Relationship between obstructive sleep apnea and markers of cardiovascular alterations in never-treated hypertensive patients

Is myocardial strain an early marker of systolic dysfunction in obstructive sleep apnoea? Findings from a meta-analysis of echocardiographic studies

AIM

We investigated the association between obstructive sleep apnoea (OSA) and subclinical systolic dysfunction through a meta-analysis of echocardiographic studies that provided data on left ventricular (LV) mechanics as assessed by global longitudinal strain (GLS).

DESIGN

The PubMed, OVID-MEDLINE, and Cochrane library databases were systematically analyzed to search English-language articles published from inception to 31 December 2021. Studies were detected by using the following terms: 'obstructive sleep apnea', 'sleep quality', 'sleep disordered breathing', 'cardiac damage', 'left ventricular hypertrophy', 'systolic dysfunction', 'global longitudinal strain', 'left ventricular mechanics', 'echocardiography' and 'speckle tracking echocardiography'.

RESULTS

The meta-analysis included 889 patients with OSA and 364 non-OSA controls from 12 studies. Compared with controls, GLS was significantly reduced in the pooled OSA group (SMD -1.24 ± 0.17, CI: -1.58 to -0.90, P  < 0.0001), as well as in the normotensive OSA subgroup (SMD: -1.17 ± 0.12 CI:-1.40 to -0.95, P  < 0.0001). Similar findings were obtained in sub-analyses performed separately in mild, moderate and severe OSA. This was not the case for LV ejection fraction (LVEF) (i.e. comparisons between controls vs. mild OSA, mild vs. moderate OSA, moderate vs. severe OSA).

CONCLUSION

GLS is impaired in patients with OSA (independently from hypertension), worsening progressively from mild to moderate and severe forms, thus allowing to identify subclinical alterations of the systolic function not captured by LVEF. Therefore, myocardial strain assessment should be implemented systematically in the OSA setting to timely detect systolic dysfunction.

Obstructive sleep apnoea and left ventricular diastolic dysfunction among first responders to the 9/11 World Trade Center terrorist attack: a cross-sectional study

OBJECTIVES

Obstructive sleep apnoea (OSA) is often linked to cardiovascular disease. A limited number of studies have reported an association between OSA and left ventricular diastolic dysfunction (LVDD). However, prior studies were performed on small patient populations. Studies have shown a high prevalence of OSA among first responders to the 9/11 World Trade Center (WTC) terrorist attack. We investigated the relationship between OSA and LVDD in a large population of WTC responders.

DESIGN

Cross-sectional study.

SETTING

One-time screening programme as part of the WTC-CHEST Study (NCT10466218), performed at a quaternary medical centre in New York City, from November 2011 to June 2014.

PARTICIPANTS

A total of 1007 participants with mean age of 51 years of mostly non-Hispanic white men were evaluated. Patients from the WTC Health Program-Clinical Center of Excellence, who were over the age of 39 years, were eligible to participate.

RESULTS

Evaluation of those without OSA diagnosis showed no significant association with LVDD when comparing those screened (Berlin Questionnaire) as OSA high risk versus OSA low risk (p=0.101). Among those diagnosed with LVDD, there was a significant association when comparing those with and without patient-reported OSA (OR 1.50, 95% CI 1.13 to 2.00, p=0.005), but the significance was not maintained after adjusting for pertinent variables (OR 1.3, 0.94 to 1.75, p=0.119). Notably, comparing those with OSA diagnosis and those low risk of OSA, the OR for LVDD was significant (1.69, 1.24 to 2.31, p=0.001), and after adjusting for waist-hip ratio, diabetes and coronary artery calcium score percentile, the relationship remained significant (OR 1.45, 1.03 to 2.04, p=0.032).

CONCLUSION

The strong association of OSA with LVDD in this population may inform future guidelines to recommend screening for LVDD in high-risk asymptomatic patients with OSA.

Association of sleep characteristics with renal function in menopausal women without recognized chronic kidney disease

OBJECTIVE

To delineate the association between sleep characteristics and renal function in peri-post menopause free of Chronic kidney disease (CKD) as well as cardiometabolic and hormone indicators.

METHODS

Cross-sectional data from a total of 823 Han-Chinese women aged 40-67 years who visited the Menopause Clinic in the Shanghai Sixth People's Hospital from November 2011 to November 2020 were analyzed through the Pittsburgh Sleep Quality Index (PSQI) and serum cystatin C (Cys-C). Logistic regression models were used to assess the association between cumulative/each sleep parameter and renal function after adjusting for cardiometabolic variables.

