Dietary glycemic index, glycemic load and metabolic profile in children with phenylketonuria.

BACKGROUND AND AIMS: No data exist in the current literature on the glycemic index (GI) and glycemic load (GL) of the diet of phenylketonuric (PKU) children. The aims of this study were to examine the dietary GI and GL in PKU children on a low-phenylalanine (Phe)-diet and to evaluate whether an association may exist between the carbohydrate quality and the metabolic profile. METHODS: Twenty-one PKU children (age 5-11 years) and 21 healthy children, gender and age matched, were enrolled. Dietary (including GI and GL) and blood biochemical assessments were performed. RESULTS: No difference was observed for daily energy intake between PKU and healthy children. Compared to healthy controls, PKU children consumed less protein (p = 0.001) and fat (p = 0.028), and more carbohydrate (% of total energy, p = 0.004) and fiber (p = 0.009). PKU children had higher daily GI than healthy children (mean difference (95% confidence interval), 13.7 (9.3-18.3)) and higher GL (31.7 (10.1-53.2)). PKU children exhibited lower blood total and low density lipoprotein cholesterol (LDL) levels (p < 0.01) and higher triglyceride level (p = 0.014) than healthy children, while glucose and insulin concentrations did not differ. In PKU children the dietary GL was associated with triglyceride glucose index (Spearman's correlation coefficient = 0.515, p = 0.034). CONCLUSION: In PKU children a relationship of the dietary treatment with GI and GL, blood triglycerides and triglyceride glucose index may exist. Improvement towards an optimal diet for PKU children could include additional attention to the management of dietary carbohydrate quality.

Diet in children with phenylketonuria and risk of cardiovascular disease: A narrative overview.

AIMS: The aim of this paper is to review the possible relationship of restricted phenylalanine (Phe) diet, a diet primarily comprising low-protein foods and Phe-free protein substitutes, with major cardiovascular risk factors (overweight/obesity, blood lipid profile, plasma levels of homocysteine, adiponectin and free asymmetric dimethylarginine (ADMA), oxidative stress and blood pressure) in PKU children. DATA SYNTHESIS: In PKU children compliant with diet, blood total cholesterol, low-density lipoprotein cholesterol (LDL-C), plasma ADMA levels and diastolic pressure were reported to be lower and plasma adiponectin levels to be higher compared to healthy controls. No difference was observed in overweight prevalence and in high-density lipoprotein cholesterol (HDL-C) levels. Inconsistent results were found for plasma homocysteine levels and antioxidant status. CONCLUSIONS: PKU children compliant with diet seem to display non-different cardiovascular risks compared with the healthy population. Well-designed longitudinal studies are required to clarify the potential underlying mechanisms associated with PKU and cardiovascular risk factors.

Breakfast: a good habit, not a repetitive custom.

In developed countries, obesity is the most frequent nutritional disorder, and overweight and obesity prevalences have increased whilst physical activity and breakfast consumption have declined. There is growing scientific interest in the possible role of breakfast in weight control and in factors such as appetite control, dietary quality and reduced risk for chronic diseases. The current article reviews the literature and discusses how the breakfast 'environment' and the composition of breakfast meals might be improved, particularly in children, so as to maintain the breakfast eating habit throughout life. Recommendations are proposed to encourage children to keep eating breakfast and the nutritional composition of the 'American breakfast' and two types of Mediterranean 'cereal breakfasts' are compared. We also propose a new breakfast type for children and adolescents that is based on chocolate hazelnut spread within a mixed breakfast type in order to reinforce positive experiences.

Enterobacter sakazakii: an emerging problem in paediatric nutrition.

Recently there has been considerable concern related to the presence of bacteria, in particular Enterobacter sakazakii, in powdered infant formula milk. E. sakazakii, a member of the family Enterobacteriaceae, is an emerging opportunistic pathogen that has been associated with cases of meningitis, necrotizing enterocolitis and sepsis in premature and full-term infants. Feeding with powdered infant formula has been epidemiologically implicated in several clinical cases. Powdered infant formula is not a sterile product; good hygienic practice is, therefore, necessary in its reconstitution to reduce the risk of infection. The ingestion of raised numbers of E. sakazakii resulting from storage at room temperature after reconstitution is highlighted as well as the uncertain routes of E. sakazakii product contamination.

Treating phenylketonuria: a single centre experience.

Hyperphenylalaninaemia (HPA) is an inherited disorder that results in raised plasma phenylalanine levels with a range of severities, including phenylketonuria (PKU). Since the first attempts at treatment using a low-phenylalanine diet and after more than 50 years of research, considerable progress has been made so we are now at a stage where mental retardation caused by high plasma phenylalanine can be prevented. We must, however, be aware of the new challenges we face in managing PKU. These include: maintaining optimal growth by providing enough phenylalanine without jeopardizing the child's psychomotor development; providing an optimal nutritional status that ensures other essential nutrients, such as long chain polyunsaturated fatty acids, are not excluded from the diet; ensuring optimal compliance to the dietary intervention; and considering patients' quality of life. New strategies, such as tetrahydrobiopterin (BH4) supplementation, need to be evaluated with regard to safety, efficacy and expected outcomes in specific types of HPA.

Phenylketonuria: dietary and therapeutic challenges.

PKU subjects need special attention in the definition of optimal supplementation of nutrients, which may be insufficient in relation to the type of diet and may otherwise manifest symptoms of deficit. In particular, it is necessary to pay great attention to the long-chain polyunsaturated fatty acid (LC-PUFA) levels in relation to correct development of the central nervous system. On the basis of numerous beneficial effects currently known, a permanent supplementation with LC-PUFAs, in particular with docosahexaenoic acid, should be considered. Moreover, new formulas, Phe-free peptides, and 'modulated' amino acid preparations might help in preventing nutritional deficiencies and imbalances, with the ultimate aim of improving growth. New strategies--such as supply of tetrahydrobiopterin--need to be optimized in terms of targets, patients and expected outcomes.