Sleep-disordered breathing and cardiovascular disease

Development and initial validation of a questionnaire to measure patient experience with oral appliance therapy

STUDY OBJECTIVES

To develop and validate a questionnaire to measure patient experience with oral appliance therapy.

METHODS

The AMEE Guide No. 87 was followed in the development and validation of a patient questionnaire to assess patient experience with oral appliance therapy.

RESULTS

Our search identified 522 articles; 5 of these articles described the use and/or validation of questionnaires to measure changes in symptoms and patient-reported outcomes in the treatment of obstructive sleep apnea. A total of 27 questions were developed. Five patients participated in pilot testing. A final review of the questionnaire was conducted by an expert panel.

CONCLUSIONS

The creation and validation of a questionnaire to assess patient experience with oral appliance therapy may provide new methods for advancing research in the field of dental sleep medicine.

CITATION

Ng ET, Perez-Garcia A, Lagravère-Vich MO. Development and initial validation of a questionnaire to measure patient experience with oral appliance therapy. J Clin Sleep Med. 2023;19(8):1437-1445.

Fuzzy AHP point factored inference system for detection of cardiovascular disease

The World health organization (WHO) reported that cardiovascular disease is the leading cause of death worldwide, particularly in developing countries. But while diagnosing cardiovascular disease, medical practitioners might have differences of opinions and faced challenging when there is inadequate information and uncertainty of the problem. Therefore, to resolve ambiguity and vagueness in diagnosing disease, a perfect decision-making model is required to assist medical practitioners in detecting the disease at an early stage. Thus, this study designs a fuzzy analytic hierarchy process (FAHP) point-factored inference system to detect cardiovascular disease. The attributes are selected and classified into sub-attributes and point factor scale using the clinical data, medical practitioners, and literature review. Fuzzy AHP is used in calculating the attribute weights, the strings are generated using the Mamdani fuzzy inference system, and the strength of each set of fuzzy rules is calculated by multiplying the attribute weights with the point factor scale. The string weights determine the output ranges of cardiovascular disease. Moreover, the results are validated using sensitivity analysis, and comparative analysis is performed with AHP techniques. The results show that the proposed method outperforms other methods, which are elucidated by the case study.

Experimental study of the negative effects of raised bedroom temperature and reduced ventilation on the sleep quality of elderly subjects

This study investigated the effects of air temperature and ventilation on the sleep quality of elderly subjects and elucidated the mechanisms involved. Sixteen subjects aged over 65 years old were exposed to four conditions in a 2 × 2 design: air temperatures of 27°C and 30°C (with a ceiling fan in operation at 30°C) and two ventilation conditions (with and without mechanical ventilation) in experimental bedrooms. Their electroencephalogram, electrooculogram, chin electromyogram, electrocardiogram, respiration, oxygen saturation, and wrist skin temperature were measured continuously during sleep. Saliva samples were collected, and blood pressure was measured both before and after sleep. The results showed that at the temperature of 30°C, the total sleep time, sleep efficiency, and duration of REM sleep of the elderly decreased by 26.3 min, 5.5%, and 5.3 min, respectively, and time awake increased by 27.0 min, in comparison with 27°C, indicating that the sleep quality of the elderly is very vulnerable to heat exposure. Even a small heat load led to an overactive sympathetic nervous system and increased wrist skin temperature, which reduced sleep quality. Improving the ventilation increased the duration of deep sleep and REM sleep by 10.3 min and 3.7 min, respectively. Higher pollutant concentrations affected the respiration and autonomous nervous systems to reduce sleep quality. The benefits of improved thermal environment and ventilation on sleep quality were found to be additive. Good ventilation and the avoidance of raised temperatures in the bedroom are thus both important for the sleep quality of the elderly.

