Are circadian rhythms in disarray in patients with chronic critical illness?

Aim: The aim of our study is to assess circadian rhythms in patients with chronic critical illness due to severe brain injury in intensive care unit by establishing the relation between melatonin and cortisol secretion, considering astronomical time and the sleep-wake cycle in chronic critical illness. Materials and methods: The study included 54 adult patients with chronic critical illness who resided in the intensive care unit for at least 30 days. The level of consciousness was determined using the CRS-R scale. We did the continuous electroencephalographic (EEG) monitoring with polygraphic leads for 24 h. Also, we determined the serum levels of cortisol and melatonin using the tandem mass spectrometry method with ultra-performance liquid chromatography. Results: 90.74 % of patients had one acrophase in melatonin secretion curve, which suggests the preservation of the rhythmic secretion of melatonin. These acrophases of the melatonin rhythm occurred during the night time in 91.8 % of patients. Most of the patients (69.3 %) slept during the period from 2:00 to 4:00 a.m. The evening levels of cortisol and melatonin had an inverse relation (rs=0.61, p<0.05), i.e., a decrease in the level of cortisol secretion accompanies an increase in melatonin. Conclusions: We concluded from our study that the rhythmic secretion of melatonin and cortisol is preserved in patients with chronic critical illness that resulted from severe brain injury. No statistically significant discrepancy between melatonin and cortisol secretion, day-and-night time and the sleep-wake cycle are found. We may focus our future work on finding more reliable methods to stabilize the preservation of circadian rhythms to protect vital organ functions.

Progression of obstructive sleep apnoea after renal denervation is not associated with hypertension exaggeration.

PURPOSE: In a cohort, observational prospective trial, we assessed the long-term dynamics of sleep-disordered breathing in patients with resistant hypertension after renal denervation and their association with blood pressure change at remote follow-up. MATERIALS AND METHODS: Twenty-eight patients with stable hypertension who were recruited for endovascular radiofrequency renal denervation in 2012-2019 and had valid both baseline and follow-up sleep study, were included in the analysis. All patients underwent physical examination, anthropometry, office and ambulatory blood pressure measurements, blood and urine tests, kidney visualization, and full polysomnography before and within 12-36 months after renal denervation. RESULTS: The average follow-up comprised 30.1 ± 8.4 months. At long-term follow-up, no significant changes in creatinine level, estimated glomerular filtration rate, body mass index were registered. There was a significant increase in sleep apnea severity indices: the mean change in apnea-hypopnea index comprised 9.0(-21.1;25.2) episodes/h, in oxygen desaturation index 6.5(-16.8;35.9) episodes/h, in the average SpO2 -1.7(-5.6;1.9)%. Over 12-month follow-up, there were no significant differences in blood pressure response in patients with and without sleep apnea. The baseline apnea-hypopnea and oxygen desaturation indices and the mean SpO2 were associated with the circadian blood pressure profile at follow-up, but did not correlate with the blood pressure response. CONCLUSIONS: Although the severity of sleep apnea worsens at > 12 months follow-up after renal denervation, this is not associated with hypertension exaggeration.

Sleep-Disordered Breathing and Prognosis after Ischemic Stroke: It Is Not Apnea-Hypopnea Index That Matters.

