Hypercortisolism and altered glucose homeostasis in obese patients in the pre-bariatric surgery assessment

Aims: Hypothalamus-pituitary-adrenal axis hyperactivity was suggested to be associated with the metabolic syndrome (MS), obesity and diabetes. The aim of this study was to test whether hypercortisolism was associated with altered glucose homeostasis and insulin resistance, hypertension and dyslipidemia in a homogeneous population of obese patients.

Materials/methods: Retrospective analysis of a set of data about obese patients attending the outpatient service of a single obesity center between January 2013 and January 2020. 884 patients with BMI >30 kg/m² were segregated in two subgroups: patients with urinary free cortisol higher than normal (UFC+; n=129) or within the normal range (UFC-; n=755).

Results: The overall prevalence of UFC+ was 14.6% and double test positivity (morning cortisol >1.8 mcg/dL following overnight dexamethasone suppression test) was detected in 1.0% of patients. Prediabetes (OR 1.74; 95%CI 1.13-2.69; p=0.012) and diabetes (OR 2.03; 95%CI 1.21-3.42; p=0.008) were associated with higher risk of UFC+, also when analysis was adjusted for confounding variables. Conversely, hypertension and dyslipidemia were not related to UFC+. Within the individuals with normal FPG and HbA1c, those with higher estimated insulin resistance (HOMA2-IR) maintained a higher risk of UFC+ (OR 2.84, 95%CI 1.06-7.63; p=0.039) and this relationship was weakened only when the body fat percentage was included into the model.

Conclusions: In obese patients, hypercortisolism was more frequent across the entire spectrum of altered glucose homeostasis including the very early stages; this relation could not be detected for the other criteria of the MS, as waist, hypertension and atherogenic dyslipidemia. This article is protected by copyright. All rights reserved.

Keywords: bariatric surgery; diabetes; hypothalamic-pituitary-adrenal axis; insulin resistance; prediabetes; urinary free cortisol.