Sleep Medicine
Volume 7, Issue 6 , Pages 498-507, September 2006

Obstructive sleep apnea–hypopnea and neurocognitive functioning in the Sleep Heart Health Study

  • Stuart F. Quan

      Affiliations

    • Department of Medicine, Arizona Respiratory, Sleep Disorders and General Clinical Research Centers, University of Arizona College of Medicine, 1501 North Campbell, Room 2305 Tucson, AZ 85724, USA
    • Corresponding Author InformationCorresponding author. Tel.: +1 520 626 6115; fax: +1 520 626 6970.
    • ,
  • Ron Wright

      Affiliations

    • Department of Psychiatry and General Clinical Research Center, University of Arizona College of Medicine, Tucson, AZ, USA
    • ,
  • Carol M. Baldwin

      Affiliations

    • College of Nursing (Southwest Borderlands), Arizona State University, Tempe, AZ, USA
    • ,
  • Kristine L. Kaemingk

      Affiliations

    • Department of Pediatrics, Steele Memorial Children's Research and General Clinical Research Centers, University of Arizona College of Medicine, Tucson, AZ, USA
    • ,
  • James L. Goodwin

      Affiliations

    • Department of Medicine and Arizona Respiratory Center, University of Arizona College of Medicine, Tucson, AZ, USA
    • ,
  • Tracy F. Kuo

      Affiliations

    • Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
    • ,
  • Alfred Kaszniak

      Affiliations

    • Department of Psychology, University of Arizona, Tucson, AZ, USA
    • ,
  • Lori L. Boland

      Affiliations

    • Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, MN, USA
    • ,
  • Elise Caccappolo

      Affiliations

    • Department of Neurology, Columbia University, New York, NY, USA
    • ,
  • Richard R. Bootzin

      Affiliations

    • Departments of Psychology and Psychiatry, Sleep Disorders Center, University of Arizona, Tucson, AZ, USA

Received 19 October 2005; received in revised form 8 February 2006; accepted 12 February 2006.

Abstract 

Background and purpose

Obstructive sleep apnea–hypopnea (OSAH) is associated with sleep fragmentation and nocturnal hypoxemia. In clinical samples, patients with OSAH frequently are found to have deficits in neuropsychological function. However, the nature and severity of these abnormalities in non-clinical populations is less well defined.

Patients and methods

One hundred and forty-one participants from the Tucson, AZ and New York, NY field centers of the Sleep Heart Health Study completed a battery of neuropsychological tests for 9–40 months (mean=24 months, SD=7 months) after an unattended home polysomnogram. Sixty-seven participants had OSAH (AHI>10) and 74 did not have OSAH (control (CTL), apnea–hypopnea index (AHI)<5). In addition to the individual tests, composite variables representing attention, executive function, MotorSpeed and processing speed were constructed from the neuropsychological test battery.

Results

There were no significant differences in any individual neuropsychological test or composite variable between the OSAH and CTL groups. However, when time spent with O2 saturations less than 85% was dichotomized into those participants in the top quartile of the distribution and those in the lower three quartiles, motor speed was significantly impaired in those who were more hypoxemic. In addition, poorer motor speed (model adjusted R2=0.242, P<0.001) and processing speed performance (model adjusted R2=0.122, P<0.001) were associated with more severe oxygen desaturation even after controlling for degree of daytime sleepiness, age, gender and educational level.

Conclusions

Mild to moderate OSAH has little impact on the selected measures of attention, executive function, motor speed and processing speed. However, hypoxemia adversely affects both motor and processing speed. These results suggest that in middle-aged to elderly adults the neuropsychological effects of clinically unrecognized mild to moderate OSAH are neither global nor large.

Keywords: Sleep disordered breathing, Obstructive sleep apnea, Neuropsychologic function, Hypoxemia, Neurocognitive function, epidomiology

 

PII: S1389-9457(06)00055-4

doi:10.1016/j.sleep.2006.02.005

Sleep Medicine
Volume 7, Issue 6 , Pages 498-507, September 2006

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