The Relationship Between Insensible Water Loss and Heat Production in Patients With Hypothyroidism Compared With Normal Subjects 1

Abstract

In normal subjects in the basal state the heat lost from the body through evaporation of water from the skin and respiratory passages has been found to be related to the total heat production. Soderstrom and DuBois (1) in 1917 measured the basal heat production and the water of vaporization from the body simultaneously in a Russell-Sage calorimeter; 27 studies in 12 normal male subjects, 20 to 50 years of age, revealed that an average of 24 per cent, with variations from 21 to 28 per cent, of their total heat production was expended in the vaporization of water.. Studies in 8 boys and 6 old men showed an average of 27 per cent of the total heat lost through vaporization in each group (1). Subsequently, Levine and Wilson (2) found that infants and children lost in this manner an average of 26 per cent of their heat production. Benedict and Root (3) in 1926 measured the basal metabolic rate and either the basal or sleeping insensible water loss in a large group of individuals comprising normal subjects and patients with diabetes or. thyrotoxicosis; from their data these authors constructed. a table for predicting metabolism from the basal or sleeping insensible weight loss. The studies of Benedict and Root (3) and those of subsequent investigators (4, 5, 6, and others) confirm in general those of Soderstrom and DuBois in normal subjects. On the basis of data available in the literature (1, 2, 6) Lavietes (7) has recently described an average relationship between basal insensible loss of weight and basal heat production in normal subjects by the equation the insensible weight loss increases above the basal when a patient assumes the sitting position (8), on activity (9, 10), in fever (1), and usually after eating (1, 11, 12). Jores (11) and Dieckhoff (12), however, found that the increase in metabolism following a protein meal was not always associated with a corresponding increase in insensible water loss, in fact in certain experiments the insensible loss did not increase at all when the metabolism increased by as much as 30 per cent. Furthermore, results of other investigators have revealed that the heat lost by vaporization in sleep (8, 9, 13) and on activity (7), even when unaccompanied by sensible perspiration, may not bear the same relation to total heat production as obtains under basal conditions.To what extent the percentage of the total heat lost by water vaporization varies in metabolic diseases which alter heat production is not entirely clear. Thus, although the percentage of heat lost by vaporization in hyperthyroidism has been studied by several authors, studies in only a few isolated cases of hypothyroidism are reported. The percentage of the total heat lost through vaporization under basal conditions has often been found increased in hyperthyroidism (1,3,4,11), even when no sensible perspiration is discernible; the few available reports in hypothyroidism indicate that the percentage heat lost through vaporization may be less than normal (1,4,9). The purpose of the present investigation was to de...

Greater body mass index is related to greater self-identified cold tolerance and greater insensible body mass loss

“…Fourthly, there could be the effect of clothing on insensible body mass loss. It is reported that the average gain from clothing was approximately 2 g [ 14 ]. We did not provide participants with the experimental clothing but previously guided all participants to wear their long sleeved-cotton shirts and long cotton trousers, so that the covering area (%BSA) and clothing layers made similar between participants.…”

“…The insensible perspiration is influenced by external and internal factors such as air temperature [ 3 – 5 ], air humidity [ 1 , 5 , 6 ], posture [ 7 ], activity [ 2 , 8 – 10 ], circadian rhythm [ 11 ], skin temperature [ 9 , 12 ], body region [ 13 ], metabolism [ 1 , 5 ], body fluid [ 8 ], obesity [ 14 ], burned skin [ 15 ], age [ 16 ], and diseases [ 14 ]. Higher air temperature, lower humidity, and higher skin temperature cause greater IBL [ 3 , 4 , 6 , 9 , 12 ].…”