Oxygen consumption in patients with hyperthyroidism before and after treatment with beta-blockade versus thyrostatic treatment: a prospective randomized study.
OBJECTIVE
To evaluate randomly the effect of thyrostatic treatment (tiamazole) versus selective (metoprolol) and nonselective beta-blockade (propranolol) on whole-body energy metabolism in women with hyperthyroidism.


BACKGROUND
beta-blockade is used as an alternative to thyrostatic drugs in the preoperative treatment of patients with hyperthyroidism. beta-blockers have well-established symptomatic effects, but in contrast to antithyroid drugs beta-blockade is thought to lack direct effects on the increased metabolism in hyperthyroidism.


METHODS
Whole-body oxygen consumption and carbon dioxide production was measured in a semiopen canopy system with paramagnetic O2 and infrared CO2 sensors. A constant flow generator and the gas-dilution method for calculation of gas flow were used. Anabolic parameters were body weight, triceps skinfold, and arm muscle circumference.


RESULTS
Tiamazole normalized oxygen consumption and induced signs of anabolism with improved nutritional state. Metroprolol did not affect oxygen consumption. Propranolol reduced elevated oxygen consumption by 54%. Body weight and other anthropometric assessments were stable after specific and nonspecific beta-blockade, which also led to symptomatic relief in approximately 90% of the patients.


CONCLUSIONS
Tiamazole was the most effective drug to oppose the adverse effects of hyperthyroidism. Therefore, thyrostatic agents are recommended for preoperative treatments of patients with severe catabolic hyperthyroidism. Whenever beta-blockers are chosen for treatment of hyperthyroidism, propranolol (beta 1 + beta 2) has an advantage because it reduces the metabolic rate, whereas selective beta 1-blockade seemed to provide only symptomatic relief, related to the normalization of heart rate.
Jansson
S
S
Department of Surgery, Sahlgrenska University Hospital, Göteborg, Sweden. Svante.Jansson@dep-surg.gu.se
Lie-Karlsen
K
K
Stenqvist
O
O
Körner
U
U
Lundholm
K
K
Tisell
L E
LE
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D013956:Antithyroid Agents / Q000627:therapeutic use*; D002245:Carbon Dioxide / Q000378:metabolism; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy* / Q000378:metabolism* / Q000601:surgery; D008713:Methimazole / Q000627:therapeutic use*; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects*; D011300:Preoperative Care; D011433:Propranolol / Q000627:therapeutic use*; D011446:Prospective Studies; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D013956:Antithyroid Agents; D002245:Carbon Dioxide; D008713:Methimazole; D011433:Propranolol; D008790:Metoprolol