Obstructive sleep apnea/hypopnea and systemic hypertension

Obstructive sleep apnea/hypopnea (OSAH) syndrome is a highly prevalent condition. Severe OSAH affects 2–6% of the population, although only 10% of subjects are correctly diagnosed and treated. OSAH is an important and unresolved public health care problem because of its role in the development of cardiovascular events, negative impact on quality of life, and as a cause of traffic accidents. Longitudinal and cross-sectional studies have shown a strong association between OSAH and hypertension. Moreover, a number of open-label studies, the majority of 21 controlled studies included in the present review, a systematic review, and 4 recent meta-analyses have shown a reduction of blood pressure (BP) of about 2 mm Hg with continuous positive airway pressure (CPAP). This lowering of blood pressure is significant in terms of reduction of both cardiovascular and cerebrovascular risk and death. The effect is greater in hypertensive subjects and in those with more severe OSAH. Accordingly, treatment with CPAP could be considered in patients with severe OSAH and hypertension even in the absence of symptoms. The challenge to researchers is to find markers for discriminating subjects in whom blood pressure will decrease from non-responders. This will help to refine relevant clinical indicators for CPAP treatment in clinical practice.     

Obstructive sleep apnea and its controversial effects on cognition

Obstructive sleep apnea syndrome is a sleep disorder that may affect many brain functions. We are interested in the cognitive consequences of the condition with regard to the quality of life of individuals with this disorder. A debate is still underway as to whether cognitive difficulties caused by obstructive sleep apnea actually induce a “pseudodementia” pattern. This work provides a brief overview of the main controversies currently surrounding this issue. We report findings and opinions on structural and cognitive brain changes in individuals affected by obstructive sleep apnea by highlighting the involvement of executive functions and the possible reversibility of signs following-treatment with continuous positive airway pressure. Much research has been done on this issue but, to the best of our knowledge, a review of the present state of the literature evaluating different points of view has not yet been carried out.     

Obstructive sleep apnea in Parkinson's disease: a study in 239 Chinese patients

ObjectiveOur objective was to explore the clinical characteristics of Parkinson's disease (PD) comorbidity with obstructive sleep apnea (OSA), explore the correlation between OSA and PD features and identify factors that are independent predictors of OSA in PD patients.MethodsIn sum, 239 PD patients were divided into two groups according to the presence of OSA (apnea–hypopnea index (AHI) score ≥5) (PD-OSA vs PD-non-OSA). Blinded to sleep apnea status, participants underwent an extensive assessment to determine demographic features, concomitant disease, disease severity, polysomnography (PSG) characteristics and non-motor symptoms (NMSs).ResultsOf the 239 patients, 66 (27.62%) had an AHI score ≥5, including 14.2% (34/239) with mild, 6.7% (16/239) with moderate, and 6.7% (16/239) with severe sleep apnea. The binary logistic regression analyses indicated that age and male gender were risk factors for OSA, while rapid eye movement (REM) sleep disorder (RBD) and higher Levodopa equivalent dose (LED) were protective factors for OSA. PD-OSA patients had higher Epworth Sleepiness Scale (ESS) scores than those of PD-non-OSA patients. No differences were found for other NMSs between groups.ConclusionOur data suggest that OSA in PD was lower in patients with RBD and higher LED. RBD and higher LDEs were significant protective factors for OSA in PD. OSA in PD was increased with age and male gender. Age and male gender were risk factors for OSA in PD. OSA can aggravate excessive daytime somnolence in PD patients but is not associated with other NMSs.     

Obstructive sleep apnea in psychiatric outpatients. A clinic-based study

Psychiatric diseases and symptoms are common among patients with obstructive sleep apnea (OSA). However, only a few studies have examined OSA in psychiatric patients. At the outpatient clinic of the Uusikaupunki Psychiatric Hospital, Finland, we used a low referral threshold to a diagnostic sleep study. An ambulatory cardiorespiratory polygraphy was performed in 114 of 221 patients. 95 patients were referred by the psychiatric clinic and 19 were examined in other clinical settings. We reviewed the medical files and retrospectively assessed the prevalence of OSA and the effect of gender, age, obesity, hypertension, type 2 diabetes, alcohol abuse, and symptoms suggesting OSA. 58 of the 221 patients (26.2%), 30 of 85 men (35.3%) and 28 of 136 women (20.6%), had OSA as determined by an apnea–hypopnea index (AHI) of 5/h or more. 20 patients (12 men and 8 women) had moderate or severe OSA (AHI ≥ 15/h). 46 patients (including 11 patients with moderate or severe OSA) were identified in the psychiatric clinic. In univariate analysis, a high body mass index, male gender, hypertension, snoring, and a history of witnessed apneas during sleep were associated with the presence of OSA. In multivariate analysis, a history of witnessed apneas did not remain significant. Age, type 2 diabetes, alcohol abuse, excessive daytime sleepiness (EDS), and fatigue did not associate with the presence of OSA. Our findings suggest that in psychiatric outpatients OSA is common but underdiagnosed. Presentation is often atypical, since many patients with OSA do not report witnessed apneas or EDS.     

