Clinical characteristics and cardiometabolic association of non-suppressed cortisol after dexamethasone suppression test in patients with pheochromocytoma

OBJECTIVE: Catecholamine excess in pheochromocytoma may contribute to elevated serum cortisol concentration. However, the clinical characteristics and cardiometabolic effects of concurrent non-suppressed cortisol concentration remain unclear. DESIGN: Retrospective multicenter cohort study. MATERIALS AND METHODS: Among 806 patients with pheochromocytoma from 5 tertiary centers, 389 who underwent a 1-mg overnight dexamethasone suppression test (ODST) were included. Non-suppressed cortisol was defined as a post-ODST cortisol concentration >1.8 μg/dL. Clinical and tumor characteristics were compared between patients with and without non-suppressed cortisol. Correlations between post-ODST cortisol concentration and catecholamine concentrations were analyzed. Logistic regression analyses identified factors associated with type 2 diabetes mellitus (T2DM) and hypertension (HTN). RESULTS: Non-suppressed cortisol was identified in 144 patients (37.0%). Despite comparable body mass index (BMI) (22.9 vs. 23.6 kg/m2, P = .050), patients with non-suppressed cortisol had more frequent HTN (61.1% vs. 46.1%, P = .004) and T2DM (31.3% vs. 17.1%, P = .001), larger tumors (4.0 vs. 3.6 cm, P = .021), and more frequent bilaterality (9.7% vs. 4.1%, P = .026). Post-ODST cortisol concentration was positively correlated with plasma metanephrine (r = 0.148, P = .011) and normetanephrine (r = 0.141, P = .016). Non-suppressed cortisol was independently associated with T2DM (odds ratio [OR] = 2.072; 95% confidence interval [CI] = 1.137-3.777; P = .017) and HTN (OR = 1.905; 95% CI = 1.079-3.361; P = .026). CONCLUSIONS: Larger tumor size, bilaterality, and higher plasma metanephrine and normetanephrine levels were associated with non-suppressed post-ODST cortisol. Post-ODST cortisol >1.8 μg/dL in patients with pheochromocytoma was independently linked to a higher prevalence of T2DM and HTN, suggesting an additive cardiometabolic burden.