Sleep-disordered breathing in the healthy elderly. Clinically significant?

We evaluated sleep/wake, medical, and psychological parameters in a cohort of healthy men and women between 50 and 80 years of age. Consistent with previous investigations of sleep-disordered breathing (SDB) in older persons, nocturnal breathing disturbances were quite common in our normal-aged subjects, with more than 15 percent experiencing five or more SDB events per hour of sleep. However, when SDB indices were correlated with comprehensive measures of daytime functioning, the number of statistically significant relationships was at or below expectations from chance alone. Additionally, comparison of high-SDB subjects (AHI greater than or equal to 5) with low-SDB subjects (AHI less than 5) failed to reveal reliable differences on measures of daytime functioning. We conclude that SDB occurring in otherwise healthy older persons is not a cause for immediate concern, although longitudinal studies may yet demonstrate significant long-term sequelae of SDB in this population.     

Geriatric sleep apnea syndrome: a preliminary description

We compared 8 patients diagnosed with geriatric sleep apnea syndrome (GSAS) with 12 healthy older controls (GCON) matched on age, sex, weight, education, and socioeconomic standing. GSAS was diagnosed if patients had an apnea + hypopnea index (AHI) greater than or equal to 10 and an impairment involving at least two of the following: hypertension, cardiac arrhythmias, or daytime hypersomnolence. In addition to significant differences on selection variables (e.g., AHI, frequency of hypertension, Multiple Sleep Latency Test), GSAS patients had significantly more sleep disturbance, were sleepier on subjective measures, were more depressed, and had lower scores on tests of nonverbal problem solving and nonverbal memory. Thus, GSAS resembles SAS described in middle-aged populations. More research is needed to determine the most efficient diagnostic parameters for identifying pathological levels of SDB in older persons.     

The effect of correction of sleep-disordered breathing on BP in untreated hypertension

OBJECTIVES: To compare BP response to 3 weeks of nasal continuous positive airway pressure (CPAP) in hypertensive patients with and without sleep-disordered breathing (SDB). DESIGN: A controlled, interventional trial of nasal CPAP in patients with and without SDB. Participants and setting: Twenty-four men, aged 30 to 60 years, with mild to moderate untreated hypertension recruited from employee health and primary care clinics. METHODS: Based on in-laboratory polysomnography, 14 hypertensive patients had SDB, defined by five or more episodes of apnea and hypopnea per hour of sleep (apnea-hypopnea index [AHI], > or = 5), and 10 had no SDB (AHI, < 5). We performed 24-h ambulatory BP monitoring on all patients at baseline, during CPAP, and after CPAP treatment. In patients with an AHI > or = 5, nasal CPAP was titrated to reduce the AHI to < 5. Patients with an AHI < 5 received CPAP of 5 cm H(2)O to control for any potential effect of CPAP per se on BP. Both groups received CPAP for 3 weeks. RESULTS: After adjusting for age and body mass index, the mean nocturnal systolic and diastolic BP changes after CPAP treatment in the SDB group were significantly different from those in the no-SDB group: -7.8 vs +0.3 mm Hg (p = 0.02), and -5.3 vs -0.7 mm Hg (p = 0.03), respectively. There was a similar, although statistically insignificant, difference in the adjusted mean daytime systolic and diastolic BP changes after CPAP treatment between the two groups (-2.7 vs +0.4 mm Hg and -2.3 vs -1.7 mm Hg, respectively). CONCLUSIONS: Three weeks of nasal CPAP treatment of SDB in hypertensive men caused the lowering of nocturnal systolic and diastolic BP values, suggesting that increased nocturnal BP in persons with hypertension was causally related to the apnea and hypopnea events of SDB.     

