Glucose Metabolism and Insulin Secretion in Infants with Symptomatic Ventricular Septal Defect

Abstract

Nineteen infants with symptomatic ventricular septal defect (VSD) were examined on, altogether, 26 occasions, when each was given an intravenous glucose tolerance test (IVGTT); concentrations of insulin- and C-peptide in plasma were determined. Comparisons were made with 14 healthy infants of the same age. The VSD infants were growth retarded with lower weight/age and length/age ratios. Glucose tolerance as indicated by glucose fasting levels and response to intravenous glucose tolerance test, including glucose disappearance rate, did not differ between the two groups. In response to the glucose load, insulin in plasma was significantly less in VSD infants. In response to the IVGTT, insulin secretion rate calculated from C-peptide levels in plasma was significantly elevated in the VSD group. We conclude that compared to healthy infants, those with symptomatic VSD have normal glucose tolerance, increased secretion rate of insulin, but decreased levels of circulating insulin in response to an intravenous glucose load. We suggest this is so because binding of insulin to peripheral receptors and/or insulin extraction in the liver somehow increases.

Glucose metabolism and insulin secretion in children with cyanotic congenital heart disease

“…The insulin determinations in plasma in the CHD group did not show the lower levels as we previously reported for infants with VSD (7). The fasting and maximum levels and circulating stress hormones which leads to an increased density of a 2 receptors and the downregulation of padrenoreceptors.…”

“…The reason for the probable increased insulin secretion is unclear. To our knowledge, there are no reports of C-peptide in children with CHD, apart from our recent study (7), and this also applies to healthy infants within this age group.…”

“…In an earlier report, we studied glucose metabolism and insulin secretion in a group of infants with symptomatic VSD and compared them with a group of healthy infants of the same age and body size (7). We found no differences in glucose tolerance, but lower insulin levels were found in the VSD group.…”

“…Weight (kg) Weight-for-age Group (n) mean (range) mean (range) mean (SD score) CHD(13) 8.5 (4-20) 6.9 (3.7-9.6) -2.1 (-6 to f l ) Control (14) 5.8 (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) 7.0 (4.0-13.0) -0.4 (-2 to f2) p value NS NS NS examined awake and after a fasting period of 8 h on the day after that those with CHD were sedated with a mixture of pethidine, promethazine and chlorpromazine at a standardized dose per kg of body weight (8), while the healthy ones underwent general anaesthesia by fluothane.…”

Energy expenditure in infants with congenital heart disease, including a meta-analysis

“…Lundell et al found increased insulin secretion in combination with low plasma insulin after an intravenous glucose tolerance test in CHD patients with ventricular septal defects compared with healthy controls. This suggested that increased peripheral binding or extraction of insulin is present in infants with CHD after carbohydrate loading (22). Furthermore, upon intravenous lipid loading, disturbances in plasma free-fatty acid levels have been described in infants with CHD (patients with a ventricular septum defect or transposition of the great arteries) (23).…”