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H. Klar Yaggi

Bio: H. Klar Yaggi is an academic researcher from Yale University. The author has contributed to research in topics: Medicine & Sleep apnea. The author has an hindex of 23, co-authored 57 publications receiving 4714 citations. Previous affiliations of H. Klar Yaggi include Veterans Health Administration & United States Department of Veterans Affairs.


Papers
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Journal ArticleDOI
TL;DR: The obstructive sleep apnea syndrome significantly increases the risk of stroke or death from any cause, and the increase is independent of other risk factors, including hypertension.
Abstract: background Previous studies have suggested that the obstructive sleep apnea syndrome may be an important risk factor for stroke. It has not been determined, however, whether the syndrome is independently related to the risk of stroke or death from any cause after adjustment for other risk factors, including hypertension. methods In this observational cohort study, consecutive patients underwent polysomnography, and subsequent events (strokes and deaths) were verified. The diagnosis of the obstructive sleep apnea syndrome was based on an apnea–hypopnea index of 5 or higher (five or more events per hour); patients with an apnea–hypopnea index of less than 5 served as the comparison group. Proportional-hazards analysis was used to determine the independent effect of the obstructive sleep apnea syndrome on the composite outcome of stroke or death from any cause. results Among 1022 enrolled patients, 697 (68 percent) had the obstructive sleep apnea syndrome. At baseline, the mean apnea–hypopnea index in the patients with the syndrome was 35, as compared with a mean apnea–hypopnea index of 2 in the comparison group. In an unadjusted analysis, the obstructive sleep apnea syndrome was associated with stroke or death from any cause (hazard ratio, 2.24; 95 percent confidence interval, 1.30 to 3.86; P=0.004). After adjustment for age, sex, race, smoking status, alcohol-consumption status, body-mass index, and the presence or absence of diabetes mellitus, hyperlipidemia, atrial fibrillation, and hypertension, the obstructive sleep apnea syndrome retained a statistically significant association with stroke or death (hazard ratio, 1.97; 95 percent confidence interval, 1.12 to 3.48; P=0.01). In a trend analysis, increased severity of sleep apnea at baseline was associated with an increased risk of the development of the composite end point (P=0.005). conclusions The obstructive sleep apnea syndrome significantly increases the risk of stroke or death from any cause, and the increase is independent of other risk factors, including hypertension.

2,766 citations

Journal ArticleDOI
TL;DR: Short and long sleep durations increase the risk of developing diabetes, independent of confounding factors, and sleep duration may represent a novel risk factor for diabetes.
Abstract: OBJECTIVE —Short-term partial sleep restriction results in glucose intolerance and insulin resistance. The purpose of this study was to assess the long-term relationship between sleep duration and the incidence of clinical diabetes. RESEARCH DESIGN AND METHODS —A cohort of men from the Massachusetts Male Aging Study without diabetes at baseline (1987–1989) were followed until 2004 for the development of diabetes. Average number of hours of sleep per night was grouped into the following categories: ≤5, 6, 7, 8, and >8 h. Incidence rates and relative risks (RRs) were calculated for the development of diabetes in each sleep duration category. Those reporting 7 h of sleep per night served as the reference group. Multivariate analysis was performed using Poisson regression. RESULTS —Men reporting short sleep duration (≤5 and 6 h of sleep per night) were twice as likely to develop diabetes, and men reporting long sleep duration (>8 h of sleep per night) were more than three times as likely to develop diabetes over the period of follow-up. Elevated risks remained essentially unchanged after adjustment for age, hypertension, smoking status, self-rated health status, education, and waist circumference (RR 1.95 [95% CI 0.95–4.01] for ≤5 h and 3.12 [1.53–6.37] for >8 h). RRs were altered considerably for the two extreme sleep groups when adjusted for testosterone (1.51 [0.71–3.19] for ≤5 h and 2.81 [1.34–5.90] for >8 h), suggesting that the effects of sleep on diabetes could be mediated via changes in endogenous testosterone levels. CONCLUSIONS —Short and long sleep durations increase the risk of developing diabetes, independent of confounding factors. Sleep duration may represent a novel risk factor for diabetes.