A community study of sleep-disordered breathing in middle-aged Chinese men in Hong Kong

BACKGROUND: Sleep-disordered breathing (SDB) in Asian populations is being increasingly recognized. This study investigated the prevalence of SDB in Chinese middle-aged office-based male workers in Hong Kong. METHODS: Sleep questionnaires were distributed to 1,542 men (age range, 30 to 60 years), and 784 questionnaires were returned. Subsequently, full polysomnographic (PSG) examinations were conducted in 153 questionnaire respondents. Subjects with an apnea-hypopnea index (AHI) > or =5 were recalled for clinical assessment. RESULTS: Questionnaire respondents were similar in age and body mass index (BMI) to the general community in the target age range and gender. Habitual snoring was reported by 23% of this cohort and was associated with excessive daytime sleepiness (EDS), hypertension, witnessed abnormal breathing pattern, BMI, and leg movements during sleep. Allowing for subject bias in undergoing PSG, the estimated prevalence of SDB and obstructive sleep apnea syndrome (OSAS) (defined as SDB in the presence of EDS) at various AHI cutoff threshold values was 8.8% and 4.1% (AHI > or =5), 6.3% and 3.2% (AHI > or =10), and 5.3% and 3.1% (AHI > or =15). Multiple stepwise logistic regression analysis identified BMI, habitual snoring, time taken to fall asleep, and age as predictors of SDB at AHI > or =5. Analysis of anthropometric parameters indicated that the relative risk of OSAS attributable to obesity was less than in white subjects. CONCLUSION: This community-based study of sleep apnea among middle-aged men in Hong Kong using full PSG demonstrated an estimated prevalence of OSAS (AHI > or =5 and EDS) at 4.1%. Increasing BMI and age were associated with SDB, although factors other than adiposity may also have an important pathogenic role in OSA in Chinese subjects.     

Predictors of sleep-disordered breathing in community-dwelling adults: the Sleep Heart Health Study

BACKGROUND: Sleep-disordered breathing (SDB) is common, but largely undiagnosed in the general population. Information on demographic patterns of SDB occurrence and its predictive factors in the general population is needed to target high-risk groups that may benefit from diagnosis. METHODS: The sample comprised 5615 community-dwelling men and women aged between 40 and 98 years who were enrolled in the Sleep Heart Health Study. Data were collected by questionnaire, clinical examinations, and in-home polysomnography. Sleep-disordered breathing status was based on the average number of apnea and hypopnea episodes per hour of sleep (apnea-hypopnea index [AHI]). We used multiple logistic regression modeling to estimate cross-sectional associations of selected participant characteristics with SDB defined by an AHI of 15 or greater. RESULTS: Male sex, age, body mass index, neck girth, snoring, and repeated breathing pause frequency were independent, significant correlates of an AHI of 15 or greater. People reporting habitual snoring, loud snoring, and frequent breathing pauses were 3 to 4 times more likely to have an AHI of 15 or greater vs an AHI less than 15, but there were weaker associations for other factors with an AHI of 15 or greater. The odds ratios (95% confidence interval) for an AHI of 15 or greater vs an AHI less than 15 were 1.6 and 1.5, respectively, for 1-SD increments in body mass index and neck girth. As age increased, the magnitude of associations for SDB and body habitus, snoring, and breathing pauses decreased. CONCLUSIONS: A significant proportion of occult SDB in the general population would be missed if screening or case finding were based solely on increased body habitus or male sex. Breathing pauses and obesity may be particularly insensitive for identifying SDB in older people. A better understanding of predictive factors for SDB, particularly in older adults, is needed.     

Blood pressure associated with sleep-disordered breathing in a population sample of children

The current criteria for sleep-disordered breathing (SDB) in children are not based on a clinically relevant outcome. The purpose of this study was to assess the association of blood pressure with SDB in a random sample of the local elementary school children (kindergarten through grade 5) using a 2-phased strategy. During phase 1, a brief questionnaire was completed for all of the children (N=5740) with a response rate of 78.5%. During phase 2, 700 randomly selected children from phase 1 with a response rate of 70.0% were assessed with a full polysomnograph and a history/physical, including an ECG; ear, nose, and throat; and pulmonary evaluation. We observed a significantly elevated systolic blood pressure associated with the apnea hypopnea index (AHI): AHI >or=1 (2.9 mm Hg); AHI >or=3 (7.1 mm Hg); and AHI >or=5 (12.9 mm Hg). The SDB and blood pressure association remained significant after adjusting for age, sex, race, body mass index percentile or waist circumference, sleep efficiency, percentage of rapid eye movement sleep, and snoring. In addition, older age, body mass index percentile, waist circumference, and snoring were significantly associated with blood pressure, independent of SDB. Based on these findings, our study suggests that SDB is significantly associated with higher levels of systolic blood pressure in children aged 5 to 12 years even after adjusting for the various confounding factors. Clinically, the data support the threshold of AHI >or=5 for the initiation of treatment for SDB. Additional research is indicated to assess the efficacy of SDB treatment on reducing blood pressure.     

