SUN-471 Hypercortisolism Assessment In Patients With Renal Impairment

Abstract Disclosure: O. Mushtaq: None. M.G. Lange: None. Q. Yousuf: None. M. Sathiavageeswaran: None. J. Waldron: None. G. Powner: None. C. Schiteanu: None. F.W. Hanna: None. Introduction: Chronic kidney disease (CKD) and autonomous hypercortisolism have significant phenotypic overlap sharing features of hypertension (HTN), insulin resistance, dyslipidaemia and fatigue. Moreover, alteration of renal cortisol metabolism and hyperactivation of the hypothalamic-pituitary axis (HPA) in CKD can result in hypercortisolism. Adrenal incidentaloma workup includes evaluation for hypercortisolaemia. Patients with co-existing CKD pose a diagnostic challenge due to the risk of confounding results and overlapping phenotype. Case Report 1: 71-year-old female with a background of CKD-5 (hypertensive and IG-A nephropathy) requiring haemodialysis, angina, pre-diabetes, was referred to Endocrinology for assessment of a radiologically benign (27mm), left adrenal incidentaloma, identified during renal transplant workup. (All values are in nmol/l) Overnight Dexamethasone test (ONDST)-119(<50) 2 Days low dose dexamethasone suppression test (LDDST) Not undertaken due to dialysis timings.Nocturnal Salivary cortisol - 3.3, 5.2, 5.4(<2.6)& Salivary Cortisone - 16.7, 22.6, 22.9(<18) Management plan included monitoring of salivary cortisol and cortisone in 6 months’ time then subsequent annual follow up. Case Report 2: 75-year-old male with background of hypertension and dyslipidaemia, presented with acute dyspnoea. He was treated for pulmonary oedema and kidney injury requiring long-term dialysis. Left sided 5.2cm adrenal incidentaloma was identified during renal workup leading to discussion in Adrenal MDT with plan for hormonal workup. ONDST- 332 LDDST- 549 &164Dexamethasone levels- >16(Adequate bioavailability)Nocturnal Salivary cortisol- 2.2, <1.6, <1.6(x3 samples) 24hour urine cortisol (UFC) (Volume 2.3L)- 37(0-129)(Despite failed ONDST and LDDST) Conservative management versus surgery were discussed with the patient who opted for conservative approach. Discussion: There are no specific guidelines regarding hypercortisolism assessment in CKD and dialysis patients. There is failure to fully suppress to dexamethasone confounding the results of ONDTS and LDDST. Urinary cortisol could be false negative given the reduced cortisol filtration with CKD. Nocturnal Salivary cortisol/cortisone may provide a better method compared to the ONDST and UFC despite documented attenuated dipping reported with CKD. Larger studies are needed to obtain CKD-aligned nocturnal salivary cortisol/cortisone values. Presentation: Sunday, July 13, 2025