Inspiratory airflow dynamics during sleep in women with fibromyalgia.

STUDY OBJECTIVES: To determine whether women with fibromyalgia have inspiratory airflow dynamics during sleep similar to those of women with upper-airway resistance syndrome (UARS). DESIGN: A descriptive study of consecutive female patients with fibromyalgia. SETTING: An academic sleep disorders center. PATIENTS OR PARTICIPANTS: Twenty-eight women with fibromyalgia diagnosed by rheumatologists using established criteria. Fourteen of the women gave a history of snoring, while 4 claimed to snore 'occasionally' and 10 denied snoring. The comparison group comprised 11 women with UARS matched for age and obesity. INTERVENTIONS: Eighteen of the 28 women with fibromyalgia and all of the women with UARS had a full-night polysomnogram. All participants had a nasal continuous positive airway pressure (CPAP) study with quantitative monitoring of inspiratory airflow and effort between atmospheric pressure and therapeutic CPAP. Fourteen patients with fibromyalgia and all patients with UARS had a successful determination of pharyngeal critical pressure. MEASUREMENTS AND RESULTS: Twenty-seven of 28 women with fibromyalgia had sleep-disordered breathing. One of the 27 had obstructive sleep apnea hypopnea while 26 had milder inspiratory airflow limitation with arousals. One patient had no apnea or hypopnea or inspiratory airflow limitation during sleep. While the patients were sleeping at atmospheric pressure, apnea-hypopnea index, arousal index, the prevalence of flow-limited breaths, and maximal inspiratory flow were similar between groups. The pharyngeal critical pressure of the patients with fibromyalgia was -6.5 +/- 3.5 cmH2O (mean +/- SD) compared to -5.8 +/- 3.5 cmH2O for patients with UARS (P = .62). Treatment of 14 consecutive patients with nasal CPAP resulted in an improvement in functional symptoms ranging from 23% to 47%, assessed by a validated questionnaire. CONCLUSION: Inspiratory airflow limitation is a common inspiratory airflow pattern during sleep in women with fibromyalgia. Our findings are compatible with the hypothesis that inspiratory flow limitation during sleep plays a role in the development of the functional somatic syndromes.

The symptoms and signs of upper airway resistance syndrome: a link to the functional somatic syndromes.

STUDY OBJECTIVES: The functional somatic syndromes are associated with a variety of symptoms/signs of uncertain etiology. We determined the prevalence of several of those symptoms/signs in patients with sleep-disordered breathing and examined the relationship between the prevalence of the symptoms/signs and the severity of sleep-disordered breathing. DESIGN: A descriptive study without intervention. SETTING: A university sleep-disorders center located in a suburban setting. PATIENTS OR PARTICIPANTS: Three groups of 25 consecutively collected patients with sleep-disordered breathing. Groups varied in their apnea hypopnea indexes (AHIs) as follows: upper airway resistance syndrome (UARS) [AHI < 10/h), mild-to-moderate obstructive sleep apnea/hypopnea (OSA/H) [AHI >or= 10 to < 40/h), and moderate-to-severe OSA/H (AHI >or= 40/h). MEASUREMENTS AND RESULTS: Patients underwent comprehensive medical histories, physical examinations, and full-night polysomnography. The diagnosis of UARS included quantitative measurement of inspiratory airflow and inspiratory effort with demonstration of inspiratory flow limitation. The percentage of women among the patients with sleep-disordered breathing (p = 0.001) and the prevalence of sleep-onset insomnia (p = 0.04), headaches (p = 0.01), irritable bowel syndrome (p = 0.01), and alpha-delta sleep (p = 0.01) was correlated with decreasing severity of AHI group. CONCLUSIONS: We conclude that patients with UARS, mild-to-moderate OSA/H and moderate-to-severe OSA/H differ in their presenting symptoms/signs. The symptoms/signs of UARS closely resemble those of the functional somatic syndromes.

Upper airway collapsibility during sleep in upper airway resistance syndrome.

STUDY OBJECTIVES: To compare upper airway collapsibility during sleep between patients with upper airway resistance syndrome (UARS), normal subjects, and patients with obstructive sleep apnea/hypopnea syndrome (OSA/H). DESIGN: A descriptive study of a series of clinical patients and a cohort of normal control subjects. SETTING: Two academic sleep-disorders centers. PATIENTS OR PARTICIPANTS: One hundred six adult patients with sleep-disordered breathing evaluated at the SUNY Sleep Disorders Center-Medicine and 12 adult subjects without habitual snoring or daytime sleepiness and with an apnea/hypopnea index (AHI) < 5/h evaluated at the Johns Hopkins Pediatric Sleep Disorders Center. INTERVENTIONS: All subjects underwent full-night polysomnography and a determination of pharyngeal critical pressure (Pcrit). All patients had a determination of therapeutic level of nasal continuous positive airway pressure (Ptherapeutic). MEASUREMENTS AND RESULTS: The mean +/- SD Pcrit of the 12 normal subjects was - 15.4 +/- 6.1 cm H(2)O; the mean Pcrit of the 22 UARS patients was - 4.0 +/- 2.1 cm H(2)O; the mean Pcrit of the 37 patients with mild-to-moderate OSA/H (AHI > or = 10/h and < 40/h) was - 1.6 +/- 2.6 cm H(2)O; and the mean Pcrit of the 47 patients with moderate-to-severe OSA/H (AHI > or = 40/h) was 2.4 +/- 2.8 cm H(2)O. The Pcrit of each group differed from that of all other groups (p < 0.01). The mean Ptherapeutic of patients with UARS was 6.9 +/- 1.7 cm H(2)O; the mean Ptherapeutic of patients with mild-to moderate OSA/H was 7.9 +/- 1.9 cm H(2)O (p = 0.08 compared with the Ptherapeutic of UARS patients); and the mean Ptherapeutic of patients with moderate-to severe OSA/H was 10.5 +/- 2.4 cm H(2)O (p < 0.0001 compared to each of the other patient groups). CONCLUSION: UARS is a syndrome of increased upper airway collapsibility during sleep. The upper airway collapsibility during sleep of patients with UARS is intermediate between that of normal subjects and that of patients with mild-to moderate OSA/H.