The effects of delta wave sleep interruption on pain thresholds and fibromyalgia-like symptoms in healthy subjects; correlations with insulin-like growth factor I.

OBJECTIVE: To assess the effects of delta wave sleep interruption (DWSI) on pain thresholds and fibromyalgia-like symptoms. To examine the potential correlations between DWSI and serum insulin-like growth factor 1 (IGF-1). METHODS: Thirteen healthy volunteers were subjected to 3 consecutive nights of DWSI (Group 1). Pain thresholds were measured by dolorimetry and symptoms by visual analog scale. Six subjects not undergoing DWSI served as dolorimetry and symptom controls (Group 2). Serum IGF-1 was measured by competitive binding radioimmunoassay before and after DWSI. RESULTS: No significant differences in pain thresholds as a function of condition (baseline, DWSI, recovery) or overnight change were detected between or within groups (p>0.05). Morning mean dolorimeter scores were lower than evening scores in both groups during all 3 conditions, and were lower in Group 1 than in Group 2 during DWSI. Group 1 subjects had higher composite symptom scores during DWSI (p< or =0.005), attributed largely to increases in fatigue. Serum levels of IGF-1 from Group 1 subjects showed no significant change after DWSI (p>0.05). CONCLUSION: In our study subjects, 3 nights of DWSI caused no significant lowering of pain thresholds compared with a control group. Subjects appeared to have lower pain thresholds in the mornings, and DWSI appeared to augment this effect. Symptoms were more apparent during DWSI, but were primarily related to fatigue. IGF-1 was not altered by 3 nights of DWSI. The low levels of IGF-1 seen in patients with fibromyalgia syndrome may result from chronic rather than acute DWSI, or may be dependent on factors other than disturbances of delta wave sleep.

Rheumatic findings in Gulf War veterans.

BACKGROUND: Rheumatic symptoms were commonly described among soldiers who served in previous wars. OBJECTIVE: To describe the frequency of rheumatology consultations, along with the diagnoses, and abnormal results on serologic testing in Gulf War veterans evaluated for Gulf War syndrome. METHODS: The medical records of the first 250 consecutive Gulf War veterans referred to the comprehensive clinical evaluation program at Wilford Hall Air Force Medical Center and Brooke Army Medical Center, San Antonio, Tex, were reviewed for demographic characteristics and frequency of subspecialty consultations. A retrospective review of rheumatic diagnoses and the frequency of abnormal serologic test results was recorded. RESULTS: Of the 250 Gulf War veterans evaluated in the comprehensive clinical evaluation program, 139 (56%) were referred for rheumatology consultation, which was the most common elective subspecialty referral. Of the patients evaluated, 82 (59%) had soft tissue syndromes, 19 (14%) had rheumatic disease, and 38 (27%) had no rheumatic disease. The most common soft tissue syndromes were patellofemoral syndrome (33 patients [25%]), mechanical low back pain (23 patients [18%]), and fibromyalgia (22 patients [17%]). Of the 19 patients with rheumatic disease, 10 had osteoarthritis, 2 had rheumatoid arthritis, 2 had gout, and 1 each had systemic lupus erythematosus, Behcet disease, parvovirus arthritis, psoriatic arthritis, and hypothyroid arthropathy. Abnormal serologic test results were common among the Gulf War patients regardless of the presence or absence of rheumatic disease. CONCLUSIONS: The rheumatic manifestations in Gulf War veterans are similar to symptoms and diagnoses described in previous wars and are not unique to active duty soldiers. Overall, the results of serologic screening were poor predictors of the presence of rheumatic disease.