Abstract:The nutritional and metabolic characteristics of adult phenylketonuria (PKU) patients in the UK with varying dietary adherence is unknown. In other countries, nutritional and metabolic abnormalities have been reported in nonadherent patients compared to adherent counterparts. A pooled analysis of primary baseline data from two UK multi-centre studies was therefore performed to establish whether this is true from a UK perspective. Adult PKU patients who had provided 3-day food records and amino acid blood sampl… Show more
“…Commercial databases contain limited information on vitamin K product content, so in the present study, we collected all available data from different nutritional programmes for every food item and product consumed by our patients, as well as assessing both vitamin K1 and K2 consumption. Considering protein intake, which was lower in the non-adherent than adherent subjects studied by Green et al [ 15 ], the non-adherence seems to be related to the very low use of FSMP and lp-products. This may be, at least in part, explained by the older age of the patients studied (in comparison to our patients).…”
Section: Discussionmentioning
confidence: 84%
“…Green et al [ 15 ] assessed the nutritional intake of macro- and micro-nutrients in sixteen adherent and fourteen non-adherent patients. Contrary to our findings, they documented that vitamin K intake was lower in non-adherent subjects, but their observations concerned only the intake of vitamin K1.…”
Section: Discussionmentioning
confidence: 99%
“…There have been reports on adequate or inadequate vitamin K intake in PKU patients on a diet [ 13 , 14 , 15 ]. Still, even in recent studies investigating possible vitamin and micronutrient deficits, the status of vitamin K is not addressed [ 16 , 17 , 18 ].…”
This is the first study to evaluate vitamin K status in relation to dietary intake and phenylalanine dietary compliance in patients with phenylketonuria (PKU). The dietary and PKU formula intake of vitamin K was calculated in 34 PKU patients, with vitamin K status determined by the measurement of prothrombin induced by vitamin K absence (PIVKA-II). Blood phenylalanine concentrations in the preceding 12 months were considered. There were significantly more phenylalanine results exceeding 6 mg/dL in patients with normal PIVKA-II concentrations than in those with abnormal PIVKA-II levels (p = 0.035). Similarly, a higher total intake of vitamin K and dietary vitamin intake expressed as μg/day (p = 0.033 for both) and %RDA (p = 0.0002 and p = 0.003, respectively) was observed in patients with normal PIVKA-II levels. Abnormal PIVKA-II concentrations were associated with a lower OR (0.1607; 95%CI: 0.0273–0.9445, p = 0.043) of having a median phenylalanine concentration higher than 6 mg/dL. In conclusion, vitamin K deficiency is not uncommon in phenylketonuria and may also occur in patients with adequate vitamin K intake. PKU patients with better dietary compliance have a higher risk of vitamin K deficiency. The present findings highlight the need for further studies to re-evaluate dietary recommendations regarding vitamin K intake, both concerning formula-based and dietary consumption of natural products.
“…Commercial databases contain limited information on vitamin K product content, so in the present study, we collected all available data from different nutritional programmes for every food item and product consumed by our patients, as well as assessing both vitamin K1 and K2 consumption. Considering protein intake, which was lower in the non-adherent than adherent subjects studied by Green et al [ 15 ], the non-adherence seems to be related to the very low use of FSMP and lp-products. This may be, at least in part, explained by the older age of the patients studied (in comparison to our patients).…”
Section: Discussionmentioning
confidence: 84%
“…Green et al [ 15 ] assessed the nutritional intake of macro- and micro-nutrients in sixteen adherent and fourteen non-adherent patients. Contrary to our findings, they documented that vitamin K intake was lower in non-adherent subjects, but their observations concerned only the intake of vitamin K1.…”
Section: Discussionmentioning
confidence: 99%
“…There have been reports on adequate or inadequate vitamin K intake in PKU patients on a diet [ 13 , 14 , 15 ]. Still, even in recent studies investigating possible vitamin and micronutrient deficits, the status of vitamin K is not addressed [ 16 , 17 , 18 ].…”
This is the first study to evaluate vitamin K status in relation to dietary intake and phenylalanine dietary compliance in patients with phenylketonuria (PKU). The dietary and PKU formula intake of vitamin K was calculated in 34 PKU patients, with vitamin K status determined by the measurement of prothrombin induced by vitamin K absence (PIVKA-II). Blood phenylalanine concentrations in the preceding 12 months were considered. There were significantly more phenylalanine results exceeding 6 mg/dL in patients with normal PIVKA-II concentrations than in those with abnormal PIVKA-II levels (p = 0.035). Similarly, a higher total intake of vitamin K and dietary vitamin intake expressed as μg/day (p = 0.033 for both) and %RDA (p = 0.0002 and p = 0.003, respectively) was observed in patients with normal PIVKA-II levels. Abnormal PIVKA-II concentrations were associated with a lower OR (0.1607; 95%CI: 0.0273–0.9445, p = 0.043) of having a median phenylalanine concentration higher than 6 mg/dL. In conclusion, vitamin K deficiency is not uncommon in phenylketonuria and may also occur in patients with adequate vitamin K intake. PKU patients with better dietary compliance have a higher risk of vitamin K deficiency. The present findings highlight the need for further studies to re-evaluate dietary recommendations regarding vitamin K intake, both concerning formula-based and dietary consumption of natural products.
