Circadian Rhythm of Serum Cortisol in Female Patients with Fibromyalgia Syndrome
Fibromyalgia syndrome (FMS) patients have disturbed sleep patterns which may lead to altered circadian rhythm in serum cortisol secretion. The aim of this study was to assess circadian changes, if any, in serum cortisol levels in female patients with FMS. Cortisol levels were estimated every 6 h during 24 h period; in 40 female patients satisfying ACR criteria for FMS (Age 36.4 ± 9.9), and 40 healthy females without FMS (Age 33.8 ± 11.1). A significant difference in the night time serum cortisol level was observed among the patients and control groups (patients, 12.9 ± 9.7 controls 5.8 ± 3.0; p < 0.01). However, no significant difference was found in serum cortisol levels in patients and control groups in the morning (patients, 28.4 ± 13.2 controls, 27.6 ± 14.5; p > 0.05), afternoon (patients, 14.4 ± 5.6 controls, 14.0 ± 6.6; p > 0.05) and evening hours (patients, 10.9 ± 5.8 controls, 8.9 ± 3.6; p > 0.05). It could be concluded that there is an abnormality in circadian secretion of cortisol in female FMS patients.
KeywordsFibromyalgia syndrome Cortisol Circadian rhythm American College of Rheumatology Criteria
- 1.Wolfe F, Smythe HA, Yunus MB, Bennett RM, Bombardier C, Goldenberg DL, Tugwell P, Campbell SM, Albeles M, Clark P, Fam AG, Farber SJ, Fiechtner JJ, Franklin CM, Gatter RA, Hamaty D, Lessard J, Lichtbroun AS, Masi AT. The American College of Rheumatology Criteria for the classification of fibromyalgia. Arthritis Rheum. 1990;33:160–72.PubMedCrossRefGoogle Scholar
- 3.Belgrand L, So A. Fibromyalgia diagnostic criteria. Rev Med Suisse. 2011;16:604–6.Google Scholar
- 9.McCain GA, Tilbe KS. Diurnal hormone variation in fibromyalgia syndrome: a comparison with rheumatoid arthritis. J Rheumatol. 1989;16(Suppl. 19):154–7.Google Scholar
- 16.Greenspan FS. The thyroid gland. In: Gardner DG editor. Basic & clinical endocrinology. 7th ed. New York: Lange Medical Books/McGraw-Hill; 2004. p. 215–251.Google Scholar