title: Physical activity, obesity, and cognitive impairment among women with systemic lupus erythematosus.
abstract: OBJECTIVE
  To examine relationships of obesity and physical inactivity to cognitive impairment in women with systemic lupus erythematosus (SLE).
  
  
  METHODS
  Body composition was measured with dual x-ray absorptiometry (DXA) for 138 women with SLE. Obesity was defined by total percent body fat. Physical activity was ascertained with the self-reported International Physical Activity Questionnaire; inactivity was defined as expenditure of <600 metabolic equivalent minutes/week. Cognitive function was assessed with a 12-index neuropsychological battery. Impairment was defined as age-adjusted Z scores ≤1.5 SDs below the mean on 1 of 3 of tests completed. Scores were obtained for the total battery and for memory and executive function components. Multivariate analyses examined the relationship of obesity and physical activity, individually and combined, to cognitive impairment, controlling for education, race/ethnicity, disease activity, glucocorticoid use, and depression.
  
  
  RESULTS
  Fifteen percent of subjects were cognitively impaired, 28% were physically inactive, and 50% were obese. Five percent of active women were impaired on the executive function battery compared to 23% of those who were inactive (P = 0.003). Obese women were more likely to be impaired on the total battery (6% versus 23%; P = 0.007) and on the executive function portion (2% versus 19%) than nonobese women. In multivariate analysis, both inactivity and DXA-defined obesity were significantly associated with impairment in executive function (inactivity: odds ratio [OR] 9.4, 95% confidence interval [95% CI] 1.7-52.8; obesity: OR 14.8, 95% CI 1.4-151.0).
  
  
  CONCLUSIONS
  Both obesity and inactivity were significantly and independently associated with impairment in cognitive function. If longitudinal studies show that physical inactivity and obesity are precursors to cognitive impairment, these may become important targets for intervention.
authors.affiliation: University of California, San Francisco, USA. patti.katz@ucsf.edu
authors.forename: Patricia
authors.initials: P
authors.lastname: Katz
authors.forename: Laura
authors.initials: L
authors.lastname: Julian
authors.forename: Mary C
authors.initials: MC
authors.lastname: Tonner
authors.forename: Jinoos
authors.initials: J
authors.lastname: Yazdany
authors.forename: Laura
authors.initials: L
authors.lastname: Trupin
authors.forename: Edward
authors.initials: E
authors.lastname: Yelin
authors.forename: Lindsey A
authors.initials: LA
authors.lastname: Criswell
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology; D015897:Comorbidity; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000453:epidemiology* / Q000503:physiopathology / Q000523:psychology; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D009765:Obesity / Q000150:complications / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D057185:Sedentary Behavior