Plasma cortisol levels in response to a cold pressor test did not predict appetite or ad libitum test meal intake in obese women

Abstract

Heightened cortisol response to stress due to hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis may stimulate appetite and food intake. In this study, we assessed cortisol responsivity to a cold pressor test (CPT) as well as appetite ratings and subsequent test meal intake (TMI) in obese women. Following an overnight fast on two counterbalanced days, 20 obese women immersed their non-dominant hand for 2min in ice water (CPT) or warm water (WW) as a control. Plasma cortisol (ng/ml), heart rate, and blood pressure, as well as ratings of stress, pain, and appetite, were serially acquired. An ad libitum liquid meal was offered at 45min and intake measured covertly. Fasting cortisol was higher at 15min (mean peak cortisol) following the CPT compared to WW. Higher stress was reported at 2 and 15min for the CPT compared to WW. Pain, an indirect marker of the acute stress, systolic and diastolic blood pressure increased following the CPT at 2min compared to WW. Hunger decreased after the CPT at 2 and 15min, and desire to eat ratings were lower following CPT compared to WW. Subjects did not have greater test meal intake (TMI) following CPT compared to WW. There was also no significant relationship between cortisol levels following stress and TMI, indicating that cortisol did not predict subsequent intake in obese women.

Figure 1

Cortisol Prior to and Following a Cold Pressor Test (CPT) and Warm Water (WW) Control Cortisol was serially measured for 120 mins to adequately assess change in levels due to the stressor compared to change related to diurnal variation. The stressor was administered between 0 and 2 min and the test meal was given at 45 min. a) Mean plasma cortisol (± SEM) levels significantly increased following the CPT, between 0 and 15 min whereas cortisol following WW steadily declined from 5 min in all obese women. The decline in cortisol measures before the meal and the rise after food intake in the warm water control are likely secondary to cortisol’s diurnal variation of secretion. † p<0.05, ^††p<0.01, ^†††p<0.001 - change from each respective baseline condition. *p<0.05, ^** p<0.01, ^***p<0.001- difference between CPT and WW control at each time point.