ABSTRACT
Objective: To investigate the prevalence of fibromyalgia [FM] among patients with Hashimoto's thyroiditis [HT] and association of thyroid antibodies with FM severity among affected individuals
Design: Cross-sectional
Setting: Two endocrinology outpatient clinics
Subjects: Euthyroid patients with HT were recruited
Intervention: Assessment for detection of fibromyalgia
Main outcome measure[s]: Prevalence of fibromyalgia and association with Hashimoto's thyroiditis. Diagnosis of FM was made using the 2010 American College of Rheumatology criteria. Serum concentrations of thyroid stimulating hormone [TSH] and anti-thyroid peroxidase [anti-TPO] antibodies were determined
Results: Average age of the patients was 38.5 years and 93.1% were female. Among the 102 patients, diagnosis of FM was made in five patients [prevalence rate, 95% CI: 4.9%, 0.7 - 9.1]. Age, sex, level of education, marital status, menopause status, duration of thyroid disease, TSH, and anti-TPO concentrations were comparable between patients with and without FM [p >0.05 in all tests]. Among patients with FM, the indices of FM severity [widespread pain index, and symptom severity] were not significantly correlated with wither TSH or anti-TPO concentrations
Conclusion: Despite previous reports suggesting an increased risk of FM in HT, among Iranian patients with HT, the prevalence of FM seems to be comparable with the prevalence reported in the female general population. A possible link between HT and FM needs further investigation in large population-based studies