Anthropometric Parameters in Patients with Fatty Acid Oxidation Disorders: A Case-Control Study, Systematic Review and Meta-Analysis.

This study compared the anthropometric parameters of patients with fatty acid oxidation disorders (FAOD) and healthy controls, showing an increased prevalence of abnormal body weight (overweight and obesity) in the FAOD group. First, differences in BMI, BMI percentiles and z-scores, and weight and weight percentiles were compared in a cohort of 39 patients with FAOD and 156 healthy controls, as well as between patients born before and after the introduction of a populational newborn screening programme (NBS) in 2014 in Poland. We also performed a systematic literature review yielding 12 studies mentioning anthropometric parameters in 80 FAOD patients and 121 control subjects, followed by a meta-analysis of data from 8 studies and our cohort. There were significant differences in body weight percentiles (p = 0.001), BMI (p = 0.022), BMI percentiles (p = 0.003) and BMI z-scores (p = 0.001) between FAOD patients and controls in our cohort but not between pre- and post-newborn-screening patients. The meta-analysis did not show any differences in weight and BMI in all tested subgroups, i.e., all FAOD patients vs. controls, medium-chain acyl-CoA dehydrogenase (MCADD) patients vs. controls and patients with FAOD types other than MCAD vs. controls. These results, however, should be interpreted with caution due to the overall low quality of evidence as assessed by GRADE, the small sample sizes and the significant heterogeneity of the included data.

Phenylketonuria Patients' and Their Caregivers' Perception of the Pandemic Lockdown: The Results of a National Online Survey.

The first pandemic lockdown dramatically impacted many aspects of everyday life, including healthcare systems. The purpose of this study was to identify problems of patients with phenylketonuria (PKU) and their parents/caregivers during that time. We aimed to analyse potential differences in the self-reported compliance and characteristics of contacts with a doctor/dietitian before and during the pandemic lockdown and the perception of access to special food and opinions on remote contacts between a particular group of respondents. All participants (n = 614) were asked to complete an online questionnaire that consisted of 31 questions on pandemic-related events and circumstances which may have directly or indirectly impacted health and treatment. The people who completed the survey were divided into three groups: parents of PKU children (n = 403), parents of PKU adults (n = 58) and PKU patients older than 16 years (n = 153). The differences among the three analysed groups were found in the number of contacts, the way of contacting a doctor/dietitian during the pandemic and satisfaction with remote contact. Caregivers of children with PKU reported better therapy compliance, more frequent contacts with specialists and more satisfaction with remote visits than adult patients. We also observed a relationship between satisfaction from remote contact and self-reported frequency of contacts with a doctor/dietitian, as well as a relationship between satisfaction from remote contact and recommended blood Phe levels reported by both patients and caregivers. Travel time exceeding three hours from the respondents' location to their doctor was associated with higher odds of their recognition of remote contact as a method of PKU treatment only in the group of caregivers. In the caregiver groups, the reported worse access to low-Phe products during the lockdown was linked to the perceived difficulty of maintaining the diet. However, such a relationship was not found among patients. In conclusion, significant differences in the perception of the pandemic lockdown and its impact on health and treatment-related issues were found.

Helicobacter pylori Infection in Children with Phenylketonuria Does Not Depend on Metabolic Control and Is Not More Frequent Than in Healthy Subjects-A Cross-Sectional Study.

In a small preliminary study, phenylketonuria and poor metabolic control were suggested as risk factors for Helicobacter pylori infection in children as detected with an antigen stool test. We aimed to determine Helicobacter pylori prevalence in an adequately sized group of individuals with phenylketonuria and healthy subjects using the standard gold test (urea breath test). Further, we correlated Helicobacter pylori infection with metabolic control. The study comprised 103 individuals with phenylketonuria and 103 healthy subjects on whom a 13C urea breath test was performed. Blood phenylalanine levels in the preceding year were analysed. The infection rate did not differ between individuals with phenylketonuria and healthy subjects (10.7% vs 15.5%; p = 0.41). The frequency of testing and phenylalanine concentrations of Helicobacter pylori-positive and Helicobacter pylori-negative patients with phenylketonuria did not differ (p = 0.92 and p = 0.54, respectively). No associations were detected for body mass index or metabolic control. Forward stepwise regression models revealed that age (p = 0.0009-0.0016) was the only independent correlate of Helicobacter pylori infection with a relatively low fraction of the variability of the condition being explained (adjR2 = 0.0721-0.0754; model p = 0.020-0.023). In conclusion, Helicobacter pylori infection in phenylketonuria is not more frequent than in the general population. Moreover, it does not depend on metabolic control.

