title: Circulating levels of phthalate metabolites are associated with prevalent diabetes in the elderly.
abstract: OBJECTIVE
  Phthalates are ubiquitous industrial high-volume chemicals known as ligands to peroxisome proliferator-activated receptors (PPARs). Because PPAR-γ agonists modulate insulin sensitivity and are used to treat type 2 diabetes, we investigated whether circulating levels of phthalate metabolites are related to prevalent type 2 diabetes.
  
  
  METHODS
  A total of 1,016 subjects, aged 70 years, were investigated in the Prospective Investigation of the Vasculature in Uppsala Seniors Study. Four phthalate metabolites were detected in almost all participant sera by an API 4000 liquid chromatograph/tandem mass spectrometer. Type 2 diabetes was defined as the use of pharmacological hypoglycemic agents or a fasting plasma glucose >7.0 mmol/L.
  
  
  RESULTS
  A total of 114 subjects were shown to have diabetes. Following adjustment for sex, BMI, serum cholesterol and triglycerides, educational level, and smoking and exercise habits, high levels of the phthalate metabolites monomethyl phthalate (MMP) (P < 0.01), monoisobutyl phthalate (MiBP) (P < 0.05), and monoethyl phthalate (MEP) (P < 0.05), but not mono(2-ethylhexyl) phthalate, were associated with an increased prevalence of diabetes. Using the fasting proinsulin-to-insulin ratio as a marker of insulin secretion and the homeostasis model assessment-insulin resistance index as a marker of insulin resistance, MiBP was mainly related to poor insulin secretion, whereas MEP and MMP mainly were related to insulin resistance.
  
  
  CONCLUSIONS
  The findings in this cross-sectional study showed that several phthalate metabolites are related to diabetes prevalence, as well as to markers of insulin secretion and resistance. These findings support the view that these commonly used chemicals might influence major factors that are regulating glucose metabolism in humans at the level of exposure of phthalate metabolites seen in the general elderly population.
authors.affiliation: Department of Occupational and Environmental Medicine, Uppsala University, Uppsala, Sweden. monica.lind@medsci.uu.se
authors.forename: P Monica
authors.initials: PM
authors.lastname: Lind
authors.forename: Björn
authors.initials: B
authors.lastname: Zethelius
authors.forename: Lars
authors.initials: L
authors.lastname: Lind
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology*; D004781:Environmental Exposure; D005260:Female; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology; D000078790:Insulin Secretion; D008297:Male; D008954:Models, Biological; D010795:Phthalic Acids / Q000097:blood*; D015995:Prevalence; D011384:Proinsulin / Q000378:metabolism
chemical_list: D007328:Insulin; D010795:Phthalic Acids; C517284:monomethyl phthalate; D011384:Proinsulin