Severity of OSAS, CPAP and cardiovascular events: A follow-up study.

BACKGROUND: Previous studies suggested obstructive sleep apnoea syndrome (OSAS) as a major risk factor for incident cardiovascular events. However, the relationship between OSAS severity, the use of continuous positive airway pressure (CPAP) treatment and the development of cardiovascular disease is still matter of debate. STUDY OBJECTIVES: The aim was to test the association between OSAS and cardiovascular events in patients with concomitant cardio-metabolic diseases and the potential impact of CPAP therapy on cardiovascular outcomes. METHODS: Prospective observational cohort study of consecutive outpatients with suspected metabolic disorders who had complete clinical and biochemical workup including polysomnography because of heavy snoring and possible OSAS. The primary endpoint was a composite of major adverse cardiovascular and cerebrovascular events (MACCE). RESULTS: Median follow-up was 81.3 months, including 434 patients (2701.2 person/years); 83 had a primary snoring, 84 had mild, 93 moderate and 174 severe OSAS, respectively. The incidence of MACCE was 0.8% per year (95% confidence interval [CI] 0.2-2.1) in primary snorers and 2.1% per year (95% CI 1.5-2.8) for those with OSAS. A positive association was observed between event-free survival and OSAS severity (log-rank test; P = .041). A multivariable Cox regression analysis showed obesity (HR = 8.011, 95% CI 1.071-59.922, P = .043), moderate OSAS (vs non-OSAS HR = 3.853, 95% CI 1.069-13.879, P = .039) and severe OSAS (vs non-OSAS HR = 3.540, 95% CI 1.026-12.217, P = .045) as predictors of MACCE. No significant association was observed between CPAP treatment and MACCE (log-rank test; P = .227). CONCLUSIONS: Our findings support the role of moderate/severe OSAS as a risk factor for incident MACCE. CPAP treatment was not associated with a lower rate of MACCE.

Self-reported obstructive sleep apnea, simple snoring, and various markers of sleep-disordered breathing as predictors of cardiovascular risk.

PURPOSE: Our objective was to investigate whether self-reported obstructive sleep apnea (OSA), simple snoring, and various markers of sleep-disordered breathing (SDB) are associated with cardiovascular risk. METHODS: We examined a representative nationwide cohort of 5177 Finnish adults aged ≥30 years. The participants underwent measurement of traditional cardiovascular risk factors and answered SDB-related questions derived from the Basic Nordic Sleep Questionnaire, which were used to operationalize self-reported OSA. The primary end point was incidence of a cardiovascular event (cardiovascular mortality, non-fatal myocardial infarction, non-fatal stroke, hospitalization for heart failure, or coronary interventions). RESULTS: During a median follow-up of 11.2 years and 52,910 person-years of follow-up, 634 participants suffered a cardiovascular event. In multivariable-adjusted Cox models, self-reported OSA (hazard ratio [HR] 1.34; 95 % confidence interval [CI] 1.04-1.73; p = 0.03) was an independent predictor of cardiovascular events. Self-reported simple snoring by itself was not associated with future cardiovascular events (HR 0.88 versus non-snorers, 95 % CI 0.75-1.04, p = 0.15). However, among snorers (n = 3152), frequent breathing cessations (HR 2.19, 95 % CI 1.26-3.81, p = 0.006) and very loud and irregular snoring (HR 1.82, 95 % CI 1.31-2.54, p < 0.001) were associated with cardiovascular risk. CONCLUSIONS: Self-reported OSA and SDB-related snoring variables are associated with cardiovascular risk, whereas simple snoring is not. In clinical practice and in surveys, questions concerning only habitual snoring should be amended with questions focusing on respiratory pauses and snoring stertorousness, which can be used to estimate the risk of OSA and cardiovascular events.

Adequate continuous positive airway pressure therapy reduces mortality in Chinese patients with obstructive sleep apnea.

