Interrelations Between Fibromyalgia, Thyroid Autoantibodies, and Depression

LUIZ SEVERIANO RIBEIRO and FERNANDO AUGUSTO PROIETTI

ABSTRACT.

Objective. To detect and quantify the association between fibromyalgia (FM) and thyroid autoimmunity.

Methods. This cross-sectional study comprised 146 women with FM and 74 case-controls, all 18 years of age or older. FM was diagnosed according to the American College of Rheumatology 1990 classification criteria. The Mini-International Neuropsychiatric Interview (MINI) was applied for the diagnosis of depression, previously considered as an important confounding factor. Thyroid autoimmunity was defined as the occurrence of detectable antithyroid peroxidase antibodies and/or antithyroglobulin antibodies by the immunometric assay. Cases of diffuse connective tissue diseases and thyroid dysfunctions (hypo or hyperthyroidism) were excluded in both groups.

Results. Univariate analysis detected an association between FM and thyroid autoimmunity (odds ratio, OR = 3.87, 95% confidence interval, CI = 1.54-10.13), depression (OR = 3.94, 95% CI = 1.97-7.93), and age (OR = 1.04, 95% CI = 1.01-1.07). In the final logistic regression model, after adjustment for depression and age, the association between FM and thyroid autoimmunity was strengthened (OR = 4.52, 95% CI = 1.86-11.0).

Conclusion. Our results suggest an association between FM and thyroid autoimmunity. (J Rheumatol 2004;31:2036-40)

Key Indexing Terms:

FIBROMYALGIA
AUTOIMMUNITY
THYROID GLAND
DEPRESSION

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From the Department of Rheumatology, Governador Israel Pinheiro Hospital, the Institute of Social Security of the Civil Servants of Minas Gerais, and the Department of Social and Preventive Medicine, Federal University of Minas Gerais, School of Medicine, Belo Horizonte, Brazil.

L.S. Ribeiro, MD, Medical Residency of Rheumatology, Governador Israel Pinheiro Hospital; F.A. Proietti, MD, ScD, Associate Professor of Epidemiology and Public Health, Federal University of Minas Gerais, School of Medicine.

Address reprint requests to Dr. L.S. Ribeiro, Rua Professor Arduíno Bolivar, 336/04 - Santo Antônio, Belo Horizonte, Minas Gerais, Brazil CEP: 30.350-140. E-mail: luizseveriano@brfree.com.br

Submitted August 28, 2003; revision accepted April 7, 2004.

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