Resection of Pheochromocytoma Improves Diabetes Mellitus in the Majority of Patients.

BACKGROUND

Catecholamine excess in patients with pheochromocytoma often results in impaired glucose tolerance, leading to diabetes mellitus. Little data are available on the long-term effect of surgery on diabetes.

OBJECTIVE

The primary aim of this study was to determine the likelihood of diabetes cure after surgery, while secondary objectives were to determine risk factors for development of diabetes preoperatively and persistence of diabetes postoperatively.

METHODS

All patients undergoing surgery for pheochromocytoma from 1996 to 2015 were retrospectively reviewed to identify those with a preoperative diagnosis of diabetes. Demographic and diabetes-specific data were collected. Median follow-up was 52.1 months.

RESULTS

Overall, 153 patients underwent surgery. Diabetes was seen in 36 (23.4%) patients. Eight patients met the exclusion criteria and were removed from the final analysis, while 22 (78.6%) patients had complete resolution of diabetes. Four patients remained on medication with improved control. Overall, 93.0% of patients had improvement of their diabetes; two patients did not improve. Patients with large, symptomatic tumors were more likely to develop preoperative diabetes, and diabetes was more likely to persist in patients who had an elevated body mass index (BMI).

CONCLUSIONS

Diabetes was found concurrently with pheochromocytoma in 23% of patients, more often in those with large, symptomatic tumors. The majority of patients had long-term resolution of diabetes after successful resection; however, some patients may continue to require treatment of diabetes after operation, especially those with a higher BMI.