Feyzullah Güçlü

Vitamin D status among adults in the Aegean region of Turkey

BackgroundVitamin D is a lipid-soluble hormone found in certain foods and synthesized from precursors in the skin when exposed to ultraviolet light. Vitamin D plays a critical role in bone metabolism and many cellular and immunological processes and low levels have been associated with several chronic and infectious diseases. Vitamin D status is assessed by measuring the concentration of serum 25-hydroxyvitamin D [25(OH)D]. Vitamin D deficiency is reported to be common worldwide, but little has been reported about the vitamin D status of adults in Turkey. In this cross-sectional study, we determined the prevalence of 25(OH)D deficiency in adults residing in a city in the Aegean region of Turkey.MethodsA survey was conducted on a representative sample of adults over 20 years old in a non-coastal city at the end of the winter season. Of the 209 households selected by random sampling, 8.6% (n = 18) were unoccupied and 21.5% (n = 45) refused to participate. Blood samples were taken and questions about medical history, vitamin supplementation, sunlight exposure, and dietary calcium and vitamin D intake were asked in face-to-face interviews of 391 adults living in the remaining households.ResultsThe mean serum 25(OH)D concentration was 16.9±13.09 ng/mL, with 74.9% of the subjects having 25(OH)D deficiency (<20 ng/mL), 13.8% having insufficiency (20-29.99 ng/mL), and 11.3% of the subjects having sufficient 25(OH)D (≥30 ng/mL) levels. 25(OH)D deficiency was more common among females (78.7%) than males (66.4%, p < 0.05).ConclusionAdults living in an urban, non-coastal setting in Turkey have a high prevalence of vitamin D deficiency.

Down-regulation of the auto-aggressive processes in patients with hypothyroid Hashimoto's thyroiditis following substitutive treatment with L-thyroxine.

BACKGROUND Hashimotos thyroiditis is a chronic, organ-specific autoimmune disease. It is the most common cause of primary hypothyroidism during the adolescent period, via autoimmune thyroid tissue destruction, affecting 2% of the population. The pathogenesis of Hashimotos thyroiditis involves a complex interaction between predisposing genetic and environmental factors. OBJECTIVE In this study, we wanted to investigate the role of cytokines such as IL-2, IL-4, IL-12 and IFN-gamma in the pathogenesis of the disease, and the changes to cytokine levels brought about by treatment with L-thyroxine. METHODS Sixty five female patients, aged 18-73 years with Hashimotos thyroiditis, referred to the Celal Bayar University Medical Faculty Endocrinology out-patients clinic, were included in this study. After a 10-12 week period of L-thyroxine treatment, all patients were restored to the euthyroid state. At the beginning and end of the treatment period, serum-free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), autoantibodies against thyroid peroxidase (anti-TPO), autoantibodies against thyroglobulin (anti-Tg) levels were measured using a chemiluminecent, immunometric method, and cytokine levels were measured using ELISA. RESULTS There was a statistically significant decrease in the serum levels of TSH (p < 0.0001) and a concomitant increase in FT4 serum levels (p < 0.0001). Also, during the post-treatment period, serum levels of anti-Tg (p < 0.01) and anti-TPO (p < 0.001) were significantly lower than during the pre-treatment period. A statistically significant decrease was shown for interleukin (IL)-12 serum levels during the post-treatment period (p < 0.001). However, the decrease in interferon (IFN)-gamma serum levels was not statistically significant (p = 0.276). On the other hand, no change was demonstrated in serum IL-2 and IL-4 levels (p = 0.953 and p = 0.313, respectively) after treatment with L-thyroxine. CONCLUSION Considering that our study involved a 10-12 week period of treatment, the statistically significant decrease in serum IL-12 levels, and the statistically non-significant decrease in IFN-gamma levels, might indicate that a T helper type 1 inflammatory process had been halted or slowed down.