RESULTS

After confounding factors, we identified that poor perceived sleep quality, shorter sleep duration (<6 h), low sleep efficiency (<75%), delayed sleep latency and worse sleep disturbance elevated more than doubled the odds ratio for declining renal function (≥0.91 mg/dL, the highest Cys-C) in postmenopause in a graded fashion. Meanwhile, multiple logistic regression analysis revealed that sleep disorder (PSQI ≥ 8), late postmenopause, highest quartile independently increased the odds ratio for declining renal function (OR 2.007, 95% CI: 1.408-2.861, OR = 3.287, 95%CI: 3.425-8.889, OR = 2.345, 95% CI: 1.310-4.199, respectively), while participants with menopausal hormone replacement (MHT) lower the odds of declining renal function (OR = 0.486, 95% CI: 0.324-0.728).

CONCLUSION

The findings proposed that maintaining good sleep quality should be attached great importance to postmenopausal women, which provides clinical evidence for the feasible early detection and effective prevention such as MHT of renal disease progression in postmenopausal women.

Is kidney a new organ target in patients with obstructive sleep apnea? Research priorities in a rapidly evolving field

The bidirectional relationship between sleep disordered breathing and chronic kidney disease (CKD) has recently gained a lot of interest. Several lines of evidence suggest the high prevalence of coexistent obstructive sleep apnea (OSA) in patients with CKD and end-stage renal disease (ESRD). In addition, OSA seems to result in loss of kidney function in some patients, especially in those with cardio-metabolic comorbidities. Treatment of CKD/ESRD and OSA can alter the natural history of each other; still better phenotyping with selection of appropriate treatment approaches is urgently needed. The aim of this narrative review is to provide an update of recent studies on epidemiological associations, pathophysiological interactions, and management of patients with OSA and CKD or ESRD.

Obstructive sleep apnoea syndrome and left ventricular hypertrophy: a meta-analysis of echocardiographic studies

AIM

We investigated the association between obstructive sleep apnoea (OSA) and subclinical cardiac organ damage through a meta-analysis of echocardiographic studies that provided data on left ventricular hypertrophy (LVH), assessed as a categorical or continuous variable.

DESIGN

The PubMed, OVID-MEDLINE, and Cochrane library databases were systematically analyzed to search English-language articles published from 1 January 2000 to 15 August 2019. Studies were detected by using the following terms: 'obstructive sleep apnea', 'sleep quality', 'sleep disordered breathing', 'cardiac damage', 'left ventricular mass', 'left ventricular hypertrophy', and 'echocardiography'.

RESULTS

Meta-analysis included 5550 patients with OSA and 2329 non-OSA controls from 39 studies. The prevalence of LVH in the pooled OSA population was 45% (CI 35--55%). Meta-analysis of studies comparing the prevalence of LVH in participants with OSA and controls showed that OSA was associated with an increased risk of LVH (OR = 1.70, CI 1.44-2.00, P < 0.001). LV mass was significantly increased in patients with severe OSA as compared with controls (SMD 0.46 ± 0.08, CI 0.29-0.62, P < 0.001) or with mild OSA. This was not the case for studies comparing patients with unselected or predominantly mild OSA and controls (0.33 ± 0.17, CI -0.01 to 0.67, P = 0.057).

CONCLUSION

The present meta-analysis expands previous information on the relationship between OSA and echocardiographic LVH, so far based on individual studies. The overall evidence strongly suggests that the likelihood of LVH increases with the severity of OSA, thus exhibiting a continuous relationship.

Primary aldosteronism is highly prevalent in patients with hypertension and moderate to severe obstructive sleep apnea

STUDY OBJECTIVES

It has been suggested that there might be a pathophysiological link and overlap between primary aldosteronism (PA) and obstructive sleep apnea (OSA). Therefore, in a prospective study, we evaluated the frequency of PA in hypertensive patients suspected of having OSA.

METHODS

We included 207 consecutive hypertensive patients (mean age 53.2 ± 12.1 years, 133 M, 74 F) referred for polysomnography on the basis of one or more of the following clinical features: typical OSA symptoms, resistant or difficult-to-treat hypertension, diabetes, or cardiovascular disease. PA was diagnosed based on thew saline infusion test.

