Endocrine Abstracts

JOINT2438

Background: Alteration of serum inflammation-based scores, used as surrogate markers of systemic inflammation, has been associated with hypercortisolism in recent studies. However, the role of altered circadian rhythm of cortisol in the context of mild autonomous cortisol secretion (MACS) has not been investigated so far.

Aim: To evaluate the association between inflammation-based scores and salivary cortisol daily rhythm in patients with MACS and non-secreting (NS) adrenal tumors.

Methods: We included 85 benign adrenal tumors, classified as NS (n=25) and MACS (n=60) according to the cortisol values after 1 mg dexamethasone suppression test (DST) ≤ or >1.8 mcg/dl, respectively. On an ordinary day, each subject collected saliva samples at the following times: 0700 (awakening), 0715, 0730, 1000, 1230, 1400, 1600, 1930, 2100, and 2300 (bedtime). Salivary cortisol was measured by liquid chromatography–tandem mass spectrometry. The following serum inflammation-based scores were calculated: neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation index (SII; platelet count * NLR). Cortisol AUC (AUC) was used as a surrogate marker to assess overall (0700–2300), morning (0700–1600) and evening (1600–2300) cortisol exposure. Student T-test, Pearson’s correlation and generalized linear models adjusted for sex, age, body mass index, presence of altered glucose metabolism, and smoking status were used to analyze the relationship between serum inflammation-based scores and cortisol measures.

Results: Evening cortisol AUC was positively correlated with post-DST cortisol levels (R=0.23; P=0.037). Cortisol levels at 1930 and 2100, and evening AUC were higher in patients with MACS than in those with NS tumors (P<0.001 for all). NLR and SII were positively associated with cortisol overall (R=0.29, P=0.010), morning (R=0.26, P=0.024) and evening (R=0.29, P=0.009) AUCs, while PLR only directly correlated with evening AUC (R=0.23, P=0.043). Generalized linear models showed that higher post-DST cortisol levels were significantly associated with increased NLR (B=0.160; 95% CI: 0.011–0.308; P=0.035) and reduced LMR (B=−0.160; 95% CI: −0.271 to −0.048; P=0.005). Increasing overall and evening cortisol AUCs were significantly directly associated with NLR (B=0.285, 95% CI: 0.0.059–0.510, P=0.013, and B=0.306, 95% CI: 0.100–0.512, P=0.004; respectively). Additionally, evening cortisol AUC directly associated with SII values (B=0.406, 95% CI: 0.107–0.705, P=0.008). Active smoking showed an independent direct contribution over NLR (P<0.001) and SII (P=0.006).

Conclusion: Cortisol exposure, particularly in the evening, is associated with surrogate markers of increased systemic inflammation in patients with benign adrenal incidentalomas.