Poor Sleep Is Associated with Higher Plasma Proinflammatory Cytokine Interleukin-6 and Procoagulant Marker Fibrin D-Dimer in Older Caregivers of People with Alzheimer's Disease

  1. Roland von Känel MD,
  2. Joel E. Dimsdale MD,
  3. Sonia Ancoli-Israel PhD,
  4. Paul J. Mills PhD,
  5. Thomas L. Patterson PhD,
  6. Christine L. McKibbin PhD,
  7. Christopher Archuleta MS,
  8. Igor Grant MD

Article first published online: 10 FEB 2006

DOI: 10.1111/j.1532-5415.2005.00642.x

Issue

Journal of the American Geriatrics Society

Journal of the American Geriatrics Society

Volume 54, Issue 3, pages 431–437, March 2006

Additional Information

How to Cite

von Känel, R., Dimsdale, J. E., Ancoli-Israel, S., Mills, P. J., Patterson, T. L., McKibbin, C. L., Archuleta, C. and Grant, I. (2006), Poor Sleep Is Associated with Higher Plasma Proinflammatory Cytokine Interleukin-6 and Procoagulant Marker Fibrin D-Dimer in Older Caregivers of People with Alzheimer's Disease. Journal of the American Geriatrics Society, 54: 431–437. doi: 10.1111/j.1532-5415.2005.00642.x

Author Information

  1. From the *Department of General Internal Medicine, University Hospital, Berne, Switzerland†Department of Psychiatry, University of California at San Diego, La Jolla, California‡Veterans Affairs San Diego Healthcare System, La Jolla, California.

*Address correspondence to Igor Grant, MD, Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, CA 92093. E-mail: igrant@ucsd.edu

Publication History

  1. Issue published online: 8 MAR 2006
  2. Article first published online: 10 FEB 2006

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Keywords:

  • Alzheimer's disease;
  • caregiver;
  • coagulation;
  • cytokines;
  • psychological stress;
  • sleep

OBJECTIVES: To determine whether objective measures of sleep correlate with plasma levels of the proinflammatory cytokine interleukin (IL)-6 and the procoagulant marker fibrin D-dimer in caregivers of patients with dementia.

DESIGN: Cross-sectional study.

SETTING: Subjects' homes.

PARTICIPANTS: Sixty-four community-dwelling spousal caregivers (69% women, mean age±standard deviation 72±9) and 36 sex-matched noncaregiving controls.

MEASUREMENTS: All participants underwent in-home full-night polysomnography. Demographic and lifestyle factors, depression, diseases, and medication that could affect inflammation, coagulation, and sleep were controlled for in analyses regressing sleep variables and caregiver status and their interaction on plasma levels of IL-6 and D-dimer.

RESULTS: Caregivers had higher levels of D-dimer (781±591 vs 463±214 ng/mL, P=.001) and IL-6 (1.42±1.52 vs 0.99±0.86 pg/mL, P<.06) and lower levels of total sleep time (369±70 vs 393±51 minutes, P=.049) and sleep efficiency (77±11 vs 82±9%, P=.04) than controls. After controlling for age and body mass index, longer wake time after sleep onset (change in coefficient of determination (ΔR2)=0.039, P=.04) and the interaction between caregiver status and higher apnea–hypopnea index (ΔR2=0.054, P=.01) were predictors of IL-6. Controlling for age, caregiver status independently predicted D-dimer levels (ΔR2=0.047, P=.01). Controlling for age and caregiver status, lower sleep efficiency (ΔR2=0.032, P=.03) and the interaction between caregiver status and more Stage 2 sleep (ΔR2=0.037, P=.02) independently predicted plasma D-dimer levels.

CONCLUSION: Poor sleep was associated with higher plasma IL-6 and D-dimer levels. These effects were most pronounced in caregivers of subjects with Alzheimer's disease. The findings suggest a mechanism that may explain how disturbed sleep might be associated downstream with cardiovascular risk, particularly in older people under chronic stress.

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