The physiological variations in serum TSH concentration have been investigated using an enzyme amplified immunoassay with improved sensitivity and precision. Blood samples were collected at regular intervals from 10 healthy volunteers during the period 1800 h to 0100 h. Spectral analysis followed by periodic regression analysis demonstrated significant serum TSH pulsatility with periodicities of 60 or 85–100 min. In addition, a significant (P < 0·001) evening rise in serum TSH concentration was demonstrated in all subjects, with levels rising at around 21·30–22·00 h.
References
1.
YenSCCVandenbcrgGTsaiCC. Ultradian fluctuations of gonadotropins. In: FeriaMHelbergFRichartRVandeWiele R, eds. Biorhythms and human reproduction.New York: John Wiley1974; 203–218.
2.
BeckWWuttkeWJ. Diurnal variations of plasma luteinizing hormone, follicle-stimulating hormone and prolactin in boys and girls from birth to puberty. J Clin Endocrinol Metab1980; 50: 635–9.
3.
MurdochAPDigglePJDunlopW. Determination of the frequency of pulsatile luteinizing hormone secretion by time series analysis. Clin Endocrinol (Oxf)1985; 22: 341–6.
4.
WehmannRENisulaBC. Radioimmunoassay of human thyrotropin: Analytical and clinical developments. Crit Rev Clin Lab Sci1984; 20: 243–83.
5.
ClarkPMSClarkJDAHolderR. Physiological variations in TSH in healthy subjects—does TSH show pulsatility and a diurnal rhythm?J Endocrinol1986; 108 (suppl): 140.
6.
GreenspanSLKlibanskiASchoenfeldD. Pulsatile secretion of thryotropin in man. J Clin Endocrinol Metab1986; 63: 661–8.
7.
JohannssonAStanleyCJSelfCH. A fast highly sensitive colorimetric immunoassay system demonstrating benefits of enzyme amplification in clinical chemistry. Clin Chim Acta1985; 148: 119–24.
8.
ClarkPMSPriceCP. Enzyme-amplified immunoassays: A new ultra sensitive assay of thyrotropin evaluated. Clin Chem1986; 32: 88–92.
9.
BruceSRatcliffeJGSwiftAD. Comparative evaluation of high sensitivity TSH kits. Commun Lab Med1986; 2: 49–55.
10.
EkinsRP. The precision profile: Its use in assay design, assessment and quality control. In: HunterWMCorrieJET, eds. Immunoassays for Clinical Chemistry.London: Churchill Livingstone1983; 76–105.
11.
PinnellAENorthernBE. New automated dye-binding method for serum albumin determination with bromocresol purple. Clin Chem1978; 24: 80–6.
12.
MostellerFTukeyTW. Data analysis and regression.Massachusetts: Addison Wesley Reading, 1977.
13.
ChatfieldC.The analysis of time series: An introduction.London: Chapman and Hall, 1980.
SatoTIshiguroKSuzukiY. Low setting of feedback regulation of TSH secretion by thyroxine in pituitary dwarfism with TSH-releasing hormone deficiency. J Clin Endocrinol Metab1976; 42: 385–9.
16.
KaplanMMToftJAReichlinS. Sustained rises in serum thyrotropin, thyroxine and triiodothyronine during long term, continuous thyrotropin-releasing hormone treatment in patients with amyotrophic lateral sclerosis. J Clin Endocrinol Metab1986; 63: 808–14.
