title: Perceived fatigue is highly prevalent and debilitating in patients with mitochondrial disease.
abstract: Perceived fatigue is a prominent symptom in patients with mitochondrial disease but to date its prevalence, impact and aetiology are poorly understood. Our aim was to determine the prevalence and assess for comorbidities associated with clinically relevant fatigue in patients with mitochondrial disease. A cross-sectional postal survey of patients with mitochondrial disease was undertaken using a validated self-completion, patient-reported outcome measures (response rate: 60%; n = 132). The prevalence and perceived functional impact of experienced fatigue were assessed using the Fatigue Impact Scale. Other putative biological mechanisms were evaluated using the Hospital Anxiety Depression scale and Epworth sleepiness scale. Data were compared with those for healthy control subjects and patients with Myalgic Encephalopathy/Chronic Fatigue Syndrome matched for age and gender. Sixty-two per cent of patients with mitochondrial disease reported excessive symptomatic fatigue (Fatigue Impact Scale ≥ 40); whilst 32% reported severe, functionally limiting fatigue symptoms (Fatigue Impact Scale ≥ 80) comparable to perceived fatigue in patients with Myalgic Encephalopathy/Chronic Fatigue Syndrome. Fatigue is common and often severe in patients with mitochondrial disease irrespective of age, gender or genotype. Future evaluation of causal factors in mitochondrial disease-associated fatigue is warranted with the potential to guide future treatment modalities.
authors.affiliation: Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Institute of Ageing and Health and NIHR Biomedical Research Centre for Ageing, Newcastle University, Newcastle upon Tyne NE4 5PL, UK. Electronic address: grainne.gorman@ncl.ac.uk.
authors.forename: Gráinne S
authors.initials: GS
authors.lastname: Gorman
authors.affiliation: Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK.
authors.forename: Joanna L
authors.initials: JL
authors.lastname: Elson
authors.affiliation: Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Institute of Ageing and Health and NIHR Biomedical Research Centre for Ageing, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: Jane
authors.initials: J
authors.lastname: Newman
authors.affiliation: Institute of Ageing and Health and NIHR Biomedical Research Centre for Ageing, Newcastle University, Newcastle upon Tyne NE4 5PL, UK; Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK.
authors.forename: Brendan
authors.initials: B
authors.lastname: Payne
authors.affiliation: Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Institute of Ageing and Health and NIHR Biomedical Research Centre for Ageing, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: McFarland
authors.affiliation: Institute of Ageing and Health and NIHR Biomedical Research Centre for Ageing, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: Julia L
authors.initials: JL
authors.lastname: Newton
authors.affiliation: Wellcome Trust Centre for Mitochondrial Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Institute of Ageing and Health and NIHR Biomedical Research Centre for Ageing, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: Douglass M
authors.initials: DM
authors.lastname: Turnbull
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006970:Disorders of Excessive Somnolence / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology; D005221:Fatigue / Q000453:epidemiology* / Q000235:genetics / Q000503:physiopathology; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000453:epidemiology* / Q000235:genetics / Q000503:physiopathology / Q000523:psychology; D018908:Muscle Weakness / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology; D010465:Perception; D015995:Prevalence; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Anxiety; Depression; Fatigue; Mitochondria; Sleep