A Prediction Model of Incident Cardiovascular Disease in Patients with Sleep-Disordered Breathing

(1) Purpose: this study proposes a method of prediction of cardiovascular diseases (CVDs) that can develop within ten years in patients with sleep-disordered breathing (SDB). (2) Methods: For the design and evaluation of the algorithm, the Sleep Heart Health Study (SHHS) data from the 3367 participants were divided into a training set, validation set, and test set in the ratio of 5:3:2. From the data during a baseline period when patients did not have any CVD, we extracted 18 features from electrography (ECG) based on signal processing methods, 30 ECG features based on artificial intelligence (AI), ten clinical risk factors for CVD. We trained the model and evaluated it by using CVD outcomes result, monitored in follow-ups. The optimal feature vectors were selected through statistical analysis and support vector machine recursive feature elimination (SVM-RFE) of the extracted feature vectors. Features based on AI, a novel proposal from this study, showed excellent performance out of all selected feature vectors. In addition, new parameters based on AI were possibly meaningful predictors for CVD, when used in addition to the predictors for CVD that are already known. The selected features were used as inputs to the prediction model based on SVM for CVD, determining the development of CVD-free, coronary heart disease (CHD), heart failure (HF), or stroke within ten years. (3) Results: As a result, the respective recall and precision values were 82.9% and 87.5% for CVD-free; 71.9% and 63.8% for CVD; 57.2% and 55.4% for CHD; 52.6% and 40.8% for HF; 52.4% and 44.6% for stroke. The F1-score between CVD and CVD-free was 76.5%, and it was 59.1% in class four. (4) Conclusion: In conclusion, our results confirm the excellence of the prediction model for CVD in patients with SDB and verify the possibility of prediction within ten years of the CVDs that may occur in patients with SDB.

Association Between Sleep Apnea and Valvular Heart Diseases

Background: Although sleep respiratory disorders are known as a relevant source of cardiovascular risk, there is a substantial lack of trials aimed to evaluate the eventual occurrence of associations between sleep apnea (SA) and valvular heart diseases (VHD).

Methods: We recruited 411 patients referring to our sleep disorder unit, among which 371 had SA. Ninety-three subjects with SA also suffered from VHD. Physical examination, echocardiography, nocturnal cardio-respiratory monitoring, and laboratory tests were performed in each patient. Patient subgroups were comparatively evaluated through cross-sectional analysis.

Results: A statistically significant increase in the prevalence of VHD was detected in relation to high apnea hypopnea index (AHI) values (p = 0.011). Obstructive sleep apnea occurrence was higher in SA patients without VHD (p < 0.0001). Conversely, central and mixed sleep apneas were more frequent among SA patients with VHD (p = 0.0003 and p = 0.002, respectively). We observed a direct correlation between AHI and BMI values (p < 0.0001), as well as between AHI and serum uric acid levels (p < 0.0001), high sensitivity C-reactive protein (p < 0.0001), and indexed left ventricular end-diastolic volume (p < 0.015), respectively. BMI and VHD resulted to be the main predictors of AHI values (p < 0.0001).

Conclusions: Our study suggests that a significant association can occur between SA and VHD. It is clinically relevant that when compared to SA patients without VHD, higher frequencies of central and mixed apneas were found in subjects with SA and VHD. Moreover, after elevated BMI, VHD represented the second predictor of AHI values.

Cardiovascular Disease in Patients with Chronic Obstructive Pulmonary Disease, Obstructive Sleep Apnoea Syndrome and Overlap Syndrome

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea syndrome (OSAS) are among the most prevalent chronic respiratory disorders. Accumulating data suggest that there is a significant burden of cardiovascular disease (CVD) in patients with COPD and OSAS, affecting negatively patients' quality of life and survival. Overlap syndrome (OS), i.e. the co-existence of both COPD and OSAS in the same patient, has an additional impact on the cardiovascular system multiplying the risk of morbidity and mortality. The underlying mechanisms for the development of CVD in patients with either OSAS or COPD and OS are not entirely elucidated. Several mechanisms, in addition to smoking and obesity, may be implicated, including systemic inflammation, increased sympathetic activity, oxidative stress and endothelial dysfunction. Early diagnosis and proper management of these patients might reduce cardiovascular risk and improve patients' survival. In this review, we summarize the current knowledge regarding epidemiological aspects, pathophysiological mechanisms and present point-to-point specific associations between COPD, OSAS, OS and components of CVD, namely, pulmonary hypertension, coronary artery disease, peripheral arterial disease and stroke.

