Impact of race and obesity on arterial endothelial dysfunction associated with sleep apnea: Results from the Heart SCORE study

Association of the Coexistence of Somnipathy and Diabetes With the Risks of Cardiovascular Disease Events, Stroke, and All‐Cause Mortality: A Systematic Review and Meta‐analysis

Background

Somnipathy and diabetes are independently associated with an increased risk of cardiovascular disease (CVD). However, whether a combination of both conditions is associated with a higher risk of CVD events remains uncertain. Therefore, the aim of this meta‐analysis was to clarify this association.

Methods and Results

We searched MEDLINE, Web of Science, EMBASE, ClinicalTrials.gov , and the Cochrane Central Register for Controlled Trials. We included randomized controlled trials, nonrandomized trials, and prospective observational cohort studies that assessed the combined effect of diabetes and comorbid somnipathy on CVD risk and mortality for at least 1 year. Outcomes included CVD, coronary heart disease, stroke, and all‐cause mortality. Twelve studies involving 582 267 participants were included in the meta‐analysis. Patients with somnipathy and comorbid diabetes exhibited increased risks of CVD, coronary heart disease, stroke, and all‐cause mortality (risk ratio [RR], 1.27 [95% CI, 1.12–1.45], P <0.0001; RR, 1.40 [95% CI, 1.21–1.62], P <0.0001; RR, 1.28 [95% CI, 1.08–1.52], P =0.004, and RR, 1.56 [95% CI, 1.26–1.94], P <0.0001, respectively).

Conclusions

The coexistence of somnipathy and diabetes is associated with higher risks of CVD, coronary heart disease, stroke, and mortality than somnipathy or diabetes alone. Resolving sleep problems in patients with diabetes may reduce the risks of CVD, stroke, and mortality.

Registration Information

https://www.crd.york.ac.uk/prospero/ . Identifier: PROSPERO CRD42021274566.

Correlates of Endothelial Function in Older Adults With Untreated Obstructive Sleep Apnea and Cardiovascular Disease

BACKGROUND

Obstructive sleep apnea (OSA) is a highly prevalent and consequential sleep disorder in older adults. Untreated moderate to severe OSA substantially increases the risk for hypertension and cardiovascular disease (CVD), which can be attributed to the accelerated progression of atherosclerosis and endothelial dysfunction.

OBJECTIVE

The aim of this study was to identify factors that can function as correlates of endothelial function in older adults with untreated, moderate to severe OSA and CVD or CVD risk factors.

METHODS

A subsample (N = 126) of adults aged 65 years and older from the HeartBEAT study were included in the analyses. Univariate analyses and multiple linear regression models were conducted to establish which demographic and CVD risk factors were the best correlates of endothelial function.

RESULTS

In the univariate analyses, sex, employment status, body mass index, waist circumference, hip-to-waist ratio, neck circumference, diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, total cholesterol to high-density lipoprotein cholesterol ratio, plasminogen activator inhibitor-1, calcium channel blocker use, and β-blocker use were associated with endothelial function at a level of P < .10. In the most parsimonious model, male sex (b = -0.305, P < .001), calcium channel blocker use (b = -0.148, P < .019), and body mass index (b = -.014, P < .037) were negatively associated with endothelial function after adjusting for the other covariates.

CONCLUSIONS

The authors identified correlates of endothelial function in older adults with untreated OSA and CVD or CVD risk factors, which are different than the correlates in middle-aged adults with the same conditions.

Noninvasive sublingual microvascular imaging reveals sex-specific reduction in glycocalyx barrier properties in patients with coronary artery disease

BACKGROUND

Risk factors for coronary artery disease (CAD) have been associated with endothelial dysfunction and degradation of the endothelial glycocalyx. This study was designed to compare sublingual microvascular perfusion and glycocalyx barrier properties in CAD patients and controls using noninvasive side stream darkfield imaging.

METHODS

Imaging of the sublingual microvasculature was performed in 52 case subjects (CAD confirmed by left heart catheterization) and 63 controls (low Framingham risk score). Red blood cell (RBC) filling percentage and functional microvascular density, measures of microvascular perfusion, and perfused boundary region (PBR), an index of glycocalyx barrier function, were measured in microvessels with a diameter ranging from 5-25 µm.

RESULTS

RBC filling percentage was lower in patients with CAD compared to controls (p < .001). Functional microvascular density did not differ between groups. The overall PBR was marginally greater in the CAD group compared to the control group (p = .08). PBR did not differ between male CAD cases and controls (p = .17). However, PBR was greater in females with CAD compared with female controls (p = .04), indicating reduced glycocalyx barrier function. This difference became more pronounced after adjusting for potential confounders.

CONCLUSIONS

Our data suggest that patients with CAD are characterized by a reduction in percentage of time microvessels are occupied by RBCs. In addition, CAD is significantly associated with impaired sublingual microvascular glycocalyx barrier function in women but not men. More research is needed to determine the significance of peripheral microvascular dysfunction in the pathophysiology of CAD, and how this may differ by sex.

