A Prospective Study on the Outcome of Pre-Prandial versus Post- Prandial Thyroid Function Tests
Keywords:Hypothyroidism, Fasting, Postprandial
The values of Thyroid stimulating hormone (TSH) are generally observed to be more in the fasting than in the postprandial state. This study aims to evaluate whether TSH and free T4 measured in fasting and postprandial state would show any difference which is of statistical significance. A total of 180 patients were divided into 3 groups, which consisted of equal number of euthyroid, subclinical and hypothyroidism patients. Serum TSH and free T4 were collected both in the fasting and postprandial state. TSH values were found to be significantly lower after food when compared to fasting in all the three groups and this result was found to be statistically significant. The significant decline in TSH values postprandially in comparison to fasting values, might lead to inappropriate diagnosis and management of patients, especially sub clinical hypothyroidism.
Kirsten D. The thyroid gland: physiology and pathophysiology. Neonatal Network. 2000;19(8):11-26.
Hak AE, PolsHA, VisserTJ, DreyhageHA, HofmanA, WittermanJC. Subclinical hypothyroidism as an independent risk factor for myocardial infarction in elderly women: The Rotterdam study. Ann Intern Med.2000;132:270-8.
Brabant G, Prank K, RanftU, SchermeyerT, Wagner TO, Hauser H, et al. Physiological regulation of circadian and pulsatilethyrotropinsecretion in normal man and woman. J ClinEndocrinolMetab. 1990; 70:403-9.
Brock G. Extra-thyroidal factors impacting thyroid hormone homeostasis: a review. J RestoratMed. 2015;4(1):40-9.
Patel YC, Alford FP, Burger HG. The 24 hour plasma thyrotropinprofile. ClinSci. 1972; 43:71-7.
Morley JE. Neuroendocrinecontrol of thyrotropinsecretion. EndocrRev. 1981;2:396-436.
Kamat V, Hecht WL, Rubin RT. Influence of meal composition on the postprandial response of the pituitary thyroid axis. EurJ Endocrinol 1995;133:75-9.
Bandophadhyay D, GoelP, BaruahH, Sharma D. Fasting or random: which venous sample is better for thyroid function testing. JARBS. 2012;4:275-8.
Scobbo RR, VondohlenTW, Hassan M, Islam S. Serum TSH variability in normal individuals: The time of sample collection. W V Med J. 2004;100:138-42.
Nair R, MahadevanS, MuralidharanRS, MadhavanS. Does fasting or postprandial state affect thyroid function testing?. Indian J EndocrinolMetabol. 2014;18(5):705