Nocturnal intermittent hypoxia and short sleep duration are independently associated with elevated C-reactive protein levels in patients with coronary artery disease

Impact of Intermittent Hypoxia Related to Obstructive Sleep Apnoea Syndrome on Low-Grade Inflammation in Hypertensive Patients: Potential Implications for Cardiovascular Risk

There is evidence for a particular relationship between low-grade inflammation (LGI) and intermittent hypoxia (IH) related to obstructive sleep apnoea syndrome (OSAS). However, despite the potential deleterious cardiovascular consequences associated with this LGI in hypertensive patients, few studies have investigated the impact of IH related to OSAS on CRP levels in this subpopulation. In total, 1404 hypertensive patients were selected retrospectively from the Sleep Laboratory database. CRP levels ≥3 mg/L but <10 mg/L were used as cut-offs to identify hypertensive patients with LGI. Logistic regressions were conducted to examine the risk of LGI associated with IH related to OSAS in hypertensive patients. LGI was frequent (33.8%) in hypertensive patients. After adjustment for confounders, multivariate logistic regressions revealed that only moderate to severe OSAS (apnoea-hypopnoea index ≥ 15/h) with high IH (oxygen desaturation index ≥ 15/h) [OR 1.51 (95% CI 1.06-2.14)] was significantly associated with LGI in hypertensive patients (p-value = 0.045). Consistent with our hypothesis, our results demonstrated the existence of a particular subtype of hypertensive patients at high cardiovascular risk characterised by the presence of LGI induced by IH hypoxia related to moderate to severe OSAS, which justifies the establishment of adequate management of this pathology to allow better cardiovascular prevention in this subpopulation.

Associations of sleep quality and exercise frequency and the risk of coronary heart disease in Chinese urban elderly: a secondary analysis of cross-sectional data

BACKGROUND

Sleep quality and exercise frequency are closely associated with coronary heart disease (CHD). Few studies focused on the joint effect of initiating sleep, sleep disorders, and exercise frequency on the risk of CHD in the elderly. We used a secondary data analysis based on Boshan Elderly cross-sectional study. We explored the sleep quality, exercise frequency, and their joint effects on the risk of CHD.

METHODS

We collected 678 participants whose age ≥ 60 years old from Boshan District Hospital. We used the Pittsburgh Sleep Quality Index to evaluate the sleep quality and obtained physical examination information from the hospital.

RESULTS

Compared with the non-CHD group, patients with CHD spent more time in initiating sleep (time ≥ 60 min, 34.59% vs. 22.93%, P = 0.025) and less time exercising (exercise frequency < 1 times/week, 23.90% vs. 17.15%, P = 0.024). In multiple logistic regression analysis, sleep latency ≥ 60 min was associated with CHD risk (adjusted OR = 1.83; 95% CI: 1.11, 2.99; P-trend = 0.008). The adjusted OR (95% CI) of CHD was 2.24 (1.16, 4.34) for sleep duration < 5 h versus 5-9 h. Compared with exercise frequency < 1 times/week, the adjusted OR for exercise frequency ≥ 1 times/week was 0.46 (95% CI: 0.26, 0.83; P = 0.010). In addition, the joint effects of long sleep latency (≥ 60 min) and sleep disorders were associated with CHD (adjusted OR = 3.36; 95% CI: 1.41, 8.02). The joint effect of exercise frequency ≥ 1 times/week and sleep onset latency within normal limits (< 30 min) was also associated with CHD, and the adjusted OR (95% CI) was 0.42 (0.21, 0.87).

CONCLUSIONS

Long sleep latency, high frequency of initiating sleep difficulty, sleep disorders, and short sleep duration were positively associated with CHD. In addition, the joint effects of long sleep latency and sleep disorders were positively correlated with CHD incidence. However, the joint effects of exercise frequency ≥ 1 times/week and normal sleep onset latency were negatively associated CHD.

Sleep, circadian rhythm characteristics, and melatonin levels in later life adults with and without coronary artery disease

STUDY OBJECTIVES

The purpose of this study was to conduct a comprehensive assessment of sleep and circadian rhythms in individuals with and without coronary artery disease (CAD).

METHODS

This was a cross-sectional study. Participants were 32 individuals, mean age = 70.9, female 46.9%, 19 with CAD, and 13 without CAD. We assessed sleep quality and 24-hour rest-activity rhythms for 14 days using wrist actigraphy and self-report measures, and circadian rhythm using dim light melatonin onset.