BACKGROUND: Sleep-disordered breathing (SDB) is highly prevalent after stroke and is considered to be a risk factor for poor post-stroke outcomes. The aim of this observational study was to evaluate the effect of nocturnal respiratory-related indices based on nocturnal respiratory polygraphy on clinical outcomes (including mortality and non-fatal events) in patients with ischemic stroke. METHODS: A total of 328 consecutive patients (181 (55%) males, mean age 65.8 ± 11.2 years old) with confirmed ischemic stroke admitted to a stroke unit within 24 h after stroke onset were included in the analysis. All patients underwent standard diagnostic and treatment procedures, and sleep polygraphy was performed within the clinical routine in the first 72 h after admission. The long-term outcomes were assessed by cumulative endpoint (death of any cause, new non-fatal myocardial infarction, new non-fatal stroke/transient ischemic attack, emergency revascularization, emergency hospitalization due to the worsening of cardiovascular disease). A Cox-regression analysis was applied to evaluate the effects of nocturnal respiratory indices on survival. RESULTS: The mean follow-up period comprised 12 months (maximal-48 months). Patients with unfavourable outcomes demonstrated a higher obstructive apnea-hypopnea index, a higher hypoxemia burden assessed as a percent of the time with SpO2 < 90%, a higher average desaturation drop, and a higher respiratory rate at night. Survival time was significantly lower (30.6 (26.5; 34.7) versus 37.9 (34.2; 41.6) months (Log Rank 6.857, p = 0.009)) in patients with higher hypoxemia burden (SpO2 < 90% during ≥2.1% versus <2.1% of total analyzed time). However, survival time did not differ depending on the SDB presence assessed by AHI thresholds (either ≥5 or ≥15/h). The multivariable Cox proportional hazards regression (backward stepwise analysis) model demonstrated that the parameters of hypoxemia burden were significantly associated with survival time, independent of age, stroke severity, stroke-related medical interventions, comorbidities, and laboratory tests. CONCLUSION: Our study demonstrates that the indices of hypoxemia burden have additional independent predictive value for long-term outcomes (mortality and non-fatal cardiovascular events) after ischemic stroke.

Clinical and neurophysiological characteristics of 89 patients with narcolepsy and cataplexy from the Russian Narcolepsy Network.

STUDY OBJECTIVES: The first reports of narcolepsy with cataplexy in Russia were made by Mankovsky (The pathogenesis of narcolepsy (the case of epidemic encephalitis with cataplexy) published in the Sovremennaya psihonevrologia) in 1925. The largest series of patients (n = 110) was reported by A. Vein (doctoral thesis: Hypersomnia Syndrome) in 1964. However, until today, narcolepsy remained relatively unknown in Russia. The aim of this study is to report clinical and polysomnography (PSG)/multiple sleep latency test (MSLT) results in the Russian population and compare them with the European Narcolepsy Network (EU-NN) data (n = 1099) reported. METHODS: Eleven sleep centers from Russia agreed to participate and completed a questionnaire including 58 questions concerning demographic, clinical, PSG, and MSLT data. RESULTS: There were 89 patients with a mean age of 35.6 ± 16.9 years (± here and further indicates standard deviation), 58% males, and 42% females. Narcolepsy started at a mean age of 25.6 ± 14.6 years (range 5-74 years). The mean Epworth Sleepiness Scale score was 18.4 ± 3.5 points (range: 11-24). Sleep paralysis was reported by 59.1%, and hallucinations by 82% of patients. In MSLT, ≥ 2 sleep-onset REM (rapid eye movement) periods (SOREMPs) were found in 81.6%. No center provided human leukocyte antigen (HLA) or cerebral spinal fluid hypocretin data. CONCLUSIONS: Clinical and neurophysiological data from this first study of the Russian Narcolepsy Network suggest a similar profile to the recently reported EU-NN data. The more severe and higher percentage of patients with cataplexy and presenting with both excessive daytime sleepiness and cataplexy may reflect low awareness of narcolepsy in Russia. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; URL: https://clinicaltrials.gov/ct2/show/NCT05375890; Name: Clinical and Neurophysiological Characteristics of Narcolepsy; Identifier: NCT05375890. CITATION: Kuts A, Poluektov M, Zakharov A, et al. Clinical and neurophysiological characteristics of 89 patients with narcolepsy and cataplexy from the Russian Narcolepsy Network. J Clin Sleep Med. 2023;19(2):355-359.

The Prognostic Role of Polysomnography Parameters in Heart Failure Patients with Previous Decompensation.