Obstructive Sleep Apnoea and Cardiac Disease Among Aboriginal Patients in the Northern Territory of Australia

BACKGROUND

There is paucity of information on obstructive sleep apnoea (OSA) and cardiac diseases among Aboriginal Australian patients. This study evaluates the association of various cardiac disease profiles among Aboriginal patients undergoing a diagnostic polysomnography (PSG).

METHOD

In this 5-year retrospective study demographics, clinical characteristics, medical and cardiac -conditions were analysed.

RESULTS

There were total of 340 eligible patients included in the study. The median age was 47 (38-57) years, 51% were males and obesity was noted in 78%. In the overall study participants, cardiac diseases were present in 46%: coronary artery disease (CAD) in 27%, pulmonary hypertension (PH) 19% and atrial fibrillation (AF) 14%. Diabetes and hypertension were noted in 42 and 41% of patients. Overall, 73/340 (21.5%) had two, 69/340 (20.3%) three, 55/340 (16.2%) four, 40/340 (11.8%) five and 10/340 (2.9%) had six comorbidities. In the overall study participants, 297/340 (87%) had OSA (Apnoea-Hypopnoea Index [AHI]>5/hour). Co-occurrence of OSA and cardiac diseases was found in 140/297 (47%), CAD being the commonest (27%). Patients with OSA had a higher number of comorbidities compared to patients without sleep apnoea. Hospital admissions frequency showed a median 2 (IQR: 0-4) times readmission rates since the diagnosis of OSA overall compliance with CPAP therapy was observed in 63 (43%).

CONCLUSION

Our study demonstrated that a significant proportion of Aboriginal patients with OSA have co-existing cardiac diseases, with CAD being the commonest. Patients with OSA had a higher number of comorbidities compared to patients without sleep apnoea. Furthermore, hospital admission frequency increased among OSA patients with multiple comorbidities.

Adherence to prescribed overnight sleep study in patients suspected of sleep apnea: problem size and influential factors

PURPOSE

Despite the serious consequences of sleep apnea, some patients do not follow their physicians' advice to undergo a sleep study. The present study aimed to determine the rate of adherence and influencing factors in conducting a polysomnography test in patients suspected of obstructive sleep apnea.

METHODS

This qualitative and quantitative analysis was conducted between July 2017 and November 2019 on patients suspected of sleep apnea. The quantitative analysis aimed at determining the rate of adherence through a retrospective cross-sectional study. The qualitative content analysis was conducted on purposefully selected subgroup of patients suspected of obstructive sleep apnea who were referred for polysomnography. The required data were collected through the semi-structured in-depth interviews and then recorded, transcribed, and analyzed using SPSS.22 and MAXQDA10.

RESULTS

Quantitative part: Of 311 patients (mean age: 47.6 ± 13.1 years) referred for polysomnography, 283 patients (91%) were at a high risk of developing obstructive sleep apnea. Among those referred for polysomnography, 31% (n = 95) adhered to recommendations for a sleep study. Qualitative part: Factors affecting adherence to polysomnography were categorized as "barriers" and "triggers." Barriers included inadequate knowledge, psychological factors, cost, and the service system. Triggers included adequate knowledge and tangible experience of consequences of the illness.

CONCLUSION

The majority of patients at risk of developing obstructive sleep apnea did not follow the recommendation for polysomnography, indicating a need for systematic interventions. Among the identified barriers, knowledge and psychological factors are modifiable ones that can be addressed with the patient. We theorize that raising awareness among patients by providing additional information and eliminating concerns may help to increase the rate of adherence. Insurance coverage or subsidy to reduce the sleep study costs may also be an effective strategy to increase adherence to recommendations for polysomnography.

A contemporary review of obstructive sleep apnea

PURPOSE OF REVIEW

This review provides a contemporary review of sleep apnea with emphasis on definitions, epidemiology, and consequences.

RECENT FINDINGS

Amyloid β-42 is one of the main peptides forming amyloid plaques in the brains of Alzheimer patients. Poorer sleep quality and shorter sleep duration have been associated with a higher amyloid burden. Decreased sleep time in the elderly is a precipitating factor in amyloid retention. Studies have shown that the dysregulation of the homeostatic balance of the major inhibitory and excitatory amino acid neurotransmitter systems of gamma-aminobutyric acid (GABA) and glutamate play a role in sleep disordered breathing (SDB).

