Intake and blood levels of fatty acids in treated patients with phenylketonuria.

BACKGROUND: Investigators in Italy and Spain have suggested that therapy for patients with phenylketonuria (PKU) may result in essential fatty acid (EFA) deficiency. Objectives of this study were to determine if the diets of patients with PKU in the United States provided adequate EFA intakes and whether patients could form long-chain polyunsaturated fatty acids. METHODS: Patients (1-13 years of age) with classic PKU undergoing therapy and their non-PKU sibling closest in age were compared. Nutrient intakes were calculated from 3-day diet diaries. Fatty acids in plasma and erythrocytes were identified and quantified. Paired t tests compared results for the patients and their non-PKU siblings. RESULTS: Twenty-eight patients and 26 siblings were studied. Mean fat intake was greatest by siblings (34.8 +/- 1.3% of energy) and lowest by Phenyl-Free-fed patients (19.5 +/- 1.2% of energy; P < 0.05). Fat intake (30.4 +/- 1.8% of energy) by Phenex-fed patients did not differ from that of siblings. Percentage of energy ingested as C18:2n-6 and C18:3n-3 did not differ significantly between patients and siblings. No clinically significant, consistent differences were found in fatty acid levels (wt%) in plasma or erythrocytes between patients with PKU and siblings. CONCLUSIONS: No patient in this study exhibited a Holman index of EFA deficiency. Siblings ingested animal protein containing C20:5n-3 and C22:6n-3 fatty acids, and this may account for their greater wt% of these plasma and erythrocyte fatty acids. Because patients with PKU do not ingest fatty acids >C18 but C20:4n-6, C20:5n-3, and C22:6n-3 were found in their plasma and erythrocytes, in vivo synthesis from C18:2n-6 and C18:3n-3 appears to occur. Lack of EFA deficiency in patients in this study may be the result of the use of canola and soy oils containing C18:2n-6 and C18:3n-3 rather than olive oil in the diets.

Maternal and child health nutrition training builds leadership skills.

For more than 30 years, the Maternal and Child Health Bureau (MCHB) has funded specialized professional training in nutrition with an emphasis on the development of leadership skills. A survey was conducted of individuals who received Maternal and Child Health nutrition training at the Center for Human Development and Disability (CHDD) at the University of Washington. Those surveyed were asked to reflect on the impact of the training on their career pathway and to report on their leadership activities. Of the 91 respondents, 83 (92%) indicated that the training supported a career pathway that emphasized maternal and child health or children with special healthcare needs. Eighty-five former trainees (93% of respondents) reported leadership activities at the local level, 61 (67%) reported leadership activities at the state level, and 46 (51%) reported leadership activities at the national level. The results of the survey indicate that specialized, intensive training in the field of nutrition develops and supports leadership skills.

Supporting development of children with chronic conditions: from compliance toward shared management.

Children with chronic conditions can meet the overall health outcomes articulated in Bright Futures (1994), a model outlining a continuum of social, developmental, and health outcome achievements that help shape an independent, healthy adult. These outcomes begin with the development of a therapeutic alliance between families and providers and end with an independent, healthy functioning adult. The achievement of these outcomes does not come without the support of providers, however. Health care providers ideally merge multiple models of practice to provide an anticipatory guidance approach throughout the child's life to assist the family in this important task. Three models have been found useful: developmental, leadership, and changing foci, which families can merge into every day life.

Vitamin D, calcium, and bone status in children with developmental delay in relation to anticonvulsant use and ambulatory status.

Reports of abnormalities in vitamin D, calcium, and bone status associated with anticonvulsant use are inconsistent and difficult to interpret because of widely varying study designs, particularly for ambulatory status. We examined the relative effects of anticonvulsant use and ambulatory status on vitamin D, calcium, and bone status in a large group (n = 338) of children who had either normal motor function (ambulatory) or were nonambulatory and either receiving anticonvulsants or not; all had developmental delays. Data included diet records, serum analyses (calcium and calcidiol), and hand-wrist radiographs evaluated for bone maturation and quality. Data were analyzed by using a general linear models (GLM) procedure. Dietary and biochemical data were compared with those of a group of 34 normal children. There were no differences in calcium or vitamin D intakes among the four study groups; however, a high percentage of intakes was below the recommended dietary allowances for calcium (56%) and vitamin D (70%). Vitamin D intakes were positively associated with serum calcium (P < 0.005) and calcidiol (P < 0.01) concentrations. Analysis of covariance indicated that ambulatory status but neither anticonvulsant use nor their interaction contributed significantly to the prediction of serum calcium (P < 0.009) and calcidiol (P < 0.0001), the Z scores for number of ossified centers (P < 0.008), bone age (P < 0.0001), and bone area (P < 0.003). A strong interaction between anticonvulsant use and ambulatory status was seen for percentage cortical area (P < 0.0008), which was entirely due to anticonvulsant use in nonambulatory children (effect size = 0.98). Results suggest that ambulatory status is more important than was recognized previously in relation to abnormalities in vitamin D, calcium, and bone statuses; that all nonambulatory children may be at risk for low serum calcidiol and osteopenia; and that routine monitoring of risk and consideration of prophylactic vitamin D supplementation are warranted.

Immune status of children with phenylketonuria.