726 citations

Journal ArticleDOI
01 Sep 2011-Sleep
TL;DR: Auto-CPAP was well tolerated, appears to improve neurological recovery from stroke, and may represent a new therapeutic approach for selected patients with acute cerebral infarction.
Abstract: Background: New approaches are needed to treat patients with stroke. Among acute ischemic stroke patients, our primary objectives were to describe the prevalence of sleep apnea and demonstrate the feasibility of providing auto-titrating continuous positive airway pressure (auto-CPAP). A secondary objective was to examine the effect of auto-CPAP on stroke severity. Methods: Stroke patients randomized to the intervention group received 2 nights of auto-CPAP, but only those with evidence of sleep apnea received auto-CPAP for the remainder of the 30-day period. Intervention patients received polysomnography 30 days post-stroke. Control patients received polysomnography at baseline and after 30 days. Acceptable auto-CPAP adherence was defined as ≥ 4 h/night for ≥ 75% nights. Change in stroke severity was assessed comparing the NIH Stroke Scale (NIHSS) at baseline versus at 30 days. Results: The 2 groups (intervention N = 31, control N = 24) had similar baseline stroke severity (both median NIHSS, 3.0). Among patients with complete polysomnography data, the majority had sleep apnea: baseline, 13/15 (86.7%) control patients; 30 days, 24/35 (68.6%) control and inter- vention patients. Intervention patients had greater improvements in NIHSS (−3.0) than control patients (−1.0); P = 0.03. Among patients with sleep apnea, greater improvement was observed with increasing auto-CPAP use: −1.0 for control patients not using auto-CPAP; −2.5 for intervention patients with some auto-CPAP use; and −3.0 for intervention patients with acceptable auto-CPAP adherence. Conclusions: The majority of acute stroke patients had sleep apnea. Auto-CPAP was well tolerated, appears to improve neurological recovery from stroke, and may represent a new therapeutic approach for selected patients with acute cerebral infarction.

143 citations

Journal ArticleDOI
TL;DR: It is demonstrated that patients with OSA have less severe cardiac injury during an acute non-fatal MI when compared to patients without OSA, which may suggest a cardioprotective role of sleep apnea during acute MI via ischemic preconditioning.
Abstract: Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia (IH) In animal models, IH has been shown to protect the myocardium during periods of ischemia by reducing infarct size However, this phenomenon of “ischemic preconditioning” has not been investigated among OSA patients with acute myocardial infarction (MI) This study investigates the role of OSA on MI severity as measured by cardiac enzymes, specifically troponin-T, among patients with an acute MI This is an observational cohort study of patients ≥18 years of age who were hospitalized with an acute MI Each participant underwent portable sleep monitoring (Apnea Link Plus); OSA was defined as an apnea–hypopnea index ≥5/h Multivariable regression analysis was conducted to assess the relationship between OSA and highly sensitive troponin-T levels In our entire cohort of acute MI patients (n = 136), 77 % of the sample had evidence of sleep disordered breathing, with 35 % of the sample having OSA (ie, an AHI >5) Higher AHI was associated with lower peak troponin-T levels in partially adjusted models (β = −00320, p = 00074, adjusted for age, gender, and race) and fully adjusted models (β = −00322, p = 00085) (additionally adjusted for smoking, hypertension, hyperlipidemia, body mass index, history of prior cardiovascular or cerebrovascular disease, diabetes and baseline admission creatinine levels) The mean value of the log-transformed peak troponin-T variable was used to dichotomize the outcome variable In both partially (OR 0949, CI 0905–0995, p = 003) and fully adjusted (OR 0918, CI 0856–0984, p = 00151) logistic regression models, the OR for AHI suggests a protective effect on high troponin-T level Our study demonstrates that patients with OSA have less severe cardiac injury during an acute non-fatal MI when compared to patients without OSA This may suggest a cardioprotective role of sleep apnea during acute MI via ischemic preconditioning

141 citations

Journal ArticleDOI
TL;DR: Treatment of OSA may represent a novel target to reduce cardiovascular health outcomes and understand the underlying pathophysiology and developing novel therapeutic approaches for cardiovascular disease.

134 citations


Cited by
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Journal ArticleDOI
TL;DR: Author(s): Go, Alan S; Mozaffarian, Dariush; Roger, Veronique L; Benjamin, Emelia J; Berry, Jarett D; Borden, William B; Bravata, Dawn M; Dai, Shifan; Ford, Earl S; Fox, Caroline S; Franco, Sheila; Fullerton, Heather J; Gillespie, Cathleen; Hailpern, Susan M; Heit, John A; Howard, Virginia J; Huff
Abstract: Author(s): Go, Alan S; Mozaffarian, Dariush; Roger, Veronique L; Benjamin, Emelia J; Berry, Jarett D; Borden, William B; Bravata, Dawn M; Dai, Shifan; Ford, Earl S; Fox, Caroline S; Franco, Sheila; Fullerton, Heather J; Gillespie, Cathleen; Hailpern, Susan M; Heit, John A; Howard, Virginia J; Huffman, Mark D; Kissela, Brett M; Kittner, Steven J; Lackland, Daniel T; Lichtman, Judith H; Lisabeth, Lynda D; Magid, David; Marcus, Gregory M; Marelli, Ariane; Matchar, David B; McGuire, Darren K; Mohler, Emile R; Moy, Claudia S; Mussolino, Michael E; Nichol, Graham; Paynter, Nina P; Schreiner, Pamela J; Sorlie, Paul D; Stein, Joel; Turan, Tanya N; Virani, Salim S; Wong, Nathan D; Woo, Daniel; Turner, Melanie B; American Heart Association Statistics Committee and Stroke Statistics Subcommittee