BACKGROUND: Severe obstructive sleep apnea (OSA) is a risk factor for mortality. The ability of continuous positive airway pressure (CPAP) therapy to mitigate this increased risk of death has not been studied in Chinese adults. The objective of our study was to compare mortality in Chinese patients with simple snoring, untreated OSA, and OSA treated with CPAP. METHODS: We recruited adults with OSA or simple snoring from our sleep medicine clinic. OSA was diagnosed using standard polysomnography. Subjects were followed at least annually for a mean of 8.9 years (SD 1.9). CPAP compliance was checked with the built-in meter. We then assessed all-cause mortality. RESULTS: Five hundred fifty simple snorers, 257 with untreated mild OSA, 316 with untreated moderate OSA, 457 with untreated severe OSA, and 235 with mild to severe OSA treated with CPAP were included. Simple snorers had a much lower mortality rate (2.98 per 1000 person-years [95% CI, 2.93 to 3.02]) than the untreated severe OSA group (11.07 per 1000 person-years [95%CI, 10.86 to 11.29]; P < 0.0001). Compared with simple snorers, fully adjusted mortality was highest in the untreated, severe OSA group (hazard ratio [HR], 3.51 [95%CI, 1.93 to 6.39]). Treatment of severe OSA patients with CPAP eliminated this increase in mortality (HR, 0.81[95%CI, 0.36-1.86]). CONCLUSIONS: Severe OSA significantly markedly increases the risk of death in Chinese patients and CPAP treatment with adequate compliance reduces this risk.

Association between sleep apnea, snoring, incident cardiovascular events and all-cause mortality in an adult population: MESA.

BACKGROUND: We assessed the association between sleep apnea, snoring, incident cardiovascular (CV) events and all-cause mortality in the Multi Ethnic Study of Atherosclerosis (MESA) cohort. METHODS: Out of 5338 respondents to a sleep questionnaire administered during the second MESA exam period, 208 had physician diagnosed sleep apnea (PDSA), 1452 were habitual snorers (HS) and 3678 were neither a habitual snorer nor had PDSA (normal participants). Cox proportional hazard analysis was used to assess the associations adjusting for age, gender, race/ethnicity, smoking, diabetes mellitus, total cholesterol, HDL, triglycerides, BMI, current alcohol use, benzodiazepine use, BP medications and statin use. RESULTS: Over a 7.5 year average follow-up period, 310 adjudicated CV events including MI, stroke, angina, resuscitated cardiac arrest, stroke death and CVD death and 189 deaths occurred. Compared to HS, PDSA was associated with higher incident CV rates in both univariate and multivariable models [hazard ratio (95%); 1.89 (1.22-2.93), p = 0.004 and 1.91 (1.20-3.04), p = 0.007, respectively]. PDSA was also associated with a higher death rates compared with HS [hazard ratio (95%); 2.13 (1.25-3.63), p = 0.006 and 2.70 (1.52-4.79), p = 0.007, respectively]. Compared with normal participants, PDSA had higher incident CV event rates in both univariate and multivariable models [hazard ratio (95%); 2.23 [1.39-3.60], p = 0.001 and 2.16 [1.30-3.58], p = 0.003, respectively]. Similarly, PDSA had a higher death rate compared with normal participants in both the univariate and multivariable models [hazard ratio (95% CI); 2.44 (1.36-4.37), p = 0.003 and 2.71 (1.45-5.08), p =0 .002, respectively]. Habitual snorers had similar incident CV event rates and death rates in both univariate and multivariable models compared with normal participants. CONCLUSION: PDSA but not habitual snoring was associated with high incident CV events and all-cause mortality in a multi-ethnic population based study of adults free of clinical CV disease at baseline.

Restless legs symptoms with sleepiness in relation to mortality: 20-year follow-up study of a middle-aged Swedish population.

AIM: The aim of the present study was to investigate restless legs symptoms with concomitant daytime sleepiness as a risk factor for mortality in a middle-aged population. METHODS: A cohort of 5102 subjects aged 30-65 years in mid-Sweden who responded to a postal questionnaire in 1983 was followed up. The questionnaire included questions about restless legs symptoms, daytime sleepiness, demographic and lifestyle variables, sleep habits, medical conditions and depression. Mortality data for the period 1983-2003 were collected and death certificates were available for all the 657 responders who died during the follow-up period. RESULTS: Restless legs symptoms with daytime sleepiness was reported by 10.3% and was associated with shorter night sleep time, several health problems and depression. During the follow-up period 379 men (21.6%) and 278 women (15.5%) died. A multivariate model adjusted for age, short night sleep time, lifestyle factors, medical conditions and depression showed that women reporting restless legs symptoms with daytime sleepiness had an excess mortality compared to women without restless legs symptoms and daytime sleepiness (hazard ratios, 1.85; 95% confidence interval, 1.20-2.85; P = 0.005). No influence on mortality risk was found in men reporting restless legs symptoms with daytime sleepiness. CONCLUSIONS: The occurrence of restless legs symptoms with daytime sleepiness in middle-aged women is associated with increased mortality risk.

