out of 1195 (whose BMI<25) had insomnia (30.6%), 235 participants of 805 (whose BMI between 25-30) had insomnia (29.2%) on the other hand it was found that 829 participants out of 1195 (who had BMI<25) had no insomnia (69.4%), while 570 participants out of 805 (who had BMI between 25-30) had no insomnia (70.8%). This difference did not reach statistical significant difference with P value 0.492. These data are shown in Table (3).

 

Sleep apnea:

On assessment of the participants using Sleep Apnea scale of Sleep Disorders Questionnaire (SA-SDQ), 1398 participant out of 2000 (69.9%) had no sleep apnea while 602 participant out of 2000 (30.1%) had sleep apnea.

 

Sleep apnea and age:

Those participants who had mild sleep apnea score were 554 out of 2000 participants (27.6%), participants who had moderate sleep apnea score were 41 out of 2000 participants (2.1%) and participants who had severe sleep apnea score were only 7 out of 2000 participants (0.4%). Out of 266 participants [with age range (20-30 years)] 87 participants had mild sleep apnea (29.3%), 3 participants (1.1%) had moderate sleep apnea and only one participant had severe sleep apnea. Out of 325 participants [with age range (30-40 years)] 97 participants had mild sleep apnea were (29.8%), 7 participants (2.0%) had moderate sleep apnea and 2 participant (0.6%) had severe sleep apnea. Out of 905 participants [with age range (40-50 years)] 223 participants had mild sleep apnea were (24.6%), 18 participants (2.0%) had moderate sleep apnea and 3 participant (0.3%) had severe sleep apnea. Out of 504 participants [with age range (50-60 years)] 76 participants had mild sleep apnea were (31.0%), 13 participants (2.6%) had moderate sleep apnea and only one participant had severe sleep apnea. This difference showed statistical significant difference with P value 0.038. These data are shown in Table (4).

 

Sleep apnea and Gender

On assessment of the participants using Sleep Apnea scale of Sleep Disorders Questionnaire (SA-SDQ) in relation to gender, it was found that male participants who had no sleep apnea were 906 participants of 1283 (70.6%) while male participants who have apnea were 377 (29.4%). On the other hand, it was found that female participants who had no sleep apnea were 492 participants of 717 (68.6%) while female participants who have apnea were 225 (31.4%). Stratification of male participants on sleep apnea scale 341 participants out of 1283 (26.6%) had mild sleep apnea while 31 participants out of 1283 (2.4%) had moderate sleep apnea and 5 participants out of 1283 (0.4%) had severe sleep apnea. On the other hand, stratification of female participants on sleep apnea scale 213participants out of 717 (29.7%) had mild sleep apnea while 10 participants out of 717 (1.4%) had moderate sleep apnea and 2 participants out of 717 (0.3%) had severe sleep apnea. All this difference did not reach statistical significant difference, with P value (0.761). These data are shown in Table (5).

 

Sleep apnea and BMI

On assessment of the participants using Sleep Apnea scale of Sleep Disorders Questionnaire (SA-SDQ) in relation to BMI, it was found that participants with BMI less than 25 who had mild sleep apnea were 335 (28.0%) out of 1195 participants, 22 participants (1.8%) had moderate sleep apnea and  5 participants (0.4%) had severe sleep apnea. On the other hand, it was found that participants with BMI between 25-30 who had mild sleep apnea were 219 (27.2%) out of 805 participants, 19 participants (2.4%) had moderate sleep apnea and only 2 participants (0.2%) had severe sleep apnea. This difference did not reach statistical significant difference.


 

Table 1. Results of assessment of participants using insomnia scale as regards participants’ different age groups.

 

Insomnia scale

Age group in years

Total

20-

30-

40-

50-

No insomnia

Number

 % within age

 

189

71.1%

 

231

71.1%

 

633

68.9%

 

346

68.7%

 

1399

69.95%

Insomnia

Number

% within age

 

77

28.9%

 

94

28.9%

 

272

30.1%

 

158

31.3%

 

601

30.05%

Total    

Number

% within age

 

266

100.0%

 

325

100.0%

 

905

100.0%

 

504

100.0%

 

2000

100.0%

P-value

0.413

 

Table 2. Results of assessment of participants using insomnia scale as regards participants’ gender.