RESULTS

Moderate-to-severe OSA was diagnosed in 94 patients (45.4% of the whole group). PA was diagnosed in 20 patients with OSA (21.3%) compared with 9 patients in the group without OSA (8.0%; P = .006). PA was also frequent in patients in whom symptoms of OSA were a sole indication for PA screening (15.4%) and in patients with and without resistant hypertension (24.5% and 17.8%, respectively). Most patients with PA and OSA were diagnosed with bilateral adrenal hyperplasia (18 patients, 90%). There were no major differences in clinical characteristics between patients with OSA with PA and those without PA. In multivariate models, moderate-to-severe OSA predicted the presence of PA (odds ratio 2.89, P = .018).

CONCLUSIONS

Patients with clinically important moderate-to-severe OSA are characterized by a relatively high frequency of PA. Our results support the recommendations to screen patients with moderate-to-severe OSA for PA, regardless of the presence of other indications for PA screening.

Obstructive Sleep Apnea-Induced Neurogenic Nocturnal Hypertension: A Potential Role of Renal Denervation?

There is a bidirectional, causal relationship between obstructive sleep apnea (OSA) and hypertension. OSA-related hypertension is characterized by high rates of masked hypertension, elevated nighttime blood pressure, a nondipper pattern of nocturnal hypertension, and abnormal blood pressure variability. Hypoxia/hypercapnia-related sympathetic activation is a key pathophysiological mechanism linking the 2 conditions. Intermittent hypoxia also stimulates the renin-angiotensin-aldosterone system to promote hypertension development. The negative and additive cardiovascular effects of OSA and hypertension highlight the importance of effectively managing these conditions, especially when they coexist in the same patient. Continuous positive airway pressure is the gold standard therapy for OSA but its effects on blood pressure are relatively modest. Furthermore, this treatment did not reduce the cardiovascular event rate in nonsleepy patients with OSA in randomized controlled trials. Antihypertensive agents targeting sympathetic pathways or the renin-angiotensin-aldosterone system have theoretical potential in comorbid hypertension and OSA, but current evidence is limited and combination strategies are often required in drug resistant or refractory patients. The key role of sympathetic nervous system activation in the development of hypertension in OSA suggests potential for catheter-based renal sympathetic denervation. Although long-term, randomized controlled trials are needed, available data indicate sustained and relevant reductions in blood pressure in patients with hypertension and OSA after renal denervation, with the potential to also improve respiratory parameters. The combination of lifestyle interventions, optimal pharmacological therapy, continuous positive airway pressure therapy, and perhaps also renal denervation might improve cardiovascular risk in patients with OSA.

Targeting subclinical organ damage in obstructive sleep apnea: a narrative review

Subclinical abnormalities in cardiac and vascular structure reflect the adverse effects triggered by a variety of risk factors on the cardiovascular (CV) system thereby representing an intermediate step in the cardiovascular continuum; such alterations are recognized as reliable markers of increased cardiovascular risk in different clinical settings including obstructive sleep apnea (OSA). The mechanisms underlying subclinical organ damage (OD) in the OSA setting are multifactorial. Hypoxemia and hypercapnia, induced by repeated collapses of upper airways, have been suggested to trigger a cascade of events such as activation of the sympathetic tone, renin-angiotensin-aldosterone system leading to endothelial dysfunction, vasoconstriction, myocardial and vascular remodeling, and hypertension. Furthermore, coexisting non-haemodynamic alterations such as increased oxidative stress, release of inflammatory substances, enhanced lipolysis and insulin resistance have been reported to play a role in the pathogenesis of both cardiac and extra-cardiac OD. In this article we reviewed available evidence on the association between OSA and subclinical cardiac (i.e., left and right ventricular hypertrophy, left atrial dilatation) and extra-cardiac organ damage (i.e., carotid atherosclerosis, arterial stiffness, microvascular retinal changes, and microalbuminuria). This association is apparently stronger for cardiac and carotid subclinical damage than for other markers (i.e., arterial stiffness and retinal changes) and mostly evident in the setting of severe OSA.

Chronic kidney disease in patients with obstructive sleep apnea. A narrative review

Prevalence of both chronic kidney disease (CKD) and obstructive sleep apnea (OSA) is continuously increasing. Moreover, the prevalence of OSA increases as kidney function declines and is higher among patients with end-stage renal disease (ESRD). In addition, OSA is recognized as a potential nontraditional risk factor for development and progression of CKD. Continuous positive airway pressure (CPAP) plays a pivotal role in the management of OSA, eliminating patients' symptoms and improving their quality of life. Recent studies suggested that CPAP treatment may have beneficial effects on kidney function among patients with OSA. This narrative review summarizes the existing knowledge on the association between CKD and OSA, with emphasis on the epidemiology, the pathophysiology of the development of CKD in OSA and vice versa, as well as the effect of CPAP on renal function.