SUMMARY

Untreated sleep disordered breathing (obstructive sleep apnea and/or central sleep apnea) are an important cause of medical mortality and morbidity. OSA is characterized by recurrent episodes of partial or complete collapse of the upper airway during sleep followed by hypoxia and sympathetic activation. Apneic events are terminated by arousal, followed by increases in pulse and blood pressure, and re-oxygenation and the release of inflammatory factors. Individuals with OSA have an increased risk of developing atrial fibrillation. Hypoxemia and poor sleep quality because of OSA increase the risk of cognitive decline in the elderly.

Long-term efficacy and safety of phrenic nerve stimulation for the treatment of central sleep apnea

STUDY OBJECTIVE

To evaluate long-term efficacy and safety of phrenic nerve stimulation (PNS) in patients with moderate-to-severe central sleep apnea (CSA) through 3 years of therapy.

METHODS

Patients in the remedē System Pivotal Trial were observed every 3 months after implant until US Food and Drug Administration approval. At the time of approval and study closure, all patients completed 24 months of follow-up; 33 patients had not reached the 36-month visit. Sleep metrics (polysomnography) and echocardiographic parameters are reported at baseline, 12, 18, and 24 months, in addition to available 36-month sleep results from polygraphy. Safety was assessed through 36 months; however, analysis focused through 24 months and available 36-month results are provided.

RESULTS

Patients were assessed at 24 (n = 109) and 36 (n = 60) months. Baseline characteristics included mean age 64 years, 91% male, and mean apnea-hypopnea index 47 events per hour. Sleep metrics (apnea-hypopnea index (AHI), central apnea index, arousal index, oxygen desaturation index, rapid eye movement sleep) remained improved through 24 and 36 months with continuous use of PNS therapy. At least 60% of patients in the treatment group achieved at least 50% reduction in AHI through 24 months. Serious adverse events (SAEs) related to the remedē System implant procedure, device, or therapy through 24 months were reported by 10% of patients, no unanticipated adverse device effects or deaths, and all events resolved. No additional related SAEs were reported between 24 and 36 months.

CONCLUSION

These data suggest beneficial effects of long-term PNS in patients with CSA appear to sustain through 36 months with no new safety concerns.

TRIAL REGISTRATION

NCT01816776.

Plasm YKL-40 Levels Are Associated with Hypertension in Patients with Obstructive Sleep Apnea

Background

Obstructive sleep apnea (OSA) is a common disease. It can cause many serious complications. OSA may increase the risk of hypertension. However, the exact mechanism of OSA causing hypertension is not fully understood. YKL-40/chitinase-3-like protein-1 plays an important role in vascular injury, repair, and generation. We sought to explore the role of YKL-40 in endothelial dysfunction and hypertension in OSA patients.

Methods

All subjects were examined by polysomnography (PSG) and the expression of YKL-40 in the plasm of the subjects was measured by luminex. Carotid intima-media thickness (CIMT) was measured by B-mode ultrasound.

Results

According to the conditions of OSA and hypertension, we studied four groups of 157 subjects, including OSA group (OSA, N=77), OSA with hypertension group (OSA+HT, N=37), hypertension group (HT, N=20), and healthly group (Con, N=23). YKL-40 levels were significantly elevated in OSA, OSA+HT, and HT group compared to Con groups. We used the ROC to predict the sensitivity and specificity of YKL-40 in all OSA patients or all hyperpietic patients. For OSA patients, the AUC of YKL-40 is 0.807 (95% confidence interval 0.725–0.888; p<0.01). For hyperpietic patients, the AUC of YKL-40 is 0.656 (95% confidence interval 0.570–0.742, p=0.01). There was a significant correlation between the parameter of OSA and hypertension and YKL-40 (P<0.05) and a significant correlation between Max-CIMT and YKL-40 (P<0.05).

Conclusion

Elevated circulating levels of YKL-40 are associated with hypertension in OSA patients. The specificity of YKL-40 suggests that it could be a potential biomarker for OSA and hypertension.

