Left Atrial Septal Pouch and Acute Thromboembolic Ischemia of the Upper Limb

BACKGROUND A left atrial septal pouch (LASP) was first described in 2010 as a new anatomical entity with potential for embolic events. The prevalences of left, right, and double septal pouches are 40.8%, 5.1%, and 3.7%, respectively. There is a concern about the risk of embolic events due to formation of thrombi in a LASP (especially stroke). CASE REPORT A 60-year-old man presented with sudden onset of right arm pain associated with sweating and neck pain radiating to his left upper extremity. On physical examination, his right arm was cyanotic and he had pain, paresthesia, and no radial pulse. The patient was diagnosed with acute arterial occlusion of his right upper extremity. An arterial embolectomy was performed with a Fogarty catheter at the level of the brachial artery, which resulted in immediate reperfusion. The patient had an embolic event and after efforts to identify the possible etiology, only an LASP was found. Therefore, we hypothesized that he experienced an embolic event in which a thrombus had formed at the site of the LASP. CONCLUSIONS The present case report is designed to raise awareness of the thrombogenic potential of LASP and the possibility of an embolic event to the upper limb of patients with it. LASP can be the source of a thrombus in a patient with a non-stroke embolic event.

P247 Added value of 3D echo in diagnosing and monitoring transcatheter valve in mac procedure in a patient with severe mitral stenosis

INTRODUCTION

Mitral annular calcification (MAC) is a chronic degenerative process involving calcification of the fibrous base of the mitral valve accounting for 12% to 26% of all mitral stenosis (MS) and eventually for significant mitral regurgitation. Calcification often extends to other parts of the mitral valve apparatus but, unlike rheumatic stenosis, does not produce commissural fusion. Surgical treatment carries a high mortality rate due to technical difficulties involving the heavily calcified annulus, advanced age and comorbidities of affected patients. In recent years, transcatheter mitral valve replacement using ballon expandable transcatheter aortic valves in severe MAC (valve-in-MAC) has been used with acceptable success rates.

PURPOSE

To describe the added value of 3D echo in the diagnostic work-up, decision making and monitoring during the interventional procedure of valve-in-MAC.

CASE PRESENTATION

Two years ago a 90-year-old female in sinus rhythm with hypertension and known coronary artery disease (CAD) was admitted with symptoms of pulmonary congestion (PC). At that time, a transthoracic 3D echocardiogram showed important MAC with a mitral valve area (MVA) estimated through 3D planimetry of 1.1 cm2, pulmonary artery pressure (PAP) of 53 mmHg, preserved biventricular function and left atrial enlargement. One year later, she was readmitted with unstable CAD and treated with percutaneous transluminal angioplasty. At that time a 3D transesophageal echocardiogram (3DTOE) showed worsening of the MVA now estimated in 0.6 cm2, a mean gradient of 19 mmHg and PAP of 88 mmHg. Albeit optimized medical therapy, her functional status worsened and less than a month later she was again readmitted in NYHA functional class III. Therefore decision making for valve-in-MAC was undertaken. Valve sizing was performed with computed tomography (CT) using the D-shape method with similar findings when compared with 3D TOE measurements. Both methods showed a favourable anatomy of the left ventricular outflow tract. Valve-in-MAC procedure was performed through transvenous transseptal access and an Edwards Sapien3-nr 29 balloon-expandable valve was deployed uneventfully, except for a residual interatrial septal defect measuring 2.2x0.8cm closed two weeks after, as she persisted with PC and pulmonary hypertension. During the procedure, 3DTOE showed a partial thrombosis involving one of the prosthesis leaflets with preserved transvalvular gradients despite anticoagulation. After that, PC resolved and PAP dropped dramatically. The patient was discharged under lifelong anticoagulation and remains asymptomatic until now.

CONCLUSION

Diagnosing and treating patients with severe MS due to MAC remains a challenge as traditional parameters and interventional procedures don’t apply for this population. Valve-in-MAC is a feasible alternative and 3DTOE may have a pivotal role in the diagnostic work-up and interventional monitoring of these cases.