A systematic review of CPAP adherence across age groups: clinical and empiric insights for developing CPAP adherence interventions

Continuous positive airway pressure (CPAP) is a highly efficacious treatment for obstructive sleep apnea (OSA) but adherence to the treatment limits its overall effectiveness across all age groups of patients. Factors that influence adherence to CPAP include disease and patient characteristics, treatment titration procedures, technological device factors and side effects, and psychological and social factors. These influential factors have guided the development of interventions to promote CPAP adherence. Various intervention strategies have been described and include educational, technological, psychosocial, pharmacological, and multi-dimensional approaches. Though evidence to date has led to innovative strategies that address adherence in CPAP-treated children, adults, and older adults, significant opportunities exist to develop and test interventions that are clinically applicable, specific to sub-groups of patients likely to demonstrate poor adherence, and address the multi-factorial nature of CPAP adherence. The translation of CPAP adherence promotion interventions to clinical practice is imperative to improve health and functional outcomes in all persons with CPAP-treated OSA.     

Obstructive sleep apnea,sleep duration and chronic kidney disease in patients with coronary artery disease

BackgroundLimited evidence is available addressing the potential role of sleep disorders on renal function. Here, we aimed to explore the associations of obstructive sleep apnea (OSA) and sleep duration (SD) with renal function in subjects with high cardiovascular risk.MethodsConsecutive subjects with coronary artery disease (CAD) underwent clinical evaluation, sleep study to define OSA and one-week wrist actigraphy to objectively measure SD. OSA was defined by an apnea-hypopnea index (AHI) of ≥15 events/hour. The estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. We analyzed the associations of OSA and SD with continuous eGFR values and according to the presence of CKD (eGFR<60 mL/min/1.73 m²) after adjusting for multiple confounding factors.ResultsWe studied 242 subjects (62.8% men). The frequency of OSA was 55.4% and the median SD was 412.8 (363.4–457.25) min. There was no difference in the eGFRs between participants with and without OSA (69.3 ± 19.1 vs. 74.6 ± 19.3 mL/min/1.73 m², p = 0.72) and the rate of eGFR <60 mL/min/1.73 m² (34.3% vs. 25.9%; p = 0.21). Similarly, we did not find differences in patients in eGFR for those with SD ≥ 6 h versus SD < 6 h (72.5 ± 20.3 vs. 71.4 ± 19.1 mL/min/1.73 m², p = 0.72). In the linear regression analysis, AHI was independently associated with an eGFR<60 mL/min/1.73 m² in the unadjusted model [−0.15 (-0.27 to −0.04)], (P = 0.01), but not in the adjusted models. Analyses of continuous SD or the stratification in SD ≥ 6 h or <6 h also revealed neutral results on eGFR.ConclusionOSA severity and SD were not independently associated with CKD in subjects with CAD.     

Treating sleep apnea in Parkinson's disease with C-PAP: feasibility concerns and effects on cognition and alertness

BackgroundObstructive sleep apnea (OSA) is highly prevalent in Parkinson disease (PD) and is known to contribute to cognitive impairment and daytime sleepiness. We investigated feasibility of continuous positive airway pressure treatment (CPAP) and its effects on subjective daytime sleepiness and cognitive profile in PD plus OSA subjects in a longitudinal three months follow up study.MethodsSeventy (age 71.7 ± 7.6, disease duration 9.9 ± 12.3, UPDRS-III 33.7 ± 12.5, MMSE 25.3 ± 3.6; years of education 7.7 ± 3.2) out of 228 consecutive PD patients undergoing in-lab video-polysomnography were found to have obstructive sleep apnea. Thirty-six subjects accepted to titrate therapeutic CPAP. Video-polysomnography, neuropsychological battery evaluating different cognitive domains and subjective scales for daytime sleepiness were scheduled at baseline and after three months. All the patients were given educational informations relative to diagnosis of OSA and benefits of OSA treatment, and an individualized training with CPAP.ResultsTwenty-seven (75%) subjects dropped out of the study due to CPAP intolerance. No demographic or disease-related variables (in particular, severity of OSA), could be found between subjects who completed the study versus those who dropped out. Nine subjects completed the three-month follow up, and there were no significant changes in subjective sleepiness, neuropsychological scores and sleep structure (except for reduction in apnea/hypopnea index and a trend toward increase in stage N3 sleep).ConclusionOur data show that feasibility of CPAP treatment can be significantly threatened by overall attrition rates. Further studies should consider well-structured adherence promoting interventions. The actual role of OSA as a determinant of the profile of subjective daytime sleepiness and cognition in PD, and the effects of CPAP in PD need to be further studied.     

