Metabolic aspects in children with congenital heart defect

Abstract

Background: Children with congenital heart defect (CHD) have often been reported as growth retarded. The underlying reasons for this growth retardation are not fully established. Low caloric intake and high metabolic rate are commonly described causes. The reasons for the demonstrated high metabolic rate are also not completely understood. Metabolic deviations may be one component in growth retardation and increased metabolic rate. Nutritional status and metabolic balance are of prog-nostic importance in children with CHD.The aims of the studies were to give information about following questions:? Are children with CHD growth retarded?? Are there signs of metabolic deviations in children with CHD?? Are there any associations between metabolic deviations and growth retardation?? Are there differences in metabolic deviations between children with different types of CHD?Methods: Three groups of children were studied; children with cyanotic CHD, children with ventricular septal defect (VSD) and a control group of healthy children.The following procedures have been performed:? Intravenous glucose load (IVGTT) in children from all three groups ? Skeletal muscle biopsies in children from all three groups ? Intravenous lipid load in children with cyanotic CHD and in children with VSD.Results: Children with CHD were growth retarded and showed relatively high values of glycerol and FFA in plasma.Children with CHD compared to control children showed differences in:? Smaller amount of insulin but greater amount of C-peptide in plasma during IVGTT? Lower concentrations of glycogen and adenosine triphosphate in skeletal muscle at rest? Lower concentrations of glucose-6-phosphate and lower activities of b-hydroxy-acyl-coenzyme A dehydrogenase in skeletal muscle at rest? Smaller diameter of type 1 fibers in skeletal muscleAssociations were found between a high degree of growth retardation in children with CHD and metabolic deviations such as:? Smaller amount of insulin in plasma in response to IVGTT? Higher concentrations of total FFA and linoleic acid in the FFA fraction in plasma after fasting? Lower maximum values for total TG and linoleic acid in the TG fraction after lipid loading? Higher maximum values for glycerol in plasma after lipid loading? Smaller differences in linoleic acid in the triglyceride fraction between fasting counts and the counts at 120 and 240 minutes after completed infusion of lipidChildren with different types of CHD had also different types of deviations.Children with cyanotic CHD compared to children with VSD showed differences in:? Greater amount of glucose (larger incremental area) in plasma after glucose loading? Higher concentration of blood lactate fasting value and maximum value after lipid loading? Higher concentrations of alanine in plasma after fasting? Lower maximum values for acetoacetate after lipid loading Conclusions:? Children with CHD were growth retarded and showed laboratory signs of starvation or stress? Children with CHD showed metabolic deviations both in the metabolism of a glucose load and in skeletal muscle metabolism compared to the control children? Several metabolic deviations after glucose and lipid loading were correlated to the degree of growth retardation, while no such correlations were noted to findings in skeletal muscle biopsies? Children with different types of CHD had somewhat different metabolic deviations