Impact of Mandibular Advancement Therapy on Endothelial Function in Severe Obstructive Sleep Apnea

RATIONALE

Endothelial dysfunction, a major predictor of late cardiovascular events, is linked to the severity of obstructive sleep apnea (OSA).

OBJECTIVES

To determine whether treatment with mandibular advancement device, the main alternative to continuous positive airway pressure, improves endothelial function in patients with severe OSA.

METHODS

In this trial, we randomized patients with severe OSA and no overt cardiovascular disease to receive 2 months of treatment with either effective mandibular advancement device or a sham device. The primary outcome, change in reactive hyperemia index, a validated measurement of endothelial function, was assessed on an intention-to-treat basis. An embedded microsensor objectively measured treatment compliance.

MEASUREMENTS AND MAIN RESULTS

A total of 150 patients (86% males; mean [SD] age, 54 [10] yr; median [interquartile range] apnea-hypopnea index, 41 [35-53]; mean [SD] Epworth sleepiness scale, 9.3 [4.2]) were randomized to effective mandibular advancement device (n = 75) or sham device (n = 75). On intention-to-treat analysis, effective mandibular advancement device therapy was not associated with improvement of endothelial function compared with the sham device. Office and ambulatory blood pressure outcomes did not differ between the two groups. Effective mandibular advancement device therapy was associated with significant improvements in apnea-hypopnea index (P < 0.001); microarousal index (P = 0.008); and symptoms of snoring, fatigue, and sleepiness (P < 0.001). Mean (SD) objective compliance was 6.6 (1.4) h/night with the effective mandibular advancement device versus 5.6 (2.3) h/night with the sham device (P = 0.006).

CONCLUSIONS

In moderately sleepy patients with severe OSA, mandibular advancement therapy reduced OSA severity and related symptoms but had no effect on endothelial function and blood pressure despite high treatment compliance. Clinical trial registered with www.clinicaltrials.gov (NCT 01426607).

Association between obstructive sleep apnea severity and endothelial dysfunction in patients with type 2 diabetes

Background

Obstructive sleep apnea (OSA) and type 2 diabetes (T2D) are associated with endothelial dysfunction a main predictor of late cardiovascular (CV) events. Despite the high prevalence of OSA in patients with T2D, the impact of OSA severity on endothelial function has not been clearly elucidated. The aim of this cross-sectional study was to determine whether increasing OSA severity is associated with poorer endothelial function in patients with T2D.

Methods

140 patients with T2D and no overt CV disease underwent polysomnography, peripheral arterial tonometry, clinic blood pressure (BP) measurement, biological assessment for CV risk factors, daytime sleepiness and health related quality of life (HRQL) questionnaires. The following commonly used cut-offs for apnea-hypopnea index (AHI) were used to define 3 categories of disease severity: AHI < 15 (no OSA or mild OSA), 15 ≤ AHI < 30 (moderate OSA), and AHI ≥ 30 (severe OSA). The primary outcome was the reactive hyperemia index (RHI), a validated assessment of endothelial function.

Results

21.4% of patients had moderate OSA and 47.6% had severe OSA. Increasing OSA severity and nocturnal hypoxemia were not associated with a significant decrease in RHI. Endothelial dysfunction (RHI < 1.67) was found in 47.1, 44.4 and 39.2% of patients with no OSA or mild OSA, moderate OSA and severe OSA, respectively (p = 0.76). After adjustment for confounders including body mass index, increasing OSA severity was associated with higher systolic BP (p = 0.03), lower circulating levels of adiponectin (p = 0.0009), higher levels of sP-selectin (p = 0.03), lower scores in 3 domains of HRQL including energy/vitality (p = 0.02), role functioning (p = 0.01), and social functioning (p = 0.04).

Conclusions

Moderate to severe OSA is very common but has no impact on digital micro-vascular endothelial function in patients with T2D.

Strong independent association between obesity and essential hypertension

Obesity and hypertension (HTN) are major risk factors for cardiovascular disease. Association between obesity and HTN has not been studied in a large populations following adjustment for comorbidities. The goal of this study was to evaluate any association between obesity and HTN after adjusting for baseline characteristics. We used ICD-9 codes for obesity and HTN from the Nationwide Inpatient Sample (NIS) databases. Two randomly selected years, 1992 and 2002, were chosen from the databases as two independent samples. We used uni- and multivariable analysis to study any correlation between obesity and HTN. The 1992 database contained a total of 6,195,744 patients. HTN was present in 37.2 % of patients with obesity versus 12% of the control group (OR: 4.36, CI 4.30-4.42, P < 0.001). The 2002 database contained a total of 7,153,982 patients. HTN was present in 50.7% of patients with obesity versus 25.6% of the control group (OR: 2.98, CI 2.96-3.00, P < 0.001). Using multivariable analysis adjusting for gender, hyperlipidaemia, age, smoking, type 2 diabetes and chronic renal failure, obesity remained correlated with HTN in both years (1992: OR 2.69, CI 2.67-2.72, P < 0.001; 2002: OR 2.98, CI 2.96-3.00, P < 0.001). The presence of obesity was found to be strongly and independently associated with HTN. The cause of this correlation is not known warranting further investigation.