Background: Sleep-disordered breathing (SDB) is a widespread comorbidity in patients with chronic heart failure (HF) and may have a deleterious effect on the pathogenesis of HF. We aimed to evaluate the prognostic role of polysomnography parameters in HF patients with previous decompensation. Methods: 123 patients were included in the prospective cohort study. In addition to the standard examination, all patients underwent polysomnography (PSG). Results: The Kaplan−Meier analysis showed the incidence of the combined endpoint differs between LVEF categories ≤25.5% vs. >25.5% (χ2 = 9.6, log rank p = 0.002), NTpro-BNP > 680 vs. ≤680 pg/mL (χ2 = 12.7, log rank p = 0.001), VO2peak categories <16 vs. ≥16 mL/min/kg (χ2 = 14.2, log rank p = 0.001), VE/VCO2 slope ≥38.5 vs. <38.5 (χ2 = 14.5, log rank p = 0.001), wake after sleep onset >40 min vs. ≤40 min (χ2 = 9.7, log rank p = 0.03), and sleep stage 2 (S2) <44% vs. ≥44% (χ2 = 12.4, log rank p = 0.001). Conclusion: Among the PSG parameters, WASO > 40 min and S2 < 44% were associated with a combined endpoint in patients with previous decompensation of HF. Moreover, higher NT-proBNP and VE/VCO2 slope, lower LVEF, and VO2peak were also independent factors of a poor prognosis.

Physical Activity Is Associated With Sleep Quality: Results of the ESSE-RF Epidemiological Study.

BACKGROUND AND HYPOTHESIS: Physical activity (PA) is an important behavioral factor associated with the quality of life and healthy longevity. We hypothesize that extremely low and extremely high levels of daily PA (including occupational PA) may have a negative impact on sleep quality and psychological well-being. OBJECTIVE: The aim of the study is to investigate the association between the level and type of PA and sleep problems in adult population. MATERIALS AND METHODS: The sample of the study consisted of the participants from the population-based cohort of The Epidemiology of Cardiovascular Risk Factors and Diseases in Regions of the Russian Federation Study (ESSE-RF). The data of three regions (Saint Petersburg, Samara, Orenburg), varying in geographic, climatic, socioeconomic characteristics, was included into analysis. The total sample consisted of 4,800 participants (1,600 from each region; 1,926 males, 2,874 females), aged 25-64. The level of PA was evaluated using three parameters: the type of PA at work, the frequency of an intensive/high PA including sport (times a week), the mean duration of leisure-time walking (minutes a day). The measures of sleep quality were sleep duration and the frequency of difficulty falling asleep, difficulty maintaining sleep, daytime sleepiness, and sleep medication use. PA and sleep characteristics were assessed by interview carried by the trained medical staff. RESULTS: When controlling for gender, age and socioeconomic status (SES) extremely high occupational PA was a significant risk factor for difficulty falling asleep three or more times a week [OR(CI95%) = 1.9(1.2-3.0), p = 0.003] while working in a sitting position or having moderate physical load at work were not associated with sleep characteristics. Having a high physical load six or more times a week was a risk factor for difficulty falling asleep controlling for gender, age and SES [OR(CI95%) = 1.9(1.4-3.4), p = 0.001]. The association between leisure-time walking and sleep characteristics was insignificant. Walking less than an hour a day was associated with increased depression scores (46.5 vs. 41.9%, p = 0.006). CONCLUSION: High physical load at work and excessively frequent intensive PA are associated with difficulties initiating sleep and may represent a risk factor for insomnia.

Sleep and Cardiovascular Risk.

Sleep is essential for healthy being and healthy functioning of human body as a whole, as well as each organ and system. Sleep disorders, such as sleep-disordered breathing, insomnia, sleep fragmentation, and sleep deprivation are associated with the deterioration in human body functioning and increased cardiovascular risks. However, owing to the complex regulation and heterogeneous state sleep per se can be associated with cardiovascular dysfunction in susceptible subjects. The understanding of sleep as a multidimensional concept is important for better prevention and treatment of cardiovascular diseases.

