Gender-driven thyroid dysfunction in systemic lupus erythematosus patients: Clinical significance of an overlooked association and global stance

Abstract

Aim of the work

This study aimed to determine the association of thyroid dysfunction in systemic lupus erythematosus (SLE) patients.

Patients and methods

Out of a cohort including 312 adult SLE patients those with thyroid dysfunction (n = 53) were further evaluated. The medical history, clinical examination, laboratory investigations and medications received were recorded. The SLICC damage index (SLICC-DI) was assessed.

Results

Thyroid dysfunction formed 17 % of the patients and their mean age was 39.5 ± 11.5 years and disease duration 5.6 ± 3.3 years were comparable to those without thyroid disorder, however female gender was predominantly higher (F:M 52:1 vs 6.2:1, p < 0.0001). The frequency of thyroid dysfunction was alike in Saudi (16 %) and non-Saudi (17.9 %) patients (p = 0.66). The majority of cases (96.2 %) had hypothyroidism, one with autoimmune thyroiditis, while only 2 (3.8 %) had hyperthyroidism. There was a significantly increased frequency of associated neuropsychiatric manifestations (64.2 % vs 45.2 %;p = 0.012), and hematological involvement (32.1 % vs 14.3 %; p = 0.011) and less complement (C4) consumption (15.1 % vs 23.6 %; p = 0.048) in those with thyroid dysfunction compared to those without. The frequency of anti-double stranded deoxyribonucleic acid (anti-dsDNA) positivity tended to be higher (71.7 % vs 66.8 %) and its titre significantly lower (316.3 ± 319.8 IU/ml vs 461.3 ± 459.1; p = 0.013). The SLICC-DI and mortality rate were comparable between groups. Only the presence of proteinuria inversely significantly correlated with the level of T4 (r = -0.31, p = 0.007).

Conclusion

Thyroid dysfunction forms a notable percentage of SLE patients with a prominent female gender propensity. The significant relation of thyroid disorders to neuropsychiatric manifestations, hematological involvement, C4 consumption and anti-dsDNA deserves recognition.