A sleep apnoea questionnaire predicts organ damage in hypertensive patients

BACKGROUND

Arterial hypertension is associated with obstructive sleep apnoea, poor quality and duration of sleep, which might contribute to hypertension-mediated organ damage.

METHODS

We investigated the presence of insomnia, restless legs syndrome, and obstructive sleep apnoea using validated questionnaires (Insomnia Severity Index, Restless Legs Syndrome Rating Scale, and STOP-Bang), and their relationship with hypertension-mediated organ damage, in hypertensive patients.

RESULTS

In 159 consecutive consenting hypertensive patients [age 47(11) years, median and (interquartile range), body mass index 25.5(5.9) kg/m², office systolic and diastolic blood pressure 144(23)/92(12) mmHg], the STOP-Bang, but not the other scores, predicted cardiac remodelling: compared to patients with a STOP-Bang score < 3, those at high risk of obstructive sleep apnoea showed higher left ventricular mass index [49.8(11.9) vs. 43.3(11.9) g/m^2.7, p < 0.0001], left atrium volume [25.7(2.5) vs. 25.0(2.8) ml/m², p = 0.003], and aortic root diameter [33.6(3.0) vs. 33.0(3.7) mm, p < 0.0001]. They did not differ for microalbuminuria and estimated glomerular filtration rate. At multivariate analysis, after adjustment for office systolic blood pressure values, the STOP-Bang score remained a predictor of left ventricular mass index; while the Insomnia Severity Index and restless legs syndrome risk score had no predictive value. However, a significant interaction between STOP-Bang and Restless Legs Syndrome Rating Scale scores in determining left ventricular remodelling was found.

CONCLUSIONS

In consecutive hypertensive stage I patients the STOP-Bang questionnaire allowed identification of a high-risk cohort featuring a more prominent cardiac damage. Hence, this inexpensive tool can be useful for risk stratification purposes in municipalities with limited access to health care resources.

Screening obstructive sleep apnea-hypopnea syndrome in hypertensive patients: a comparative study of the efficiency of the Epworth sleepiness scale

Background

Untreated Obstructive Sleep Apnea Hypnopnea Syndrome (OSAHS) is a known factor contributing to resistant hypertension (HT). Continuous Positive Airways Pressure (CPAP) is effective to decrease blood pressure (BP) in severe OSAHS. In our clinical practice, hypertensive patients seem less symptomatic with regard to severe OSAHS than normotensive patients, leading to a risk of underdiagnosis when OSAHS is screened with Epworth Sleepiness Scale (ESS). We aimed to confirm that severe OSAHS is less symptomatic in HT patients than normotensive patients using ESS.

Methods

We retrospectively compared two age, gender-matched groups - 100 hypertensive patients and 100 normotensive patients - with severe OSAHS defined as an AHI (Apnea Hypopnea Index) ≥30. OSAHS was considered symptomatic when ESS > 10.

Results

The two groups of patients did not differ significantly with respect to main characteristics including Body Mass Index (BMI), AHI and ODI (Oxygen Desaturation Index). Systolic and Diastolic BP were higher in HT patients (p < 0.01). HT patients were less symptomatic with regard to severe OSAHS with a lower ESS (10.0 vs 11.9, p < 0.01), and a lower number of patients with an ESS > 10 (30% vs 58%, p < 0.01). In multivariable analysis adjusted on age, gender, Obesity, Systolic BP, Diastolic BP, AHI and ADO, normotension was significantly associated with symptomatic OSAHS (OR = 2.83, [1.298–6.192], p < 0.01).

Conclusions

In our study on patients with severe OSAHS, ESS score was lower in hypertensive patients than in normotensive patients. This discrepancy may lead to an underestimation of severe OSAHS in hypertensive patients.