Effect of early sleep apnoea treatment with adaptive servo-ventilation in acute stroke patients on cerebral lesion evolution and neurological outcomes: study protocol for a multicentre, randomized controlled, rater-blinded, clinical trial (eSATIS: early Sleep Apnoea Treatment in Stroke).

BACKGROUND: Sleep-disordered breathing (SDB) is highly prevalent in acute ischaemic stroke and is associated with worse functional outcome and increased risk of recurrence. Recent meta-analyses suggest the possibility of beneficial effects of nocturnal ventilatory treatments (continuous positive airway pressure (CPAP) or adaptive servo-ventilation (ASV)) in stroke patients with SDB. The evidence for a favourable effect of early SDB treatment in acute stroke patients remains, however, uncertain. METHODS: eSATIS is an open-label, multicentre (6 centres in 4 countries), interventional, randomized controlled trial in patients with acute ischaemic stroke and significant SDB. Primary outcome of the study is the impact of immediate SDB treatment with non-invasive ASV on infarct progression measured with magnetic resonance imaging in the first 3 months after stroke. Secondary outcomes are the effects of immediate SDB treatment vs non-treatment on clinical outcome (independence in daily functioning, new cardio-/cerebrovascular events including death, cognition) and physiological parameters (blood pressure, endothelial functioning/arterial stiffness). After respiratory polygraphy in the first night after stroke, patients are classified as having significant SDB (apnoea-hypopnoea index (AHI) > 20/h) or no SDB (AHI < 5/h). Patients with significant SDB are randomized to treatment (ASV+ group) or no treatment (ASV- group) from the second night after stroke. In all patients, clinical, physiological and magnetic resonance imaging studies are performed between day 1 (visit 1) and days 4-7 (visit 4) and repeated at day 90 ± 7 (visit 6) after stroke. DISCUSSION: The trial will give information on the feasibility and efficacy of ASV treatment in patients with acute stroke and SDB and allows assessing the impact of SDB on stroke outcome. Diagnosing and treating SDB during the acute phase of stroke is not yet current medical practice. Evidence in favour of ASV treatment from a randomized multicentre trial may lead to a change in stroke care and to improved outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT02554487 , retrospectively registered on 16 September 2015 (actual study start date, 13 August 2015), and www.kofam.ch (SNCTP000001521).

Sleep Duration, Lipid Profile and Insulin Resistance: Potential Role of Lipoprotein(a).

Lipoprotein (a) (Lp(a)) is considered a genetic factor for cardiovascular disease playing an important role in atherogenesis and thrombosis, but the evidence about its association with sleep duration is controversial. We evaluated the relation between self-reported sleep duration and Lp(a). Among 1600 participants of the population-based sample, we selected 1427 subjects without previously known cardiovascular events, who answered the questions about their sleep duration; had valid lipid profile results (total cholesterol, low- and high-density lipoproteins, Lp(a), apolipoprotein AI (ApoAI), ApoB, and ApoB/ApoAI); and did not take lipid-lowering drugs (mean age 46 ± 12 years). We performed a structured interview, which included questions about lifestyle, medical history, complaints, and sleep duration (How long have you been sleeping per night during the last month?). Sleep duration was classified as follows: <6 h/night-short, 6-9 h/night-normal, and ≥10 h/night-long. Overall, 73 respondents (5.2%) were short-sleepers and 69 (4.8%) long-sleepers. Males were slightly more prevalent among short-sleepers. The groups matched by age, body mass index, blood pressure, diabetes mellitus, and hypertension rate. Short-sleepers had lower rates of high total cholesterol (≥5.0 mmol/L), lower Lp(a) levels and lower rates of increased Lp(a) ≥0.5 g/L, and higher insulin and insulin resistance (assessed by the homeostatic model assessment for insulin resistance (HOMA-IR)). ApoAI, ApoB, their ratio, and other lab tests were similar in the groups. The multinomial logistic regression demonstrated that only the short sleep duration was independently (odds ratio (OR) 0.29, 95% confidence interval (CI) (0.09-0.91), p = 0.033) associated with Lp(a) (χ2 = 41.58, p = 0.003). Other influencing factors were smoking and HOMA-IR. Such an association was not found for long-sleepers. In conclusion, a short-sleep duration is associated with Lp(a). The latter might mediate the higher insulin resistance and higher cardiometabolic risks in short-sleepers.