Nasal CPAP treatment for obstructive sleep apnea: developing a new perspective on dosing strategies and compliance

Nasal continuous positive airway pressure (CPAP) is presently considered as the “treatment of choice” for obstructive sleep apnea (OSA). Though some OSA patients adhere to treatment recommendations and ultimately respond quite well to CPAP therapy, there is a substantial subgroup for which compliance is a particularly difficult issue. Despite receiving recommendations to the contrary and for reasons that are incompletely understood, the majority of OSA patients settle for a partial compliance pattern. Whether a partial compliance schedule is beneficial or harmful is virtually unexamined: Unlike other medical treatments, there are few data concerning the “dose–response relationship” of CPAP to its desired effects. We argue that CPAP “dose” is a function not only of CPAP pressure but of time-on-CPAP as well. Critical questions that remain unanswered are what “dose” of CPAP is needed to effect an appropriate treatment outcome and which treatment outcomes should form the basis of our recommendations. Recent placebo-controlled studies comparing CPAP to suboptimal CPAP pressures may be informative in this regard. Directions for future research are suggested.     

Identification and treatment of obstructive sleep apnea in adults and children with epilepsy: a prospective pilot study

OBJECTIVE: To determine the effect of treating obstructive sleep apnea (OSA) on seizure frequency in adults and children with epilepsy in a prospective study. Several case series documented an improvement in seizure control with treatment of coexisting OSA, but published series did not sample a clinic population, were not prospective in design, and did not account for concurrent changes in antiepileptic drug (AED) doses or levels. PATIENTS AND METHODS: Adult patients and the parents of pediatric patients seen in the University of Michigan Epilepsy and Pediatric Neurology Clinics were given validated questionnaires. Thirteen adults (aged 20-56) and 5 children (aged 14-17) were selected for polysomnography (PSG) based on frequency of seizures and risk for OSA. Seizure frequency was compared during 8-week baseline and treatment phases and AED levels were done to document stability in medication levels. RESULTS: Six of 13 adults and 3 of 5 children met PSG criteria for OSA. Three adults and 1 child were treated with continuous positive airway pressure (CPAP), were tolerant of the device, and had no change in AED doses; all four had at least a 45% reduction in seizure frequency during CPAP treatment. One adult was treated with an oral appliance with a reduction in nocturnal seizures only, and 2 adults and 2 children were intolerant of CPAP. CONCLUSIONS: Treatment of OSA in patients with epilepsy may improve seizure control and a large randomized placebo-controlled trial appear warranted.     

Daytime sleepiness after long-term continuous positive airway pressure (CPAP) treatment in obstructive sleep apnea syndrome

A modified maintenance of wakefulness test was performed in 58 patients with obstructive sleep apnea (OSA) syndrome before treatment and after long-term (554 ± 28 days) home therapy with nasal continuous positive airway pressure (CPAP). Before treatment the patients had a shorter mean sleep latency than controls (16 ± 1 vs. 27 ± 1 in, mean ± SEM, P < 0.001) After treatment, the mean sleep latency increased to 20 ± 1 min P < 0.002 as compared to baseline), but was still shorter than in controls (P < 0.001). The incomplete normalization of the mean latency contrasted with the patient's claim that they no longer felt sleepy. The improvement in daytime alertness was significantly correlated with the reduction in sleep fragmentation after CPAP treatment and with the baseline mean sleep latency. These results support the hypothesis that sleep disruption related to respiratory events plays a role in the pathogenesis of daytime sleepiness.     

