The recovery time of hypothalamic-pituitary-adrenal axis after curative surgery in Cushing's disease and its related factor.

PURPOSE: Patients with Cushing's disease (CD) experienced transient central adrenal insufficiency (CAI) after successful surgery. However, the reported recovery time of hypothalamic-pituitary-adrenal (HPA) axis varied and the related factors which could affect recovery time of HPA axis had not been extensively studied. This study aimed to analyze the duration of CAI and explore the factors affecting HPA axis recovery in post-operative CD patients with biochemical remission. METHODS: Medical records of diagnosis with CD in Huashan Hospital were reviewed between 2014 and 2020. 140 patients with biochemical remission and regular follow-up after surgery were enrolled in this retrospective cohort study according to the criteria. Demographic details, clinical and biochemical information at baseline and each follow-up (within 2 years) were collected and analyzed. RESULTS: Overall, 103 patients (73.6%) recovered from transient CAI within 2 years follow-up and the median recovery time was 12 months [95% confidence intervals (CI): 10-14]. The age was younger and midnight ACTH at baseline was significantly lower, while the TT3 and FT3 levels were significantly higher in patients with recovered HPA compared to patients with persistent CAI at 2-year follow-up (p < 0.05). In persistent CAI group, more patients underwent partial hypophysectomy. TT3 at diagnosis was an independent related factor of the recovery of HPA axis, even after adjusting for gender, age, duration, surgical history, maximum tumor diameter, surgical strategy, and postoperative nadir serum cortisol level (p = 0.04, OR: 6.03, 95% CI: 1.085, 22.508). Among patients with unrecovered HPA axis at 2-year follow-up, 23 CAI patients (62%) were accompanied by multiple pituitary axis dysfunction besides HPA axis, including hypothyroidism, hypogonadism, or central diabetes insipidus. CONCLUSION: HPA axis recovered in 73.6% of CD patients within 2 years after successful surgery, and the median recovery time was 12 months. TT3 level at diagnosis was an independent related factor of postoperative recovery of HPA axis in CD patients. Moreover, patients coexisted with other hypopituitarism at 2-year follow-up had a high probability of unrecovered HPA axis.