 

Insomnia scale

Gender

Total

Male

Female

No insomnia

Number

% within sex group

 

917

71.5%

 

482

67.2%

 

1399

69.95%

Insomnia

Number

% within sex group

 

366

28.5%

 

235

32.8%

 

601

30.05%

Total    

Number

% within sex group

 

1283

100.0%

 

717

100.0%

 

2000

100.0%

P-value

0.047*

* Significant at P<0.05

 

 

Table 3. Results of assessment of participants using insomnia scale as regards participants’ BMI.

 

Insomnia scale

BMI

Total

< 25

25-30

No insomnia

Number

% within BMI group

 

829

69.4%

 

579

70.8%

 

1399

69.95%

Insomnia

Number

% within BMI group

 

366

30.6%

 

235

29.2%

 

601

30.05%

Total     

Number

 % within BMI group

 

1195

100.0%

 

805

100.0%

 

2000

100.0%

P value

0. 492

 

 

Table 4. Results of assessment of participants using sleep apnea scale as regards participants’ age group.

 

SA-S scale

Age group in years

Total

20-

30-

40-

50-

Normal

Number

% within age

 

184

69.2%

 

219

66.4%

 

661

73.1%

 

334

66.3%

 

1398

69.9%

SA-S (mild)   

Number

% within age

 

87

29.3%

 

97

29.8%

 

223

24.6%

 

76

31.0%

 

554

27.6%

SA-S (moderate)     

Number

% within age

 

3

1.1%

 

7

2.2%

 

18

2.0%

 

13

2.6%

 

41

2.1%

SA-S (severe)    

Number

% within age

 

1

0.4%

 

2

0.6%

 

3

0.3%

 

1

0.2%

 

7

0.4%

Total     

Number

% within age

 

266

100.0%

 

325

100.0%

 

905

100.0%

 

504

100.0%

 

2000

100.0%

P-value

0.038*

* Significant at P<0.05

 

 

Table 5. Results of assessment of participants using sleep apnea scale as regards participants’ gender.

 

SA-S scale

Gender

Total

Male

Female

Normal

Number

% within sex group

 

906

70.6%

 

492

68.6%

 

1398

69.9%

SA-S(mild)   

Number

% within sex group

341

26.6%

213

29.7%

 

554

27.6%

SA-S (moderate)   

Number

% within sex group

 

31

2.4%

 

10

1.4%

 

41

2.1%

SA-S (severe)  

Number

% within sex group

 

5

0.4%.

 

2

0.3%

 

7

0.4%

Total Number

1283

717

2000

P value

0.761

 

 


Discussion

 

Sleep disorders are under-estimated in the general population studies due to many reasons such as that many sleep disorders may have either no symptoms or only vague or mild symptoms14. Another reason for the under-diagnosis of sleep disorders is a lack of proper understanding of the sleep health, either in the public or by medical professionals15.

In Egypt; studies investigating the epidemiology of sleep disorders among Egyptians  are scarce that can be due to false believe that the prevalence of sleep complaints are rare in comparison to other health problems, resource limitations, lack of valid data, difficulties in data gathering and limitation of programmed organizations and evaluation16.

In our study, it was found that about 601 participants (30.05%) out of 2000 had insomnia, 602 participants (30.10%) had sleep apnea. This is congruent with Morina et al.17, who found that of the total sample assessments using sleep disorder questionnaire, 35.3% were dissatisfied with their sleep, 29.9% reported insomnia symptoms, and 9.5% met criteria for an insomnia syndrome.

On discussing the demographic risk factors in relation to insomnia; a multivariable analyses were performed to examine effect of age as independent predictors on insomnia scale, we found no statistical significant difference between percentages of insomnia in different age groups; (P value = 0.413). These findings opposed that reported by Morina et al.17, who hypothesize that aging has great impact on sleep disorders.

