title: Circadian rhythm of TSH levels in subjects with Alzheimer's disease (AD).
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  The circadian rhythm in serum TSH levels in AD patients differs greatly from that of the general population.
authors.affiliation: Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Youyi Road, Yanjiagang, YuZhong District, Chongqing, 400016, China.
authors.forename: Jian-Mei
authors.initials: JM
authors.lastname: Chen
authors.forename: Chang-Quan
authors.initials: CQ
authors.lastname: Huang
authors.forename: Ming
authors.initials: M
authors.lastname: Ai
authors.forename: Li
authors.initials: L
authors.lastname: Kuang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood*; D016022:Case-Control Studies; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine