Thyroid dysfunction and anti-thyroid antibodies in Egyptian patients with systemic lupus erythematosus: Correlation with clinical musculoskeletal manifestations

Abstract

Aim of the workTo study the prevalence of thyroid dysfunction and anti-thyroid antibodies (ATA) in Egyptian patients with systemic lupus erythematosus (SLE), and their association with musculoskeletal manifestations of the disease. Patients and methodsCross sectional study included 100 SLE patients and 100 matched controls. Clinical manifestations at any time during disease course were reported. Detailed musculoskeletal examination was done using Ritchie articular index (RAI), 44-Swollen joint count and fibromyalgic tender points. Phalen’s test was used to diagnose carpal tunnel syndrome. Free-thyroid hormones (FT3 and FT4), thyroid stimulating hormone (TSH), anti-thyroglobulin (anti-TG) and anti-thyroid peroxidase (anti-TPO) antibodies were measured. ResultsThe prevalence of thyroid dysfunction was significantly higher in patients than controls (18% vs. 4%, p=0.003) and all were females. Prevalence of subclinical hypothyroidism (SCHT) and clinical hypothyroidism (CHT) is 10% (p=0.002) and 4% (p=0.121) versus non among controls while, that of subclinical hyperthyroidism (4%) was not significantly different. Prevalence of anti-TPO and anti-TG is higher in patients than controls (35% vs 11%, p<0.001 and 22% vs. 6%, p=0.001). All patients with SCHT had anti-TPO and half of them had anti-TG while all patients with CHT had both antibodies. Hypothyroidism was associated significantly with aging (p=0.01), longer disease duration (p<0.001), high BMI, high RAI scores, arthritis, positive Phalen’s test and fibromyalgia (p<0.001 for all) in comparison to euthyroid patients. ConclusionHypothyroidism was more prevalent in SLE patients and its detection is recommended to reduce the risk of musculoskeletal related morbidity.