Risk factors for sleep disordered breathing in heterogeneous geriatric populations

This cross-sectional, multivariate study investigated associations between sleep disordered breathing (SDB) and putative risk factors in a heterogeneous group of 720 individuals over the age of 50 years studied during all-night in-lab polysomnography. Results indicated that: aged men were more likely to show impaired respiration during sleep than aged women; excessive daytime somnolence and parasomniac symptoms (snoring, gasping during sleep) were associated with SDB but insomnia was not; obesity accounted for more variance in SDB than age per se, implying that the prevalence of SDB in some elderly persons could be related to the deposition of body fat seen as individuals grow older. All four risk factors (age, sex, obesity, and symptomatic status) were statistically significant and independent predictors of impaired respiration in sleep in the elderly.     

Daytime polysomnography for early diagnosis and treatment of patients with suspected sleep-disordered breathing

Excessive daytime sleepiness (EDS) is a common complaint among patients with sleep-disordered breathing (SDB). Population-based studies on traffic and industrial accidents suggest a relationship between EDS and life-threatening events, and adults with EDS have cognitive and memory problems. Nocturnal polysomnography (nPSG) is essential for diagnosing SDB but it is time and energy consuming. We examined the usefulness of daytime polysomnography (dPSG) for the early diagnosis and treatment of patients with suspected SDB. We studied 108 consecutive patients aged 51.9 +/- 13.5 years (mean+/-SD). All patients underwent dPSG and nPSG. The number of apnea/hypopnea episodes per hour (apnea/hypopnea index: AHI) and the number of 3% desaturation episodes per hour (desaturation index: DSI) were calculated. All patients were classified into two groups. The REM group consisted of subjects who had an AHI < or = 25/h, AHI(REM)/AHI(NREM) > 2, and AHI(NREM) < 15/h. Those who did not satisfy these criteria were placed in the NREM group. Continuous positive airway pressure (CPAP) titration was performed for patients whose AHI was > or =20/h on dPSG. Using the international classification of sleep disorders, 96 patients were diagnosed as obstructive sleep apnea [including five upper airway resistance syndrome (UARS) patients], six patients were snoring, four had idiopathic hypersomnia due to a medical condition, and two had circadian rhythm sleep disorders. The sensitivity of dPSG for AHI was 81.0%, specificity was 100%, and accuracy was 83.5%. The sensitivity and accuracy of dPSG for AHI in the REM group were considerably lower than in the NREM group. There was no significant difference for optimal CPAP between dPSG and nPSG. In the five patients with UARS, their AHI, DSI, and arousal index on dPSG were 0.92 +/- 1.2/h, 2.9 +/- 3.4/h, and 29.3 +/- 3.5/h, respectively, and their AHI and DSI on nPSG were 3.2 +/- 2.5/h and 2.8 +/- 2.4/h, respectively. However, their respiratory effort-related arousals were 37.9 +/- 7.4/h, and their arousal index was 33.2 +/- 6.3/h. The five patients with UARS were also treated with CPAP, and their daytime sleepiness was improved. Although dPSG has limitations, these results indicate that dPSG recording is clinically useful for the diagnosis of and determination of types of treatment in patients with suspected SDB.     