The Association Between Obstructive Sleep Apnea and Carotid Intima-Media Thickness: A Systematic Review and Meta-Analysis

Obstructive sleep apnea (OSA) has been suggested as a risk factor for carotid atherosclerosis. The present meta-analysis aimed to evaluate the association between OSA and carotid intima-media thickness (CIMT). Eighteen studies comparing CIMT of patients with OSA versus non-OSA patients were included. Quantitative data synthesis was used to pool weighted standardized difference in means (SMD) of CIMT in a random-effects model. Compared to healthy controls, patients with OSA had a significantly higher CIMT (SMD: 0.881; 95% confidence interval [CI]: 0.647-1.115; P < .001). Due to the great heterogeneity, a subgroup analysis was conducted based on the study design. The pooled SMD of CIMT between patients with OSA and healthy controls were 0.810 (95% CI: 0.676-0.943; P < .001) and 1.008 (95% CI: 0.506-1.510; P < .001) in matched and unmatched group, respectively. Moreover, the correlation of apnea-hypopnea index and CIMT was moderate ( r = .389; 95% CI: 0.315-0.459; P < .001). After adjustment for several major confounders, OSA is an independent risk factor for CIMT. These findings remind clinicians to screen for cardiovascular diseases in patients with OSA.

Sleep Disordered Breathing: Hypertension and Cardiac Structure and Function

Obstructive sleep apnea (OSA) is a common form of sleep disordered breathing and has a relatively high prevalence in the general population. The frequency and severity of OSA is associated with age, male sex, and obesity, and OSA has been linked to cardiovascular complications and death. Importantly, OSA has a strong association with both prevalent and incidental hypertension and has a particularly high prevalence in patients with resistant hypertension. In these patients, CPAP and other OSA-directed treatments have been proposed as therapy to help control blood pressure (BP), especially in patients who have not attained optimal BP control despite maximum pharmacological therapy. OSA has also been associated with alterations in cardiac structure and function, although most studies are small and highly limited in study design. Existing data suggest an association between OSA greater left ventricle (LV) mass and hypertrophy that appears independent of confounders including hypertension and obesity. Although less clear and more controversial, OSA severity has been linked to LV systolic and diastolic function, pulmonary hypertension, and right ventricular hypertrophy. Further studies are needed to confirm the potential causal role of OSA in these observed associations with cardiac abnormalities.

Hypertension and obstructive sleep apnea

Obstructive sleep apnea (OSA) is a major modifiable risk factor of hypertension and hypertensive patients with OSA are at increased risk for cardiovascular diseases. A substantial number of studies have revealed that OSA and hypertension have synergistic effects on the cardiovascular system and, therefore, it is clinically important and relevant to increase our understanding of the pathophysiological interactions between OSA and hypertension. In our present review, after briefly reviewing the characteristics and pathophysiological effects of OSA, we focus on the current understanding of OSA-associated hypertension, the potential approaches for treatment of OSA and the effect of OSA treatment on hypertension management. We hope our present review will shed light for future studies that investigate effective therapeutic strategies to simultaneously improve the management of OSA and hypertension.

The relationship between snoring and left ventricular hypertrophy of China: a cross-sectional study

BACKGROUND

Population-based investigations studying the association between snoring and left ventricular hypertrophy (LVH) are lacking. Therefore, our study aims to investigate whether snoring is significantly associated with LVH, and to make clear the effect of varying degrees of snoring intensity on LVH.

METHODS

A total of 10,139 participants were involved in this cross-sectional study. Snoring status and snoring intensity were evaluated by a structured questionnaire. LVH was defined as left ventricular mass index ≥ 51 g/m(2.7) for both men and women.

RESULTS

The total prevalence of LVH was 10.0%. the prevalence increased significantly in snorers according to snoring intensity, including low (10.3%), normal (13.1%), strong (14.7%) and very strong (16.7%). After adjustment for age, race, gender, educational status, physical activity, annual income, current smoking status, current drinking status, sleep duration, hypertension, body mass index, waist circumference, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, total cholesterol and fasting plasma glucose, snoring (OR, 1.371; 95% CI, 1.147-1.637, P < 0.001) was significantly associated with LVH. In addition, among the four kinds of intensity of snoring, normal (OR, 1.436; 95% CI, 1.126-1.832, P = 0.004), strong (OR, 1.462; 95% CI, 1.124-1.902, P < 0.001) and very strong (OR, 1.813; 95% CI, 1.273-2.684, P < 0.001), rather than low (OR, 1.094; 95% CI, 0.834-1.434, P = 0.518) were significantly associated with LVH.

CONCLUSIONS

Snoring is independently associated with LVH. What's more, with the rise in snoring intensity, snoring will exert an increasing effect on LVH.