An Egyptian study on insomnia symptoms in 2007 found that advanced age (≥ 75 years) was significantly associated with increased risk for early morning awakening, non-restful sleep and short sleep18. In contrast also to our results, a multivariate models on subjects age 15 and older: 4,972 in the United Kingdom, 4,115 in Germany and 3,970 in Italy. These subjects were representative of 160 million inhabitants indicate that the aging process per se is responsible for the increase of insomnia often reported in older people19. 

As regards the gender, our results showed that females had a significantly higher risk than males in developing insomnia as we found that participants who had insomnia were 366 males out of 601(28.5%) & 235 (32.8%) out of 601 participants were females with statistical significant difference (P value =0.047). These results are consistent with Klink et al.20, who stated that a strong risk factor for complaints of initiating and maintaining sleep was female gender.

In our results the mean BMI showed no relation with insomnia; agreeing with our results, a population-based, cross-sectional study has reported that no association was found between sleep duration and body weight in adults.21.

In contrast, Kripke et al.22 in their population-based study, described a monotonic trend in BMI (with values of 26-26.5) over the range of sleep duration (3 to ≥ 10 hours) in men. In women, however, they found a U shaped relationship between BMI and sleep duration, with both very short and very long sleep duration associated with high BMI.

In our study, we found that age was an independent risk factor for developing sleep apnea as individuals around 40s were more prone for than other age groups with significant P value (P value 0.038).

 

These results are congruent with what Edward et al.23 found as the age of distribution of sleep apnea based on Sleep Disorders Clinic criteria did not increase monotonically with age. Rather, the prevalence of this diagnosis changed with age in a quadratic fashion, increasing from over 1% in the youngest age group to almost 5% in the middle age group and then returning to less than 2% in the older subjects.

On looking to the gender as a risk factor for developing sleep apnea, we found no statistical significant difference between males and females. In contrast to our results, a Korean study done by Kim et al., showed that the prevalence of SDB was 27% and 16% in both men and women aged 40 to 69 years, respectively.

In our results, the mean BMI showed no relation with occurrence of sleep apnea. These findings were agreeing with our expectations as we excluded participants with BMI>30 to avoid effect of obesity on sleep.

 

[Disclosure: Authors report no conflict of interest]

 

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الملخص العربي

 

الأرق وتوقف التنفس الانسدادي أثناء النوم بين المصريين : دراسة بالمستشفى

 

لاضطرابات النوم تصنيف عالمي يضم حوالي سبعة وثمانين اضطرابا ولكل اضطراب تعريف خاص وطرق لتشخيصه. استعصاء النوم أو تقطعه أو انخفاض جودته، يعود سلبا على صحة المريض النفسية والجسدية. ويؤثر على نشاط المصاب خلال النهار.

تهدف هذه الدراسة إلى محاولة إلقاء الضوء على اضطرابات النوم ومعرفه مدي انتشارها بين الأفراد المصريين الأصحاء وذلك باستخدام استطلاعات اضطرابات النوم. شملت الدراسة 2000 من الأفراد الأصحاء (ذكور وإناث) تتراوح أعمارهم بين 20-60 عام، وتمت الدراسة في قسم وعيادة الأمراض العصبية بكلية الطب بجامعة القاهرة. وقد تم تقييم المرضى بعمل تقييم إكلينيكي وذلك بأخذ التاريخ الشخصي المفصل والفحص الإكلينيكي الكامل الي جانب تقييم من خلال استطلاع أعراض الأرق واستطلاع توقف التنفس أثناء النوم. وقد أظهرت نتائج البحث  أن 30.05٪ من المشاركين يعانون من الأرق بينما 30.1٪ من المشاركين يعانون من توقف التنفس أثناء النوم. وقد استخلصتا من البحث أن اضطرابات النوم شائعة الحدوث وترتبط بعوامل عديدة منها السن وجنس المريض وقد خرج البحث بالتوصيات الآتية: دراسة الموضوع من الجانب الوراثي والجيني وكذا تطبيق نتائج البحث للمساعدة علي تقييم واختيار العاملين في بعض الوظائف مثل السائقين والعاملين في فترات الليل.

 

 

 



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