Resting metabolic rate in malnourished babies in relation to total body potassium

ABSTRACT

Fasting metabolic rate was investigated in 53 malnourished children and 17 controls of similar age. Total body potassium (TBK) was also measured in 18 of the malnourished children and in all the controls, so that metabolic rates could be compared in relation to a measure of metabolically active tissue. In newly admitted malnourished children specific potassium depletion was corrected orally while they were given a maintenance diet. Resting metabolism correlated better with TBK than with weight, height or surface area in control and recovered children, but metabolic rate per unit TBK decline with increasing body-weight (r=-0.51). This negative correlation became insignificant if metabolic rate was expressed in terms of TBK3/4. In the malnourished children resting metabolic rate was reduced compared with control and recovered values, when expressed in terms of weight, height or surface area. The results were confirmed by a comparison of metabolic rates per unit TBK3/4, which showed a reduction of about 27 percent in the malnourished children. No significant difference was found between children with marasmus and those with oedematous malnutrition. During rapid growth fasting metabolism was increased. We conclude that oxygen consumption in metabolically active tissues is reduced in all forms of untreated infantile malnutrition. (AU)