Topic: CIRCADIAN RHYTHMS OF TSH, T4 and T3 Title: Free triiodothyronine has a distinct circadian rhythm that is delayed but parallels thyrotropin levels
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چکیده
Results: 100% of individuals showed a sinusoidal signal in TSH, for FT4 76% and for FT3 86% (p<0.05). For FT4 and FT3 the amplitude was low. For TSH, the acrophase occurred at a clock time of 0240 h and for FT3 approximately 90 minutes later at 0404h. The group cosinor model predicts that TSH hormone levels remain above the mesor between 2020 h and 0820 h and for FT3 from 2200 h to 1000 h. Cross correlation of FT3 with TSH showed that the peak correlation occurred with a delay of 0.5–2.5 hours. When time adjusted profiles of TSH and FT3 were compared, there was a strong correlation between FT3 and TSH levels ( =0.80, p<0.0001). In contrast, cross correlation revealed no temporal relationship between FT4 and TSH.
منابع مشابه
Free triiodothyronine has a distinct circadian rhythm that is delayed but parallels thyrotropin levels.
CONTEXT TSH is known to have a circadian rhythm, but the relationship between this and any rhythm in T(4) and T(3) has not been clearly demonstrated. OBJECTIVE With a view to optimizing thyroid hormone replacement therapy, we have used modern assays for free T(4) (FT4) and free T(3) (FT3) to investigate circadian rhythmicity. SETTING The study was performed at a university hospital. DESIG...
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