Abstract P247 Figure. 3D echo timeline valve in MAC

Staged Percutaneous Intervention for Concurrent Chronic Total Occlusions in Patients With ST-Segment-Elevation Myocardial Infarction: A Systematic Review and Meta-Analysis

Background

Studies have shown that chronic total occlusion (CTO) in a noninfarct‐related artery in patients with ST‐segment–elevation myocardial infarction is linked to increased mortality. It remains unclear whether staged revascularization of a noninfarct‐related artery CTO in patients with ST‐segment–elevation myocardial infarction translates to improved outcomes. We performed a meta‐analysis to compare outcomes between patients presenting with ST‐segment–elevation myocardial infarction with concurrent CTO who underwent percutaneous coronary intervention of noninfarct‐related artery CTO versus those who did not.

Method and Results

We conducted an electronic database search of all published data. The primary end point was major adverse cardiovascular events. Secondary end points were all‐cause mortality, cardiovascular mortality, myocardial infarction, repeat revascularization with either percutaneous coronary intervention or coronary artery bypass grafting, stroke, and heart failure readmission. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed. Random effects model was used and heterogeneity was considered if I² >25. Six studies (n=1253 patients) were included in the analysis. There was a significant difference in major adverse cardiovascular events (OR, 0.54; 95% CI, 0.32–0.91), cardiovascular mortality (OR, 0.43; 95% CI, 0.20–0.95), and heart failure readmissions (OR, 0.57; 95% CI, 0.36–0.89), favoring the patients in the CTO percutaneous coronary intervention group. No significant differences were observed between the 2 groups for all‐cause mortality (OR, 0.47; 95% CI, 0.22–1.00), myocardial infarction (OR, 0.78; 95% CI, 0.41–1.46), repeat revascularization (OR, 1.13; 95% CI, 0.56–2.27), and stroke (OR, 0.51; 95% CI, 0.20–1.33).

Conclusions

In this meta‐analysis, CTO percutaneous coronary intervention of the noninfarct‐related artery in patients presenting with ST‐segment–elevation myocardial infarction was associated with a significant reduction in major adverse cardiovascular events, cardiovascular mortality, and heart failure readmissions.

Allergic recurrent coronary stent thrombosis: A mini-review of Kounis syndrome

Kounis syndrome (KS) consists of an association between hypersensitivity reactions triggered by various environmental and pharmacological factors and acute coronary syndromes. Blood supply may be compromised by either vasospasm (type I), native plaque destabilization (type II) or stent thrombosis (type III). Although the prognosis is generally favorable, treatment should include aggressive anti-thrombotic and anti-allergic therapies. A case compatible with type III KS, manifested as a macular rash followed by two episodes of stent thrombosis after primary angioplasty (PCI) of the right coronary artery is presented, and complemented by a review on the topic.

Heart failure and endothelial nitric oxide synthase G894T gene polymorphism frequency variations within ancestries

The G894T polymorphism in endothelial nitric oxide synthase enzyme gene plays an important role in heart failure (HF) and its frequency varies among populations. We investigated this association in highly admixed samples in terms of ancestry. The cohort included 210 HF patients and 106 healthy individuals. Self-reported race and NYHA class were analyzed for HF patients. G894T polymorphism was analyzed by polymerase chain reaction (PCR) and by restriction fragment length polymorphism technique. Ancestry was estimated using a PCR reaction containing 46 autosomal ancestry informative markers and an analysis by capillary electrophoresis. The GG homozygous genotype had a higher frequency in HF patients (63.8%) than in healthy individuals (48.1%), showing an increased chance (odds ratio 1.90, 95% confidence interval 1.18-3.05). The ancestry profiles in patients and controls were similar, with a major European contribution (57.1% and 63.2%), followed by African (30.2% and 24.0%) and Native American (12.7% and 12.8%), without a significant difference between both samples (p = 0.28). The GG genotype is associated to HF prognosis, and this association remains present in highly admixed sample groups.

Coil embolization to successfully treat annular rupture during transcatheter aortic valve replacement

Aortic annular rupture is one of the most feared complications of transcatheter aortic valve replacement (TAVR). This complication often presents as sudden cardiac tamponade with hypotension and requires urgent intervention. The traditional rescue strategy for such cases is emergency surgical intervention, yet the mortality remains high considering most patients who undergo TAVR are not candidates for open heart surgery. As such, there is a need for percutaneous alternatives to treat this critical complication. Here, we describe a case of annular rupture during TAVR that was successfully treated with coil embolization at the rupture site. This case illustrates the use of coil embolization as a treatment strategy in patients with acute aortic annular rupture who are at high-risk for surgical intervention.

