Abstract
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 30 min 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/m2. 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.
