RESEARCH - Objective measures of disordered sleep in fibromyalgia

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Objective Measures of Disordered Sleep in Fibromyalgia

RONALD D. CHERVIN, MIHAELA TEODORESCU, RAMESH KUSHWAHA, ANDREA M.

DELINE, CHRISTINE B. BRUCKSCH, CHRISTINE RIBBENS-GRIMM, DEBORAH L.

RUZICKA, PHYLLIS K. STEIN, DANIEL J. CLAUW and LESLIE J. CROFFORD

From the Sleep Disorders Center, and Department of Neurology,

University of Michigan, Ann Arbor, MI; Wisconsin Sleep Institute and

Division of Allergy, Pulmonary and Critical Care Medicine, Department

of Medicine, University of Wisconsin, Madison, WI; the Division of

Rheumatology, Department of Internal Medicine, University of Michigan,

Ann Arbor; Washington University School of Medicine, St. Louis, MO;

and the Division of Rheumatology, Department of Internal Medicine,

University of Kentucky, Lexington, KY, USA.

Performed at the University of Michigan, Ann Arbor, MI, USA; and

supported by the University of Michigan GCRC (NIH M01 RR000042), NIH

K24 AR02139 to Dr. Crofford; and grants from Pfizer, Inc. and the

Arthritis Foundation, Michigan Chapter.

R.D. Chervin, MD, MS, Professor of Neurology, Sleep Disorders Center,

Department of Neurology, University of Michigan; M. Teodorescu, MD,

MS, Assistant Professor of Pulmonary Medicine, Wisconsin Sleep

Institute and Division of Allergy, Pulmonary and Critical Care

Medicine, Department of Medicine, University of Wisconsin; R.

Kushwaha, PhD, Biomedical Engineer, Sleep Disorders Center, Department

of Neurology, University of Michigan; A.M. Deline, BS, BSN; C.B.

Brucksch, Clinical Care Coordinator; C. Ribbens-Grimm, Research

Associate, Division of Rheumatology, Department of Internal Medicine,

University of Michigan; D.L. Ruzicka, RN, PhD, Clinical Research

Program Manager, Sleep Disorders Center, Department of Neurology,

University of Michigan; P.K. Stein, PhD, Research Associate Professor

of Medicine, Washington University School of Medicine; D.J. Clauw, MD,

Professor of Rheumatology, Division of Rheumatology, Department of

Internal Medicine, University of Michigan; L.J. Crofford, MD,

Professor, Division of Rheumatology, Department of Internal Medicine,

University of Michigan, and Professor and Chief, Division of

Rheumatology, Department of Internal Medicine, University of Kentucky.

Abstract

Objective. Patients with fibromyalgia syndrome (FM) complain of

inadequate sleep, which could contribute to common symptoms including

sleepiness, fatigue, or pain. However, measures that consistently and

objectively distinguish FM patients remain elusive.

Methods. Fifteen women with FM and 15 age- and gender-matched controls

underwent 3 nights of polysomnography; Multiple Sleep Latency Tests to

assess sleepiness; testing of auditory arousal thresholds during

non-REM stage 2 and stage 4 sleep; overnight assessment of urinary

free cortisol; and analysis of 24-hour heart rate variability.

Results. On the second night of polysomnography, women with FM in

comparison to controls showed more stage shifts (p = 0.04) but did not

differ significantly on any other standard polysomnographic measure or

on the Multiple Sleep Latency Tests. Alpha EEG power during deep

non-REM sleep, alone or as a proportion of alpha power during

remaining sleep stages, also failed to distinguish the groups, as did

auditory arousal thresholds. Urinary free cortisol did not differ

between FM and control subjects in a consistent manner. However,

decreased short-term heart rate variability (HRV) and especially

ratio-based HRV among FM subjects suggested diminished parasympathetic

and increased sympathetic activity, respectively. Other HRV measures

suggested decreased complexity of HRV among the FM subjects.

Conclusion. Standard measures of sleep, a gold-standard measure of

sleepiness, quantified alpha-delta EEG power, auditory arousal

thresholds, and urinary free cortisol largely failed to distinguish FM

and control subjects. However, HRV analyses showed more promise, as

they suggested both increased sympathetic activity and decreased

complexity of autonomic nervous system function in FM.

http://jrheum.org/content/36/9/2009.abstract

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