Jian-Mei Chen1, Chang-Quan Huang, Ming Ai, Li Kuang. 1. Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Youyi Road, Yanjiagang, YuZhong District, Chongqing, 400016, China.
Abstract
OBJECTIVES: The circadian rhythm of serum thyroid stimulating hormone (TSH) levels in patients with Alzheimer's disease was measured by means of a case-control study. METHODS: Serum samples from cases and controls were collected continuously for 2 days, and then once every 2 h (even number time-point during the first day and odd number time-point in the second). TSH was detected by radioimmunoassay. RESULTS: AD patients had no significant circadian rhythm in serum TSH levels, whereas normal controls did. In normal controls, serum TSH levels from 19:00 to 20:00 were the lowest (19:00, 3.89 ± 0.97 mIU/L; 20:00, 3.76 ± 0.84 mIU/L) and those in the period 2:00-4:00 were the highest (2:00, 6.15 ± 0.94 mIU/L; 3:00, 6.32 ± 1.04 mIU/L; 4:00, 6.39 ± 1.13 mIU/L; F = 6.762, df = 23, P = 0.002). However, in AD patients, 24-h serum TSH levels were 3.80-4.03 mIU/L (F = 0.897, df = 23, P = 0.996). At the 24 time-points, except for the four time-points from 16:00 to 19:00, TSH levels in AD patients were significantly lower than those in normal controls. CONCLUSIONS: The circadian rhythm of serum TSH levels in AD patients did not appear, and their serum TSH levels were significantly lower than those in normal controls. SIGNIFICANCE: The circadian rhythm in serum TSH levels in AD patients differs greatly from that of the general population.
OBJECTIVES: The circadian rhythm of serum thyroid stimulating hormone (TSH) levels in patients with Alzheimer's disease was measured by means of a case-control study. METHODS: Serum samples from cases and controls were collected continuously for 2 days, and then once every 2 h (even number time-point during the first day and odd number time-point in the second). TSH was detected by radioimmunoassay. RESULTS:ADpatients had no significant circadian rhythm in serum TSH levels, whereas normal controls did. In normal controls, serum TSH levels from 19:00 to 20:00 were the lowest (19:00, 3.89 ± 0.97 mIU/L; 20:00, 3.76 ± 0.84 mIU/L) and those in the period 2:00-4:00 were the highest (2:00, 6.15 ± 0.94 mIU/L; 3:00, 6.32 ± 1.04 mIU/L; 4:00, 6.39 ± 1.13 mIU/L; F = 6.762, df = 23, P = 0.002). However, in ADpatients, 24-h serum TSH levels were 3.80-4.03 mIU/L (F = 0.897, df = 23, P = 0.996). At the 24 time-points, except for the four time-points from 16:00 to 19:00, TSH levels in ADpatients were significantly lower than those in normal controls. CONCLUSIONS: The circadian rhythm of serum TSH levels in ADpatients did not appear, and their serum TSH levels were significantly lower than those in normal controls. SIGNIFICANCE: The circadian rhythm in serum TSH levels in ADpatients differs greatly from that of the general population.