0696 The O2VERLAP Study: High Cpap Use Levels Found In Overlap Syndrome (OSA And COPD) Patients

Introduction

CPAP therapy is prescribed to help manage disordered breathing during sleep time periods. Most users, especially those with non-severe obstructive sleep apnea (OSA), use it only for some portion of their sleep period. Patients with Overlap Syndrome have both OSA and chronic obstructive pulmonary disease (COPD). While there has been some research on CPAP use levels in this patient population, there has been little indication that they use CPAP any differently than those with OSA only.

Methods

The O2VERLAP Study was a large comparative effectiveness trial enrolling people with COPD and OSA and using two different methods of providing information and support to current users of CPAP therapy. The study utilized an electronic national recruitment strategy and 332 participants were enrolled. CPAP data from the 12-week study period was analyzed. The Pittsburgh Sleep Quality Index was used to determine both estimated total sleep period (TSP) and total sleep time (TST). Because participants were all current users of CPAP, data from the total sample was combined and used. The percentage of TST and TSP that CPAP was used was calculated as CPAP use divided by either TST or TSP.

Results

The mean TST was 6.8 hours, TSP was 8.1 hours, and CPAP use was 6.7 hours. CPAP was used during 98.5% of the TST and during 82.7% of the TSP. Over 35% of the sample used CPAP at a level that was equal to or greater than their total sleep period.

Conclusion

Most OSA study populations use CPAP for some fraction of their night’s sleep. This COPD/OSA study population used CPAP to a markedly high level, including over one-third of the sample (n=~100) who used CPAP more than their self-reported sleep period. Further research on the extent and reasons for non-sleep period (i.e., daytime) CPAP use in COPD patients is warranted.

Support

PPRND #1507-31666.

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.

Long-term follow-up of sleep disordered breathing in older adults

OBJECTIVE

The current study was designed to determine whether, with increasing age, sleep apnea improves, becomes worse, or stays the same.

BACKGROUND

There is a high prevalence of sleep disordered breathing (SDB) in older adults, but little is known about longitudinal changes. This study followed older adults to examine the natural history of SDB.

METHODS

Subjects were randomly selected community-dwelling elderly (n=427). A subset of subjects was studied approximately every 2 years over an 18-year period. Overnight sleep recordings and sleep questionnaires were completed at each time point.

RESULTS

Multiple linear regression showed that three variables were associated with change in respiratory disturbance index (RDI):body mass index (BMI) at initial visit (P=0.001), change in BMI (P=0.02), and a consistent self-report of high blood pressure (P=0.005). RDI increase was associated with BMI increase and presence of self-reported high blood pressure.

CONCLUSIONS

The changes in RDI that occurred were associated only with changes in BMI and were independent of age. This underscores the importance of managing weight for older adults, particularly those with hypertension.

Sleep apnea and health-related quality of life in African-American elderly

The relationship between health-related quality of life (HRQOL) and sleep apnea was examined in a sample of elderly African-Americans screened for snoring and daytime sleepiness. Seventy African-Americans over the age of 65 years completed a comprehensive sleep questionnaire, the Quality of Well-Being Scale (QWB), and the Medical Outcomes Study (MOS) Core Measures of HRQOL (116-item Long Version) and had sleep recorded. Those with moderate-severe sleep apnea had significantly lower Physical Component summary scores than those with no sleep apnea (p < 0.05). After controlling for medical conditions, sleep apnea was significantly related to both general physical functioning and general mental health functioning in those with mild apnea (apnea-hypopnea index [AHI] < 15), but not in those with moderate to severe apnea. There was an initial decrease in HRQOL up to an AHI level of 15, at which point HRQOL remained at a lowered level. The QWB scores of our sleep apnea sample were similar to the QWB scores found in patients with depression and chronic obstructive pulmonary disease (COPD), suggesting that sleep disturbances may impact daily living and health as much as other medical conditions.

