Addison's disease, or adrenal insufficiency (AI), in the context of type 1 diabetes (T1D) is primarily clinically manifested by recurrent hypoglycemia (RH). Due to the non-specificity of adrenal autoantibodies, the use of baseline cortisol levels (CB) for screening has been suggested as a possible alternative. This study aims to assess the relevance of AI screening through CB in cases of unexplained RH in T1D patients.

This was a retrospective descriptive study. All requests in the year 2023 for CB measurements in T1D patients with unexplained RH were recorded. Thyroid-Stimulating Hormone (TSH) was measured in all patients beforehand.

A total of 121 requests were identified. The diagnostic suspicion was supported by the presence of other clinical and laboratory signs. Melanodermia, hypotension, asthenia, and weight loss were reported in 9%, 6%, 3%, and 3% of cases, respectively. Biochemically, 11.5% of requests were motivated by thyroid dysfunction associated with RH, while hyperkalemia was reported in only 3% of patients. No pathological CB indicative of AI was found. In this cohort, CB was not correlated with blood glucose levels (P=0.167) but significantly correlated with glycemic control (HbA1c), P=0.032.

AIs are rare, and routine screening for them in the context of T1D is not recommended. In practice, the presence of RH in a T1D patient has always posed a diagnostic challenge due to the severity of symptoms and the multitude of possible causes. In this cohort, CB helped rule out the diagnostic suspicion of AI.