Is vitamin D related to pathogenesis and treatment of Hashimoto's thyroiditis?

OBJECTIVE: The aim of this study was to investigate vitamin D status by measuring serum 25(OH)D levels in euthyroid patients with Hashimoto's thyroiditis (HT) who lived and worked on the sunny island of Crete, Greece, and to evaluate whether vitamin D3 supplementation is beneficial for the management of HT patients with vitamin D deficiency. SUBJECTS AND METHODS: We studied 218 HT patients, euthyroid Caucasian Cretan Greek citizens: 180 females and 38 males. Among these patients, 186 (85.3%) had vitamin D deficiency defined as serum 25(OH)D levels < 30 ng/mL. The mean age of all these 218 HT patients was 35.3 ± 8.5 years. The mean age of the 186 vitamin D deficient HT patients (173 females and 13 males) was 37.3 ± 5.6 years. The 186 vitamin D deficient HT patients received vitamin D3 (cholecalciferol, CF) orally, 1200-4000 IU, every day for 4 months aiming to maintain serum 25(OH)D levels ≥ 40 ng/mL. Anthropometric characteristics (height, weight, waist circumference), systolic and diastolic blood pressure, serum concentration of 25(OH)D, thyrotropin (TSH), free thyroxine (FT4), anti-thyroid peroxidase (anti-TPO), antithyroglobulin (anti-TG), calcium and phosphorus levels and thyroid and kidney sonographic findings were recorded and measured before and after CF administration. RESULTS: There was a significant negative correlation only between serum 25(OH)D levels and anti-TPO levels among all 218 HT patients. Also, anti-TPO levels were significantly higher in 186/218 vitamin D deficient HT patients compared to 32/218 HT patients with no vitamin D deficiency (364 ± 181IU/mL versus 115.8 ± 37.1IU/mL, P<0.0001). Supplementation of CF in 186 vitamin D deficient HT patients caused a significant decrease (20.3%) in serum anti-TPO levels. Although at the end of the 4 months period of the study body mass index (BMI), serum anti-TG and TSH levels decreased by 2.2%, 5.3% and 4% respectively, these differences were not significant. No changes in the sonographic findings were observed. CONCLUSION: The majority (85.3%) of the Greek Caucasian patients with HT studied who lived and worked in Crete had low serum 25(OH)D levels inversely correlated with serum anti-TPO thyroid antibodies. After 4 months of CF supplementation in the 186 HT patients with vitamin D deficiency, a significant decrease (20.3%) of serum anti-TPO levels was found. These findings suggest that vitamin D deficiency may be related to pathogenesis of HT and that its supplementation could contribute to the treatment of patients with HT.

Coexistence of Hashimoto's thyroiditis with papillary thyroid carcinoma. A retrospective study.

OBJECTIVE: The association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) remains controversial in medical bibliography. The main objective of our study was to determine the prevalence of PTC and HT coexistence in histopathologic material of thyroidectomized patients. DESIGN: In a retrospective study, the clinicohistopathologic data of 140 patients (19 males/121 females), who underwent a total or near total thyroidectomy for any thyroid pathology from January 2005 to December 2009 at the Naval Hospital of Crete, were analysed. The mean age of the patients was 52 years (range 16-74). RESULTS: HT was detected in 42 (30%) and PTC in 32 (22.9%) specimens. Coexistence of HT with PTC was present in 12 (8.6%) specimens. Among 32 specimens with PTC, the prevalence of HT was 37.5%. Among 42 specimens with HT, the prevalence of PTC was 28.6%. There was no statistically significant difference between the presence of PTC and HT in histopathologic material. CONCLUSIONS: The prevalence of PTC and HT coexistence in histopathologic material of 140 thyroidectomized patients was 8.6%, whereas the difference between PTC and HT was not statistically significant.