title: Increased plasma levels of toxic pollutants accompanying weight loss induced by hypocaloric diet or by bariatric surgery.
abstract: BACKGROUND
  Weight loss reduces the risk of several diseases. Increases of plasma organochlorine and pesticide compounds, however, have been observed with weight loss induced by a dietary intervention and by a gastroplasty. This increased concentration of toxic pollutants could be a side-effect of weight loss and a risk for health problems. The aim of this study was: 1) to observe if there is a relationship between the plasma concentration of organochlorines and BMI at steady state weight, and 2) to determine, after a bariatric surgical intervention, if the magnitude of the weight loss has a direct effect on this concentration.
  
  
  METHODS
  Weight loss was obtained in obese individuals by a hypocaloric diet program until resistance and in morbidly obese individuals by a bariatric operation (biliopancreatic diversion - duodenal switch [BPD-DS]). Normal-weight individuals were tested to serve as controls. Blood samples were analyzed for organochlorine and pesticide compounds at baseline in all groups, after resistance to weight loss in obese individuals, and at 3 months and 1 year after surgery in morbidly obese individuals.
  
  
  RESULTS
  At steady state weight, organochlorine and pesticide compounds were found in all groups, and the sum of all organochlorine compounds correlated with age and not BMI. Weight loss averaged 12.1% of the initial body weight after dieting and 20.9% at 3 months after surgery, respectively. This weight loss yielded significant increases in total plasma organochlorine concentration (increase of 23.8% for obese and 51.8% for morbidly obese individuals). For morbidly obese individuals, the weight loss at 1 year after surgery (46.3%) yielded a 388.2% increase in total plasma organochlorine concentration.
  
  
  CONCLUSIONS
  Plasma organochlorine concentration increases with weight loss and is related to the magnitude. Future research will have to determine if: 1) this pollutant concentration remains elevated over time and 2) there are long-term effects of this high concentration on health.
authors.affiliation: Department of Social and Preventive Medicine, Laval University, Québec, Canada.
authors.forename: Olivier
authors.initials: O
authors.lastname: Hue
authors.forename: Julie
authors.initials: J
authors.lastname: Marcotte
authors.forename: Félix
authors.initials: F
authors.lastname: Berrigan
authors.forename: Martin
authors.initials: M
authors.lastname: Simoneau
authors.forename: Jean
authors.initials: J
authors.lastname: Doré
authors.forename: Picard
authors.initials: P
authors.lastname: Marceau
authors.forename: Simon
authors.initials: S
authors.lastname: Marceau
authors.forename: Angelo
authors.initials: A
authors.lastname: Tremblay
authors.forename: Normand
authors.initials: N
authors.lastname: Teasdale
mesh_terms: D000328:Adult; D015904:Biliopancreatic Diversion; D015992:Body Mass Index; D031204:Caloric Restriction; D016022:Case-Control Studies; D005500:Follow-Up Studies; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000178:diet therapy / Q000601:surgery; D015431:Weight Loss / Q000502:physiology*
chemical_list: D006843:Hydrocarbons, Chlorinated