Edge Vascular Response After Resorption of the Everolimus-Eluting Bioresorbable Vascular Scaffold - A 5-Year Serial Optical Coherence Tomography Study

BACKGROUND

The edge vascular response (EVR) has been linked to important prognostic implications in patients treated with permanent metallic stents. We aimed to investigate the relationship of EVR with the geometric changes in the everolimus-eluting bioresorbable scaffold using serial optical coherence tomography (OCT) analysis.

METHODS AND RESULTS

In the first-in-man ABSORB trial, 28 patients (29 lesions) underwent serial OCT at 4 different time points (Cohort B1: post-procedure, 6, 24, and 60 months [n=13]; Cohort B2: post-procedure, 12, 36, and 60 months [n=15]) following implantation of the scaffold. In Cohort B1, there was no significant luminal change at the distal or proximal edge segment throughout the entire follow-up. In contrast, there was a significant reduction of the lumen flow area (LFA) of the scaffold between post-procedure and 6 months (-1.03±0.49 mm(2)[P<0.001]), whereas between 6 and 60 months the LFA remained stable (+0.31±1.00 mm(2)[P=0.293]). In Cohort B2, there was a significant luminal reduction of the proximal edge between post-procedure and 12 months (-0.57±0.74 mm(2)[P=0.017]), whereas the lumen area remained stable (-0.26±1.22 mm(2)[P=0.462]) between 12 and 60 months. The scaffold LFA showed a change similar to that observed in Cohort B1.

CONCLUSIONS

Our study demonstrated a reduction in the scaffold luminal area in the absence of major EVR, suggesting that the physiological continuity of the lumen contour is restored long term. (Circ J 2016; 80: 1131-1141).

Decreased exercise capacity and sleep-disordered breathing in patients with hypertrophic cardiomyopathy

BACKGROUND

Mechanisms of decreased exercise capacity in patients with hypertrophic cardiomyopathy (HCM) are not well understood. Sleep-disordered breathing (SDB) is a highly prevalent but treatable disorder in patients with HCM. The role of comorbid SDB in the attenuated exercise capacity in HCM has not been studied previously.

METHODS

Overnight oximetry, cardiopulmonary exercise testing, and echocardiographic studies were performed in consecutive patients with HCM seen at the Mayo Clinic. SDB was considered present if the oxygen desaturation index (number of ≥ 4% desaturations/h) was ≥ 10. Peak oxygen consumption (VO2 peak) (the most reproducible and prognostic measure of cardiovascular fitness) was then correlated with the presence and severity of SDB.

RESULTS

A total of 198 patients with HCM were studied (age, 53 ± 16 years; 122 men), of whom 32% met the criteria for the SDB diagnosis. Patients with SDB had decreased VO2 peak compared with those without SDB (16 mL O2/kg/min vs 21 mL O2/kg/min, P < .001). SDB remained significantly associated with VO2 peak after accounting for confounding clinical variables (P < .001) including age, sex, BMI, atrial fibrillation, and coronary artery disease.

CONCLUSIONS

In patients with HCM, the presence of SDB is associated with decreased VO2 peak. SDB may represent an important and potentially modifiable contributor to impaired exercise tolerance in this unique population.

Experimental sleep restriction causes endothelial dysfunction in healthy humans

BACKGROUND

Epidemiologic evidence suggests a link between short sleep duration and cardiovascular risk, although the nature of any relationship and mechanisms remain unclear. Short sleep duration has also been linked to an increase in cardiovascular events. Endothelial dysfunction has itself been implicated as a mediator of heightened cardiovascular risk. We sought to determine the effect of 8 days/8 nights of partial sleep restriction on endothelial function in healthy humans.

METHODS AND RESULTS

Sixteen healthy volunteers underwent a randomized study of usual sleep versus sleep restriction of two-thirds normal sleep time for 8 days/8 nights in a hospital-based clinical research unit. The main outcome was endothelial function measured by flow-mediated brachial artery vasodilatation (FMD). Those randomized to sleep restriction slept 5.1 hours/night during the experimental period compared with 6.9 hours/night in the control group. Sleep restriction was associated with significant impairment in FMD (8.6±4.6% during the initial pre-randomization acclimation phase versus 5.2±3.4% during the randomized experimental phase, P=0.01) whereas no change was seen in the control group (5.0±3.0 during the acclimation phase versus 6.73±2.9% during the experimental phase, P=0.10) for a between-groups difference of -4.40% (95% CI -7.00 to -1.81%, P=0.003). No change was seen in non-flow mediated vasodilatation (NFMD) in either group.

