@article {1043, title = {Fasting glycemia in sleep disordered breathing: lowering the threshold on oxyhemoglobin desaturation.}, journal = {Sleep}, volume = {31}, year = {2008}, month = {2008 Jul}, pages = {1018-24}, abstract = {

STUDY OBJECTIVES: Commonly used definitions of sleep-disordered breathing (SDB) are based on identifying discrete events of breathing abnormalities during sleep that are accompanied by an oxyhemoglobin desaturation (delta SaO2) of at least 4\%. However, it is not known whether disordered breathing events with oxyhemoglobin desaturation less than 4\% are associated with clinical sequelae such as abnormalities in fasting glycemia.

DESIGN: Cross-sectional study.

SUBJECTS AND SETTING: Participants from the Sleep Heart Health Study (SHHS) with a fasting glucose measurement made within a year of the baseline polysomnogram.

MEASUREMENTS AND RESULTS: SDB severity was defined using the apnea-hypopnea index (AHI) and the hypopnea index (HI) by counting events with different levels of oxyhemoglobin desaturation (0.0\%-1.9\%, 2.0\%-2.9\%, 3.0\%-3.9\%, > or = 4.0\%). Fasting glucose levels were used to classify individuals into normal (<100 mg/dL), impaired (100-125 mg/dL), and diabetic (> or = 126 mg/dL) groups. Ordinal logistic regression was used to determine the adjusted relative odds of an abnormal glucose value across quartiles of the hypopnea index, independent of factors such as age, body mass index, waist circumference, and usual sleep duration. The prevalence of impaired and diabetic fasting glucose in the analytical sample was 32.9\% and 5.8\%, respectively. The covariate-adjusted relative odds of impaired or diabetic fasting glucose in the highest versus the lowest AHI quartile was 1.35 (95\% CI: 1.04-1.76) for events with a delta SaO2 > or = 4.0\%, 1.72 (95\% CI: 1.20-2.48) for events with a delta SaO2 between 3.0\%-3.9\%, 1.41 (95\% CI: 1.07-1.86) for events with a delta SaO2 between 2.0\%-2.9\%, and 1.07 (95\% CI: 0.84-1.37) for events with a delta SaO2 between 0.0\%-1.9\%. The corresponding odds ratios for the HI were 1.47 (95\% CI: 1.13-1.92), 2.25 (95\% CI: 1.59-3.19), 1.44 (95\% CI: 1.09-1.90), and 1.15 (95\% CI: 0.90-1.47), respectively.

CONCLUSIONS: The results of this study indicate that SDB events accompanied by oxyhemoglobin desaturation of between 2\% to 4\% are associated with fasting hyperglycemia. These findings suggest that milder degrees of SDB may predispose to adverse metabolic outcomes.

}, keywords = {Aged, Blood Glucose, Body Mass Index, Cohort Studies, Cross-Sectional Studies, Diabetes Mellitus, Type 2, Fasting, Female, Humans, Male, Middle Aged, Odds Ratio, Oxygen, Oxyhemoglobins, Polysomnography, Reference Values, Sleep Apnea, Obstructive}, issn = {0161-8105}, author = {Stamatakis, Katherine and Sanders, Mark H and Caffo, Brian and Resnick, Helaine E and Gottlieb, Dan J and Mehra, Reena and Punjabi, Naresh M} } @article {1018, title = {Sleep-disordered breathing and cardiovascular disease: an outcome-based definition of hypopneas.}, journal = {Am J Respir Crit Care Med}, volume = {177}, year = {2008}, month = {2008 May 15}, pages = {1150-5}, abstract = {

RATIONALE: Epidemiologic studies on the consequences of sleep-disordered breathing invariably use the apnea-hypopnea index as the primary measure of disease severity. Although hypopneas constitute a majority of disordered breathing events, significant controversy remains about the best criteria used to define these events.

OBJECTIVES: The current investigation sought to assess the most appropriate definition for hypopneas that would be best correlated with cardiovascular disease.

METHODS: A community sample of middle-aged and older adults was recruited as part of the Sleep Heart Health Study. Full-montage polysomnography was conducted and hypopneas were defined using different thresholds of oxyhemoglobin desaturation with and without arousals. Prevalent cardiovascular disease was assessed based on self-report. Logistic regression analysis was used to characterize the independent association between the hypopnea index and prevalent cardiovascular disease.

