Anthropometrics and fat mass, but not fat-free mass, are compromised in infants requiring parenteral nutrition after neonatal intestinal surgery

Background Children with intestinal failure (IF) receiving long-term parenteral nutrition (PN) have altered body composition (BC), but data on BC changes from start of PN onwards are lacking. Objectives We aimed to assess growth and BC in infants after neonatal intestinal surgery necessitating PN and at risk of IF, and to explore associations with clinical parameters. Methods A prospective cohort study in infants after intestinal surgery. IF was defined as PN dependency for >60 d. SD scores (SDS) for anthropometry were calculated until 6-mo corrected age. In a subgroup, fat mass (FM) and fat-free mass (FFM) were measured with air-displacement plethysmography at 2- and 6-mo corrected age. SDS for length-adjusted FM index and FFM index were calculated. Associations between cumulative amount of PN and BC parameters were analyzed with linear mixed-effect models. Results Ninety-five neonates were included (54% male, 35% born <32 wk) and 39 infants (41%) had IF. Studied infants had compromised anthropometric parameters during follow-up. At 6-mo corrected age, they remained smaller (median weight-for-age SDS -0.9 [IQR -1.5, 0.1], P < 0.001) than the normal population. In 57 infants, 93 BC measurements were performed. FM index SDS was lower than in healthy infants at 2- and 6-mo corrected age (-0.9 [-1.6, -0.3], P < 0.001 and -0.7 [-1.3, 0.1], P = 0.001, respectively), but FFM index SDS did not differ. A higher cumulative amount of PN predicted a higher FM index in female infants but lower FM index in male infants. Conclusions In this cohort of infants receiving PN after intestinal surgery, compromised anthropometrics, decreased FM, and adequate FFM were observed during the first 6 mo. Male and female infants seemed to respond differently to PN when it comes to FM index. Continuing growth monitoring after the age of 6 mo is strongly recommended, and further research should explore the benefit of incorporating ongoing BC monitoring during follow-up.

Automated summary

The study aimed to assess the growth and body composition changes in infants receiving parenteral nutrition (PN) after intestinal surgery and found compromised anthropometric parameters, decreased fat mass, and adequate fat-free mass in the first 6 months due to intestinal failure. Male and female infants responded differently to PN in terms of fat mass index.