Differential response to cold pressor test in normal weight versus overweight college students is blunted by palatable reward (LB767)

There is increasing evidence that obesity contributes to dysregulation of the hypothalamic pituitary adrenal (HPA) axis; however, the magnitude and direction of dysfunction remains unclear. The objectives of this experiment were to identify differences in non‐stress and stress salivary cortisol concentrations in normal weight (NW) and overweight/obese (OW) college students. Furthermore, we aimed to determine if access to palatable reward differentially blunts activation of the HPA axis in response to a physical stressor. Body mass index (BMI) was calculated and participants were placed in a reward or no reward group. Participants underwent a cold presser test (CPT), placement of the non‐dominant hand into ice water for 90 seconds. The reward group had free access to candy (reward) during the CPT; the control group was not offered candy. Salivary samples were collected before CPT (Pre) and 15 minutes after the start of the CPT (Post). Cortisol was measured by enzyme linked immunoassay (Salimetrics). Pre cortisol was elevated in OW versus NW. CPT without reward increased cortisol in both NW and OW, with OW having a greater increase from Pre than NW. Reward blunted the CPT‐induced cortisol increase similarly in NW and OW. These data suggest that overweight individuals have higher baseline HPA activity and an exaggerated response to physical stress than normal weight individuals; however, effects of reward were similar in both groups.