Nocturnal Hypoglycemia Identified by a Continuous Glucose Monitoring System in Patients with Primary Adrenal Insufficiency (Addison's Disease)

Background: Hypoglycemia can be a symptom in patients with Addison's disease. The common regimen of replacement therapy with oral glucocorticoids results in unphysiological low cortisol levels in the early morning, the time of highest insulin sensitivity. Therefore patients with Addison's disease are at risk for unrecognized and potentially severe nocturnal hypoglycemia also because of a disturbed counterregulatory function. Use of a continuous glucose monitoring system (CGMS) could help to adjust hydrocortisone treatment and to avoid nocturnal hypoglycemia in these patients. Methods: Thirteen patients with Addison's disease were screened for hypoglycemia wearing a CGMS for 3-5 days. Results: In one patient we identified a hypoglycemic episode at 3: 45 a. m. with a blood glucose level of 46mg/dL, clearly beneath the 95% tolerance interval of minimal glucose levels between 2 and 4 a.m. (53.84mg/dL). After the hydrocortisone replacement scheme was changed, the minimum blood glucose level between 2 and 4 a. m. normalized to 87mg/dL. Conclusions: Continuous glucose monitoring can detect nocturnal hypoglycemia in patients with primary adrenal insufficiency and hence prevent in these patients an impaired quality of life and even serious adverse effects.