Endocrine Abstracts

JOINT3825

Introduction: Connshing syndrome (CS) is characterized by concomitant cortisol excess in patients with primary aldosteronism (PA). There is only one study in the literature on the relationship between CS and thyroid and this study reported that anti-TPO and anti-Tg levels were similar in CS and PA patients and anti-TPO levels increased only in CS patients after adrenalectomy. The aim of this study was to evaluate thyroid autoantibody levels, ultrasonography (USG) features and cyto/histopathology results in CS and to compare the findings with PA and adrenal Cushing’s syndrome patients.

Methods: Between 2019 and 2023, patients admitted to our Endocrinology outpatient clinic and diagnosed with CS, PA or adrenal Cushing’s syndrome were retrospectively reviewed. Patients with PA who also exhibited autonomous cortisol secretion (ACS) were classified as having CSIf any of the 24-hour urinary cortisol, nocturnal salivary cortisol or 1 mg DST values were elevated, the patient was diagnosed with OCS. Demographic data, thyroid autoantibody levels, thyroid function tests, plasma aldosterone, renin activity (PRA) and cortisol levels were recorded. Additionally, chronic thyroiditis and nodules on USG and cyto-histopathological features were documented. All parameters were compared among the three patient groups.

Results: A total of 125 patients with CS (n=21), PA (n=62), and adrenal Cushing’s syndrome (n=42) were included in the study. Thyroid autoantibody levels, autoantibody positivity rates and thyroid function tests were similar among the groups. Plasma aldosterone, PRA and aldosterone/PRA ratios were lower in the Cushing’s syndrome group than in the CS and PA groups, whereas no significant difference was observed between the PA and CS groups. Basal cortisol levels were similar in all groups. No significant differences were found in the presence, number or characteristics of nodules on USG, but chronic thyroiditis was significantly lower in CS (P=0.021). A total of 66 patients had 252 nodules, of which 52 underwent fine-needle aspiration biopsy. The cytologic results of the nodules were similar.

Conclusions: Thyroid autoantibody titers and positivity rates in CS are not different from those in patients with PA and adrenal Cushing’s syndrome, but the appearance of chronic thyroiditis on USG is significantly lower. The groups were similar in other USG features. Prospective studies with a larger number of cases are needed to elucidate the pathophysiologic mechanisms involved in the potential effects of CS on the thyroid.