MEASUREMENTS AND MAIN RESULTS: Using a sample of 6,106 adults with complete data on cardiovascular disease status and polysomnography, the current study found that hypopneas associated with an oxyhemoglobin desaturation of 4\% or more were associated with prevalent cardiovascular disease independent of confounding covariates. The adjusted prevalent odds ratios for quartiles of the hypopnea index using a 4\% desaturation criterion were as follows: 1.00 (<1.10 events/h), 1.10 (1.01-3.20 events/h), 1.33 (3.21-7.69 events/h), and 1.41 (>7.69 events/h). Hypopnea measures based on less than 4\% oxyhemoglobin desaturation or presence of arousals showed no association with cardiovascular disease.

CONCLUSIONS: Hypopneas comprise a significant component of sleep-disordered breathing in the general community. By varying the criteria for defining hypopneas, this study demonstrates that hypopneas with a desaturation of at least 4\% are independently associated with cardiovascular disease. In contrast, no association was observed between cardiovascular disease and hypopneas associated with milder desaturations or arousals.

}, keywords = {Aged, Apnea, Cardiovascular Diseases, Cohort Studies, Female, Humans, Male, Middle Aged, Odds Ratio, Oxyhemoglobins, Polysomnography, Sleep Apnea Syndromes, Terminology as Topic}, issn = {1535-4970}, doi = {10.1164/rccm.200712-1884OC}, author = {Punjabi, Naresh M and Newman, Anne B and Young, Terry B and Resnick, Helaine E and Sanders, Mark H} } @article {1041, title = {Subjective and objective sleep quality in patients on conventional thrice-weekly hemodialysis: comparison with matched controls from the sleep heart health study.}, journal = {Am J Kidney Dis}, volume = {52}, year = {2008}, month = {2008 Aug}, pages = {305-13}, abstract = {

BACKGROUND: Studies examining sleep in the hemodialysis (HD) population have largely lacked an adequate comparison group. It therefore is uncertain whether poor sleep quality in the HD population reflects age, chronic health conditions, or effects of conventional HD therapy.

STUDY DESIGN: Cross-sectional matched-group study.

SETTING \& PARTICIPANTS: Forty-six in-center HD patients were compared with 137 community participants participating in the Sleep Heart Health Study matched for age, sex, body mass index, and race.

PREDICTOR: HD patients compared with community-dwelling non-HD participants.

OUTCOMES \& MEASUREMENTS: Home unattended polysomnography was performed and scored by using similar protocols. Sleep habits and sleepiness were assessed by using the Sleep Habits Questionnaire and Epworth Sleepiness Scale.

RESULTS: Average age of study samples was 63 years, 72\% were white, and average body mass index was 28 +/- 5 kg/m(2). HD patients were significantly more likely than community participants to have short sleep (odds ratio, 3.27; 95\% confidence interval, 1.16 to 9.25) and decreased sleep efficiency (odds ratio, 5.5; 95\% confidence interval, 1.5 to 19.6). HD patients reported more difficulty getting back to sleep (odds ratio, 2.25; 95\% confidence interval, 1.11 to 4.60) and waking up too early (odds ratio, 2.39; 95\% confidence interval, 1.01 to 5.66). There was no association between polysomnography sleep time and self-reported sleep time (r = 0.09; P = 0.6) or between the Epworth Sleepiness Scale and severity of sleep apnea (r = 0.10; P = 0.5) in the HD population.

LIMITATIONS: The study was limited to participants older than 45 years.

CONCLUSIONS: Kidney failure treated with thrice-weekly HD is significantly associated with poor subjective and objective sleep quality.

}, keywords = {Aged, Aged, 80 and over, Body Mass Index, Cross-Sectional Studies, Disease Progression, Female, Follow-Up Studies, Heart Rate, Humans, Incidence, Kidney Failure, Chronic, Male, Middle Aged, Odds Ratio, Pennsylvania, Polysomnography, Prognosis, Renal Dialysis, Retrospective Studies, Risk Factors, Severity of Illness Index, Sleep, Sleep Apnea Syndromes, Surveys and Questionnaires}, issn = {1523-6838}, doi = {10.1053/j.ajkd.2008.04.019}, author = {Unruh, Mark L and Sanders, Mark H and Redline, Susan and Piraino, Beth M and Umans, Jason G and Chami, Hassan and Budhiraja, Rohit and Punjabi, Naresh M and Buysse, Daniel and Newman, Anne B} }