CONCLUSION

In healthy individuals, moderate sleep restriction causes endothelial dysfunction.

CLINICAL TRIAL REGISTRATION URL

ClinicalTrials.gov. Unique identifier: NCT01334788.

Validity of cardiovascular risk prediction models in Latin America and among Hispanics in the United States of America: a systematic review

OBJECTIVE

To assess the use and validity of prediction models to estimate the risk of cardiovascular disease (CVD) in Latin America and among Hispanic populations in the United States of America.

METHODS

This was a systematic review of three databases: Ovid MEDLINE (1 January 1950-15 April 2010), LILACS (1 January 1988-15 April 2010), and EMBASE (1 January 1988-15 April 2010). MeSH search terms and domains were related to CVD, prediction rules, Latin America (including the Caribbean), and Hispanics in the United States. Database searches were supplemented by correspondence with experts in the field.

RESULTS

A total of 1 655 abstracts were identified, of which five cohorts with a total of 13 142 subjects met inclusion criteria. A Mexican cohort showed that the predicted/observed event-rate ratio for coronary heart disease (CHD) according to the Framingham risk score (FRS) was 1.68 (95% CI, 1.26-2.11); incident myocardial infarction, 1.36 (95% CI, 0.90-1.83); and CHD death, 1.21 (95% CI, 0.43-2.00). In Ecuador, a prediction model for CVD and total deaths in hypertensive patients had an area under the curve (AUC) of 0.79 (95% CI, 0.72-0.86), while the World Health Organization method had an AUC of 0.74 (95% CI, 0.67-0.82). A study predicting mortality risk in people with Chagas' disease had an AUC of 0.81 (95% CI, 0.72-0.90). Among a United State s cohort that included Hispanics, FRS overestimated CVD risk for Hispanics with an AUC of 0.69. Another study in the United States that assessed FRS factors predicting CVD death among Mexican-Americans had an AUC of 0.78.

CONCLUSIONS

The evidence regarding CVD risk prediction rules in Latin America or among Hispanics in the United States is modest at best. It is likely that the FRS overestimates CVD risk in Hispanics when not properly recalibrated.

Effects of experimental sleep restriction on caloric intake and activity energy expenditure

BACKGROUND

Epidemiologic studies link short sleep duration to obesity and weight gain. Insufficient sleep appears to alter circulating levels of the hormones leptin and ghrelin, which may promote appetite, although the effects of sleep restriction on caloric intake and energy expenditure are unclear. We sought to determine the effect of 8 days/8 nights of sleep restriction on caloric intake, activity energy expenditure, and circulating levels of leptin and ghrelin.

METHODS

We conducted a randomized study of usual sleep vs a sleep restriction of two-thirds of normal sleep time for 8 days/8 nights in a hospital-based clinical research unit. The main outcomes were caloric intake, activity energy expenditure, and circulating levels of leptin and ghrelin.

RESULTS

Caloric intake in the sleep-restricted group increased by +559 kcal/d (SD, 706 kcal/d, P=.006) and decreased in the control group by -118 kcal/d (SD, 386 kcal/d, P=.51) for a net change of +677 kcal/d (95% CI, 148-1,206 kcal/d; P=.014). Sleep restriction was not associated with changes in activity energy expenditure (P=.62). No change was seen in levels of leptin (P=.27) or ghrelin (P=.21).

CONCLUSIONS

Sleep restriction was associated with an increase in caloric consumption with no change in activity energy expenditure or leptin and ghrelin concentrations. Increased caloric intake without any accompanying increase in energy expenditure may contribute to obesity in people who are exposed to long-term sleep restriction.

TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT01334788; URL: www.clinicaltrials.gov.

Sleep-disordered breathing and excessive daytime sleepiness in patients with atrial fibrillation

BACKGROUND

An important consequence of sleep-disordered breathing (SDB) is excessive daytime sleepiness (EDS). EDS often predicts a favorable response to treatment of SDB, although in the setting of cardiovascular disease, particularly heart failure, SDB and EDS do not reliably correlate. Atrial fibrillation (AF) is another highly prevalent condition strongly associated with SDB. We sought to assess the relationship between EDS and SDB in patients with AF.