Seasonal effects on the continuous positive airway pressure adherence of patients with obstructive sleep apnea

ObjectiveThis study examined seasonal differences in continuous positive airway pressure (CPAP) therapy adherence among patients with obstructive sleep apnea (OSA).MethodsPatients aged ≥20 years with OSA who had used CPAP devices on the automatic setting for >12 consecutive months (n = 141) were included in this retrospective study from December 2015–2016. The information of CPAP use (pressure, hours of actual use) was extracted from database downloaded from patients’ CPAP devices. Patients were divided into adherent and non-adherent groups using the cutoff point of 70% CPAP use for ≥4 h daily over the 1-year study period. CPAP use data were averaged for each season.ResultsPatients in the adherent group were significantly older than those in the non-adherent group (p < 0.001). In the adherent group, the rate of ≥4 h daily CPAP use was significantly lower, the daily duration of CPAP use was significantly shorter, and the residual apnea–hypopnea index (AHI; events/hour) was significantly higher in summer than in other seasons (all p < 0.001). In the non-adherent group, the duration of daily CPAP use and the AHI differed significantly between winter and summer (p = 0.008 and p < 0.001, respectively).ConclusionsSeasonal changes were associated with the CPAP adherence of patients with OSA. The study findings suggest that there is possibility of increasing the duration of CPAP use by adjusting the bedroom environment in hot and humid seasons.     

Auditory event-related potentials before and after treatment with nasal continuous positive airway pressure in sleep apnea syndrome

Auditory event-related potentials (ERP), multiple sleep latency tests, mini-mental state exam, and depression tests were studied in 15 patients with obstructive sleep apnea syndrome (OSA). The P3 wave latency of ERP was significantly increased compared with 15 age-matched control subjects. After 4 weeks and after 1 year of treatment of OSA by nasal continuous positive airway pressure (CPAP), there was no significant improvement in the abnormalities of ERP. These observed changes in ERP were not correlated with excessive daytime sleepiness, depression, nocturnal hypoxemia, and sleep fragmentation. The cause of increased P3 latency has not been elucidated, but a chronic cerebral insult was suspected.     

Different scoring rules for respiratory event-related leg movements: effects on the prevalence of periodic limb movements during sleep and their association with depressive symptoms in patients with obstructive sleep apnea

BackgroundWe compared the prevalence of periodic leg movements during sleep (PLMS) according to two different scoring rules of the American Academy of Sleep Medicine (AASM) 2012 and World Association of Sleep Medicine (WASM) 2016 and determined their association with depressed mood in patients with obstructive sleep apnea (OSA).MethodsPLMS, defined as a periodic leg movements index of >15, were diagnosed on a diagnostic and continuous positive airway pressure (CPAP) titration polysomnography using the AASM 2012 and WASM 2016 rules. The Beck Depression Inventory (BDI) and Epworth Sleepiness Scale (ESS) were used, and multiple regression analyses were performed.ResultsAmong 160 OSA patients, the proportion with PLMS scored by the WASM 2016 criteria was significantly higher than that scored by the AASM 2012 criteria in a diagnostic study (20.6% vs. 16.3%, respectively; P = 0.016) but not in CPAP titration study and only in patients with severe OSA. In adjusted models, PLMS were positively associated with BDI scores and a BDI of ≥10 on both diagnostic and CPAP titration studies when scored by the WASM 2016. By contrast, when scored by the AASM 2012, PLMS were associated with BDI scores (but not BDI of ≥10) only in a CPAP titration study.ConclusionsThere are significant differences in the prevalence of PLMS and their association with depressed mood depending on the scoring rules in patients with OSA. The current AASM scoring criteria underestimate the prevalence of PLMS, and PLMS are more likely associated with depressed mood according to the WASM scoring criteria.     

Diagnosing obstructive sleep apnea patients with isolated nocturnal hypoventilation and defining obesity hypoventilation syndrome using new European Respiratory Society classification criteria: an Indian perspective

BackgroundRecently, new classification criteria for obesity hypoventilation syndrome (OHS) have been described. OHS prevalence according to new criteria has not been reported in obstructive sleep apnea (OSA). Prevalence of OHS has not been previously reported from India.MethodsRetrospective study was carried out in OSA patients for whom both arterial blood gases (ABG) and end-tidal CO₂ (etCO₂) records were available. OHS was defined according to old and new criteria. Analysis was carried out among various groups: patients without OHS (Group A), patients with sleep hypoventilation but without daytime hypercapnia (Group B) and patients with daytime hypercapnia (Group C).ResultsOut of 367 patients with OSA (body mass index, BMI) 31.9 ± 12.27 kg/m²), finally 128 obese OSA patients were included for analysis. Of those, 15 (5.9%, 95% confidence interval (CI) 3.5–9.4) and 45 patients (17.8%, 95% CI 13.4–22.9) fulfilled prevalence of OHS according to old and new criteria, respectively. Continuous positive airway pressure (CPAP) titration failed in 9.6%, 53.3% and 66.7% in Groups A, B, and C, respectively. For all parameters of OSA severity (apnea–hypopnea index (AHI), Nadir O₂, T90) and positive airway pressure (PAP) requirements, patients in Group B were in between those in Groups A and C. Statistically significant difference was seen between Group A and Group B, and between Groups A and C, but not between Groups B and C.ConclusionOne in six OSA patients and one in three obese OSA patients (BMI >30 kg/m²) have OHS according to new criteria. Since patients with isolated nocturnal hypoventilation were as sick as patients with daytime hypercapnia, screening for sleep hypoventilation should be carried out in all obese OSA patients.     