Electrocardiographically indicated cardiovascular disease in sleep-disordered breathing

The evidence for a role of sleep-disordered breathing (SDB) in cardiovascular disease (CVD) is inconclusive and limited to clinic-based studies or population-based studies using historical CVD data. The authors investigated cross-sectional association of SDB, assessed by overnight polysomnography and described by frequency of apnea/hypopnea episodes (Apnea-Hypopnea Index, AHI), with screen-detected CVD consisting of cardiologist-confirmed, electrocardiographically indicated coronary artery disease (ECG-CAD), left ventricular hypertrophy (ECG-LVH), arrhythmias, and conduction abnormalities in a general population. Using multiple logistic regression with adjustments for covariables, there was no significant association of AHI with ECG-CAD, ECG-LVH by voltage, arrhythmias, or conduction abnormalities. There was, however, an association between AHI and ECG-LVH by Cornell criteria. Using AHI as categorical variable, the adjusted odds of ECG-CAD in AHI >or= 5 vs <5 was increased, but not significantly, at 1.30, 95% confidence interval (CI) 0.67, 2.51. The adjusted odds of ECG-LVH by Cornell criteria in AHI >or= 15 vs <5 was significant at 3.19, 95% CI 1.16, 8.76. The authors found a weak or no association between screen-detected CVD and sleep apnea, but did find a threefold increased odds of screen-detected LVH, using Cornell criteria, in moderate or worse SDB. These findings contribute to accumulating evidence of possible association between CVD and sleep apnea in the general population and underscore the need to better understand how SDB affects cardiovascular pathology.     

Prevalence and severity of sleep disordered breathing in a group of morbidly obese patients.

BACKGROUND: Obesity may be complicated by sleep disordered breathing (SDB). The presence of SDB is associated with increased morbidity and mortality. Patient characteristics, pulmonary function tests and daytime arterial blood gas analyses may help to identify patients with SDB. These variables and the prevalence and severity of sleep disordered breathing were studied in a group morbidly obese patients. METHODS: Forty-eight patients, 19 men and 29 women who were referred to our clinic of internal medicine because of their obesity were included. Characteristics, pulmonary function tests and daytime arterial blood gas analyses of groups with different grades of SDB were compared. RESULTS: Male subjects had significantly more apnoeas/hypopnoeas per hour (AHI) (18.4 +/- 20.9 versus 4.8 +/- 9.4) with more desaturation, a lower mean saturation (92.6 +/- 4.1 versus 96.1 +/- 1.6) and a lower saturation nadir (73.8 +/- 12.0 versus 83.1 +/- 6.7). Five (26%) of the male subjects and none of the female subjects had severe SDB (AHI > or = 25). Subjects were divided into three groups according to the severity of their SDB: twenty-nine subjects (23 women and 6 men) with AHI < 5, 14 subjects (6 women and 8 men) with AHI > or = 5 and < 25 and 5 subjects, all men, with AHI > or = 25. Except for gender no significant differences were found between the three groups. CONCLUSION: Our study confirms the findings that morbidity obese men have SDB more frequently and more severely than obese women. Patient characteristics other than gender, pulmonary function tests and daytime blood gas analyses have no predictive value.     

Symptom burden of sleep-disordered breathing in mild-to-moderate congestive heart failure patients.

The symptom burden resulting from sleep-disordered breathing (SDB) in patients with mild-to-moderate congestive heart failure (CHF) is unclear. The current authors monitored 24-h activity levels and compared subjective and objective measures of daytime sleepiness in 39 CHF patients, New York Heart Association class 2-3, on optimal medication. A total of 22 patients were classified as SDB (apnoea/hypopnoea index (AHI) median (range) 22.3 (16.6-100) events.h-1), and 17 as no SDB (NoSDB; AHI 3.7 (0-12.3) events.h-1). SDB was defined as AHI>or=15 events.h-1. Patients were assessed by 24-h activity monitoring (actigraphy) for a period of up to 14 days, a single objective sleepiness test (Oxford Sleep Resistance test) and Epworth Sleepiness Scale. The duration of daytime activity was significantly shorter in the SDB group compared with the NoSDB group. The SDB group also had increased time in bed and poorer sleep quality, as shown by the fragmentation index. Objectively the SDB group when compared with the NoSDB group were significantly sleepier, subjectively the groups did not differ. The amount of napping was similar for both groups. Despite the lack of subjective symptoms of daytime sleepiness, congestive heart failure patients with sleep-disordered breathing were objectively sleepier during the day and had reduced daytime activity with longer periods in bed and poorer sleep quality when compared with those without sleep-disordered breathing.     

