[Metabolic adaptation in hyperthyroidism. Implication of insulin].
Hyperthyroidism is associated with intense metabolic disturbances. Thus, an increase of basal metabolism and thermogenesis is noted. Glucose data include increased muscle utilization and hepatic production. Its oxydative catabolism is enhanced, while its use for glycogen synthesis is reduced. Lipid turnover is also increased. In vivo and in vitro improvement of muscle proteolysis in animals induces a reduction of total body protein content; protein synthesis is also paradoxically stimulated. In contrast, this mechanism remains unproved in man. The role of insulin, whose levels usually increase during glucose tolerance tests, is also studied. Glucose tolerance impairment may be related to lower insulin-inhibited glucose production whereas insulin-stimulated glucose peripheral utilization is unmodified. In man, receptor assays demonstrate reduced amount of binding-sites on various cell, while animals studies lead to contradictory results; thus, receptor studies do not demonstrate any clear mechanism for insulin resistance in hyperthyroidism.
Tauveron
I
I
Laboratoire d'Etude du Métabolisme Azoté, INRA, Centre de Clermont-Fd Theix, Ceyrat, France.
Grizard
J
J
Thieblot
P
P
Bonin
D
D
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004734:Energy Metabolism; D006706:Homeostasis; D006801:Humans; D006980:Hyperthyroidism / Q000378:metabolism / Q000503:physiopathology*; D007444:Inulin / Q000502:physiology*; D011506:Proteins / Q000378:metabolism; D011972:Receptor, Insulin / Q000502:physiology
D001786:Blood Glucose; D011506:Proteins; D007444:Inulin; D011972:Receptor, Insulin
Adaptation métabolique en hyperthyroïdie. Implication de l'insuline.