Obstructive sleep apnea and risk of motor vehicle accident

ObjectiveTo evaluate the association between obstructive sleep apnea (OSA) and risk of motor vehicle accident (MVA).MethodsWe conducted a cohort study at Kaiser Permanente Washington using electronic health plan data and linked Washington State Department of Transportation MVA records. We included persons 18–79 years of age during 2005–2014. OSA was ascertained via diagnosis codes. The primary outcome, first MVA during cohort follow-up, was ascertained from state MVA records. Risk factors for MVAs, including medical conditions and medication use, were ascertained from health plan data. Multivariable Cox proportional hazards models were used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (CI) for the association between OSA and study outcomes.ResultsAmong the 879,547 eligible persons, the unadjusted rate of MVA in those with and without OSA was 238 and 229 per 10,000 person-years, respectively. A diagnosis of OSA was associated with a 17% increased risk of MVA (adjusted HR = 1.17; 95% CI: 1.13 to 1.20).ConclusionIn this large population-based study, a diagnosis of OSA was associated with a modestly increased risk of MVA.     

Hypercoagulability in patients with obstructive sleep apnea

BACKGROUND: Obstructive sleep apnea (OSA) has been linked to cardiovascular complications such as stroke and myocardial infarction. Previous studies demonstrate that OSA patients show elevated fibrinogen levels and increased platelet aggregation that are reversed with 1 night of nasal continuous positive airway pressure treatment (NCPAP). Questioning overall coagulability in OSA, we examined whole blood coagulability in 11 chronically NCPAP treated OSA subjects, 22 previously untreated OSA subjects, and in 16 of these after 1 night of NCPAP treatment. PATIENTS AND METHODS: During full polysomnography, subjects from each group had blood drawn prior to bedtime (21:00 h) and upon waking in the morning (07:00 h). RESULTS: Untreated OSA patients had faster P.M. clotting times than chronically treated OSA patients (3.33+/-0.31 versus 6.12+/- 0.66 min, P<0.05 by ANOVA). A.M. values showed similar results (4.31+/- 0.34 min versus 7.08+/-0.52 min, P<0.05 by ANOVA) for the respective groups. One overnight treatment with nasal CPAP did not produce a significant change in A.M. whole blood coagulability (4.35 +/-0.43 to 5.31+/-0.53 min; n=16; P=0.1) in 16 treated subjects. CONCLUSIONS: These data indicate a relationship between obstructive sleep apnea and blood hypercoagulability status that appears to be reversed by chronic NCPAP treatment. These data suggest that NCPAP might protect against the development of cardiovascular complications in OSA patients.     

Linguistic and psychometric validation of the Chinese version of the self-efficacy measures for sleep apnea questionnaire

Objectives

The self-efficacy measure for sleep apnea (SEMSA) questionnaire was shown to be an effective tool to assess adherence-related cognitions on continuous positive airway pressure (CPAP) therapy in obstructive sleep apnea (OSA) subjects. SEMSA helps to solicit fundamental information for formulating strategies to promote CPAP adherence for better treatment outcomes. The objective of our study was to perform a linguistic and psychometric evaluation of a Chinese version of the SEMSA (SEMSA-C).

Methods

Data were obtained from 100 subjects in a randomized controlled trial (RCT) on CPAP education. Subjects were newly diagnosed of OSA and naïve to CPAP therapy.

Results

A 26-item SEMSA-C was obtained by a rigorous linguistic validation process. Internal consistency was high with Cronbach α > 0.88. One-week test–retest intraclass correlation coefficient (ICC) ranged from 0.70 to 0.82. Principal component factor analysis identified three of the same hypothesized factors (perceived risks, outcome expectancies, and treatment self-efficacy) as in the original version. CPAP adherence was associated with outcome expectancies and treatment self-efficacy at 3-month assessment. Further, SEMSA-C demonstrated an improvement in self-efficacy after CPAP use.

Conclusions

SEMSA-C shows similar psychometric properties as the original English version. It is a reliable and responsive instrument to measure perceived risks, outcome expectancies, and treatment self-efficacy in Chinese subjects with OSA.