A community study of sleep-disordered breathing in middle-aged Chinese women in Hong Kong: prevalence and gender differences

STUDY OBJECTIVES: To investigate the prevalence of sleep-disordered breathing (SDB) and obstructive sleep apnea syndrome (OSAS) in community-based, middle-aged Chinese women, and to compare the differences between gender with a similar study in men. DESIGN: A cross-sectional study conducted in Hong Kong from 1998 to 2000. SETTING: Sleep questionnaires were distributed to women (30 to 60 years old) in three offices and two community centers. All were invited to undergo full polysomnography in a sleep laboratory. PARTICIPANTS: Questionnaires were distributed to 1,532 women, and 854 questionnaires were returned. Polysomnography was conducted in 106 respondents. Measurements and results: Conservative estimated prevalence of SDB (apnea-hypopnea index [AHI] > = 5) and OSAS (AHI > or = 5 plus excessive daytime sleepiness [EDS]) were 3.7% and 2.1%, respectively. Age-specific prevalence of OSAS was 0.5%, 2.2%, and 6.1% in the 30- to 39-year-old, 40- to 49-year-old, and 50- to 60-year-old age groups, respectively. Stepwise multiple logistic regression analysis identified body mass index (BMI) and age as predictors of SDB. Compared to Chinese men, the prevalence of SDB and OSAS in women was lower, but the gender difference decreased with age. The AHI of affected women was also significantly lower despite comparable BMI. Compared to men, women with SDB had same degree of self-reported snoring and a similar degree of EDS despite the lower AHI. CONCLUSIONS: This study demonstrated an estimated prevalence of OSAS at 2.1% among middle-aged Chinese women in Hong Kong, with a 12-fold rise from the fourth to the sixth decade of life. BMI and age were significant independent predictors of SDB. Compared to men, women with SDB had lower AHIs, despite similar BMIs.     

Changes in cognitive function associated with sleep disordered breathing in older people

OBJECTIVES: Sleep disordered breathing (SDB) is very common in older people and is known to be associated with complaints of impaired daily functioning, including excessive daytime sleepiness and cognitive impairments. As part of a larger study on SDB and aging, it became possible to examine the relationship between SDB and cognition in older men and women. DESIGN: A population-based longitudinal study. SETTING: In-home interviews and home sleep recordings in the greater San Diego area. PARTICIPANTS: Community-dwelling people age 65 and older with high risk for SDB were originally studied from 1981 through 1985 and then followed every 2 years. Data from the 46 subjects who completed Visit 3 and Visit 4 are presented. MEASUREMENTS: Subjects were interviewed in the home about their sleep and medical condition before each visit. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Daytime sleepiness was based on self-report. Objective sleep was recorded in the home and scored for sleep, apneas and hypopneas, and oximetry variables. RESULTS: Increases in respiratory disturbance index (RDI) (P= .036) and increases in daytime sleepiness (P= .002) were associated with decreases in cognitive performance (i.e., increases in cognitive impairment). Increases in RDI were also associated with increases in daytime sleepiness (P= .012). Change in MMSE scores was therefore regressed onto changes in RDI, daytime sleepiness, age, and education, resulting in decreases in MMSE scores being associated with increases in daytime sleepiness (P= .019) but not with changes in RDI (P= .515). There was no significant relationship between changes in oxygen saturation levels and changes in MMSE. CONCLUSIONS: The results of this study suggest that declining cognitive function is associated primarily with increases in daytime sleepiness. Although cognitive decline was also associated with increases in RDI, this association did not hold in the more inclusive model which also included variable of SDB, oximetry, sleep and subjective report. One theoretical model could suggest that any relationship between SDB and cognitive function may be mediated by the effect of SDB on daytime sleepiness. These results suggest that older patients suffering from mild to moderate SDB may benefit from the treatment of SDB, even if they are not markedly hypoxemic.     

