title: Obesity in adolescents with chronic fatigue syndrome: an observational study.
abstract: OBJECTIVE
  Identify the prevalence of obesity in patients with chronic fatigue syndrome (CFS) compared with healthy adolescents, and those identified with CFS in a population cohort.
  
  
  METHODS
  Cross-sectional analysis of multiple imputed data.
  
  
  METHODS
  Data from UK paediatric CFS/myalgic encephalomyelitis (CFS/ME) services compared with data collected at two time points in the Avon Longitudinal Study of Parents and Children (ALSPAC).
  
  
  METHODS
  1685 adolescents who attended a CFS/ME specialist service between 2004 and 2014 and 13 978 adolescents aged approximately 13 years and 16 years participating in the ALSPAC study.
  
  
  METHODS
  Body mass index (BMI) (kg/m2), sex-specific and age-specific BMI Z-scores (relative to the International Obesity Task Force cut-offs) and prevalence of obesity (%).
  
  
  RESULTS
  Adolescents who had attended specialist CFS/ME services had a higher prevalence of obesity (age 13 years: 9.28%; age 16 years: 16.43%) compared with both adolescents classified as CFS/ME in ALSPAC (age 13 years: 3.72%; age 16 years: 5.46%) and those non-CFS in ALSPAC (age 13 years: 4.18%; age 16 years: 4.46%). The increased odds of obesity in those who attended specialist services (relative to non-CFS in ALSPAC) was apparent at both 13 years (OR: 2.31 (1.54 to 3.48)) and 16 years, with a greater likelihood observed at 16 years (OR: 4.07 (2.04 to 8.11)).
  
  
  CONCLUSIONS
  We observed an increased prevalence of obesity in adolescents who were affected severely enough to be referred to a specialist CFS/ME service. Further longitudinal research is required in order to identify the temporal relationship between the two conditions.
authors.affiliation: School of Social & Community Medicine, University of Bristol, Bristol, UK.
authors.forename: T
authors.initials: T
authors.lastname: Norris
authors.affiliation: NIHR Bristol Biomedical Research Unit in Nutrition and University of Bristol, Bristol, UK.
authors.forename: K
authors.initials: K
authors.lastname: Hawton
authors.affiliation: NIHR Bristol Biomedical Research Unit in Nutrition and University of Bristol, Bristol, UK.
authors.forename: J
authors.initials: J
authors.lastname: Hamilton-Shield
authors.affiliation: Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: E
authors.initials: E
authors.lastname: Crawley
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D015673:Fatigue Syndrome, Chronic / Q000150:complications* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D063766:Pediatric Obesity / Q000150:complications* / Q000453:epidemiology; D015995:Prevalence; D006113:United Kingdom / Q000453:epidemiology
keywords: ALSPAC; CFS/ME; Obesity; Observational