The Impact of the First 2020 COVID-19 Lockdown on the Metabolic Control of Patients with Phenylketonuria.

The present study assessed patients' metabolic control of phenylketonuria (PKU) during the first 2020 COVID-19 lockdown in Poland. Blood (phenylalanine) Phe results of the tests of 535 patients, performed in 2019 and in the first months of 2020, were analysed. The six-week lockdown period was compared to the preceding six-week period as well as to the two corresponding periods of 2019 (three non-lockdown periods). More patients failed to perform Phe tests in the lockdown period (32.7%) than in non-lockdown periods (15.6%, 15.1%, 17.2%; p < 0.001 for all). The median Phe levels for those patients who performed testing in all the four periods did not differ between periods. However, these patients tended to perform only one test during the lockdown (ORs: 1.43 to 1.60; 95% CI: from 1.01-2.04 to 1.11-2.30, p-value 0.02 to 0.005). Patients who did not take blood during the lockdown (46.7%) performed significantly fewer blood tests in the remaining periods (median : 1 <0-1> vs. 2 <1-4>; p < 0.001). In conclusion, direct assessment of patients' compliance based upon Phe levels during the pandemic lockdown was not possible. Pre-pandemic non-compliant patients frequently failed to perform the test during the lockdown, whereas the previously compliant ones were more likely to perform only one test. This strongly suggests that metabolic control might have worsened.

The Impact of the COVID-19 Pandemic on the Perception of Health and Treatment-Related Issues among Patients with Phenylketonuria in Poland-The Results of a National Online Survey.

There is agreement that the pandemic has affected the healthcare system and behaviour of patients. This study aims to identify problems encountered by patients with phenylketonuria (PKU) and their parents/caregivers during the six-week pandemic lockdown in Poland (15 March to 30 April 2020). To determine the factors that influenced health and treatment-related issues, as well as the respondents' perception of the impact of the pandemic, study participants were asked to complete a non-validated online questionnaire comprising 31 questions (including 27 single-choice, two multiple-choice and two open-ended ones). A total of 571 patients or their parents completed the questionnaire, with 9.5% of respondents not performing any blood phenylalanine (Phe) test in the analysed period, 21.3% declaring a blood Phe increase, and 15.3% a decrease. Increased problems in contacting the doctor or dietitian were reported by 26.1% of subjects, whereas 39.3% of them felt restricted access to dietary products. Most (63.4%) participants were satisfied with remote contact with their PKU clinic. Better compliance was associated with higher odds of acceptance of remote contact and of reporting fewer problems with contacting the doctor, and with lower odds of missing Phe testing. Self-reported high stress was associated with higher odds of reporting the limited availability of low-Phe products and Phe-free formulas, as well as with increased Phe concentrations and non-PKU-related health problems. These patients also had poor dietary compliance and experienced more problems in contacting specialists. Health and treatment-related problems experienced during the pandemic lockdown were related to a higher intensity of stress in patient's family and worse therapy compliance before the pandemic. Previous experience of remote visits resulted in a better perception of this method of contact. It seems that this form of communication should be popularized and improved to increase therapy effectiveness in case of different limitations in the future. Special attention should be paid to vulnerable patients who may be at extra risk when the provision of standard care is affected.

Carriership of the rs113883650/rs2287120 haplotype of the SLC7A5 (LAT1) gene increases the risk of obesity in infants with phenylketonuria.

PURPOSE: Phenylketonuria (PKU) can be effectively treated with the use of a low-phenylalanine diet. However, some patients become overweight despite proper dietary treatment. We hypothesized that this phenomenon could be explained by the presence of specific variants within the genes involved in phenylalanine transport or in the phenylalanine transamination/oxygenation pathway. METHODS: We selected a clinically homogenous group of 100 infants with PKU and assessed their growth patterns in the context of dietary phenylalanine tolerance. Next, within the sample, we performed exome sequencing and assessed a potential relationship between the observed phenotypical variability and the presence of structural variants in a priori selected genes of interest. RESULTS: We detected a highly significant association between overweight and carriership of the rs113883650/rs2287120 haplotype of the SLC7A5 (LAT1) gene, which encodes the main transmembrane transporter of large neutral amino acids and of thyroid hormones. CONCLUSIONS: Our findings suggest a pharmacogenetic effect of the relatively common rs113883650/rs2287120 haplotype of the SLC7A5 gene. This can have practical implications for patients with PKU, since treatment protocols need to be reassessed to better prevent overweight in the carriers of the above variant.