Evidence for mild thyroidal impairment in women undergoing endurance training

Journal Article · Fri Jan 01 00:00:00 EST 1982 · J. Clin. Endocrinol. Metab.; (United States)

DOI:https://doi.org/10.1210/jcem-54-1-53· OSTI ID:5795731

Boyden, T W ^[1]; Pamenter, R W; Stanforth, P; Rotkis, T; Wilmore, J H

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1. Univ. of Arizona, Tucson

The effects of endurance training on body composition and the pituitary-thyroid axis were studied in 29 healthy, young (mean age, 28.7 yr), regularly menstruating women. Women who were initially jogging a mean of 13.5 miles/week were selected for this study to minimize dropouts. Body composition, measured by hydrostatic weighing, and nonfasting plasma concentrations of T/sub 4/, T/sub 3/, rT/sub 3/, TSH, and TRH-stimulated TSH, measured by RIA, were examined initially and after each subject's weekly mileage had increased to 30 miles (..delta..30, mean total body weight did not change, mean fat weight decreased (-1.02 kg/ P<0.005), and mean lean weight increased (+0.75 kg; P<0.05). T/sub 4/ and unstimulated TSH did not change. However, mean (+/- SE) T/sub 3/ decreased from 107.2 +/- 4.4 to 97.9 +/- 3.4 ng/dl (P<0.025), and mean rT/sub 3/ decreased from 170.9 +/- 13.9 to 154.6 +/- 13.2 pg/ml (P<0.025). The decrease in T/sub 3/ and rT/sub 3/ were accompanied by significantly greater TSH responses to TRH stimulation (mean (+/- SE) area under TSH curve, 1381.4 +/- 123 vs. 1712.8 +/- 202 ..mu..IU/ml-min; P < 0.01). These results indicate that physically active women who undergo additional endurance training 1) become more lean without a change in total body weight, and 2) have changes in T/sub 3/, rT/sub 3/, and TRH-stimulated TSH indicative of mild thyroidal impairment.

• OSTI ID: 5795731
• Journal Information: J. Clin. Endocrinol. Metab.; (United States), Vol. 54:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
EXERCISE
BIOLOGICAL EFFECTS
THYROXINE
RADIOIMMUNOASSAY
TRIIODOTHYRONINE
TSH
WOMEN
BODY COMPOSITION
BIOLOGICAL STRESS
EXPERIMENTAL DATA
METABOLISM
THYROID
TRH
AMINO ACIDS
ANIMALS
BODY
CARBOXYLIC ACIDS
DATA
ENDOCRINE GLANDS
FEMALES
GLANDS
HORMONES
INFORMATION
ISOTOPE APPLICATIONS
MAMMALS
MAN
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PRIMATES
RADIOASSAY
THYROID HORMONES
TRACER TECHNIQUES
VERTEBRATES
551000* - Physiological Systems
550601 - Medicine- Unsealed Radionuclides in Diagnostics