While certain facts relative to the occurrence of low metabolic rates have been definitely established, there are other factors concerning which there is little conclusive knowledge. Although a low rate of metabolism is common to all the conditions under consideration in this paper, it is quite apparent that the causes of this low rate are different.
The basal metabolic rate is maintained in the organism in part by thyroxine, which acts in the tissues as a catalyst and, to some extent, regulates the rate of energy transformation. It is a known fact that in normal individuals approximately 40 per cent of the heat production, as measured by the consumption of oxygen, is controlled by the thyroid gland. When the thyroid gland is destroyed and the organism has had sufficient time to become free from thyroxine, the basal metabolic rate drops to from —40 to —45 per cent.
When in association
BERKMAN JM. LOW BASAL METABOLIC RATE AND THE USE OF DESICCATED THYROID. JAMA. 1936;106(24):2042-2046. doi:10.1001/jama.1936.02770240006002