Is there an association between altered baroreceptor sensitivity and obstructive sleep apnoea in the healthy elderly?

Obstructive sleep apnoea (OSA) is associated with a rise in cardiovascular risk in which increased sympathetic activity and depressed baroreceptor reflex sensitivity (BRS) have been proposed. We examined this association in a sample of healthy elderly subjects with unrecognised OSA. 801 healthy elderly (aged ≥65 years) subjects undergoing clinical, respiratory polygraphy and vascular assessment were examined. According to the apnoea-hypopnoea index (AHI), the subjects were stratified into no OSA, mild-moderate OSA and severe OSA cases. OSA was present in 62% of the sample, 62% being mild-moderate and 38% severe. No differences were found for BRS value according to sex and OSA severity. 54% of the group had normal BRS value, 36% mild impairment and 10% severe dysfunction. BRS was negatively associated with body mass index (p=0.006), 24-h systolic (p=0.001) and diastolic pressure (p=0.001), and oxygen desaturation index (ODI) (p=0.03). Regression analyses revealed that subjects with lower BRS were those with hypertension (OR 0.41, 95% CI 0.24-0.81; p=0.002) and overweight (OR 0.42, 95% CI 0.25-0.81; p=0.008), without the effect of AHI and ODI. In the healthy elderly, the presence of a severe BRS dysfunction affects a small amount of severe cases without effect on snorers and mild OSA. Hypertension and obesity seem to play a great role in BRS impairment.

Prevalence and determinants of subjective sleepiness in healthy elderly with unrecognized obstructive sleep apnea.

OBJECTIVE: Obstructive sleep apnea (OSA) is associated with behavioral consequences such as excessive daytime sleepiness (EDS). The aim of this study was to establish the presence of sleepiness in elderly with unrecognized OSA and the factors explaining its occurrence. METHODOLOGY: A total of 825 healthy elderly (aged ≥65 years) undergoing clinical, respiratory polygraphy, and heart-rate variability analysis were studied. According to the apnea-hypopnea index (AHI), the subjects were stratified in four categories: no-OSA (AHI <5), mild (5 > AHI <15), moderate (15 ≥ AHI <30), and severe OSA (AHI ≥30). Participants with EDS were defined on the basis of the Epworth Sleepiness Scale (ESS) score ≥10. RESULTS: Overall, the mean ESS score was 5.7 ± 5.6, 14.9% showing EDS with an increasing trend according to OSA severity (p <0.001). Sleepy subjects were more frequently men, having a greater body mass index (BMI), alcohol intake, depression score, and indices of OSA severity (23% of severe OSA cases being sleepy). No differences were present between sleepy and non-sleepy subjects in regard to other clinical, metabolic, and autonomic nervous system measurements. Regression analyses adjusted for age, gender, BMI, hypertension, depression score, autonomic sleep fragmentation, and AHI and/or oxygen desaturation index revealed that gender (p <0.0001), depression score (p <0.0001), and BMI (p = 0.01) were the only significant factors affecting the presence of sleepiness in this population. CONCLUSIONS: In healthy elderly with OSA, the prevalence of EDS was low, and it affected only severe cases. Despite a weak association between the ESS score and the AHI index, male gender and depression score were the most significant predictors for the occurrence of sleepiness.

Protective Effect of Long-Term CPAP Therapy on Cognitive Performance in Elderly Patients with Severe OSA: The PROOF Study.

OBJECTIVE: Obstructive sleep apnea syndrome (OSA) leads to a deterioration in cognitive functions, with regard to memory and executive functions. However, few studies have investigated the impact of treatment on these cognitive functions in elderly subjects. METHODS: The study was conducted in a large cohort of subjects aged 65 years or older (the PROOF cohort). Subjects were not diagnosed or treated for OSA. Subjects underwent a polygraphic recording. Cognitive performance was assessed in all OSA subjects at baseline and 10 years later, whether or not they were receiving continuous positive airway pressure (CPAP) therapy. RESULTS: A group of 126 patients were analyzed. Only 26% of them were treated, with therapy initiated at the discretion of the primary care physician. Among treated subjects, self-reported compliance with therapy was good (> 6 h/night on average), and 66% of them reported an improvement in their quality of life. Patients receiving CPAP treatment had a higher apneahypopnea index (p = 0.006), a higher oxygen desaturation index (p < 0.001), and experienced more pronounced daytime repercussions (p = 0.004). These patients showed a statistically significant improvement in mental agility (similarities test; p < 0.0001) and memory performance (Grober and Buschke delayed free recall; p = 0.02). CONCLUSION: CPAP treatment is associated with the maintenance of memory performance over time.

Sleep breathing disorders and cognitive function in the elderly: an 8-year follow-up study. the proof-synapse cohort.