Non-pharmacological interventions for sleep and quality of life: a randomized pilot study

OBJECTIVE

to estimate the effects of non-pharmacological interventions to improve the quality of sleep and quality of life of patients with heart failure.

METHOD

pilot study of a randomized controlled trial with 32 individuals assigned to four groups. Sleep was assessed using the Pittsburgh Sleep Quality Inventory, while health-related quality of life was assessed using the Minnesota Living with Heart Failure Questionnaire, at the baseline and at the 12th and 24th weeks. The means of the outcomes according to intervention groups were compared using analysis of covariance; effect sizes were calculated per group.

RESULTS

all groups experienced improved quality of sleep and health-related quality of life at the end of the intervention (week 12) and at follow-up (week 24), though differences were not statistically significant (p between 0.22 and 0.40). The effects of the interventions at the 12th week ranged between -2.1 and -3.8 for the quality of sleep and between -0.8 and -1.7 for quality of life, with similar values at the 24th week.

CONCLUSION

the effects found in this study provide information for sample size calculations and statistical power for confirmatory studies. Brazilian Clinical Trials Registry - RBR 7jd2mm.

Correlation Analysis between Obstructive Sleep Apnea Syndrome (OSAS) and Heart Rate Variability

BACKGROUND

Heart rate variability (HRV) represents the sympathetic nervous system activity induced by apnea or hypopnea events among OSAS patients. However, few studies have been conducted to clarify the association between HRV parameters and polysomnography (PSG) diagnostic indices. In our study, we postulate that the prevalence of cardiac arrhythmias is associated with OSAS, and HRV parameters may be an effective method for OSAS screening.

METHODS

Overall, 168 participants had been collected from 2011 to 2016 in the Second Affiliated Hospital of Soochow University. By apnea-hypopnea index (AHI), patients were separated into three subsets: AHI < 5 as control group, 5≤AHI<30 as mild-moderate OSAS group and AHI≥30as severe OSAS group. HRV and PSG parameters were collected based on electrocardiography and polysomnography system. Correlation analyses between standard deviation of R-R intervals (SDNN), SDNN index, RMSSD, PNN50, low frequency (LF), high frequency (HF) and LF/HF ratio and the AHI, ODI and MI were performed by Spearman's correlation analysis.

RESULTS

Compared with control group (64.5%) or mild-moderate OSAS group (67.3%), the prevalence of arrhythmias was considerably greater in severe OSAS group (P<0.05). Moreover, we demonstrated that LF/HF was greater in two OSAS groups than the normal group.

CONCLUSION

Correlation analyses revealed a significant and positive relation between the LF/HF and AHI, ODI and MI in OSAS patients. Severe OSAS could be attributed to enhanced danger of incident arrhythmia. LF/HF ratio as a relevant feature may be an effective parameter for detecting OSAS.

Quality of life, depression and dietary intake in Obstructive Sleep Apnea patients

BACKGROUND

The aim of this study was to analyze the association between depression, quality of life and dietary intake in newly diagnosed Obstructive Sleep Apnea (OSA) patients.

METHODS

From 153 eligible patients suffering from sleep disturbances, 64 met inclusion and exclusion criteria. The polysomnography was used for OSA diagnosis. The quality of life (QOL) was assessed by WHOQOL-BREF questionnaire, self-reported chronotype by morningness-eveningness questionnaire and level of depression by Beck's Depression Inventory. Blood pressure and parameters of glucose and lipid metabolism were assessed by routine methods. The dietary intake was evaluated by 24-hr dietary recalls.

RESULTS

Significantly negative associations were found between depression inventory and QOL. Better QOL for physical health and social relationships was observed in the "definitely morning" chronotype. The "morning type" of patients was positively related to the intake of fat, monounsaturated fatty acids and vitamin B12. Correlations between QOL and diastolic blood pressure, HDL-cholesterol, TG, fasting glucose, as well as protein and vitamin B6 intake were found.

CONCLUSIONS

In conclusion, both chornotype and depression influence QOL in OSA patients where morning type is associated with better physical health and social relationships and increase in depression index deteriorate physical health, psychological and social relationship QOL domains. QOL as well as depression and chornotype are also influenced by selected cardio-metabolic factors and dietary intake.