AJP - Endocrinology and Metabolism, Vol 245, Issue 4 373-E378, Copyright © 1983 by American Physiological Society
Effects of ketosis on glucose flux in children and adults
M. W. Haymond, C. Howard, E. Ben-Galim and D. C. DeVivo
Sequential glucose flux studies were carried out in five normal and six
epileptic children and ten adult volunteers using [6,6-2H2]glucose to
determine the effect of ketosis on carbohydrate homeostasis in children and
adults. All subjects were studied after 14 and 30-38 h of fasting while
consuming a normal diet and the epileptic children under 14 h of fasting
while consuming an isocaloric ketogenic diet (75% fat wt/wt). Glucose flux,
when expressed per kilogram body weight, was inversely correlated with the
degree of ketosis in children (P less than 0.001) and in adults (P less
than 0.01), but not when both children and adults were considered together
(r = 0.078). When glucose flux was corrected for estimated brain weight,
the relationship between glucose flux and ketonemia was linearly related in
children (P less than 0.001), in adults (P less than 0.02), and when all
subjects were considered together (P less than 0.001). The inverse
relationship between ketonemia and glucose flux corrected for estimated
brain mass is consistent with a partial replacement of glucose by ketone
bodies for cerebral metabolism and may provide a more rational means of
expressing glucose flux data to take into account the higher brain-to-body
ratio in children.
