title: Excess Body Weight during Childhood and Adolescence Is Associated with the Risk of Multiple Sclerosis: A Meta-Analysis.
abstract: Several epidemiological studies have reported the association between obesity and multiple sclerosis (MS).
  
  
  
  A literature search of the observational studies, published as original articles in English before December 2015, was performed using electronic databases.
  
  
  
  Five observational studies were included, of which 3 were case-control studies and 2 were cohort studies. The pooled relative risk (RR) for overweight and obesity during childhood and adolescence compared with normal weight (body mass index = 18.5-24.9 kg/m2) was 1.44 (95% CI 1.22-1.70) and 2.01 (95% CI 1.63-2.48), respectively. In subgroup analyses, we found that excess body weight during childhood and adolescence increased the risk of MS in the female group (overweight: pooled RR = 1.62, 95% CI 1.35-1.94; obesity: pooled RR = 2.25, 95% CI 1.77-2.85), but not in the male group (overweight: pooled RR = 1.19, 95% CI 0.91-1.55; obesity: pooled RR = 1.22, 95% CI 0.79-1.90).
  
  
  
  Excess body weight during childhood and adolescence was associated with an increased risk of MS; severe obesity demonstrated a stronger risk. A statistically significant association was found in the female group, but not in the male group.
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, Shijiazhuang, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Yu
authors.forename: Ying-Li
authors.initials: YL
authors.lastname: Liu
authors.forename: Su-Fen
authors.initials: SF
authors.lastname: Qi
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Zhao
authors.forename: Dian-Wu
authors.initials: DW
authors.lastname: Liu
authors.forename: Qing-Bao
authors.initials: QB
authors.lastname: Tian
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000453:epidemiology*; D064887:Observational Studies as Topic; D050177:Overweight / Q000453:epidemiology*; D063766:Pediatric Obesity / Q000453:epidemiology*; D012307:Risk Factors