STUDY OBJECTIVES: Sleep breathing disorder (SBD) may be an important factor in age-related cognitive decline. In a cohort of healthy elderly subjects, we performed an 8-y longitudinal study to assess whether changes in cognitive function occur in untreated elderly patients with SBD and without dementia and the factors implicated in these changes. DESIGN: A population-based longitudinal study. SETTING: Clinical research settings. PARTICIPANTS: A total of 559 participants of the PROOF study aged 67 y at the study entry and free from neurological disorders were examined. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Abnormal breathing events were defined by an apnea-hypopnea index (AHI) > 15. The raw cognitive data and averaged Z-scores for the attentional, executive, and memory functions were collected at the baseline and follow-up. At baseline, AHI > 15 was found in 54% of subjects with 18% having an AHI > 30. At follow-up, the presence of abnormal breathing events was associated with a slight but significant decline in the attentional domain (P = 0.01), which was more evident in the subjects with an AHI > 30 (P = 0.004). No significant changes over time were observed in the executive and memory functions. Several indices of chronic hypoxemia, defined either as a cumulative peripheral oxygen saturation (SpO2) < 90% or a minimal SpO2, accounted for portions of the variance in the decline in attention. All observed effects were small, accounting for 4-7% of variance in multivariate models. CONCLUSION: In healthy elderly subjects, various components of sleep breathing disorder at baseline were associated with small changes in selected cognitive functions specific to the attention domain after controlling for multiple comorbidities, such as sleepiness, hypertension, diabetes, anxiety, and depression. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifiers NCT 00759304 and NCT 00766584.

Sleep perception in non-insomniac healthy elderly: a 3-year longitudinal study.

OBJECTIVES: Older adults complain of sleep disturbances more often than younger adults do. It is not clear whether the age-related rise in sleep problems is related to aging itself or to health-related quality of life. The aim of this study was to explore the presence of self-reported sleep problems in healthy elderly individuals and to evaluate whether changes occurred over a 3-year follow-up. METHODS: A total of 314 older community-dwelling volunteers, aged 71.6±1.0 years old, were examined and followed for 3 years. All of the subjects completed questionnaires evaluating anxiety, depression, and sleepiness and the Pittsburgh Sleep Quality Index (PSQI) at the first and second evaluations. On the basis of the PSQI items, the subjects were classified as good or bad sleepers and as short, normal, or long sleepers. RESULTS: At baseline, 53% of the subjects reported good sleep, with 61% reporting a sleep duration of approximately 7 hr. The total sleep time and the numbers of short, normal, and long sleepers were similar at baseline and at 3 years later. Over time, there was a slight increase (p<0.001) in bad sleepers (53%) and a rise in the occasional hypnotic intake (p<0.001). Considering individual variation, the majority of subjects remained stable at follow-up for sleep duration (65%), sleep quality (75%), and medication (83%). CONCLUSIONS: In a healthy older population, the majority of the subjects did not report bad and short sleep at baseline and did not have significant changes in self-perceived sleep 3 years later. These findings suggest that the reported sleep disturbances described in the elderly are more dependent on physical, environmental, and health factors rather than on age-dependent sleep changes. CLINICAL TRIAL REGISTRATION: NCT 00759304 and NCT 00766584.

Carotid artery atherosclerosis and sleep disordered breathing in healthy elderly subjects: the Synapse cohort.

BACKGROUND: Sleep-disordered breathing (SDB) has emerged as an independent risk factor for carotid atherosclerosis (CA) and cerebrovascular disease in middle-aged subjects. Currently, there is no study providing a causal relationship between SDB and cerebrovascular lesions in elderly. OBJECTIVE: To assess the impact of SDB on CA in a cohort of healthy elderly subjects. METHODS: Seven hundred and fifty-five participants of a cross-sectional study on the association between SDB and cardiovascular morbidity, aged 68yr at study entry, were examined. All subjects underwent carotid ultrasonography and risk factors for atherosclerosis including smoking, metabolic syndrome and hypertension were examined. An apnea + hypopnea index (AHI)>15 was considered indicative of SDB. RESULTS: Presence of carotid lesion was found in 35% of the sample, predominantly in men and in overweight subjects. The most frequent alteration was arteriosclerosis present in 74% of cases, with stenosis >50% found in only 9% of subjects. No significant difference in the prevalence of carotid lesion was found between subjects with and without SDB, subjects with an AHI>30, even though, having a slight increase in CA. At the logistic regression analysis, male gender (p<0.001), systolic and diastolic blood pressure (p<0.001), dyslipidemia (p=0.003) and hypertension (p=0.009) were the variables independently associated with carotid lesions even in severe cases. CONCLUSION: The incidence of CA in healthy elderly subjects is mediated more by gender, metabolic factors and hypertension than by presence of SDB. Further clinical studies including extensive evaluation of all atherosclerotic factors are needed to elucidate the predisposing role of SDB for cerebrovascular risk.