OBJECTIVE: To determine the effect of differences in plasma phenylalanine (Phe) concentrations (< 363 umol/L, 363 to 605 umol/L, and > 605 umol/L) on hematological and immunological parameters in 22 children with phenylketonuria (PKU). METHODS: Children with PKU were divided into one of three groups based on fasting plasma Phe levels. Hematologic and immunologic parameters of the children with PKU were compared between the groups and also compared with published values from age-matched children without PKU. RESULTS: Hematologic and immunologic parameters did not differ among children with different plasma Phe concentrations. Specifically, no significant differences between groups of PKU children with differing plasma Phe levels were found for plasma levels of albumin, hemoglobin, amino acids, IgM, complement C3, interleukins 1 and 2, erythrocyte, leukocyte and differential cell counts, hematocrit, percentages and numbers of CD4+, CD8+, CD3+ and total lymphocytes, or CD4 to CD8 ratio. Mean plasma IgG and IgA concentrations of the PKU children were, however, significantly lower than values from similar aged children. Moreover, positive correlations were obtained between plasma albumin and percentages and numbers of CD3+ and CD4+, between plasma IgG and interleukins 1 and 2, and between intakes of energy, protein, iron and plasma IgG levels. No correlations were found between plasma Phe and immunological parameters. CONCLUSION: While differences in plasma Phe concentrations up to concentrations of 866 umol/L do not appear to affect selected immune system parameters, further studies are needed to investigate the relationship between dietary nutrient intake, nutritional status, antibody biosynthesis and cytokine production. Assessment of plasma and cell membrane lipids and trace mineral status of PKU children would be helpful to determine if relationships exist between these nutrients and antibody production.

MR imaging of phenylketonuria.

Cranial MR imaging was performed on nine patients (13-27 years old) with classical phenylketonuria in order to define the spectrum of abnormal findings and to determine if these could be related to clinical or biochemical findings. MR abnormalities consistent with demyelination were found in varying degrees in a distribution corresponding to previous histopathologic studies. Specifically, increased signal was seen on T2-weighted sequences, most marked in the periventricular deep cerebral white matter. These changes were more prominent posteriorly, especially about the optic radiations. Comparison with clinical history and MR findings in this small series revealed that patients with adequate dietary control of phenylalanine levels had less severe white matter abnormalities than did patients with poorly controlled phenylalanine intake.

Anticonvulsant medication use and circulating levels of total thyroxine, retinol binding protein, and vitamin A in children with delayed cognitive development.

Circulating thyroxine (T4), retinol binding protein (RBP), and vitamin A were measured in conjunction with nutritional status assessment of 707 cognitively delayed children, ages 3.0-9.0 y. Twenty percent were receiving anticonvulsant (AC) medication. T4 was lower and RBP and vitamin A were higher (p less than 0.0001) among AC than non-AC subjects. Molar ratios of vitamin A:RBP did not differ between the two groups nor did intakes of protein or vitamin A. Lower T4 and higher RBP were found among children who received diphenylhydantoin (DPH), phenobarbital, or AC combinations, but vitamin A was higher only among those who received DPH. RBP and vitamin A were lower (p less than 0.05) among children with infections and vitamin A was lower (p less than 0.05) among those with serum zinc less than 70 micrograms/dL (less than 10.7 mumol/L); differences between AC and non-AC subjects remained when other variables were considered.

Measurement of body fat in Turner syndrome.

Fourteen individuals with the Turner syndrome (gonadal dysgenesis with X chromosome chromosome abnormalities) were evaluated for obesity using hydrostatic weighing and skinfold measurements. While skinfold estimates of body fat correlated well with clinical impression, hydrostatic weighing appeared to falsely overestimate percent body fat. We suggest that reduced skeletal mass and/or occult lymphedema in Turner syndrome may invalidate the formula used to calculate percent body fat derived from hydrostatic weights. In this population and possibly in other disorders where skeletal mass is reduced from the normal, the use of hydrostatic weighing may be inappropriate.

Supplement use: vitamin intakes and biochemical indexes in 40- to 108-month-old children.

Intakes and related biochemical indexes of ascorbic acid, thiamin, riboflavin, pyridoxine, vitamin B-12, and folic acid were examined for adequacy in 30 normal children aged 40 to 108 months. Comparisons were made between intake and biochemical index values of children who reported regular use of vitamin supplements and those who reported none. Three-day food records provided nutrient intake data; blood samples, drawn following an overnight fast, were analyzed for biochemical indexes. Student's t-test and the Pearson r were used for comparisons. Mean intakes of most nutrients differed significantly between the supplemented and nonsupplemented groups only when supplements were considered. Mean biochemical indexes differed significantly for riboflavin (p less than .005). Correlations between intakes and respective biochemical indexes were significant for riboflavin (p less than .01) and vitamin B-12 (p less than .01) in the supplemented group and for folate with RBC folate (p less than .005) in the nonsupplemented group. No deficiencies in either group were evident from biochemical indexes; improvement in indexes with supplement use was interpreted as being only relative and not suggestive that such use is beneficial.

Phenylalanine intakes of 1- to 6-year-old children with phenylketonuria undergoing therapy.

Mean of median phenylalanine intakes of 1- to 6-yr-old treated phenylketonuria patients who were growing normally were evaluated by age, sex, and treatment group assignment. Total daily means of median phenylalanine intakes of subjects in treatment group 1 were significantly different from those of subjects in treatment group 2 except at the median age of 69 months. Total daily phenylalanine intakes varied from 285 +/- 10 to 453 +/- 30 mg (mean +/- SEM) by subjects in treatment group 1. Total daily phenylalanine intakes of subjects in treatment group 2 varied from 349 +/- 12 to 530 +/- 42 mg (mean +/- SEM). Mean, median phenylalanine intakes by males ranged from 30 mg/kg of body weight by the younger to 23 mg/kg of body weight by the older subjects. Means of median phenylalanine intakes of females varied from 32 mg/kg of body weight by the younger to 21 mg/kg of body weight by the older subjects. No child had a median phenylalanine intake below 10 mg/kg of body weight.