Emotional health in early-treated adults with phenylketonuria (PKU): Relationship with cognitive abilities and blood phenylalanine

Abstract

Introduction: Mental health, physical health and cognitive skills have been scarcely investigated in the same sample of adults with PKU (AwPKU). This is striking since emotional difficulties may potentially contribute to cognitive impairments and vice-versa. Here we aim to fill this gap.Method: Thirty-six early-treated AwPKU and 40 controls were given an extensive battery of cognitive tasks assessing complex executive functions, inhibitory control, short -term-memory, sustained attention, visuospatial attention, language production (reading and naming), visuomotor coordination, spoken language and orthographic processing. In addition, participants were given tasks tapping emotion recognition and completed questionnaires to assess depression (BDI-II), empathy (IRI) and mental/physical health-related quality of life (SF-36).Results: As a group, AwPKU performed significantly worse than controls especially in tasks tapping complex executive functions and across tasks when speed was measured but did not differ for emotional-health and physical health. In the PKU group, cognitive measures and measures of physical health-related quality of life were inter-correlated (differently than in the control group), and both measures were associated with metabolic control: better metabolic control, better cognition and better physical health. Instead, cognitive measures and measures of emotional-health/ mental-health related quality of life did not correlate with one another and better metabolic control was not associated with better emotional health. Instead, some negative correlations were found. Better metabolic control was associated with worse perspective taking and more distress in socially stressful situations. Furthermore, difficulties in keeping the diet were associated with less emotional well-being.Conclusions: Taken together, these results indicate the advantages, but also possible emotional difficulties related to maintain a PKU diet, suggesting the importance of developing alternative therapy options.

A non-interventional observational study to identify and validate clinical outcome assessments for adults with phenylketonuria for use in clinical trials

“…Although the relationship between metabolic control and PKU-associated neuropsychological comorbidities requires further studying, a recent study demonstrated the correlation between blood Phe levels >360 μmol/L and neuropsychological symptoms arguing for lifelong metabolic control [15] . Nevertheless, these mental health problems may not only be attributed to elevated blood Phe levels but also to the burden of diet and stress related to living with a chronic disease, impairing the QoL of adults living with PKU [5] , [9] , [18] , [19] , [33] . As the burden of diet among other PKU-specific QoL domains are not considered in generic HRQoL questionnaires, a PKU-specific QoL questionnaire (PKU-QOL) was previously developed to understand the impacts of PKU and its treatment on the emotional, social, and physical aspects of patients with PKU [34] .…”

“…As adults with PKU often become lost-to-follow-up, most observational or prospective studies are including patients with relatively good metabolic control who are generally more engaged and likely to participate in clinical studies [6] , [33] , [38] , [39] . Accordingly, the patient sample interviewed in this study was biased by including patients who were regularly seen at clinic.…”

Dietetic Management of Adults with Phenylketonuria (PKU) in the UK: A Care Consensus Document

“…Those with late-treated PKU are more likely to require special community care packages [ 5 ]. The burden of dietary treatment to individuals and carers cannot be underestimated [ 6 , 7 , 8 , 9 ].…”

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

“…Bilder et al [ 4 ] also showed that rates of autism spectrum disorders and eating disorders are significantly higher in the adult PKU population compared to the general population, similarly for rates of depression and anxiety in the overall PKU population [ 7 , 8 ]. Jahja et al [ 9 ] reported that adolescent and adult PKU patients demonstrated poorer social cognition and had poorer social skills than controls, with a tendency towards lower or delayed autonomy [ 10 ] and emotional difficulties related to maintaining a PKU diet [ 11 ]. Moreover, patients often feel social isolation and limits on socialisation [ 12 ], with many of them identified as having significant neurocognitive, mental health and general health problems [ 7 , 10 , 13 , 14 ].…”