Pre-Surgery Cortisol Levels as Biomarker of Evolution after Bariatric Surgery: Weight Loss and Weight Regain

Abstract

Bariatric surgery; Morning serum cortisol; Weight loss

Cirugía bariátrica; Cortisol sérico matutino; Pérdida de peso

Cirurgia bariàtrica; Cortisol sèric matinal; Pèrdua de pes

Background: Bariatric surgery (BS) is effective for achieving significant weight loss. However, weight regain (WR) is an emerging problem. Objective: To assess the prognostic value of morning serum cortisol, a 1 mg dexamethasone suppression test (DST), 24 h urinary free cortisol (UFC) and late-night salivary cortisol (LNSC) in a cohort of patients with severe obesity (pwSO) undergoing BS in terms of weight loss and WR. Methods: Patients scheduled for BS underwent the following procedures at baseline, 12 months and 24 months after BS: medical history, anthropometric data, blood analysis and cortisol tests. We evaluated total weight loss (TWL) ≥ 30% at 1 year and WR after 2 years as an increase of ≥10% of the maximum weight lost. Results: In total, 142 subjects were included; 101 (71.1%) were females and the mean age was 45.9 ± 9.2 years. Up to 76.8% of subjects achieved ≥30% TWL, without statistically significant differences in DST results or morning serum cortisol, UFC or LNSC levels. However, a higher pre-surgery morning serum cortisol level was a significant predictor of a WR ≥ 10% (cortisol 17.8 [IQR 13.1-18.5] vs. 12.0 [IQR 8.8-15.8] μg/dL; p < 0.01); OR of 1.216 (95% CI 1.069-1.384); AUC [0.761, CI: (0.616-0.906); p < 0.01]. A cut-off value of cortisol > 13.0 μg/dL was predictive of a WR ≥ 10% (sensitivity 0.71; specificity 0.63). Conclusions: No cortisol test was useful in predicting weight loss; however, the pre-surgery morning serum cortisol level was able to predict a WR ≥ 10% in a cohort of pwSO 2 years after BS. A cut-off value of cortisol > 13 μg/dL might be an easy tool to identify patients at higher risk of WR, enabling healthcare providers to implement tailored, long-term strategies to minimize this outcome.

The study was conducted in accordance with the Declaration of Helsinki, and the protocol approved by the Ethics Committee of the Hospital Universitari Vall d’Hebron, Barcelona, PR(AG)320/2018 on 18 July 2019.