Banner photo, a collage of different things relating to the SLEEP cohort study, including a chart depicting breathing or heart rate, women sitting in a lecture hall, a bed and a nightstand, a woman working performing research on a computer, a man presenting research at a convention, and the SLEEP logo, which is a crescent moon over the Madison skyline.


When the Wisconsin Sleep Cohort Study began over 30 years ago, very little was known about sleep apnea and little attention was given to sleep problems. Thanks to our participants’ generous contribution of time and effort in “sleeping for science,” research of the WSC Study has played a large part in improving sleep and health. WSC Study research has produced over 100 publications in prominent scientific journals. The WSC Study has been continuously funded by grants from the National Institutes of Health (specifically, National Heart, Lung, and Blood Institute; National Institute on Aging; National Center for Research Resources) as well as the UW Institute for Clinical and Translational Research and the UW-Madison Alzheimer’s Disease Research Center.

In the News

WSC Study research was cited in this 2019 New York Times article on treatment of sleep apnea.

Screenshot of a New York Times article titled
Via The New York Times

New York Times

“We Beat Sleep Apnea. It Should Be Easier for You to Do It, Too.”

The history of the WSC Study lab was profiled in the Wisconsin State Journal.

Screenshot of a Wisconsin State Journal article titled
Via Wisconsin State Journal Archive

Wisconsin State Journal

“Lab sheds light on sleep”

Publication Highlights 2010-2020

See a full list of WSC publications here.

Year Summary of Findings Citation
2021 Hypertension is associated with the longitudinal course of sleep quality over time.  People with hypertension exhibited a greater decline in % total sleep time in rapid eye movement sleep and less decline in % deep sleep over time than those without hypertension. Hypertensive individuals also had a higher probability of having ‘difficulties in falling asleep’ compared to people without hypertension. Moon C, Hagen EW, Johnson HM, Brown RL, Peppard PE. Longitudinal sleep characteristics and hypertension status: results from the Wisconsin Sleep Cohort Study. J Hypertens. 2021 Apr 1;39(4):683-691.
2020 More rapid eye movement (REM) sleep is associated with lower death rates. Leary EB, Watson KT, Ancoli-Israel S, Redline S, Yaffe K, Ravelo LA, Peppard PE, Zou J, Goodman SN, Mignot E, Stone KL. Association of Rapid Eye Movement Sleep With Mortality in Middle-aged and Older Adults. JAMA Neurol. 2020 Jul 6;77(10):1–12.
2020 Systemic blood pressure (BP) is normally 10-20% lower during sleep compared with wake. However, some individuals do not experience this BP ‘dipping’ during sleep. In both cross-sectional and longitudinal analyses, we found objective and subjective features of insomnia and poor sleep quality are associated with nondipping BP. Our findings suggest nondipping might be one possible mechanism by which poor sleep quality is associated with worse cardiovascular outcomes. Lyu B, Hagen EW, Ravelo LA, Peppard PE. Blood pressure dipping and sleep quality in the Wisconsin Sleep Cohort. J Hypertens. 2020 Mar;38(3):448-455.
2019 Transition to full retirement is associated with an average 1-year
increase of 48 minutes napped per week. This change is attributable to a frequency gain of 1 extra nap every other week. Changes in nap duration with full retirement were negligible.
Harden CM, Peppard PE, Palta M, Barnet JH, Hale L, Nieto FJ, Hagen EW. One-year changes in self-reported napping behaviors across the retirement transition. Sleep Health. 2019 Dec;5(6):639-646.
2018 Compared with low levels of physical activity, intermediate levels of physical activity at baseline predicted better subsequent sleep outcomes.  Specifically, intermediate levels of physical activity predicted lower risk of  short sleep time, awakenings after sleep onset, and lower sleep efficiency as measured with polysomnography. Mesas AE, Hagen EW, Peppard PE. The bidirectional association between physical activity and sleep in middle-aged and older adults: a prospective study based on polysomnography. Sleep. 2018 Sep 1;41(9):zsy114.
2017 In general, insomnia symptoms at age 50 were not predictive of earlier overall retirement. However, with regard to reason for retirement, all measures of insomnia were associated with increased rates of retirement due to poor health/disability. Hale L, Singer L, Barnet JH, Peppard PE, Hagen EW. Associations Between Midlife Insomnia Symptoms and Earlier Retirement. Sleep Health. 2017 Jun;3(3):170-177.
2017 Progression through menopause is associated with greater severity of sleep-disordered breathing. This association is independent of aging and changes in body mass index. Mirer AG, Young T, Palta M, Benca RM, Rasmuson A, Peppard PE. Sleep-disordered breathing and the menopausal transition among participants in the Sleep in Midlife Women Study. Menopause. 2017 Feb;24(2):157-162.
2016 Transitioning to retirement is associated with longer sleep duration, later bedtimes, and later wake times. These changes were detectable about 1 year postwork transition and were persistent up to 3 years later. Hagen EW, Barnet JH, Hale L, Peppard PE. Changes in Sleep Duration and Sleep Timing Associated with Retirement Transitions. Sleep. 2016 Mar 1;39(3):665-73.
2015 Asthma was associated with increased risk of new-onset obstructive sleep apnea. Teodorescu M, Barnet JH, Hagen EW, Palta M, Young TB, Peppard PE. Association between asthma and risk of developing obstructive sleep apnea. JAMA. 2015 Jan 13;313(2):156-64. Erratum in: JAMA. 2015 Jul 7;314(1):86.
2014 Obstructive sleep apnea during REM sleep is associated with onset of hypertension.  This is an important finding because patients with REM-related OSA may be minimally symptomatic and frequently do not complain of excessive daytime sleepiness, which may lead to delay in diagnosis and therapy. Mokhlesi B, Finn LA, Hagen EW, Young T, Hla KM, Van Cauter E, Peppard PE. Obstructive sleep apnea during REM sleep and hypertension. Results of the Wisconsin Sleep Cohort. Am J Respir Crit Care Med. 2014 Nov 15;190(10):1158-67.
2013 Prevalence of sleep-disordered breathing measured in the Wisconsin Sleep Cohort over 2007-2010 was substantially higher compared with measures from 2 decades prior (relative increases between 14% and 55%). Peppard PE, Young T, Barnet JH, Palta M, Hagen EW, Hla KM. Increased prevalence of sleep-disordered breathing in adults. Am J Epidemiol. 2013 May 1;177(9):1006-14.
2012 After adjusting for age, sex, body mass index, and smoking, sleep-disordered breathing was associated with total mortality and cancer mortality in a dose–response fashion. Nieto FJ, Peppard PE, Young T, Finn L, Hla KM, Farré R. Sleep-disordered breathing and cancer mortality: results from the Wisconsin Sleep Cohort Study. Am J Respir Crit Care Med. 2012 Jul 15;186(2):190-4. 
2010 Insomnia, whether assessed via polysomnographic markers or via self-report, was found to be a risk factor for depression symptoms at follow-up among participants who had been free of depression 4 years earlier in our population-based, observational study. Szklo-Coxe M, Young T, Peppard PE, Finn LA, Benca RM. Prospective associations of insomnia markers and symptoms with depression. Am J Epidemiol. 2010 Mar 15;171(6):709-20.