Patterns in the Development of Postoperative Diabetes Insipidus after Pituitary Adenoma Resection: A 2016-2019 National Analysis

Abstract Purpose: Postoperative diabetes insipidus (DI) is a known occurrence after pituitary adenoma (PA) resection. It is reported in up to 30% of procedures with associated postsurgical morbidity and prolonged length of stay. This study aimed to evaluate preoperative factors that may be associated with postoperative DI after pituitary tumor resection. Methods: Data from the 2016-2019 National Inpatient Sample (NIS) was analyzed. Diagnosis related group code was used to identify the hospitalizations for PA resection. Comorbidities were defined by the Elixhauser Comorbidity Index given ICD-10 codes. Univariable and multivariable logistic regression models, accounting for sampling design, were built to determine factors associated with postoperative DI. Results: 61,105 PA patients were included; 55,125 patients did not develop DI, whereas 5,980 patients did. Compared to White patients, Black patients (OR=1.47;p<0.001) and Hispanic patients (OR=1.34;p=0.003) experienced increased odds of postoperative DI. Older age was associated with decreased odds of postoperative DI (OR 1-year increase in age=0.98;p<0.001). Hypertension (OR=0.65;p<0.001) was associated with decreased odds of postoperative DI. Neurological disorders (OR=2.65;p<0.001), paralysis (OR=2.38;p<0.001), and hypothyroidism (OR=2.39;p<0.001) were associated with increased odds of postoperative DI. Endoscopic surgery provided no significant advantage to avoiding postoperative DI (p=0.127). Conclusions: Black and Hispanic patients had significantly increased odds of postoperative DI. Further investigation is needed to uncover the source of these disparities. Hypothyroidism and neurological conditions, likely due to tumor characteristics, increased odds of postoperative DI. Finally, this study contributed to the argument that endoscopic approach does not improve postoperative DI risk in the ongoing debate in the literature.