RESULTS

Melatonin levels prior to habitual bedtime were significantly lower in individuals with CAD than in those without CAD (median area under the curve = 12.88 vs 26.33 pg/ml × h, P = .049). The median circadian timing measured by dim light melatonin onset was the same for the 2 groups with 20:26 [hours:minutes] for individuals with CAD and 19:53 for the control group (P = .64, r = .14). Compared to the control group, the CAD group had significantly lower amplitude (P = .03, r =-.48), and lower overall rhythmicity (pseudo-F-statistic P = .004, r = -.65) in their 24-hour rest-activity rhythms.

CONCLUSIONS

This is one of the first studies to comprehensively assess both sleep and circadian rhythm in individuals with CAD. Compared to non-CAD controls, individuals with CAD had lower levels of melatonin prior to habitual bedtime and a lower 24-hour rest-activity rhythm amplitude and overall rhythmicity. Future studies using larger sample sizes should further investigate the possibility of suppressed circadian rhythmicity in individuals with CAD.

CITATION

Moon C, Benson CJ, Albashayreh A, Perkhounkova Y, Burgess HJ. Sleep, circadian rhythm characteristics, and melatonin levels in later life adults with and without coronary artery disease. J Clin Sleep Med. 2023;19(2):283-292.

Sleep-disordered breathing is independently associated with elevated natriuretic peptide levels in patients with cardiovascular diseases

Sleep disorders and sleep duration have attracted considerable attention as potential modifiable risk factors for the development and progression of heart failure (HF). However, whether these sleep behaviors could aggravate the underlying cardiac condition remains ambiguous. We evaluated the associations between the levels of plasma B-type natriuretic peptide (BNP) and sleep-disordered breathing (SDB), sleep quality and quantity, or daytime sleepiness in cardiovascular diseases (CVD) patients. A total of 1717 consecutive patients with CVD [median age, 66 years (55-74 years); female, 27.5%] were enrolled. SDB was screened by nocturnal pulse oximetry; sleep quality and quantity were determined by Pittsburg Sleep Quality Index, and daytime sleepiness was examined by Epworth Sleepiness Scale. The median plasma BNP level was 54.9 pg/ml (23.5-146.4 pg/ml). Multiple regression analyses showed that the BNP level in the highest quintile (BNP > 181.8 pg/ml) was associated with SDB (severe: OR, 5.88; 95% CI 3.17-10.88; moderate: OR, 3.62; 95% CI 2.17-6.02; mild: OR, 2.22: 95% CI 1.42-3.47). There were no significant associations between other sleep parameters and higher BNP levels. The relationship between SDB and BNP levels was unchanged regardless of the previous history of symptomatic HF. SDB was independently associated with the elevated plasma BNP level in patients with a variety of CVD.

Frequent nightmares and its associations with psychological and sleep disturbances in hospitalized patients with cardiovascular diseases

AIMS

Frequent nightmares can pose a serious clinical problem, especially in association with sleep and psychological disturbances, in the general population. However, this association has not been investigated in inpatients with cardiovascular (CV) diseases. Furthermore, whether CV medications could induce iatrogenic nightmares remains unknown. In a cross-sectional designed study, we evaluated the prevalence and determinants of frequent nightmares and its association with sleep and psychological disturbances among hospitalized CV patients.

METHODS AND RESULTS

A total of 1233 patients (mean age, 64 ± 15 years; 25.1% female) hospitalized for various CV diseases in a single university hospital were enrolled. We assessed nightmares and sleep characteristics using the Pittsburgh Sleep Quality Index (PSQI), sleep-disordered breathing (SDB) using nocturnal pulse oximetry, and psychological disturbances using Hospital Anxiety and Depression Scale (HADS). Overall, 14.8% and 3.6% of the patients had at least one nightmare per month and per week (frequent nightmares), respectively. In this cohort, 45.9% had insomnia (modified PSQI > 5), 28.0% had SDB (3% oxygen desaturation index > 15), 18.5% had depression (HADS-depression ≥ 8), and 16.9% had anxiety (HADS-anxiety ≥ 8). Frequent nightmares were not associated with CV medications and SDB but were associated with depression [odds ratio (OR) = 4.61, 95% confidence interval (CI) = 2.03-10.48], anxiety (OR = 5.32, 95% CI = 2.36-12.01), and insomnia (OR = 7.15, 95% CI = 2.41-21.22).