METHODS

We conducted a prospective study of 151 patients referred for direct current cardioversion for AF who also underwent sleep evaluation and nocturnal polysomnography. The Epworth Sleepiness Scale (ESS) was administered prior to polysomnography and considered positive if the score was ≥ 11. The apnea-hypopnea index (AHI) was tested for correlation with the ESS, with a cutoff of ≥ 5 events/h for the diagnosis of SDB.

RESULTS

Among the study participants, mean age was 69.1 ± 11.7 years, mean BMI was 34.1 ± 8.4 kg/m(2), and 76% were men. The prevalence of SDB in this population was 81.4%, and 35% had EDS. The association between ESS score and AHI was low (R(2) = 0.014, P = .64). The sensitivity and specificity of the ESS for the detection of SDB in patients with AF were 32.2% and 54.5%, respectively.

CONCLUSIONS

Despite a high prevalence of SDB in this population with AF, most patients do not report EDS. Furthermore, EDS does not appear to correlate with severity of SDB or to accurately predict the presence of SDB. Further research is needed to determine whether EDS affects the natural history of AF or modifies the response to SDB treatment.

Diagnostic accuracy of the Berlin Questionnaire in detecting sleep-disordered breathing in patients with a recent myocardial infarction

BACKGROUND

The Berlin Questionnaire (BQ) has been used to identify patients at high risk for sleep-disordered breathing (SDB) in a variety of populations. However, there are no data regarding the validity of the BQ in detecting the presence of SDB in patients after myocardial infarction (MI). The aim of this study was to determine the performance of the BQ in patients after MI.

METHODS

We conducted a cross-sectional study of 99 patients who had an MI 1 to 3 months previously. The BQ was administered, scored using the published methods, and followed by completed overnight polysomnography as the "gold standard." SDB was defined as an apnea-hypopnea index of ≥ 5 events/h. The sensitivity, specificity, and positive and negative predictive values of the BQ were calculated.

RESULTS

Of the 99 patients, the BQ identified 64 (65%) as being at high-risk for having SDB. Overnight polysomnography showed that 73 (73%) had SDB. The BQ sensitivity and specificity was 0.68 and 0.34, respectively, with a positive predictive value of 0.68 and a negative predictive value of 0.50. Positive and negative likelihood ratios were 1.27 and 0.68, respectively, and the BQ overall diagnostic accuracy was 63%. Using different apnea-hypopnea index cutoff values did not meaningfully alter these results.

CONCLUSION

The BQ performed with modest sensitivity, but the specificity was poor, suggesting that the BQ is not ideal in identifying SDB in patients with a recent MI.

Outcomes of surgical treatment for nonfunctioning pituitary adenomas: a systematic review and meta-analysis

BACKGROUND

Surgery is commonly used in the management of pituitary nonfunctioning adenomas (NFPA). The goal of this systematic review and meta-analysis is to evaluate the effect of surgery on mortality, surgical complications, pituitary function and vision.

METHODS

We searched MEDLINE, EMBASE and Cochrane CENTRAL, queried experts and reviewed the reference list of included publications. Eligible studies were comparative and noncomparative longitudinal studies that enroled patients with NFPA who underwent surgery (alone or in combination with other therapies). Reviewers, working independently and in duplicate, determined study eligibility with adequate reproducibility and extracted descriptive, quality and outcome data. Risks, relative risks (RR) and 95% confidence intervals (CIs) were estimated from each study and pooled using random-effects meta-analysis.

RESULTS

Most included studies were uncontrolled case series in which patients received a combination of surgery and radiotherapy. The overall quality of the evidence was very low. Median follow-up was 4·29 years. When surgery was not combined with radiotherapy, there was an increased risk of tumour recurrence (RR 1·97; 95% CI, 1·15-3·35). Complications were more likely with the transcranial than with the transsphenoidal approach (mortality RR 4·89; 95% CI, 3·15-6·47; new anterior pituitary deficits RR 4·90; 95% CI, 2·94-7·82; and persistent diabetes insipidus RR 2·50; 95% CI, 1·05-5·35). Overall, transsphenoidal surgery had fairly low perioperative mortality (≤ 1%) and low complication rate (≤ 5% for all patient-important outcomes), but only less than a third of the patients had improvement in pituitary function.

