Comparison of Three Methods Used in Assessment of Carbohydrate Absorption in Malnourished Children

Abstract

James, W. P. T. (1972). Archives of Disease in Childhood, 47, 531. Comparison of three methods used in assessment of carbohydrate absorption in malnourished children. The results of oral lactose and sucrose tolerance tests were compared with jejunal disaccharidase activities and the absorption rates of lactose and sucrose from a perfused segment of jejunum in 8 malnourished children before and after treatment.Treated children, with nearly normal utilization of circulating glucose, showed a good correlation between the oral tolerance test results and the jejunal absorption rates of lactose and sucrose. Malnourished children often showed normal rises in blood glucose despite low disaccharidase activities and poor jejunal absorption rates of glucose, lactose, and sucrose. These rises were considered to reflect poor glucose uptake by peripheral tissues rather than adequate absorption of sugars from the distal small intestine.Jejunal absorption of lactose and sucrose was only limited by the disaccharidase activities when these were very low; the rate of disaccharide absorption was usually closely related to the rate of glucose absorption, despite a wide range in disaccharidase activities.Several tests have been used in children and adults in an attempt to establish whether patients are able to hydrolyse and absorb the different forms of carbohydrate in the diet.The 3 clinical methods at present available are the oral tolerance test, the direct measurement on jejunal mucosa of carbohydrase activities, and observations on the faecal pH and output of water and sugar. Other methods, including hydrogen excretion measurements of the breath, and intubation studies of the small intestine for sampling after feeds or perfusion of the jejunum, are at present used only as research tools.Diarrhoea is a more prominent feature of carbohydrate intolerance in children than in adults.This difference presumably reflects the importance of the adult colon in reducing the loss of water (Dawson, 1970). Colonic bacterial fermentation, with the production of organic anions from unabsorbed sugar, will also affect the amount of carbohydrate and water in the stool, and this fermentation process may differ in children and adults. In children the severity of the diarrhoea and measure-

Improved accuracy of lactose tolerance test in children, using expired H2 measurement.

“…lactose intolerance, and should be replaced by more mnces in the stool, with reliable methods-such as the H2 test. low pH, if present, are Although we did not aim to use the H2 test for -ntiation (James, 1972; differentiating lactose malabsorption from lactose [ , 1977), but only a few intolerance, we confirmed the observation of Maffei Low these abnormalities. et al (1977) that the increase in H2 excretion tends stools examined showed to be early in lactose-intolerant patients (Fig.…”

“…Extrapolating therefore not surprising these results to larger populations, the incidence of a ingestion differentiates false normal A-glucose would have been 38-62% Lctose absorption and for lactose malabsorption, and 22-53 % for lactose es, 1972; Harrison and intolerance, and the incidence of a false abnormal intolerance (Garza and A-glucose 9-19 % for lactose tolerance (Table 2). tn and Walker-Smith, Thus, A-glucose during the LTT, appears to bean (James, 1972; Krasilni-unreliable indicator of lactose malabsorption and et al, 1975). lactose intolerance, and should be replaced by more mnces in the stool, with reliable methods-such as the H2 test.…”

Carbohydrate malabsorption in acutely malnourished children and infants: a systematic review

“… 23 showed that 39% of children with SAM had an abnormal lactose loading test, whereas 16% had an abnormal glucose + galactose loading test before the nutritional recovery. James, 17 however, showed no significant improvement in lactose or sucrose absorption after treatment.…”

“… 16 Although not validated, if the blood glucose rises less than 30 mg/100 mL after the oral carbohydrate is administered, then intolerance is considered likely; increments of less than 20 mg/100 mL are generally considered diagnostic of malabsorption. 17 …”

“…(1967) 29 Kwashiorkor No 15 Lactose 2 20.4 ± 13.62* 24.0 ± 15.11* – – Glucose + galactose 1 + 1 39.27 ± 20.17* 43.4 ± 15.53* – – Prinsloo et al. (1971) 26 SAM a No 10 Lactose 2 24.5 ± 16.5* – – – Glucose + galactose 1 + 1 27.9 ± 23.04* – – – James (1972) 17 MAM and SAM a Yes 8 Lactose 2 38.5 ± 22.61* – 28.75 ± 17.5* – Sucrose 2 42.5 ± 29.35* – 51.57 ± 12.46* – Bilir. (1972) 18 MAM and SAM a Yes 12 …”