CONCLUSIONS

Frequent nightmares were not uncommon in patients hospitalized for CV diseases. Although the cause-effect relationship is unclear, frequent nightmares were associated with psychological disturbances and insomnia, but not iatrogenic factors, among hospitalized CV patients. Cardiologists should be more conscientious to nightmare complaints with respect to screening for psychological disturbances and insomnia.

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

BACKGROUND

Limited 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.

METHODS

Consecutive 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.

RESULTS

We 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.

CONCLUSION

OSA severity and SD were not independently associated with CKD in subjects with CAD.

Diagnostic accuracy and suitability of instruments that screen for obstructive sleep apnoea, insomnia and sleep quality in cardiac patients: a meta-analysis

BACKGROUND

A number of clinical guidelines recommend that all cardiac rehabilitation patients should be screened for potential sleep disorders with a validated screening instrument. There is currently no consensus on what specific tools should be used.

OBJECTIVE

To identify tools that are practical to use in the clinical environment and have high diagnostic accuracy.

METHODS

We systematically searched online databases to identify patient reported outcome instruments that have been used in published research studies to assess the likelihood of obstructive sleep apnoea (OSA) in cardiac patients. In studies that provided diagnostic data, these data were extracted and verified via an evidence-based diagnostic calculator. Where sufficient numbers of studies were available, a meta-analysis was conducted to determine pooled estimates of specificity, sensitivity and diagnostic odds ratios. Selected papers were qualitatively assessed using the Standards for Reporting Diagnostic accuracy studies (STARD).

RESULTS

Of the 21 instruments identified, six detected likelihood of OSA, two assessed daytime sleepiness, five assessed insomnia and eight examined sleep quality. A meta-analysis of 14 studies that assessed diagnostic accuracy of moderate OSA, revealed moderate sensitivity for the Berlin Questionnaire, Sens = 0.49 (95% CI 0.45-0.52) and good sensitivity for the Stop-BANG, Sens = 0.93 (95% CI 0.87-0.96) but poor specificity at standard cut-off criteria.

CONCLUSION

There are promising practical tools available to screen patients with OSA and other sleep disorders in cardiac rehabilitation settings, but specificity could be improved. Additional assessment of sleep quality may enhance prognostic ability with both OSA and insomnia screening.

Associations of Inflammation, Physical Activity, and Sleep in a Diverse Population of Women

Background: Cardiovascular disease (CVD) is the leading cause of mortality in United States with a recent rise seen in young adults, particularly women. Systemic inflammation, physical activity, and sleep are each individually linked to CVD risk. Whether there is an interaction of these variables, however, is unclear. We evaluated physical activity and sleep among racially ethnically diverse women, ages 20-79 years, to assess associations with systemic inflammation. Methods: We performed a cross-sectional study of 506 women (61% racial/ethnic minority; mean (standard deviation [SD]) age = 37 [15.7] years, body mass index 26.0 [5.7] kg/m²) enrolled in the American Heart Association (AHA) Go Red for Women Strategically Focused Research Network at Columbia University Irving Medical Center (CUIMC). Inflammation, assessed by C-reactive protein (CRP), was analyzed in the Biomarkers Core Laboratory at CUIMC. Physical activity and sleep were assessed using validated questionnaires. Multivariable models adjusted for demographic and clinical confounders were used to evaluate associations between CRP, physical activity, and sleep. Results: Mean (SD) physical activity was 282 (557.2) minutes/week, and mean (SD) sleep duration was 6.75 (1.24) hours/night. Mean CRP was 2.08 (3.56), and 17% of participants were categorized as high risk for obstructive sleep apnea (OSA). Participants who slept <6 hours/night were less likely to be physically active ≥150 minutes/week (odds ratios, ORs [95% confidence interval, CI]: 0.53 [0.33-0.84]). This association was nonsignificant after adjustment. High risk of OSA was associated with CRP ≥2 mg/L (OR [95% CI]: 1.91 [1.11-3.30]) following adjustment. Stratification by race/ethnicity showed that high risk of OSA was associated with CRP ≥2 mg/L among racial/ethnic minorities but not white women (OR [95% CI]: 2.75 [1.43-5.30] vs. 0.94 [0.31-2.88]). Conclusion: High risk of OSA and elevated CRP was significantly associated in women, particularly minority women. Both play a role in CVD, highlighting potential causes for the increased risk of CVD in younger women.