CONCLUSIONS

Observational evidence supports the association between a combined approach of transsphenoidal surgery with radiotherapy and improvements in visual field defects and reduction in tumour recurrence.

Clinical review: Adult height in patients with congenital adrenal hyperplasia: a systematic review and metaanalysis

CONTEXT

Treatment for patients with congenital adrenal hyperplasia (CAH) may affect the final height of these patients.

OBJECTIVE

Our objective was to determine the distribution of achieved height in patients with classic CAH diagnosed at infancy or early childhood and treated with glucocorticoids.

DATA SOURCES

We searched MEDLINE, EMBASE, Cochrane Library, ISI Web of Science, and Scopus through September 2008; the reference sections of included studies; and expert files.

STUDY SELECTION

Eligible studies included patients diagnosed with CAH before age 5 and followed to final height.

DATA EXTRACTION

Reviewers working in duplicate independently extracted data on study characteristics and outcomes and determined each study's risk of bias.

DATA SYNTHESIS

The sd score (SDS) for final height and corrected height (defined as final height SDS - midparental height SDS) were estimated from each study and pooled using random-effects metaanalysis. The I(2) statistic was used to assess inconsistency in results across studies.

RESULTS

We found 35 eligible studies, most of which were retrospective single-cohort studies. The final height SDS achieved by CAH patients was -1.38 (-1.56 to -1.20; I(2) = 90.2%), and the corrected height SDS was -1.03 (-1.20 to -0.86; I(2) = 63.1%). This was not significantly associated with age at diagnosis, gender, type and dose of steroid, and age of onset of puberty. Mineralocorticoid users had a better height outcome in comparison with the nonusers (P = 0.02).

CONCLUSION

Evidence derived from observational studies suggests that the final height of CAH patients treated with glucocorticoids is lower than the population norm and is lower than expected given parental height.

Aspirin for the primary prevention of cardiovascular events: a systematic review and meta-analysis comparing patients with and without diabetes

OBJECTIVE

The negative results of two randomized controlled trials (RCTs) have challenged current guideline recommendations for using aspirin for primary prevention of cardiovascular events among patients with diabetes. We therefore sought to determine if the effect of aspirin for primary prevention of cardiovascular events and mortality differs between patients with and without diabetes.

RESEARCH DESIGN AND METHODS

We conducted a systematic search of MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus since their inceptions until November 2008 for RCTs of aspirin for primary prevention of cardiovascular events. Blinded pairs of reviewers evaluated studies and extracted data. Random-effects meta-analysis and Bayesian logistic regression were used to estimate the ratios of relative risks (RRs) of outcomes of interest among patients with and without diabetes. A 95% CI that crosses 1.00 indicates that the effect of aspirin does not differ between patients with and without diabetes.

RESULTS

Nine RCTs with moderate to high methodological quality contributed data to the analyses. The ratios of RRs comparing the benefit of aspirin among patients with diabetes compared with patients without diabetes for mortality, myocardial infarction, and ischemic stroke were 1.12 (95% CI 0.92-1.35), 1.19 (0.82-1.17), and 0.70 (0.25-1.97), respectively.

CONCLUSIONS

Whereas estimates of benefit among patients with diabetes remain imprecise, our analysis suggests that the relative benefit of aspirin is similar in patients with and without diabetes.

Obstructive sleep apnea, inflammation, and the metabolic syndrome

The combination of metabolic syndrome and obstructive sleep apnea (OSA) has been termed "syndrome Z." The prevalence of both OSA and metabolic syndrome is increasing worldwide, in part linked to the epidemic of obesity. Beyond their epidemiologic relationship, growing evidence suggests that OSA may be causally related to metabolic syndrome. We are only beginning to understand the potential mechanisms underlying the OSA-metabolic syndrome interaction. Although there is no clear consensus, there is growing evidence that alterations in the hypothalamic-pituitary axis, generation of reactive oxygen species (ROS) due to repetitive hypoxia, inflammation, and generation of adipokines may be implicated in the changes associated with both OSA and metabolic syndrome. Whether some or all of these metabolic alterations mechanistically link OSA to metabolic syndrome remains to be proven, but it is an area of intense scientific interest.