Biomaterial Database

Decreased free fraction of serum thyroid hormones during carbohydrate overfeeding. 1984

S Welle, and M O'Connell, and E Danforth, and R Campbell

The impact of the increased T3 production induced by overfeeding is likely to be lessened if overfeeding also decreases the free fraction of thyroid hormones. Therefore, we examined the effect of 17 to 20 days of carbohydrate overfeeding of five men on total serum T4 and T3 concentrations, the free fraction of these hormones, and serum concentrations of thyroid-hormone binding proteins, TBG, TBPA, and albumin. Total serum T4 concentrations were unchanged by overfeeding and total serum T3 concentrations increased 42%. However, the free fraction of both T4 and T3 decreased during the overfeeding period, so that free T3 concentrations increased only 21% and free T4 concentrations decreased 17%. There was an increase in serum concentrations of both TBG (12%) and TBPA (20%), but no change in the concentration of albumin. We conclude that there is an increase in free T3 concentrations during overfeeding, in spite of a decrease in the free fraction of T3. However, the physiological effects of this increase in free T3 concentrations may be diminished by the decrease in free T4 concentrations.

UI	MeSH Term	Description	Entries
D006963	Hyperphagia	Ingestion of a greater than optimal quantity of food.	Overeating,Polyphagia,Polyphagias
D008297	Male		Males
D011228	Prealbumin	A tetrameric protein, molecular weight between 50,000 and 70,000, consisting of 4 equal chains, and migrating on electrophoresis in 3 fractions more mobile than serum albumin. Its concentration ranges from 7 to 33 per cent in the serum, but levels decrease in liver disease.	Proalbumin,Transthyretin
D004040	Dietary Carbohydrates	Carbohydrates present in food comprising digestible sugars and starches and indigestible cellulose and other dietary fibers. The former are the major source of energy. The sugars are in beet and cane sugar, fruits, honey, sweet corn, corn syrup, milk and milk products, etc.; the starches are in cereal grains, legumes (FABACEAE), tubers, etc. (From Claudio & Lagua, Nutrition and Diet Therapy Dictionary, 3d ed, p32, p277)	Carbohydrates, Dietary,Carbohydrate, Dietary,Dietary Carbohydrate
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D012709	Serum Albumin	A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.	Plasma Albumin,Albumin, Serum
D013963	Thyroid Hormones	Natural hormones secreted by the THYROID GLAND, such as THYROXINE, and their synthetic analogs.	Thyroid Hormone,Hormone, Thyroid,Hormones, Thyroid
D013974	Thyroxine	The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.	L-Thyroxine,Levothyroxine,T4 Thyroid Hormone,3,5,3',5'-Tetraiodothyronine,Berlthyrox,Dexnon,Eferox,Eltroxin,Eltroxine,Euthyrox,Eutirox,L-3,5,3',5'-Tetraiodothyronine,L-Thyrox,L-Thyroxin Henning,L-Thyroxin beta,L-Thyroxine Roche,Levo-T,Levothroid,Levothyroid,Levothyroxin Deladande,Levothyroxin Delalande,Levothyroxine Sodium,Levoxine,Levoxyl,Lévothyrox,Novothyral,Novothyrox,O-(4-Hydroxy-3,5-diiodophenyl) 3,5-diiodo-L-tyrosine,O-(4-Hydroxy-3,5-diiodophenyl)-3,5-diiodotyrosine,Oroxine,Sodium Levothyroxine,Synthroid,Synthrox,Thevier,Thyrax,Thyroxin,Tiroidine,Tiroxina Leo,Unithroid,L Thyrox,L Thyroxin Henning,L Thyroxin beta,L Thyroxine,L Thyroxine Roche,Levo T,Thyroid Hormone, T4
D013975	Thyroxine-Binding Proteins	Blood proteins that bind to THYROID HORMONES such as THYROXINE and transport them throughout the circulatory system.	Thyroxine Transport Protein,Thyroxine-Binding Protein,Thyroxine Binding Protein,Thyroxine Binding Proteins