When the paediatric heart is affected : impact on nutrition, growth and body composition from infancy to adolescence

Abstract: BackgroundChildren with complex congenital heart disease (CHD) and very low birth weight (VLBW) infants with a patent ductus arteriosus (PDA) are two distinct groups of patients with different clinical care needs. Irrespective of the type of heart condition, nutritional intake and growth is largely affected in these individuals during infancy. Although medical care for these conditions has significantly improved in the last several decades, there is still a considerable need for improvement in nutritional support to reach satisfactory growth and development in both these patient groups. In children with complex CHD, there often is underlying malnutrition related to the type and severity of cardiac defect, which constitutes the reason for increased energy metabolism and feeding difficulties. In VLBW infants with a haemodynamically significant PDA (hsPDA), additional fluid regulation may result in a subsequent decrease in macronutrient intake. Current knowledge regarding the consequences of growth restrictions and nutritional intake during infancy, as well as body composition and nutritional intake later in childhood, is scarce. The overall aim of this thesis was to explore energy and nutritional intakes in infants, children and adolescents with complex CHD or hsPDA, as well as investigate growth and body composition in these patient groups.Methods In this thesis, four observational studies were conducted. In paper I, the study population consisted of 11 CHD infants and 22 matched controls. A follow up study (paper III) was conducted on these CHD infants at 9 years of age and compared to a new set of age-matched controls (n=10). In paper II, 42 VLBW infants with hsPDA, and 48 referents with VLBW were studied. In paper IV, 44 children and adolescence with Fontan circulation were compared to 38 matched controls. From infancy to adolescence, data on energy, macro- and micronutrient intakes was retrieved from hospital records, from 3-day food diaries or from food frequency questionnaires. Further, anthropometric measures and dual-energy X-ray absorptiometry (DXA) scans were performed and venous blood samples were analysed. ResultsIn paper I, infants with complex CHD had a higher dietary fat intake and lower carbohydrate and iron intakes compared to controls. Additionally, energy intake did not meet the requirements for growth in the CHD infant cohort, resulting in significantly lower Body Mass index (BMI) for age z-score. In paper II, fluid intakes was restricted after hsPDA diagnosis in VLBW infants resulting in a decrease in energy and protein intakes. The z-score of weight change during the first 28 days of life depended on both PDA status and energy intake. In the follow-up study of the complex CHD infants (paper III), growth was comparable to controls at 9 years of age suggesting a catch-up effect. Despite comparable BMI z-scores, the children with CHD had a higher abdominal fat mass index (FMI) and higher daily intake of fat, particularly from saturated fats, compared to controls. In paper IV, the Fontan population had a daily mean vitamin D intake of 9.9 µg and a mean serum 25‑hydroxyvitamin D of 56 nmol/L however, 42% had below sufficient levels. These factors were not associated with lean mass index (LMI), Fat mass index (FMI), or biomarkers of liver status. The Fontan population had significantly less LMI, but higher FMI than controls. Male adolescents with Fontan circulation had a greater mean abdominal FMI than male controls and higher cholesterol levels than females with Fontan circulation.ConclusionInfants with complex CHD, and VLBW infants with hsPDA did not grow as expected with the energy and nutrition provided to them. Follow-up at 9 years of age showed children with complex CHD had caught-up in growth but had increased abdominal FMI and higher intake of saturated fatty acids. In children and adolescents with Fontan circulation, vitamin D levels and intake was not associated with body composition or liver biomarkers. However, it was noted that the Fontan population had a lower LMI and higher FMI compared to controls. Nutritional progress in children with heart conditions can promote growth and improve dietary quality between infancy and adolescence, potentially working to counteract later health risks.