No Effect of Caloric Restriction on Salivary Cortisol Levels in Overweight Men and Women

作者：Tam Charmaine S; Frost Elizabeth A; Xie Wenting; Rood Jennifer; Ravussin Eric; Redman Leanne M^*

来源：Metabolism-Clinical and Experimental, 2014, 63(2): 194-198.

DOI：10.1016/j.metabol.2013.10.007

• Cortisol
• Obesity
• Calorie restriction
• Weight loss

Objective. The effect of weight loss by diet or diet and exercise on salivary cortisol levels, a measure of hypothalamic pituitary adrenal activity, in overweight individuals is not known. The objective was to test the hypothesis that 24 weeks of moderate caloric restriction (CR) (25%) by diet or diet and aerobic exercise would alter morning and diurnal salivary cortisol levels.
Design and Setting. Randomized control trial in an institutional research center.
Participants. Thirty-five overweight (BMI: 27.+/- 8 0.7 kg/m(2)) but otherwise healthy participants (16 M/19 F).
Intervention. Participants were randomized to either calorie restriction (CR: 25% reduction in energy intake, n = 12), calorie restriction + exercise (CR + EX: 12.5% reduction in energy intake + 12.5% increase in exercise energy expenditure, n = 12) or control (healthy weight-maintenance diet, n = 11) for 6 months.
Main outcome measure. Salivary cortisol measured at 8:00, 8:30, 11:00, 11:30, 12:30, 13:00, 16:00 and 16:30. Morning cortisol was defined as the mean cortisol concentration at 08:00 and 08:30. Diurnal cortisol was calculated as the mean of the 8 cortisol measures across the day.
Results. In the whole cohort, higher morning and diurnal cortisol levels were associated with impaired insulin sensitivity (morning: P = 0.004, r(2) = 0.24; diurnal: P = 0.02, r(2) = 0.15). Using mixed model analysis, there was no significant effect of group, time or sex on morning or diurnal cortisol levels.
Conclusion. A 10% weight loss with a 25% CR diet alone or with exercise did not impact morning or diurnal salivary cortisol levels.

• 出版日期2014-2