5,449 citations

Journal ArticleDOI
TL;DR: The American Heart Association's 2020 Impact Goals for Cardiovascular Diseases and Disorders are revealed, with a focus on preventing, treating, and preventing heart disease and stroke.
Abstract: Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .e3 1. About These Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .e7 2. American Heart Association's 2020 Impact Goals. . . . . . . . . . . . . . . . .e10 3. Cardiovascular Diseases . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .e21 4. Subclinical Atherosclerosis . . . . . . . . . . . . . . . . . . . . .e45 5. Coronary Heart Disease, Acute Coronary Syndrome, and Angina Pectoris . . . . . . . . .e54 6. Stroke (Cerebrovascular Disease) . . . . . . . . . . . . . . . . . . . . . . . . . . . .e68 7. High Blood Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .e88 8. Congenital Cardiovascular Defects . . . . . . . . . . . . . . . . . . . . . . . . . . . .e97 9. Cardiomyopathy and Heart Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . .e102 10. Disorders …

5,260 citations

Journal ArticleDOI
01 Jan 2011-Stroke
TL;DR: In this paper, the authors provided evidence-based recommendations for the prevention of future stroke among survivors of ischemic stroke or transient ischemi-chemic attack, including the control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke.
Abstract: The aim of this updated guideline is to provide comprehensive and timely evidence-based recommendations on the prevention of future stroke among survivors of ischemic stroke or transient ischemic attack. The guideline is addressed to all clinicians who manage secondary prevention for these patients. Evidence-based recommendations are provided for control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke. Recommendations are also provided for the prevention of recurrent stroke in a variety of specific circumstances, including aortic arch atherosclerosis, arterial dissection, patent foramen ovale, hyperhomocysteinemia, hypercoagulable states, antiphospholipid antibody syndrome, sickle cell disease, cerebral venous sinus thrombosis, and pregnancy. Special sections address use of antithrombotic and anticoagulation therapy after an intracranial hemorrhage and implementation of guidelines.

4,545 citations

Journal ArticleDOI
01 Dec 2019-Stroke
TL;DR: These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks.
Abstract: Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

3,819 citations

Journal ArticleDOI
TL;DR: The prevalence of sleep-disordered breathing in the United States for the periods of 1988-1994 and 2007-2010 is estimated using data from the Wisconsin Sleep Cohort Study, an ongoing community-based study with participants randomly selected from an employed population of Wisconsin adults.
Abstract: Sleep-disordered breathing is a common disorder with a range of harmful sequelae. Obesity is a strong causal factor for sleep-disordered breathing, and because of the ongoing obesity epidemic, previous estimates of sleep-disordered breathing prevalence require updating. We estimated the prevalence of sleep-disordered breathing in the United States for the periods of 1988–1994 and 2007–2010 using data from the Wisconsin Sleep Cohort Study, an ongoing community-based study that was established in 1988 with participants randomly selected from an employed population of Wisconsin adults. A total of 1,520 participants who were 30–70 years of age had baseline polysomnography studies to assess the presence of sleep-disordered breathing. Participants were invited for repeat studies at 4-year intervals. The prevalence of sleep-disordered breathing was modeled as a function of age, sex, and body mass index, and estimates were extrapolated to US body mass index distributions estimated using data from the National Health and Nutrition Examination Survey. The current prevalence estimates of moderate to severe sleep-disordered breathing (apnea-hypopnea index, measured as events/hour, ≥15) are 10% (95% confidence interval (CI): 7, 12) among 30–49-year-old men; 17% (95% CI: 15, 21) among 50–70-year-old men; 3% (95% CI: 2, 4) among 30–49-year-old women; and 9% (95% CI: 7, 11) among 50–70 year-old women. These estimated prevalence rates represent substantial increases over the last 2 decades (relative increases of between 14% and 55% depending on the subgroup).

3,301 citations