Polysomnographic phenotype as a risk factor for cardiovascular diseases in patients with obstructive sleep apnea syndrome: a retrospective cohort study

Background

Obstructive sleep apnea syndrome (OSAS) is associated with the development of cardiovascular diseases caused by hypoxemia during sleeping. We classified OSAS phenotypes based on polysomnographic findings and aimed to evaluate that the unique phenotypes would be differentially associated with risk of cardiovascular disease.

Methods

This retrospective and observational study assessed adult patients who underwent polysomnography at the Wonju Severance Christian Hospital from November 2008 to February 2018. The OSAS phenotypes were classified as apnea-predominant, hypopnea-predominant, and respiratory effort-related arousal (RERA)-predominant based on the polysomnography results. The polysomnographic data were collected and analysed, and clinical features such as medical history and comorbidities were assessed by a review of the electronic medical records.

Results

A total of 860 adult patients were classified as apnea-predominant (n=220), hypopnea-predominant (n=119), or RERA-predominant (n=275). The hypopnea-predominant group had significantly higher rates of hyperlipidaemia (P<0.001), heart failure (15.5%, P<0.001), and coronary artery disease (20.9%, P=0.005) than the other groups. After classifying the patients according to severity of the hypopnea index, logistic regression analyses adjusted for age, sex, and smoking history revealed that the hypopnea index increased the risk for coronary artery disease and heart failure.

Conclusions

The hypopnea-predominant group would be a specific phenotype that has a differential association with the risks for coronary artery disease and heart failure.

Association of Sleep Duration and Insomnia Symptoms with Components of Metabolic Syndrome and Inflammation in Middle-Aged and Older Adults with Metabolic Syndrome in Taiwan

The study determined the association of sleep duration and insomnia symptoms with the components of metabolic syndrome and inflammation in middle-aged and older adults with metabolic syndrome in Taiwan. This cross-sectional study used the database compiled in Taiwan between 2004–2013. A total of 26,016 volunteers aged 35 years and above were selected. Metabolic syndrome was defined according to the International Diabetes Federation. Compared with regular sleep duration (6–8 h/day), short (<6 h/day) or long sleep duration (>8 h/day) and insomnia symptoms significantly increased the odds ratios of high waist circumference, high blood pressure, low high-density lipoprotein-cholesterol, high triglycerides, high fasting blood glucose, and high C-reactive protein. Insomnia symptoms did not modify the effects of sleep duration on the components of metabolic syndrome and inflammation. Our study suggests that short or long sleep duration and insomnia symptoms may have an adverse effect on metabolic syndrome and inflammation.

Excessive Daytime Sleepiness Is Associated With Depression Scores, But Not With Sleep-Disordered Breathing in Patients With Cardiovascular Diseases

BACKGROUND

Excessive daytime sleepiness (EDS) is a significant public health concern, with sleep-disordered breathing (SDB) being a common cause. However, their precise relationship in patients with cardiovascular disease (CVD) is unclear. Furthermore, whether comorbid psychological disorders could contribute to EDS remains unknown. We aimed to assess the prevalence of EDS and its related factors, including SDB and depression, in patients with CVD.Methods and Results:We analyzed data from 1,571 patients admitted for various CVDs in a single university hospital (median age, 67 [56-76] years; 29.6% women). We assessed EDS using the Japanese version of the Epworth Sleepiness Scale (ESS; median 6.0 [4.0-9.0]). The presence of EDS (ESS >10, n=297 [18.9%]) did not differ between patients with and without SDB, which was screened with nocturnal pulse oximetry. In contrast, the patients with EDS had higher depression scores (Hospital Anxiety and Depression Scale subscore for depression [HADS-D] and Patient Healthcare Questionnaire [PHQ]-9). The depression scores, measured by HADS-D (odds ratio [OR] 1.14; 95% confidence interval [CI], 1.07-1.22) and PHQ-9 (OR, 1.14; 95% CI, 1.07-1.20) were independent determinants of EDS. These relationships among EDS, SDB, and depression were consistent among the subgroups with cardiovascular comorbidities.

CONCLUSIONS

The presence of EDS is associated with depressive symptoms, but not with SDB, in patients with CVD, suggesting that these patients should be thoroughly assessed for psychological disturbances.