Bisphenol A and Muscle Insulin Sensitivity

This study examine oral bisphenol A consumption on muscle insulin sensitivity and hepatic glucose suppression. Half of the participants will receive a diet plus BPA and the other half will receive a diet plus no bisphenol A.

Evidence linking bisphenol A exposure with diabetes risk remains mainly associative in nature, and mechanism linking bisphenol A to type 2 diabetes remains unclear. The investigator's preliminary data suggests that in young adults, single oral BPA consumption significantly decreased glucose, insulin, and C-Peptide responses to an oral glucose tolerance test, suggesting that immediate consumption of bisphenol A has an effect on muscle insulin sensitivity, hepatic glucose suppression and/or digestion and absorption to lower blood glucose, insulin, and C-Peptide concentrations. The present experimental study evaluating the effects of bisphenol A over several days on the pathogenesis of type 2 diabetes will directly assess each of these potential mechanisms using gold standard measures (euglycemic hyperinsulinemic clamp technique and hepatic glucose suppression with glucose stable isotope infusion, and fecal microbiota).

This experimental study is a 2-group randomized, clinical trial comparing a 4-day energy balance diet plus oral BPA consumption at 50 ug/kg body weight (Diet+BPA) vs. 4-day energy balance diet plus oral placebo consumption (Diet+No BPA). Forty participants will be randomized to Diet+BPA and Diet+No BPA and will reside in a supervised environment at Cal Poly's sleep research facilities for 6 days (2-day baseline run-in, followed by 4-day treatment). Main outcome measures (muscle insulin sensitivity and hepatic glucose suppression) will be assessed at baseline and treatment periods.

This study will be a double-blinded study. Research staff collecting data and participants will not know treatment allocation.

Three hour euglycemic hyperinsulinemic clamp technique with stable glucose isotope infusion to determine rate of glucose disposal

Inclusion Criteria: non-dieting sedentary (≤3 hour/week of aerobic exercise) normal-weight (BMI = 18.5 to 24.9 kg/m2) weight-stable for the previous 6 months free of any metabolic or chronic disease non-smoking, and sedentary Exclusion Criteria: Hemoglobin A1C based on the American Diabetes Association guidelines of 5.7 to 6.4% (Prediabetes) or >6.4% (Diabetes) impaired glucose tolerance type 1 diabetes type 2 diabetes colitis or any inflammatory bowel condition neurologic or psychiatric conditions smoking special diets (e.g. vegetarian, low-carbohydrate, Paleolithic, etc.) pregnant women or women trying to become pregnant

De-identified individual participant data for all primary and secondary outcome measures will be made available.

Data access will be freely available for download on the Cal Poly Digital Commons website. Requestors will be required to sign a data access agreement.