Predictors of heart rhythm disturbances in hypertensive obese patients with obstructive sleep apnea.

OBJECTIVE: To assess the incidence and predictors of heart rhythm and conduction disturbances in hypertensive obese patients with and without obstructive sleep apnea (OSA). METHODS: This is an open, cohort, prospective study. Out of 493 screened patients, we selected 279 hypertensive, obese individuals without severe concomitant diseases: 75 patients without sleep-disordered breathing (non-SDB group), and 204 patients with OSA (OSA group). At baseline, all patients underwent examination, including ECG, Holter ECG monitoring, and sleep study. During follow-up (on 3, 5, 7 and 10th years; phone calls once per 6 months), information about new events, changes in therapy and life style was collected, diagnostic procedures were performed. As the endpoints, we registered significant heart rhythm and conduction disorders as following: atrial fibrillation (AF), ventricular tachycardia, atrioventricular block (AV) 2-3 degree, sinoatrial block, significant sinus pauses (> 2000 ms), and the required pacemaker implantation. RESULTS: The median follow-up was 108 (67.5-120) months. The frequency of heart rhythm disorders was higher in OSA patients (29 cases, χ2 = 5.5; Р = 0.019) compared to the non-SDB patients (three cases; OR: 3.92, 95% CI: 1.16-13.29). AF was registered in 15 patients (n = 12 in OSA group; Р = 0.77). Heart conduction disturbance developed in 16 patients, without an association with the rate of coronary artery disease onset. Regression analysis showed that only hypertension duration was an independent predictor of AF (OR: 1.10, 95% CI: 1.04-1.16; Р = 0.001). In case of heart conduction disturbances, apnea duration was the strongest predictor (Р = 0.002). CONCLUSIONS: Hypertensive obese patients with OSA demonstrate 4-fold higher incidence of heart rhythm and conduction disturbances than subjects without SDB. Hypertension duration is an independent predictor for AF development, while sleep apnea/hypopnea duration is the main factor for heart conduction disorders onset in hypertensive obese patients with OSA.

Estimation of a priori probabilities of sleep stages: A cycle-based approach.

This paper presents a model for the estimation of a priori probabilities of sleep epoch classes based on the epoch location in a sleep cycle. These probabilities are used as additional features for sleep stage classification based on the analysis of respiratory effort. The model was validated with data of 685 subjects selected from the Sleep Heart Health Study dataset. The model improves a base algorithm by 8 percent points and demonstrates Cohen's kappa of 0.56 ± 0.12. Our results will contribute to the development of screening tools for unobtrusive sleep structure estimation.

Bioradiolocation-based sleep stage classification.

This paper presents a method for classifying wakefulness, REM, light and deep sleep based on the analysis of respiratory activity and body motions acquired by a bioradar. The method was validated using data of 32 subjects without sleep-disordered breathing, who underwent a polysomnography study in a sleep laboratory. We achieved Cohen's kappa of 0.49 in the wake-REM-light-deep sleep classification, 0.55 for the wake-REM-NREM classification and 0.57 for the sleep/wakefulness determination. The results might be useful for the development of unobtrusive sleep monitoring systems for diagnostics, prevention, and management of sleep disorders.

Sleep architecture measurement based on cardiorespiratory parameters.