Incidence of sleep-disordered breathing in patients with hypertrophic cardiomyopathy

The authors investigated the prevalence of sleep-disordered breathing (SDB) together with its clinical correlations in patients with hypertrophic cardiomyopathy (HCM). A total of 113 consecutive patients including 63 patients with HCM (40 men; mean age, 59.5±13.0 years; New York Heart Association class, 2.0±0.9) underwent cardiorespiratory polygraphy in addition to their clinical work-up including echocardiography. Patients with an apnea-hypopnea-index (AHI) ≥5/h were considered to have SDB. If thoracic and abdominal inspiration efforts were documented, SDB was considered to be obstructive sleep apnea (OSA), otherwise SDB was considered to be central sleep apnea (CSA). The age- and sex-matched control group of 50 patients had exclusion of coronary artery disease by angiography, and normal left ventricular (ejection fraction ≥55%) and valvular function. SDB was diagnosed in 52 patients (82.5% vs 72% in the control group; P =not significant) with a mean AHI of 23.0±17.8/h. Severity of SDB was higher in patients with HCM than in the control group (AHI 12.2±7.6/h; P =.003). OSA was documented in 39 patients (AHI 21.2±16.5/h) and CSA in 13 (AHI 28.4±20.9/h). The severity of SDB correlated with New York Heart Association functional class (η=0.9, η(2) =0.811) and with left ventricular end-diastolic (r=0.6, P <.01) and left atrial (r=0.4, P <.01) diameter. No correlations were found between SDB and other clinical or echocardiographic parameters. SDB is common in patients with hypertrophic cardiomyopathy, with a predominance of OSA and correlations with markers of left ventricular function.     

Continuous respiratory monitoring for sleep apnea screening by ambulatory hemodynamic monitor

AIM:To validate the sleep-disordered breathing components of a portable electrocardiography and hemodynamic monitor to be used for sleep apnea screening.METHODS:Sleep-disordered breathing(SDB) is associated with cardiovascular disease.Patients with existing cardiovascular disease may have unrecognized SDB or may develop SDB while under the care of a cardiologist.A screening device for SDB,easy to use and appealing to cardiologists,would assist in referral of appropriate patients for full polysomnography(PSG).A cardiac and respiratory monitor(CPAM) was attached to patients undergoing PSG and an apnea/hypopnea index(AHI) generated.The CPAM device produced respiration rate,snoring rate,individual apnea/hypopnea events and an SDB severity score(SDBSS).In addition to AHI,an expert over-reader annotated individual breaths,snores and SDB breathing events to which the automated algorithms were compared.RESULTS:The test set consisted of data from 85 patients(age:50.5 ± 12.4 years).Of these,57 had a positive PSG defined as AHI ≥ 5.0(mean:30.0 ± 29.8,negative group mean:1.5 ± 1.2).The sensitivity and specificity of the SDBSS compared to AHI was 57.9% and 89.3%,respectively.The correlation of snoring rate by CPAM compared to the expert overreader was r = 0.58(mean error:1.52 snores/min),while the automated respiration rate had a correlation of r = 0.90(mean error:0.70 breaths/min).CONCLUSION:This performance assessment shows that CPAM can be a useful portable monitor for screening and follow-up of subjects for SDB.     

Women with Sleep Apnea Have Lower Levels of Sex Hormones

Background: Low levels of sex hormones, especially progesterone, are suspected as a risk factor for sleep-disordered breathing (SDB). Objective: To test the hypothesis that serum levels of progesterone, estradiol, and 17-OH progesterone are lower in those women with clinically significant SDB. Design: Clinical cohort of convenience. Setting: University Hospital Sleep Laboratory. Methods: We investigated sleep and breathing parameters and serum levels of sex hormones in 53 consecutive women (ages 24 to 72 years) being evaluated for symptoms of daytime sleepiness. Analysis of hormonal status by specific radioimmunoassays and fluorescence immunoassays was done from blood samples taken after an overnight polysomnography. Results: Across the cohort, taking account of age and cycle time or postmenopausal status, those with an apnea-hypopnea index (AHI) greater than 10/hrs of sleep had significantly lower levels of 17-OH progesterone, progesterone, and estradiol than those with an AHI less than 10. Conclusion: We conclude that reductions in female sex hormones are associated with an increased probability of SDB in women with daytime sleepiness.     