“…The multidisciplinary team and the patient’s family have the challenge of providing means for adhering to the diet, which is extremely restrictive and has little variety of preparations. 3 Studies show that adherence to the diet decreases with age, making follow-up more difficult for adolescents, adults and pregnant women. 4 …”
Objective: To characterize metabolic control and verify whether it has any relation with socioeconomic, demographic, and body composition variables in children and adolescents with phenylketonuria (PKU) diagnosed in the neonatal period. Methods: This cohort study collected retrospective data of 53 phenylketonuric children and adolescents. Data on family income, housing, and mother’s age and schooling level were collected, and anthropometric measures of body composition and distribution were taken. All dosages of phenylalanine (Phe) from the last five years (2015-2019) were evaluated and classified regarding their adequacy (cutoffs: 0-12 years: 2-6 mg/dL; 12-19 years: 2-10 mg/dL). Adequate metabolic control was considered if ≥7%) of the dosages were within desired ranges. Results: The mean (±standard deviation) age in the last year was 10.1±4.6 years. Most of them were under 12 years old (33/53; 62.3%) and had the classic form of the disease (39/53; 73.6%). Better metabolic control was observed among adolescents (68.4 versus 51.4%; p=0.019). Overweight was found in 9/53 (17%) and higher serum Phe levels (p<0.001) were found in this group of patients. Metabolic control with 70% or more Phe level adequacy decreased along with the arm muscle area (AMA) (ptendency=0.042), being 70.0% among those with low reserve (low AMA), and 18.5% among those with excessive reserve (high AMA). Conclusions: Adequate metabolic control was observed in most patients. The findings suggest that, in this sample, the levels of phenylalanine may be related to changes in body composition.
“…Generally, many patients have a poor acceptance of protein substitutes and parents struggle to ensure that their children take them as prescribed [11,12]. Poor adherence to a low-phenylalanine diet and protein substitute increases with age and is associated with worsening of blood phenylalanine control [11,13,14]. Furthermore, children may take up to an hour to take their full dose of protein substitute, with some failing to take the prescribed quantity [15].…”
Dietary restriction of phenylalanine combined with a protein substitute prevents intellectual disability in patients with phenylketonuria (PKU). However, current protein substitutes are associated with low adherence owing to unpalatability and burdensome administration regimens. This prospective, observational acceptability study in children with PKU assessed the use of a prolonged-release protein substitute designed with an ethyl cellulose and arginate coating masking the bitter taste, smell and reducing the osmolarity of free amino acids. The study product was mixed with the subject’s food or drink and replaced ≥1 dose per day of the subject’s usual protein substitute for 7 days. Seven of 13 subjects were able to take their prescribed dose over the 7 day period. Most subjects mixed the test protein substitute with food or fruit juice. Reduced blood phenylalanine levels (n = 5) and improved phenylalanine/tyrosine ratio (n = 4) were recorded from baseline to Day 7, respectively. Four subjects reported fewer gastrointestinal symptoms compared to baseline. There were no cases of diarrhoea, constipation, bloating, nausea or vomiting. No adverse reactions were reported. In conclusion, the novel prolonged-release protein substitute was taken in a different way to a typical protein substitute and enabled satisfactory blood phenylalanine control. The study product was well tolerated; subjects experienced fewer gastrointestinal symptoms than with their previous treatment. Although the results of this pilot study provide reassuring data, longer-term studies evaluating adherence and blood phenylalanine control are necessary.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.