Endocrine Abstracts

There is increasing interest in the role of vitamin D deficiency in a number of chronic health problems including autoimmune diseases. The aetiology and pathogenesis of most autoimmune disorders remain obscure and a number of factors have been implicated in their pathogenesis, one of the most recent agents found to be associated with autoimmunity is vitamin 25(OH)D. The aim of the study was to assess total vitamin 25(OH)D status in patients with autoimmune thyroiditis with subclinical and overt hypothyroidism.

Methods and materials: 70 patients (54 females and 16 males) and 20 apparently healthy individuals with matched age and sex were underwent a detailed clinical examination, thyroid function tests (TSH, fT₄, fT₃, thyroid peroxidase antibodies) and serum total vitamin 25(OH)D.

Results: The patient group with autoimmune thyroiditis was classified according to the level of TSH into subclinical and overt hypothyroid groups. Levels of serum TSH were significantly increased in subclinical (6.80±1.84 μIU/ml) and hypothyroid (10.24±2.09 μIU/ml) groups as compared to control group (2.16±0.39 μIU/ml) (P<0.05). The thyroid peroxidase antibodies level was 312.83±7.19 IU/ml in subclinical hypothyroid group and was 529.31±9.62 IU/ml in the hypothyroid group. The levels of serum total 25(OH)D were significantly decreased in subclinical (18.8±1.2 nmol/l) and overt hypothyroid groups (21.9±1.1 nmol/l) as compared to control group (27.1±1.2 nmol/l), (P<0.05). A highly significant negative correlation was found between serum TSH, thyroid peroxidase antibodies and total 25(OH)D levels (P<0.001). Also highly significant positive correlation was found between the levels of serum total 25(OH)D and serum fT₄ (P<0.001). There was significant positive correlation between TSH and thyroid peroxidase antibodies levels (P<0.05).