Endocrine Abstracts

The observed increase in the incidence of Hashimoto’s thyroiditis (HT) requires the research on environmental factors that may initiate or model its course. There have been reports of the impact of vitamin D3 deficiency on HT development.

Objective: To assess the degree of deficiency of 25OHD3 and the relationship between the disease duration and 25OHD3 levels in patients with HT.

Material and methods: 310 people were enrolled in the study: 155 patients with HT-144 women (93%), 11 men (7%) and 155 healthy volunteers-139 (90%) women and 16 men (10%); mean age: 49±18, 58±17, 49±17 and 56±16 years respectively. Serum 25OHD3 concentration was measured in all subjects. The relationship between HT duration and 25OHD3 concentrations was evaluated in HT group. The analysis was also performed in HT subjects and the disease duration of < 1 year and < 2 years. Vitamin D deficiency was defined as 25OHD3 < 30 ng/ml.

Results: In HT patients 25OHD3 level was lower than in the control group: 23.2 ng/ml (Q₁-Q₃: 18.6-29.0) vs 25.6 ng/ml (Q₁-Q₃: 21.0–31.4; P=0.006).There was a significant correlation between the disease duration and 25OHD3 concentrations in HT patients (R=−0.32; P< 0.001). The correlation was moderate and negative. The regression coefficient of impact the disease duration on the mean 25OHD3 values in the HT group was −0.615. The adjusted coefficient of determination was 8.4%. Analysis in HT group and duration of disease < 1 year (n=30) and < 2 years (n=46) showed no significant correlation between duration of HT and 25OHD3 concentrations respectively: R=0.23; P=0.223; and R=0.16; P=0.295.

Conclusions: Vitamin D3 deficiency is more prevalent in HT patients, and may adversely affect and enhance the abnormal response of the autoimmune process in later stages of the disease without significant impact of its initiation.