Tissue Doppler Imaging predicts central sleep apnea in patients with chronic heart failure: data from the Daunia Registry

BACKGROUND

Tissue Doppler imaging (TDI) is used to improve risk stratification in patients with chronic heart failure (CHF). So far, few studies have used this method to investigate the characteristics of subjects with CHF and Cheyne-Stokes breathing (CSB). The aim of this study was therefore to evaluate whether TDI assessment may predict the presence of CSB in patients with CHF.

MATERIALS AND METHODS

A total of 41 consecutive patients with CHF enrolled in the Daunia Heart Failure Registry underwent echocardiography assessment and nocturnal polygraphy to evaluate the presence of sleep apnea and CSB. Conventional echocardiography and TDI parameters were calculated. We have also quantified by TDI a combined index (EAS index) of diastolic and systolic performance: E'/(A' × S').

RESULTS

Subjects with evidence of CSB (N = 8) were characterized by lower values of A' (5·03 ± 2·64 vs. 7·88 ± 2·64 cm/s, P < 0·01). A' and EAS index values were related to Cheyne-Stokes episode rates (r = -0·49 and 0·52, P < 0·05 and <0·01 respectively), EAS index values also with the number of episodes of central apnea (r = 0·39, P < 0·05). A' values predicted the presence of CSB at poly-somnography examination with an OR 0·62 (95% CI 0·40-0·96, P < 0·05) even after correction for age and gender.

CONCLUSIONS

Tissue Doppler imaging values (A') are associated with the presence of sleep apnea at nocturnal polygraphy.

Obstructive Sleep Apnoea and Vascular Disease in Patients with Type 2 Diabetes

Obstructive sleep apnoea (OSA) is common and is associated with many vascular risk factors, such as hypertension, insulin resistance, albuminuria, dyslipidaemia, increased inflammation and endothelial dysfunction. Epidemiological studies have shown that OSA is associated with increased cardiovascular disease (CVD) and that continuous positive airway pressure (CPAP) might reduce CVD events in patients with OSA. In addition, OSA has also been shown to be associated with albuminuria, chronic kidney disease, a wide range of ocular diseases and peripheral neuropathy. Considering that CVD and microvascular complications are major contributors to the morbidity, mortality and the economic burden of diabetes and that OSA is common in patients with type 2 diabetes (T2D), it is important to understand the role of OSA in the development and/or progression of vascular disease in patients with T2D and to explore the impact of CPAP on diabetes-related vascular outcomes. The purpose of this article is to review the evidence for the relationship and impact of OSA on vascular disease and vascular risk factors particularly in patients with T2D.

Diastolic dysfunction in controlled hypertensive patients with mild-moderate obstructive sleep apnea

BACKGROUND

Hypertension and severe obstructive sleep apnea (OSA) may independently contribute to left ventricular diastolic dysfunction. However, scanty data is available on this issue in hypertensives with mild-moderate OSA.

METHODS AND RESULTS

We performed polysomnography, echocardiography and 24h ambulatory blood pressure monitoring in 115 treated essential hypertensives with suspicion of OSA. After exclusion of severe/treated OSA and/or cardiovascular disease patients, mild-moderate OSA (5 ≤ apnoea/hypopnoea index<30 events·h(-1)) was diagnosed in 47.3% of the remaining 91 patients, while 52.7% were free of OSA. Transmitral early (E) and late (A) peak flow velocities were assessed in 69 patients, and mitral annular velocity (E') in 53. Compared to non-OSA, mild-moderate OSA heart rate was higher (p=0.031) while E/A was lower (p<0.001) without differences in 24h mean systolic and diastolic blood pressures (125.36 ± 12.46/76.46 ± 6.97 vs 128.63 ± 11.50/77.70 ± 7.72 mmHg, respectively, NS). Patients with E'< 10 cm/s and E/A<0.8 showed a lower mean SpO2 than subjects with normal diastolic function (p=0.004; p<0.001). In a logistic regression model age, mean SpO2, daytime heart rate and nocturnal diastolic blood pressure fall were associated with altered relaxation pattern, independently from BMI and gender.

CONCLUSIONS

In controlled hypertensives mild-moderate OSA may be associated with early diastolic dysfunction, independently from age, gender and mean blood pressure and in the absence of concentric left ventricular hypertrophy. Moreover nocturnal hypoxia may be a key factor in determining early diastolic dysfunction, under the synergic effects of hypertension and mild-moderate OSA.