BODY FAT OF NEWBORN INFANTS OF DIABETIC MOTHERS

Abstract

The body fat of newborn infants of diabetic mothers (diab. infants), normal full-term infants (norm, infants), and control infants, i. e. infants of the same gestational age as the diab. infants but born to normal mothers was determined by anthropometric measurements of the subcutaneous fat, partly by using a skin-fold caliper and partly by measuring the layers of subcutaneous tissue on X-ray films of the lower leg and chest. The thickness of the subcutaneous layer of fat was found to be increased in diab. infants by 38-46% as compared with normal infants and by 50% as compared with the control infants. In this connection, the author refers to his previous studies of total body water in diab. infants and normal infants, since the fat content may be estimated on the basis of knowledge of total body water. These studies showed that the total body water of diab. infants is 10 per cent below that of normal infants. The techniques used cannot accurately determine the absolute fat content in the body but it is illustrated by an example that the overweight of 560 g in diab. infants compared with normal control infants may be explained by an increased fat and glycogen content. Glycogen is formed in various quantities in the course of the transformation of carbohydrate into fat and is deposited, with binding of water, in the intracellular compartment. From the investigations it may be concluded that at birth diab. infants are obese and thus have a relatively low total body water. The obesity may increase the resistance to respiration and strain the cardiovascular system. The apparent paradox that despite a low body water diab. infants show a tendency to oedema, large urinary output, and marked weight loss after birth may be explained by the phenomenon that apart from being obese, they contain various quantities of glycogen which binds water in the intracellular compartment. After birth, a rapid breakdown of glycogen occurs, involving a release of water, and this results in a tendency to oedema, large urinary output, and subsequent weight loss due to the excretion of water.