P1.03: Intravenous glucose nocturnal infusion reduces growth hormone secretion in children on total parenteral nutrition

Abstract

Introduction: Most children with intestinal failure (IF) benefit from home parenteral nutrition (HPN). It allows a familial life with normal children activities such as going to school, sports, and being at home. In order to do so, PN is provided with cyclic infusion at night. Children with IF on HPN should have normal growth. However, some children grow under their genetic target height and present with decreased height velocity. Methods: We report the case of two children on HPN who presented with decreased height velocity while their weight gain was normal. After ruling out usual etiology (insufficient protein intake, acidosis, sodium deficiency, IFALD…), growth hormone (GH) deficiency was considered. Extensive testings were performed such as IgF1 levels, GH secretion stimulation test and nocturnal GH secretion. PN dependency was assessed using the PN/REE index (parenteral nutrition non-protein energy intake divided by resting energy expenditure calculated using Schofield equation, expressed in percentage). Results: These two children needed extremely high PN caloric intake to achieve a normal weight gain with a PN dependency index of 163% and 150%. Table 1 shows their clinical characteristics. Table 2 shows the results of the biological testings. These two children showed a normal GH peak under stimulation, but a low nocturnal GH secretion meaning they were able to produce GH under stimulation, but their nocturnal physiological secretion was inhibited. Their mean glycemia during PN perfusion was high compared to fasting glycemia which should normally be observed at night in children. Hyperglycemia is a well known inhibitor of GH secretion. Conclusion: Children with very high PN dependency are at risk of developing reduced height. In some children, GH secretion seems to be inhibited by nocturnal high glucose infusion. A longer PN infusion time can be proposed and/or a decrease in glucose intake with an increase in lipid intake. Also, growth hormone supplementation might be discussed and should be evaluated in this setting.