Identification and treatment of sleep problems in the elderly

For many adults, changes in sleep occur with aging. An estimated 15 million elderly, or 50% of older Americans, experience some sleep problem. The elderly complain that their sleep is more fragmented and that as they have gotten older, they experience more daytime sleepiness. Laboratory studies have confirmed these complaints. Research has shown that it is not the need for sleep that decreases with age, but rather the ability to sleep. Circadian rhythm disturbances, sleep disorders such as sleep disordered breathing and periodic movements in sleep, medical illness, medication use, and impaired cognitive functioning all contribute to poor sleep and decreased daytime alertness. In institutionalized elderly, sleep is even more disturbed and disrupted. With careful assessment, many of these problems can be addressed and treated, and sometimes cured.

Evaluation of sleep disordered breathing with unattended recording: the Nightwatch System

There is a need for studies to determine how new ambulatory systems compare to traditional polysomnography (PSG). Thirty-four subjects were recorded with the Nightwatch (NW) System (Heathdyne Inc.) at home and then recorded with PSG in the laboratory. NW records were scored automatically using the NW algorithm with manual editing. There were no significant differences in mean RDI, AI, number of apneas or hypopneas or oximetry varibles between the systems. Correlations of RDI on the Nightwatch system and laboratory nights were significant (r = 0.63). Every case of RDI > or = 10 on the PSG was also identified by Nightwatch. Specificity was lower on Nightwatch (66%); however, all three cases of false positives could be explained physiologically, i.e. by body position. Overall the NW system correlated well with traditional PSG for respiratory disturbance.

Morbidity, mortality and sleep-disordered breathing in community dwelling elderly

A population-based probability sample of elderly individuals (n = 426), who were originally studied between 1981 and 1986 (mean age at initial study was 72.5 years), were followed for mortality. Those with > or = 30 respiratory disturbances per hour of sleep had significantly shorter survival (p = 0.0034), but the respiratory disturbance index (RDI) was not an independent predictor of death. When Cox proportional hazards analysis was done, only age (the strongest predictor), cardiovascular disease and pulmonary disease were independent predictors of death. It may be that factors that are secondary to or associated with sleep-disordered breathing (SDB), such as cardiovascular or pulmonary disease, predispose these elderly to death.

Sleep-disordered breathing in African-American elderly

Although sleep-disordered breathing (SDB) has been shown to be very prevalent in the elderly, little has been done to examine differences between the elderly of different racial groups. It has been well documented that SDB often results in hypertension and that hypertension is more common in African-Americans than in Caucasians. Therefore, one might suspect that SDB might be more common in African-Americans. Caucasians (n = 346) and African-Americans (n = 54) older than 65 yr of age were studied. African-Americans reported less satisfaction with sleep (p = 0.017), more difficulty falling asleep (p < 0.001), more daytime sleepiness (p = 0.0014), and more frequent morning headaches (p = 0.0043). African-Americans napped 0.8 times more frequently per evening (p = 0.05) and 11 min longer per nap (p = 0.019) than did Caucasians, and they showed a trend toward more total sleep time (428 versus 408 min). Of greater interest was the fact that more African-Americans had severe SDB with a relative risk twofold as great (relative risk = 2.13) as that for Caucasians, which was confirmed in a logistic regression analysis where race was associated with the presence of SDB (RDI > or = 30) independently of age, sex, and body mass index. The mean RDI for those African-Americans with severe SDB was significantly higher than that for Caucasians (72.1 versus 43.3; p = 0.014).

Natural history of sleep disordered breathing in community dwelling elderly

Mild sleep disordered breathing is very common in the elderly, but little is known about the course of the disorder over time. Twenty-four elderly people from a population-based study were recorded three times over an 8.5-year period. There were no significant changes in either apnea index or in respiratory disturbance index (RDI) over time, even when controlled for body mass index. For most subjects, there was great variability over time in the number of respiratory disturbances. The sensitivity of RDI > or = 15 at visit 1 predicting RDI > or = 15 at visit 3 was only 20%. The predictive value was 50%. Sleep disordered breathing measured at a single point in time is rather weakly predictive of the severity of breathing disorder 4-8 years later.