This paper presents a method for the detection of wakeful state, rapid eye movement sleep (REM), light sleep (N1&N2) and deep sleep (N3&N4) based on cardiorespiratory parameters. Experiments were conducted with data of 625 subjects without sleep-disordered breathing selected from the SHHS dataset. Compared to previous studies, our method considers results of neighboring epochs classification and epoch position over record time. The method demonstrates Cohen's kappa of 0.57 ± 0.13 and the accuracy of 71.4 ± 8.6 %. The results might contribute to the development of screening tools for diagnostics, prevention, and management of sleep disorders.

Is Mixed Apnea Associated with Non-Rapid Eye Movement Sleep a Reversible Compensatory Sign of Heart Failure?

BACKGROUND: Sleep-disordered breathing is common in heart failure (HF), and prolonged circulation time and diminished pulmonary volume are considered the main possible causes of sleep apnea in these patients. However, the impact and interrelation between sleep apnea and HF development are unclear. We report the case of a patient with complete elimination of non-rapid-eye-movement (NREM) sleep-associated mixed apnea in HF after heart transplantation. CASE REPORT: After unsuccessful 12-month conventional treatment with abrupt exacerbation of biventricular HF IV class (according to New York Heart Association Functional Classification), a 26-year-old man was admitted to the hospital. Based on a comprehensive examination including endomyocardial biopsy, dilated cardiomyopathy was diagnosed. Heart transplantation was considered the only possible treatment strategy. Polysomnography showed severe NREM sleep-associated mixed sleep apnea [apnea-hypopnea index 43/h, in rapid eye movement (REM) sleep 3.7/h, in NREM sleep 56.4/h, mean SatO2 93.9%], and periodic breathing. One-month post-transplantation polysomnography did not show sleep-disordered breathing (apnea-hypopnea index 1.0/h; in REM sleep - 2.8/h, in NREM sleep 0.5/h, mean SatO2 97.5%). The patient was discharged from the hospital in improved condition. CONCLUSIONS: NREM sleep-associated mixed apnea occurring in severe systolic HF due to dilated cardiomyopathy might be reversible in case of successful HF treatment. We suggest that mixed sleep apnea strongly associated with NREM sleep occurs in HF, when the brain centers regulating ventilation are intact, and successful HF compensation might be highly effective regarding sleep-breathing disorders without non-invasive ventilation. This is important to know, especially with regard to the recently published data of potentially unfavorable effects of adaptive servoventilation in systolic HF, and the lack of other treatment options.

Sleep stage classification based on respiratory signal.

One of the research tasks, which should be solved to develop a sleep monitor, is sleep stages classification. This paper presents an algorithm for wakefulness, rapid eye movement sleep (REM) and non-REM sleep detection based on a set of 33 features, extracted from respiratory inductive plethysmography signal, and bagging classifier. Furthermore, a few heuristics based on knowledge about normal sleep structure are suggested. We used the data from 29 subjects without sleep-related breathing disorders who underwent a PSG study at a sleep laboratory. Subjects were directed to the PSG study due to suspected sleep disorders. A leave-one-subject-out cross-validation procedure was used for testing the classification performance. The accuracy of 77.85 ± 6.63 and Cohen's kappa of 0.59 ± 0.11 were achieved for the classifier. Using heuristics we increased the accuracy to 80.38 ± 8.32 and the kappa to 0.65 ± 0.13. We conclude that heuristics may improve the automated sleep structure detection based on the analysis of indirect information such as respiration signal and are useful for the development of home sleep monitoring system.

Sleep stage classification based on bioradiolocation signals.

This paper presents an algorithm for the detection of wakeful state, rapid eye movement sleep (REM) and non-REM sleep based on the analysis of respiratory movements acquired through a bioradar. We used the data from 29 subjects without sleep-related breathing disorders who underwent a polysomnography study at a sleep laboratory. A leave-one-subject-out cross-validation procedure was used for testing the classification performance. Cohen's kappa of 0.56 ± 0.16 and accuracy of 75.13 ± 9.81 % were achieved when compared to polysomnography results. The results of our work contribute to the development of home sleep monitoring systems.

