Endocrine Abstracts

Background: Low levels of DHEAS, such as <1.04 µmol/l, have been used as a criterion for autonomous cortisol secretion (ACS) in patients with adrenal incidentalomas. Age- and gender-specific cut-off levels could theoretically improve DHEAS as a marker of HPA-axis suppression and as a criterion for ACS.

Objective: We aimed to find cut-off levels of DHEAS that are best associated with HPA-axis suppression and determine whether they are correlated with clinical outcomes.

Methods: We studied 989 patients with adrenal incidentalomas, investigated between 2005 and 2015 at two hospitals in southern Sweden and followed up for 14 years. Patients were divided into 10 groups according to age, separated as age <50, 50-<60, 60-<70, 70-<80 or ≥80 years, and gender.

Results: In patients with ACTH <2.0 pmol/l, DHEAS was <1.04 µmol/l in 0, 14, 10, 22, and 33% of males and in 40, 26, 46, 50, and 100% of females in the described age groups. Therefore, the sensitivity for HPA-axis suppression may be low in males, and females <60 years. ACTH was not related to age in males or females. Therefore, we studied DHEAS levels below the 25th percentile as a marker of HPA-axis suppression. The levels for the different age groups were <2.50, <2.10, <1.20, <0.93, and <0.81 µmol/l in males and <1.10, <1.00, <0.81, <0.81, and <0.81 µmol/l in females and were termed “low DHEAS”. The odds ratio for cortisolDST ≥50 nmol/l was higher for low DHEAS than DHEAS <1.04 µmol/l in males, 1.92 (1.17-3.14) vs 1.59 (0.92–2.76), but was similar in females, 1.73 (1.19-2.51) vs 1.67 (1.17-2.38), adjusted for age. Low DHEAS was associated with pre-existing cardiovascular disease, odds-ratio 1.63 (1.14-2.33) and mortality, relative risk 1.57 (1.14-2.18), both adjusted for gender, age, and smoking.

Conclusion: Age-specific DHEAS is a more appropriate marker of HPA-axis suppression in men but seems not to perform better in females. Furthermore, the proposed age- and gender-specific cut-off levels were associated with pre-existing cardiovascular disease and increased mortality.