CORRESPONDENCE
Author disclosures are available with the text of this letter at www.atsjournals.org.
Author disclosures are available with the text of this letter at www.atsjournals.org.
Tomoyuki Kawada, M.D., Ph.D. Nippon Medical School Tokyo, Japan
Ze-Zhou Song, M.S. Zhejiang Provincial People’s Hospital Hangzhou, China
References
References 1. Bakker JP, Weng J, Wang R, Redline S, Punjabi NM, Patel SR; The MultiEthnic Study of Atherosclerosis. Associations between obstructive sleep apnea, sleep duration, and abnormal fasting glucose. Am J Respir Crit Care Med 2015;192:745–753. 2. Twedt R, Bradley M, Deiseroth D, Althouse A, Facco F. Sleep duration and blood glucose control in women with gestational diabetes mellitus. Obstet Gynecol 2015;126:326–331. 3. Chen X, Wang R, Zee P, Lutsey PL, Javaheri S, Alcantara ´ C, Jackson CL, Williams MA, Redline S. Racial/ethnic differences in sleep disturbances: the multi-ethnic study of atherosclerosis (MESA). Sleep 2015;38:877–888. 4. Peterson BT, Chiao P, Pickering E, Freeman J, Zammit GK, Ding Y, Badura LL. Comparison of actigraphy and polysomnography to assess effects of zolpidem in a clinical research unit. Sleep Med 2012; 13:419–424. 5. Grandner MA, Hale L, Moore M, Patel NP. Mortality associated with short sleep duration: the evidence, the possible mechanisms, and the future. Sleep Med Rev 2010;14:191–203. 6. Jackson CL, Redline S, Kawachi I, Williams MA, Hu FB. Racial disparities in short sleep duration by occupation and industry. Am J Epidemiol 2013;178:1442–1451. 7. Eastwood PR, Malhotra A, Palmer LJ, Kezirian EJ, Horner RL, Ip MS, Thurnheer R, Antic NA, Hillman DR. Obstructive sleep apnoea: from pathogenesis to treatment. Current controversies and future directions. Respirology 2010;15:587–595.
Copyright © 2016 by the American Thoracic Society
The Impact of Obesity on the Association between Obstructive Sleep Apnea and Glucose Metabolism To the Editor: It was with great interest that I read the article by Bakker and colleagues (1), which concluded that obstructive sleep apnea (OSA) is independently associated with glucose metabolism and that this association may vary by ethnicity. It is well known that OSA in nonobese individuals is significantly associated with impaired glucose metabolism; however, OSA is not associated with abnormal glucose tolerance categories (2). That is to say, the association of OSA with glucose metabolism is different between obese and nonobese individuals. In the study by Bakker and colleagues (1), the differences in the association of OSA with glucose metabolism between obese and nonobese individuals were ignored. As in the study by Bakker and colleagues (1), some individuals with OSA are not obese, especially those of Asian descent (3). Therefore, further studies should be performed to confirm the differences of the association of OSA with glucose metabolism between obese and nonobese individuals and whether this association could vary by ethnicity. n
580
1. Bakker JP, Weng J, Wang R, Redline S, Punjabi NM, Patel SR; The Multi-Ethnic Study of Atherosclerosis. Associations between obstructive sleep apnea, sleep duration, and abnormal fasting glucose. Am J Respir Crit Care Med 2015;192: 745–753. 2. Kim NH, Cho NH, Yun CH, Lee SK, Yoon DW, Cho HJ, Ahn JH, Seo JA, Kim SG, Choi KM, et al. Association of obstructive sleep apnea and glucose metabolism in subjects with or without obesity. Diabetes Care 2013;36: 3909–3915. 3. Lin QC, Zhang XB, Chen GP, Huang DY, Din HB, Tang AZ. Obstructive sleep apnea syndrome is associated with some components of metabolic syndrome in nonobese adults. Sleep Breath 2012;16: 571–578.
Copyright © 2016 by the American Thoracic Society
Reply From the Authors: Dr. Kawada expresses concern about our use of actigraphy to quantify habitual sleep duration (1). We did use the medium threshold (40 counts per epoch) to differentiate wake from sleep. Prior studies have not found clear benefits in terms of agreement with polysomnography by using either a higher or lower threshold in adults (2, 3). Although actigraphy is known to underestimate wake after sleep onset as a result of scoring of quiet wakefulness as sleep, there is little evidence to suggest this offset leads to systematic bias. In particular, a prior study found similar performance of actigraphy in quantifying sleep in those with and without sleep apnea (4). Dr. Kawada is also concerned by our categorization of sleep duration. The decision to define short sleep duration as
Author disclosures are available with the text of this letter at www.atsjournals.org.
