Association among acrylamide, blood insulin, and insulin resistance in adults

OBJECTIVE - Exposure to acrylamide in foodstuffs and smoking has become a worldwide concern. The effect of acrylamide on glucose homeostasis is not known. The goal of the present study was to test the hypothesis that trace acrylamide exposure might be independently associated with both reduced blood insulin and reduced insulin resistance. RESEARCH DESIGN AND METHODS - We examined 1,356 participants with reliable measures of glucose homeostasis and Hb adducts of acrylamide (HbAA) and glycidamide from the National Health and Nutrition Examination Survey, 2003-2004. Glucose homeostasis was assessed by the measurement of plasma glucose, serum insulin, and the homeostasis model assessment of insulin resistance (HOMA-IR). RESULTS - In a linear regression model, a 1-unit increase in log HbAA was associated with a decrease in serum insulin (β coefficient = -0.20 ± 0.05, P = 0.001) and HOMA-IR (β coefficient = -0.23 ± 0.05, P < 0.001). After HbAA concentrations were divided into quartiles in the fully adjusted models, the adjusted serum insulin level and HOMA-IR significantly decreased across quartiles of HbAA (P_trend < 0.001 for both). In subgroup analysis, the association of HbAA levels with HOMA-IR and insulin levels was stronger in subjects who were white or had ever smoked or in subjects with a lower education level or a BMI <25 or >30 kg/m². CONCLUSIONS - Acrylamide is associated with reduced serum insulin levels in adults. Further clinical and animal studies are warranted to clarify the putative causal relationship.