Prenatal Stress and Stress Coping Style Interact to Predict Metabolic Risk in Male Rats

Abstract

Both prenatal stress (PNS) exposure and a passive stress-coping style have been identified as risk factors for insulin resistance in rats. In the current study, we test the hypothesis that PNS and stress-coping style may interact in predicting susceptibility for metabolic disease. To test this hypothesis, adult male control and PNS offspring were behaviorally characterized using a defensive burying test to have either a passive or proactive stress-coping style. In adulthood, all rats were fed either a standard chow or a high-fat diet for 3 weeks. After 3 weeks of diet exposure, glucose and insulin levels were assessed during an oral glucose tolerance test. Under high-fat diet conditions, PNS rats display elevated glucose and insulin responses to the oral glucose tolerance test, indicative of glucose intolerance. Interestingly, these effects of PNS were far more pronounced in rats characterized by a passive stress-coping style. Additionally, the passively coping PNS rats also gained more weight on the high-fat diet than all other rats tested. This observation suggests that a stressful prenatal environment in combination with a passive stress-coping strategy may prime an individual to be sensitive to diet-induced obesity and type 2 diabetes.