PKU and COVID19: How the pandemic changed metabolic control

Background: COVID19 pandemic urged the need to take severe measures for reducing the epidemic spread. Lockdowns were imposed throughout countries and even Inborn errors of metabolism (IEMs) affected patients had to face it and adapt, with management strategies changes coming along. Phenylketonuria (PKU) is an inborn error of phenylalanine (Phe) metabolism causing, when not treated, blood Phe increases and consequent central nervous system (CNS) damage. Dietary intervention is the main recognized treatment and must be maintained long-life, however adherence is often suboptimal in adulthood. Aim of this study was to evaluate whether and how the pandemic had impacted PKUs metabolic control and what factors may have played a role as potential modifiers. Methods: Patients >4 yo and in follow-up at our Metabolic Clinic were enrolled in this study, divided into subgroups according to age (GROUP A < 12 yo; GROUP B > 12 yo). Videoconsults were conducted on a minimum monthly basis and collected DBS were studied and compared to previous year same time-period in order to evaluate possible changes. Results: 39% of patients (n = 121) increased the number of performed DBS. Non-compliant patients were reduced (11-3%) with a - 14% of patients with mean Phe levels >600 umol/l and a - 8% of patients with 100% DBS above same level. GROUP A maintained substantially unchanged metabolic control among two analyzed time-periods. On the contrary, GROUP B demonstrated significant reductions in mean blood Phe concentrations (p < 0.0001) during the pandemic (mean 454 umol/l, SD +/- 252, vs. 556.4 umol/l, SD +/- 301). Discussion: COVID19 pandemic strongly impacted people's life with lifestyle habits changing consistently. PKU patients had to adapt their dietary restrictions to the new environment they were exposed to and, if younger patients could have been less exposed (meals strictly according to diet plan independently from setting), adolescent and adults strongly reflected the obligation to stay home by showing better metabolic control. Multiple factors could have played a role in that and the availability of teleconsultancy may have contributed allowing easier connections, but our data demonstrate how the pandemic and the environment can strongly impact PKUs adherence to treatment and how removing distance barriers can ameliorate and optimize metabolic compliance.

Automated summary

The COVID19 pandemic had a significant impact on the metabolic control of PKU patients, especially in older patients. During the pandemic, there was a significant reduction in the average blood phenylalanine concentration in PKU patients, with younger patients being less affected and adults showing better metabolic control. This highlights how external factors, such as a pandemic, can influence PKU patients' adherence to treatment and the potential benefits of teleconsultancy in improving metabolic compliance.