Endocrine Abstracts

: The observed increase in the incidence of Hashimoto’s thyroiditis (HT) requires research on factors that may affect its development. One of them may be vitamin D deficiency which is an epidemiological problem all over the world.

Aim: The assessment of influence vitamin D deficiency on the HT activity.

Material and methods: 310 people were enrolled in the study: 155 patients with HT (a-TPO and/or a-TG positivity)-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. For analysis purposes the HT group was divided into two subgroups: without (E) and with l-thyroxine treated hypothyroidism (H): 45 patients aged 50±14 and 110 patients aged 50±17 respectively. Serum 25OHD3, TSH, a-TPO, a-TG, 25OHD3 levels were measured in all subjects. 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 is no difference between 25OHD3 concentration in subgroup E and control group (28.7 vs 25.6 ng/ml; P=0.4) but 25OHD3 level was significantly lower in subgroup H than in subgroup E (21.5 ng/ml; Q₁-Q₃: 17.8–27.3 vs 28.7 ng/ml; Q₁-Q₃: 21.4-33.2; P< 0.001). The study showed higher 25OHD3 level in a-TPO negative than in a-TPO positive patients (32 ng/ml; Q₁-Q₃: 25.6-37.7 vs 22.1 ng/ml; Q₁-Q₃: 18.1–28.4; P<0.001); the same was observed in a-TG negative and a-TG positive subjects (28.7 ng/ml; Q₁-Q₃: 23.2–32.7 vs 20.2 ng/ml; Q₁-Q₃: 15.4–23.6; P<0.001). In subgroup E 25OHD3 level was similar independently of a-TPO or a-TG positivity.

Conclusions: Evidence of a link between increased level of antithyroid antibodies in hypothyroid patients with HT and 25OHD3 deficiency may suggest that this group is particularly prone to the vitamin D deficiency and can benefit from its alignment.