Increased mortality among sleepy snorers: a prospective population based study.

BACKGROUND: The long term health consequences of snoring and sleep apnoea syndrome are still uncertain. This study was conducted to assess the mortality risk associated with snoring and excessive daytime sleepiness (EDS), the two main symptoms of sleep apnoea syndrome, in men. METHODS: In 1984 a sample of 3100 men aged 30-69 responded to a postal questionnaire including questions about snoring, EDS, and the prevalence of various diseases (response rate 77.1%). Mortality data for the period 1985-1995 were collected for the complete sample. RESULTS: During the 10 year follow up period 213 men died, 88 of cardiovascular diseases. Compared with subjects with no snoring or EDS in 1984, men with isolated snoring or EDS displayed no significantly increased mortality. The combination of snoring and EDS was associated with a significant increase in mortality. However, the relative rates decreased with increasing age, and in men aged 60 and above no effect on mortality was found. Men below the age of 60 with both snoring and EDS had an age adjusted total death rate which was 2.7 times higher than men with no snoring or EDS (95% CI 1.6 to 4.5). The corresponding age adjusted hazard ratio for cardiovascular mortality was 2.9 (95% CI 1.3 to 6.7) for subjects with both snoring and EDS. Further adjustment for body mass index and reported hypertension, cardiac disease, and diabetes reduced the relative mortality risk associated with the combination of snoring and EDS to 2.2 (95% CI 1.3 to 3.8) and the relative risk of cardiovascular mortality to 2.0 (95% CI 0.8 to 4.7). CONCLUSION: Snoring without EDS does not appear to carry an increased risk of mortality. The combination of snoring and EDS appears to be associated with an increased mortality rate, but the effects seems to be age dependent. The increased mortality is partly explained by an association between "snoring and EDS" and cardiovascular disease.

Complications of palatoplasty for snoring or sleep apnoea.

A questionnaire was sent to consultant Otolaryngologists (483) throughout the UK to identify any mortality associated with uvulopalatoplasty and other forms of palatoplasties for snoring and/or obstructive sleep apnoea. The response rate was 76.8 per cent (371). Six intra- and post-operative deaths were reported and four were known to have obstructive sleep apnoea. Life-threatening morbidity occurred in at least seven patients (three known apnoeic), two required immediate tracheostomy and two were managed in the intensive care unit. This suggests that the apnoeic patients undergoing palatoplasties experienced significant mortality and morbidity. Pre-operative sleep study should be performed in all snoring patients to identify the apnoeic subgroup. Continuous positive airway pressure, management of excessive obesity, elective tracheostomy and other strategies should be first considered before palatoplasties in these patients.

Long-term compliance with nasal continuous positive airway pressure (CPAP) in obstructive sleep apnea patients and nonapneic snorers.

In a prospective study aimed at evaluating objectively the compliance with nasal continuous positive airway pressure (CPAP) treatment, 233 obstructive sleep apnea (OSA) (apnea index, > 10 apneas/hour) patients and 36 nonapneic snorers were studied. The compliance to treatment was measured by the mean rate of use of the CPAP device, obtained from a built-in time counter. The follow-up period was 874 +/- 48 in OSA patients and 675 +/- 83 in snorers. CPAP was proposed to all OSA patients but only to those snorers who felt improved after an initial laboratory night on CPAP. Nineteen OSA patients refused CPAP. Of the 214 OSA patients who accepted CPAP, 181 are still on treatment, with a mean daily rate of use of 5.6 +/- 0.1 hours (mean +/- SEM); 22 patients stopped CPAP after a variable period of time; 10 patients died and one acromegalic patient was considered cured after hypophysectomy for a pituitary adenoma. Depending upon the definition of acceptable compliance, the compliance rate in this group was between 77% and 89%. The mean rate of use was correlated with indices of disease severity (apnea index, apnea+hypopnea index, minimal SaO2 during sleep, daytime PaO2, pulmonary artery pressure). Thirty-six nonapneic snorers accepted CPAP. In this group, 26 are still on CPAP, with a mean daily rate of use of 5.4 +/- 0.5 hours; one patient died; one underwent uvolopalatopharyngoplasty without follow-up; and eight stopped CPAP. The compliance rate in this group was between 58% and 78%. This study shows that CPAP is reasonably accepted by OSA patients as well as by nonapneic snorers.(ABSTRACT TRUNCATED AT 250 WORDS)