Salivary cortisol increases after bariatric surgery in women.

Cortisol increases have been associated with psychological and physiological stress; however, cortisol dynamics after weight loss (bariatric) surgery have not been defined. Obese participants not using exogenous glucocorticoids were eligible to participate. Female participants (n=24) provided salivary cortisol samples at bedtime, upon awakening the following morning, and 30min after awakening before, and at 6 or 12 months after bariatric surgery. The Medical Outcomes Study Short Form-12 version 2 questionnaire regarding health-related quality of life was also completed. Preoperatively, mean body mass index was 45.1 ±8.1 kg/ m 2 . Mean late night (1.8 ± 1.1 nmol/l), awakening (10.7 ± 7.4 nmol/l), and after-awakening (11.5 ± 7.9 nmol/l) salivary cortisol values were within normal ranges. The cortisol awakening response (mean 21.1 ± 79.7%, median 13.7 %) was at the low end of normal. Preoperatively, participants had lower mental and physical health-related quality of life scores than US adult norms (p<0.001). Salivary cortisol was not correlated with measures of health-related quality of life. Mean BMI decreased over time (p<0.001) and participants experienced improved physical and mental health-related quality of life (p≤0.011). Postoperative late night salivary cortisol was not different from preoperative values. Awakening and after-awakening cortisol levels were higher than preoperative values (15.3 ± 7.7 nmol/l, p = 0.013; 17.5 ± 10.2 nmol/l, p=0.005; respectively), but the cortisol awakening response was not changed (mean 26.7 ± 66.2%; median 7.8%). Morning salivary cortisol increased at long-term follow-up after bariatric surgery. Although self-evaluated mental and physical health improved after surgery, the cortisol awakening response is at the low end of normal, which may indicate continued physiological stress.