Prevalence of hypothyroidism in rheumatoid arthritis and its correlation with disease activity

Abstract Background: Several recent studies have shown an increased incidence of hypothyroidism in many chronic inflammatory diseases, especially rheumatoid arthritis, and others studies have shown a relationship between hypothyroidism in patients with rheumatoid disease and the degree of disease activity. Aim of the study: To know the extent of hypothyroidism in a sample of patients with rheumatoid arthritis in Al-Assad and Al-Mowasat University Hospital in Damascus, to link this to the effectiveness of rheumatoid disease, and to compare with a group of healthy controls. Materials and methods: a cross-sectional/case-control study was conducted on 134 patients diagnosed with rheumatoid arthritis, and a healthy cohort of 134 people from the University Hospitals in Damascus. The presence of hypothyroidism was compared between the two groups of patients and controls. Hypothyroidism in patients was also compared with the disease activity index, after dividing them according to the effectiveness index (DAS28-ESR) into three groups: mild, moderate, and severe disease activity. The data was analyzed using the statistical analysis program (SPSS) version (25) and the variable was considered statistically significant when the P-Value is less than (0.05). Results: The average age of both patients and controls was (50.6±3.9) and (44.3±2.01) years, respectively. The proportion of females in the sample of patients was (%84.3) and the percentage of females in the control sample (%80.6), the number of patients with hypothyroidism was 43 patients (%32), and the number of infected controls was 10 people (%7.5) P-Value < 0.000. The type of hypothyroidism in patients was classified into clinical hypothyroidism (%67.44) and subclinical hypothyroidism (%32.56). %24.6 of patients and %6 of controls had positive TPO antibodies (P-Value < 0.000). The study has shown a positive correlation between hypothyroidism and disease efficacy indicator (DAS28-ESR). Conclusion: Increased incidence of hypothyroidism and TPO antibodies in patients with rheumatoid disease compared to healthy subjects, and an increase in the degree of disease activity in patients with rheumatoid disease diagnosed with hypothyroidism compared to patients with rheumatoid disease without hypothyroidism.