Daytime Sleepiness Relates to Snoring and Sleep Apnea in Women

In This Article

Abstract and Introduction

Abstract

Objectives: The aim was to investigate the significance of snoring and sleep apnea on daytime symptoms in a population-based sample of women.
Method: From the general population, 400 women aged 20 to 70 years were randomly selected, with oversampling of habitually snoring women. The women were investigated using full-night polysomnography and a questionnaire. The apnea-hypopnea index (AHI) was calculated, and women who acknowledged snoring loudly and disturbingly often or very often were considered habitual snorers.
Results: Habitual snoring was independently related to excessive daytime sleepiness (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.31 to 3.99), to falling asleep involuntarily during the day (OR, 2.11; 95% CI, 1.06 to 4.21), to waking up unrefreshed (OR, 2.14; 95% CI, 1.30 to 3.52), to daytime fatigue (OR, 2.77; 95% CI, 1.54 to 4.99), and to a dry mouth on awakening (OR, 2.00; 95% CI, 1.22 to 3.27) after adjustment for AHI, age, body mass index (BMI), smoking, total sleep time, percentage of slow-wave sleep, and percentage of rapid eye movement (REM) sleep. An AHI≥15/h was only related to a dry mouth on awakening after adjustment for snoring, age, BMI, smoking, total sleep time, percentage of slow-wave sleep, and percentage of REM sleep (OR, 2.24; 95% CI, 1.14 to 4.40). An AHI of 5 to 15/h was not related to any daytime symptom.
Conclusions: Excessive daytime sleepiness and daytime fatigue are related to habitual snoring independent of the apnea-hypopnea frequency, age, obesity, smoking, and sleep parameters in a population-based sample of women, but not to the AHI. This indicates that snoring is an independent cause of excess daytime sleepiness and not merely a proxy for sleep apnea.

Introduction

Approximately 7 to 15% of women snore habitually, and 2 to 2.5% of women have obstructive sleep apnea syndrome (OSAS) with nocturnal apneas and daytime sleepiness.^{[1,2,3,4,5,6]} A frequency of 5 to 15 apneas and hypopneas per hour of sleep is generally considered as mild sleep apnea, and a frequency>15/h indicates moderate-to-severe sleep apnea.^[7]

Excessive daytime sleepiness is the main symptom of OSAS, while snoring is often regarded as a harmless sign of the disorder. Other symptoms of sleep apnea in women include fatigue, morning headache, nocturia, and dry mouth at awakening.^{[1,8,9,10,11]} Young and colleagues^[1] reported daytime sleepiness in snoring men and women in the general population without sleep apnea, and that a majority of men and women with sleep apnea do not complain of daytime sleepiness. Gottlieb and colleagues^[12] reported an increased score in the Epworth sleepiness scale (ESS) score in snoring men and women in different categories of the apnea-hypopnea frequency. Symptoms of sleep apnea are also reported to occur at a lower apnea-hypopnea index (AHI) in women as compared with men.^[13] We found no previous study investigating whether typical symptoms of sleep apnea are related to the AHI independent of snoring and vice versa. The aim of this study was to investigate the significance of snoring and nocturnal apneas on daytime symptoms in a population-based sample of women.

Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/misc/reprints.shtml).

Cite this: Daytime Sleepiness Relates to Snoring Independent of the Apnea-hypopnea Index in Women From the General Population - Medscape - Nov 01, 2008.