Sleep-disordered breathing and nocturia in older adults

OBJECTIVES: To investigate the relationship between sleep-disordered breathing (SDB) and nocturia episodes in community-dwelling older adults. DESIGN: A cross-sectional study. SETTING: Community. PARTICIPANTS: Community-dwelling older adults (N=72) recruited from independent living facilities and adult learning centers in Atlanta, Georgia. MEASUREMENTS: Three-day voiding diary, ambulatory sleep recording, focused physical examination, Epworth Sleepiness Scale, and Geriatric Depression Scale. RESULTS: Fifty-eight of the 72 subjects completed the study. The mean age+/-standard deviation was 77.7+/-6.7; 44 (76%) were female. Of the 58 subjects, 26 (45%) had an apnea-hypopnea index (AHI) of less than 10 per hour of sleep, 21 (36%) had an AHI between 10 and 24 per hour sleep, and 11 (19%) had an AHI of 25 or higher per hour of sleep. The mean nocturia episodes were 1.7+/-1.1, 1.6+/-0.9, and 2.6+/-1.4 for subjects in these groups, respectively (F=3.82; P=.028). Those with an AHI of 25 or higher had more nocturia episodes, higher mean arterial blood pressure, and higher body mass index than those with a lower AHI. CONCLUSION: These results suggest that older adults with severe SDB have a greater number of nocturia episodes. These findings underscore the importance of considering SDB as a differential diagnosis in the evaluation of older patients with nocturia.     

Sleep disordered breathing in the elderly

Sleep disordered breathing (SDB), i.e., obstructive, central or mixed sleep apneas, has been recognized as a common occurrence in the elderly. Aging is per se associated with a decrease in the quality of sleep; SDB may further disrupt the sleep architecture in older subjects. The prevalence of obstructive sleep apnea (OSA) increases with aging; available studies report prevalence rates of 11-62%. Furthermore, OSA has been associated with increased mortality in older adults. Central apneas and periodic breathing occur with increased frequency either in subjects with neurological disorders such as infarction, tumor, sequelae of infection, diffuse encephalopathies, or in chronic heart failure. Patients with cerebrovascular disease (stroke, or transient ischemic attacks) have a markedly high prevalence of SDB, mainly OSA. In these patients, SDB is associated with a poorer functional prognosis at 3 and 12 months after the acute event, and a higher mortality. The clinical impact of SDB on cognitive function appears to be modest in patients without dementia, although there is a moderate increase in daytime sleepiness. In Alzheimer's disease (AD) however, SDB occurs more frequently than in non-demented older subjects, and its severity is correlated with the degree of cognitive impairment. The hypothesis of a causal relationship between AD and SDB remains a subject of controversy. The possibility of SDB should be considered in the elderly in the differential diagnosis of "reversible dementias", increased daytime sleepiness, or unexplained right-sided heart failure.     

Effects of environment light during sleep on autonomic functions of heart rate and breathing

Purpose

Poor sleep hygiene including sleeping in the daytime or with the lights on at night is discovered during the assessment of many sleep disorders including sleep apnea. The aim of this study was to investigate whether environmental light affected autonomic control of heart rate, sleep-disordered breathing (SDB), and/or breathing patterning.

Methods

Seventeen non-obese healthy volunteers without witnessed snoring and apneas were recruited. Studies were performed at home using a type 3 portable monitor combined with actigraphy for sleep-wake timing, using a randomly assigned, crossover between dark, or 1,000 lx of fluorescent lighting environment. The outcomes were low-frequency power divided by high-frequency power (LF/HF ratio) in the analysis of heart rate variability, the apnea-hypopnea index (AHI), and ventilatory pattern variability before and after sleep onset between environments.

Results

The LF/HF ratio and AHI were both significantly higher in light as compared to dark. Before sleep onset, the coefficient of variation (CV) for breath-to-breath tidal volume representing breathing irregularity tended to be higher in light than in dark environment. The CV values for tidal volume after sleep onset were significantly decreased compared with before sleep onset in both sleep environments. Mutual information of the ventilatory pattern was significantly lower before sleep onset than after sleep onset, only in the light environment.

Conclusions

Sleeping in the light has effects like that of a stressor as it is associated with neuroexcitation, SDB, and resting breathing irregularity in healthy volunteers. These findings may be relevant to many sleep disorders associated with poor sleep hygiene.