@article {1137, title = {Brachial artery diameter, blood flow and flow-mediated dilation in sleep-disordered breathing.}, journal = {Vasc Med}, volume = {14}, year = {2009}, month = {2009 Nov}, pages = {351-60}, abstract = {

Clinic-based, case-control studies linked sleep-disordered breathing (SDB) to markers of endothelial dysfunction. We attempted to validate this association in a large community-based sample, and evaluate the relation of SDB to arterial diameter and peripheral blood flow. This community-based, cross-sectional observational study included 327 men and 355 women, aged 42-83 years, from the Framingham Heart Study site of the Sleep Heart Health Study. The polysomnographically derived apnea-hypopnea index and the hypoxemia index (percent sleep time with oxyhemoglobin saturation below 90\%) were used to quantify the severity of SDB. Brachial artery ultrasound measurements included baseline diameter, percent flow-mediated dilation, and baseline and hyperemic flow velocity and volume. The baseline brachial artery diameter was significantly associated with both the apnea-hypopnea index and the hypoxemia index. The association was diminished by adjustment for body mass index, but remained significant for the apnea-hypopnea index. Age-, sex-, race- and body mass index-adjusted mean diameters were 4.32, 4.33, 4.33, 4.56, 4.53 mm for those with apnea-hypopnea index < 1.5, 1.5-4.9, 5-14.9, 15-29.9, >/= 30, respectively; p = 0.03. Baseline flow measures were associated with the apnea-hypopnea index but this association was non-significant after adjusting for body mass index. No significant association was observed between measures of SDB and percent flow-mediated dilation or hyperemic flow in any model. In conclusion, this study supports a moderate association of SDB and larger baseline brachial artery diameter, which may reflect SDB-induced vascular remodeling. This study does not support a link between SDB and endothelial dysfunction as measured by brachial artery flow-mediated dilation.

}, keywords = {Adult, Aged, Aged, 80 and over, Blood Flow Velocity, Brachial Artery, Cross-Sectional Studies, Female, Humans, Hyperemia, Hypoxia, Laser-Doppler Flowmetry, Male, Middle Aged, Polysomnography, Regional Blood Flow, Severity of Illness Index, Sleep Apnea Syndromes, Ultrasonography, Vasodilation}, issn = {1358-863X}, doi = {10.1177/1358863X09105132}, author = {Chami, Hassan A and Keyes, Michelle J and Vita, Joseph A and Mitchell, Gary F and Larson, Martin G and Fan, Shuxia and Vasan, Ramachandran S and O{\textquoteright}Connor, George T and Benjamin, Emelia J and Gottlieb, Daniel J} } @article {1122, title = {Sleep-disordered breathing and mortality: a prospective cohort study.}, journal = {PLoS Med}, volume = {6}, year = {2009}, month = {2009 Aug}, pages = {e1000132}, abstract = {

BACKGROUND: Sleep-disordered breathing is a common condition associated with adverse health outcomes including hypertension and cardiovascular disease. The overall objective of this study was to determine whether sleep-disordered breathing and its sequelae of intermittent hypoxemia and recurrent arousals are associated with mortality in a community sample of adults aged 40 years or older.

METHODS AND FINDINGS: We prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in 6,441 men and women participating in the Sleep Heart Health Study. Sleep-disordered breathing was assessed with the apnea-hypopnea index (AHI) based on an in-home polysomnogram. Survival analysis and proportional hazards regression models were used to calculate hazard ratios for mortality after adjusting for age, sex, race, smoking status, body mass index, and prevalent medical conditions. The average follow-up period for the cohort was 8.2 y during which 1,047 participants (587 men and 460 women) died. Compared to those without sleep-disordered breathing (AHI: <5 events/h), the fully adjusted hazard ratios for all-cause mortality in those with mild (AHI: 5.0-14.9 events/h), moderate (AHI: 15.0-29.9 events/h), and severe (AHI: >or=30.0 events/h) sleep-disordered breathing were 0.93 (95\% CI: 0.80-1.08), 1.17 (95\% CI: 0.97-1.42), and 1.46 (95\% CI: 1.14-1.86), respectively. Stratified analyses by sex and age showed that the increased risk of death associated with severe sleep-disordered breathing was statistically significant in men aged 40-70 y (hazard ratio: 2.09; 95\% CI: 1.31-3.33). Measures of sleep-related intermittent hypoxemia, but not sleep fragmentation, were independently associated with all-cause mortality. Coronary artery disease-related mortality associated with sleep-disordered breathing showed a pattern of association similar to all-cause mortality.

CONCLUSIONS: Sleep-disordered breathing is associated with all-cause mortality and specifically that due to coronary artery disease, particularly in men aged 40-70 y with severe sleep-disordered breathing. Please see later in the article for the Editors{\textquoteright} Summary.

}, keywords = {Aged, Coronary Artery Disease, Female, Humans, Hypoxia, Male, Middle Aged, Odds Ratio, Proportional Hazards Models, Prospective Studies, Risk Factors, Sex Factors, Sleep Apnea Syndromes, Survival Analysis}, issn = {1549-1676}, doi = {10.1371/journal.pmed.1000132}, author = {Punjabi, Naresh M and Caffo, Brian S and Goodwin, James L and Gottlieb, Daniel J and Newman, Anne B and O{\textquoteright}Connor, George T and Rapoport, David M and Redline, Susan and Resnick, Helaine E and Robbins, John A and Shahar, Eyal and Unruh, Mark L and Samet, Jonathan M} }