New insights into the management of rhythm and conduction disorders after acute myocardial infarction.

PATIENT: Male, 53 FINAL DIAGNOSIS: Myocardial infarction Symptoms: Chest pain • tachycardia MEDICATION: - Clinical Procedure: - Specialty: Cardiology. OBJECTIVE: Challenging differential diagnosis. BACKGROUND: Comorbidities, including obesity and sleep-breathing disorders, can adversely influence outcomes in acute myocardial infarction (AMI), and should be considered in diagnosis and treatment administration. CASE REPORT: The case demonstrates the difficulties of treating a middle-aged Caucasian patient with multiple comorbidities that could be overcome by a personalized approach and evaluation of concomitant sleep-breathing disorders (by polysomnography study). Diagnosis and treatment of sleep apnea by positive airway pressure (PAP therapy) played a pivotal role in heart rate and rhythm control. CONCLUSIONS: In this case, effective PAP therapy enabled titration of antiarrhythmic drugs (to maximal doses) to achieve heart rate control and to eliminate severe ventricular tachyarrhythmias and contributed to the better recovery in a post-AMI patient with left ventricular systolic dysfunction.

Transcriptional changes in bone marrow stromal cells of patients with heart failure.

It is proposed that patients with heart failure may have not only myocardial dysfunction, but also a reduced regenerative capacity of stem cells. However, very little is known about bone marrow stromal cell (BMSC) characteristics in heart failure and its comorbidities (obesity and/or diabetes). We hypothesized that metabolic alterations associated with the latter will be reflected in altered expression of key genes related to angiogenesis, inflammation, and tissue remodeling in patient-derived BMSCs. We found that BMSCs of heart failure patients with lower body mass index have enhanced expression of genes involved in extracellular matrix remodeling. In particular, body mass index<30 was associated with upregulated expression of genes encoding collagen type I, proteases and protease activators (MMP2, MMP14, uPA), and regulatory molecules (CTGF, ITGß5, SMAD7, SNAIL1). In contrast, these transcript levels did not differ significantly between BMSCs from obese heart failure patients and healthy subjects. Comorbidities (including obesity and diabetes) are known to play role in heart failure progression rate and outcome of the disease. We thus suggest that key molecular targets identified in this study should become the target of the subsequent focused studies. In the future, these targets may find some use in the clinical setting.

Prognosis and cardiovascular morbidity and mortality in prospective study of hypertensive patients with obstructive sleep apnea syndrome in St Petersburg, Russia.

BACKGROUND: To assess the impact of obstructive sleep apnea-hypopnea syndrome (OSAHS) on prognosis and cardiovascular morbidity and mortality in relation to other major cardiovascular risk factors. MATERIAL/METHODS: This prospective study recruited 234 patients from an out-patient clinic. Based on the Berlin questionnaire, 147 patients (90 males, mean age 52.1 ± 10.4 years) with highly suspected sleep breathing disorders were included in the study. Based on cardiorespiratory monitoring, patients were divided into 2 groups: 42 patients without sleep breathing disorders (SBD), and 105 patients with OSAHS. Among these, 12 patients started CPAP therapy and formed the third group. RESULTS: The mean follow-up period was 46.4 ± 14.3 months. Event-free survival was lowest in the untreated OSAHS patients (log rank test 6.732, p = 0.035). In the non-adjusted regression model, OSAHS was also associated with a higher risk of cardiovascular events (OR = 8.557, 95% CI 1.142-64.131, p = 0.037). OSAHS patients demonstrated higher rates of hospitalization compared to the control group without SBD (OR 2.750, 95%CI 1.100-6.873, p = 0.04). CONCLUSIONS: OSAHS hypertensive patients, and in particular, according to our model, patients with severe OSAHS (AHI ≥ 30/h), are at higher risk of fatal and non-fatal cardiovascular events. Moreover, untreated OSAHS patients demonstrate higher rates of hospitalization caused by the onset or deterioration of cardiovascular disease.