Effect of 64-Hour Sleep Deprivation on the Circadian Waveform of Thyrotropin (TSH): Further Evidence of Sleep-Related Inhibition of TSH Release*

Half-hourly sampling of plasma TSH was done across 3 days in four normal young men. Sleep was denied for 64 h from 0700 h on awakening from accommodation sleep until polygraphic sleep was resumed at 7100 h of the third day (D3) such that 2 consecutive nights of usual 2300–0700 h sleep were missed. This protocol allowed examination of any modulatory effects on the daily patterns in TSH concentrations during sleep deprivation on Dl-2 (1100–3500, 3500–5900 h) or during resumption of usual nightly sleep on D3 (5900–8300) compared to that of a previously studied group of normal young men. The circadian nature of the daily TSH waveform was evidenced by its daily repetition within a subject both basally and during Dl-2 sleep deprivation and by its synchronization within the basal, deprived, or resumed sleep days. The peaks in each subject’s daily TSH patterns on Dl-2 were consistently longer, and the daily maxima and cosine acrophases on Dl-2 were consistently later than those on D3 when basal sleep was resumed....