Author disclosures are available with the text of this letter at www.atsjournals.org.
Tomoyuki Kawada, M.D., Ph.D. Nippon Medical School Tokyo, Japan
Ze-Zhou Song, M.S. Zhejiang Provincial People’s Hospital Hangzhou, China
References
References 1. Bakker JP, Weng J, Wang R, Redline S, Punjabi NM, Patel SR; The MultiEthnic Study of Atherosclerosis. Associations between obstructive sleep apnea, sleep duration, and abnormal fasting glucose. Am J Respir Crit Care Med 2015;192:745–753. 2. Twedt R, Bradley M, Deiseroth D, Althouse A, Facco F. Sleep duration and blood glucose control in women with gestational diabetes mellitus. Obstet Gynecol 2015;126:326–331. 3. Chen X, Wang R, Zee P, Lutsey PL, Javaheri S, Alcantara ´ C, Jackson CL, Williams MA, Redline S. Racial/ethnic differences in sleep disturbances: the multi-ethnic study of atherosclerosis (MESA). Sleep 2015;38:877–888. 4. Peterson BT, Chiao P, Pickering E, Freeman J, Zammit GK, Ding Y, Badura LL. Comparison of actigraphy and polysomnography to assess effects of zolpidem in a clinical research unit. Sleep Med 2012; 13:419–424. 5. Grandner MA, Hale L, Moore M, Patel NP. Mortality associated with short sleep duration: the evidence, the possible mechanisms, and the future. Sleep Med Rev 2010;14:191–203. 6. Jackson CL, Redline S, Kawachi I, Williams MA, Hu FB. Racial disparities in short sleep duration by occupation and industry. Am J Epidemiol 2013;178:1442–1451. 7. Eastwood PR, Malhotra A, Palmer LJ, Kezirian EJ, Horner RL, Ip MS, Thurnheer R, Antic NA, Hillman DR. Obstructive sleep apnoea: from pathogenesis to treatment. Current controversies and future directions. Respirology 2010;15:587–595.
Copyright © 2016 by the American Thoracic Society
The Impact of Obesity on the Association between Obstructive Sleep Apnea and Glucose Metabolism To the Editor: It was with great interest that I read the article by Bakker and colleagues (1), which concluded that obstructive sleep apnea (OSA) is independently associated with glucose metabolism and that this association may vary by ethnicity. It is well known that OSA in nonobese individuals is significantly associated with impaired glucose metabolism; however, OSA is not associated with abnormal glucose tolerance categories (2). That is to say, the association of OSA with glucose metabolism is different between obese and nonobese individuals. In the study by Bakker and colleagues (1), the differences in the association of OSA with glucose metabolism between obese and nonobese individuals were ignored. As in the study by Bakker and colleagues (1), some individuals with OSA are not obese, especially those of Asian descent (3). Therefore, further studies should be performed to confirm the differences of the association of OSA with glucose metabolism between obese and nonobese individuals and whether this association could vary by ethnicity. n
580
1. Bakker JP, Weng J, Wang R, Redline S, Punjabi NM, Patel SR; The Multi-Ethnic Study of Atherosclerosis. Associations between obstructive sleep apnea, sleep duration, and abnormal fasting glucose. Am J Respir Crit Care Med 2015;192: 745–753. 2. Kim NH, Cho NH, Yun CH, Lee SK, Yoon DW, Cho HJ, Ahn JH, Seo JA, Kim SG, Choi KM, et al. Association of obstructive sleep apnea and glucose metabolism in subjects with or without obesity. Diabetes Care 2013;36: 3909–3915. 3. Lin QC, Zhang XB, Chen GP, Huang DY, Din HB, Tang AZ. Obstructive sleep apnea syndrome is associated with some components of metabolic syndrome in nonobese adults. Sleep Breath 2012;16: 571–578.
Copyright © 2016 by the American Thoracic Society
Reply From the Authors: Dr. Kawada expresses concern about our use of actigraphy to quantify habitual sleep duration (1). We did use the medium threshold (40 counts per epoch) to differentiate wake from sleep. Prior studies have not found clear benefits in terms of agreement with polysomnography by using either a higher or lower threshold in adults (2, 3). Although actigraphy is known to underestimate wake after sleep onset as a result of scoring of quiet wakefulness as sleep, there is little evidence to suggest this offset leads to systematic bias. In particular, a prior study found similar performance of actigraphy in quantifying sleep in those with and without sleep apnea (4). Dr. Kawada is also concerned by our categorization of sleep duration. The decision to define short sleep duration as