Table 1. Population Characteristics*
Variables	Total Population(n=395)	Total Population According to AHI					Total Population According to Snoring Status
Variables	Total Population(n=395)	AHI < 5/h(n=133)	AHI 5 to < 15/h(n=128)	p Value	AHI ≥ 15/h(n=134)	p Value	Nonsnorers(n=234)	Snorers(n=161)	p Value
AHI, events/h	14±16	2±1	9±3		30±17		11±15	18±6	^†
Age, yr	50±11	44±11	51±10		56±9	^‡	48±12	53±9	^†
BMI, kg/m²	27±5	25±4	27±5	^‡	29±5	^†	26±4	28±5	^†
Habitual snoring	38	21	39		55	^†	0	100
Smoking	21	22	18		24		17	28	^§
Total sleep time, min	388±68	398±64	387±73		378±65		388±71	388±63
Slow-wave sleep, %	10±6	11±6	9±5		9±6		10±6	9±6
REM sleep, %	18±6	19±6	18±6		16±6		18±6	18±6

*Data are presented as mean±SD or %; p values for continuous variables according to AHI category are calculated using analysis of variance equality of variances; p value for trend is given for habitual snoring according to AHI category.
†p < 0.0001.
‡p < 0.005.
§p < 0.05.

Table 2. Habitual Snoring and Daytime Symptoms, Univariate and Multivariate Analysis
Variables	Nonsnorers (n=234)	Snorers (n=161)	p Value
ESS score ≥ 10, %	36	44	0.2
Adjusted OR (95% CI)*	1	1.35 (0.86-2.14)
Excessive daytime sleepiness, %	16	30	0.004
Adjusted OR (95% CI)*	1	2.28 (1.31-3.99)
Falling asleep involuntarily during the daytime, %	9	17	0.03
Adjusted OR (95% CI)*	1	2.11 (1.06-4.21)
Waking up unrefreshed, %	21	37	0.003
Adjusted OR (95% CI)*	1	2.14 (1.30-3.52)
Daytime fatigue, %	13	30	0.0007
Adjusted OR (95% CI)*	1	2.77 (1.54-4.99)
Headaches on awakening, %	28	40	0.06
Adjusted OR (95% CI)*	1	1.57 (0.98-2.51)
Dry mouth on awakening, %	20	41	0.006
Adjusted OR (95% CI)*	1	2.00 (1.22-3.27)
Nocturia, %	38	48	0.5
Adjusted OR (95% CI)*	1	1.16 (0.73-1.85)

*Adjusted for age, BMI, AHI, smoking, total sleep time, percentage of REM sleep, and percentage of slow-wave sleep.

Table 3. AHI and Daytime Symptoms, Univariate and Multivariate Analysis
Variables	AHI < 5/h(n=133)	AHI 5 to < 15(n=128)	p Value	AHI ≥ 15/h(n=134)	p Value
ESS score ≥ 10, %	37	36	0.97	45	0.2
Adjusted OR (95% CI)*	1	1.01 (0.58-1.75)		1.48 (0.81-2.70)
Excessive daytime sleepiness, %	18	22	0.4	25	0.5
Adjusted OR (95% CI)*	1	1.33 (0.068-2.62)		1.29 (0.62-2.69)
Falling asleep involuntarily during the daytime, %	8	12	0.4	15	0.3
Adjusted OR (95% CI)*	1	1.42 (0.58-3.48)		1.59 (0.61-4.14)
Waking up unrefreshed, %	24	30	0.4	32	0.7
Adjusted OR (95% CI)*	1	1.31 (0.71-2.40)		1.13 (0.58-2.21)
Daytime fatigue, %	18	21	0.6	22	0.8
Adjusted OR (95% CI)*	1	1.22 (0.60-2.47)		0.91 (0.42-1.98)
Headaches on awakening, %	31	32	0.8	37	0.8
Adjusted OR (95% CI)*	1	0.91 (0.52-1.61)		0.92 (0.49-1.71)
Dry mouth on awakening, %	16	27	0.3	43	0.02
Adjusted OR (95% CI)*	1	1.44 (0.75-2.75)		2.24 (1.14-4.40)
Nocturia, %	29	43	0.5	55	0.1
Adjusted OR (95% CI)*	1	1.24 (0.70-2.18)		1.68 (0.90-3.12)

*Adjusted for age, BMI, habitual snoring, smoking, total sleep time, percentage of REM sleep, and percentage of slow-wave sleep.

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