Naslov
Thyroid Hormone Economy in Response to Extreme Cold Exposure in Healthy Factory Workers

Autori
Solter, Miljenko ; Brkić, Kornelije ; Petek, Marijan ; Posavec, Ljubica ; Sekso, Mladen

Izvornik
The Journal of clinical endocrinology and metabolism (0021-972X) 68 (1989), 1; 168-172

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Thyroid Hormone ; Thyroxyne ; Triiodothyronine ; Thyroxyne Binding Globulin ; Cold Exposure

Sažetak
The effect of cold exposure on serum total T4 (TT4), total T3 (TT3), free T4 (FT4), free T3 (FT3), rT3, TSH, TBG and T3 resin uptake were investigated in 82 euthyroid factory workers. Twenty-five workers (Group I) were exposed intermittently (cca 3, 5 h daily) to extreme cold (minus 40 to minus 20 Celsius degree) during the 8-h work shift, and 47 (Group II) were exposed to moderate cold (minus 10 to 8 Celsius degree) for the entire 8 h. Ten individuals working at room temperature for the same period also were studied. After cold exposure, serum TT4 decreased in Group I and did not exchange in Group II, whereas FT4 did not change in Group I and increased in Group II. After exposure, serum TT3 and rT3 decreased significantly on both groups, while FT3 did not change in either. The basal serum TT4 levels in Groups I and II were significantly lower then those in the control group, whereas those of FT4 and FT3 were higher. Thus, cold exposure had opposite effects on total thyroide hormones and their free fractions, consistent with a cold- induced decrease in thyroid- binding capacity. A postexposure decrease in serum TBG was found in women in Group II, but not in men in either Group II or Group I, suggesting tht factors other than decreased TBG are also involved. The results suggested the posssibilities that: 1)decreased thyroid hormone binding capacity is an adaptive response to cold exposure, and/or 2) increased free thyroid hormone levels in response to cold exposure result in new higher equilibrium between extracellular and intracellular FT4 and FT3.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

POVEZANOST RADA