Do Phthalates—Used in Plastics and Make-up—Lead to Diabetes?
Swedish Study Looks at Question in the Elderly Population
Phthalates are used in industrial high-volume chemicals, and they are known as ligands to peroxisome proliferator-activated receptors (PPARs). These PPRA-γ agonists can be used to treat type 2 diabetes because they modulate insulin sensitivity. Because of this connection, researchers recently studied if the circulating levels of phthalate metabolites in the body are related to prevalent diabetes in the elderly population.
The research was done in Sweden, and it was published online April 12, 2012, and will appear in the print in the journal Diabetes Care. The article is “Circulating Levels of Phthalate Metabolites Are Associated With Prevalent Diabetes in the Elderly.”
Using the Prospective Investigation of the Vasculature in Uppsala Seniors Study, researchers looked at 1,016 subjects (age: 70 years). An API 4000 liquid chromatograph/tandem mass spectrometer showed 4 phthalate metabolites circulating in almost all participants’ blood. The subjects were also tested for type 2 diabetes—defined as either fasting plasma glucose of > 7.0 mmol/L or use of pharmacological hypoglycemic agents.
Of the 1,016 patients, 114 had type 2 diabetes. There were adjustments done for sex, BMI, serum cholestoeral and triglycerides, level of education, lifestyle habits (smoking and exercise in particular); after those adjustments, high levels of 3 phthalate metabolites were seen to be associated with a higher prevalence of type 2 diabetes: monomethyl phthalate (MMP) (p < 0.01), monoisobutyl phthalate (MiBP) ( p < 0.05), and monoethyl phthalate (MEP) (p < 0.05).
Mono(2-ethylhexyl) phthalate was not associated with an increased diabetes prevalence.
As a marker of insulin secretion, researchers used the fasting proinsulin-to-insulin ratio; they used the homeostasis model assessment-insulin resistance index s a marker of insulin resistance. Using these 2 markers, MiBP was related to poor insulin secretion, but MEP and MMP were connected to insulin resistance.
This study supports the idea that phthalates may have an impact on major factors that are regulating glucose metabolism—particularly at the level the elderly population is exposed to.