What is the relationship between Addison's disease and Type 1 Diabetes Mellitus (Type 1 DM)?

From the Guidelines

Addison's disease is associated with Type 1 Diabetes Mellitus (Type 1 DM) as people with Type 1 DM are at increased risk for other autoimmune diseases, including primary adrenal insufficiency (Addison disease).

Relationship Between Addison's Disease and Type 1 DM

• The association between Addison's disease and Type 1 DM is due to the autoimmune nature of both conditions, with Type 1 DM resulting from cell-mediated autoimmune destruction of the pancreatic b-cells 1.
• People with Type 1 DM are prone to other autoimmune disorders, including Hashimoto thyroiditis, Graves disease, celiac disease, Addison disease, vitiligo, autoimmune hepatitis, myasthenia gravis, and pernicious anemia 1.
• The high prevalence of autoimmune diseases in people with Type 1 DM highlights the importance of comprehensive medical evaluation and assessment of comorbidities, including screening for thyroid dysfunction and celiac disease 1.
• While the exact mechanisms underlying the association between Addison's disease and Type 1 DM are not fully understood, it is clear that people with Type 1 DM are at increased risk for developing other autoimmune diseases, including primary adrenal insufficiency (Addison disease) 1.

From the Research

Relationship Between Addison's Disease and Type 1 Diabetes Mellitus

The relationship between Addison's disease and Type 1 Diabetes Mellitus (Type 1 DM) is characterized by their co-occurrence in autoimmune polyendocrine syndromes (APSs) 2. Key aspects of this relationship include:

• Addison's disease can occur simultaneously with Type 1 DM in defined syndromes with distinct pathophysiology and characteristics, such as APS-1 and APS-2 2.
• The combination of autoimmune adrenal insufficiency with autoimmune thyroid disease and/or Type 1 DM defines APS-2 2.
• Continuous glucose monitoring (CGM) can suggest adrenal insufficiency in patients with Type 1 DM, particularly in cases of recurrent hypoglycemic episodes at dawn and reduced insulin requirement 3.
• Addison's disease can be initially symptomless and characterized by slow progression up to acute adrenal crisis, which represents a potentially life-threatening condition 3, 4.

Clinical Implications

The co-existence of Addison's disease and Type 1 DM can lead to:

• Challenges in acute clinical management, including the risk of hypoglycemia and diabetic ketoacidosis 4, 5.
• Increased risk of premature death due to diabetic complications and cardiovascular disease 5.
• Treatment challenges, including the need to balance and synchronize insulin and glucocorticoid replacement therapies 5.
• Deterioration of glycemic control and increased rate of hypoglycemia 6.

Screening and Management

Screening for autoimmune diseases, such as Addison's disease, is important in patients with Type 1 DM, as it can help identify patients at higher risk of developing these conditions 6. Management strategies for patients with both Addison's disease and Type 1 DM include:

• Insulin and glucocorticoid replacement therapies 5.
• Periodic and careful evaluation of CGM data to suspect adrenal insufficiency 3.
• Balancing and synchronizing insulin and glucocorticoid replacement therapies to minimize the risk of hypo- and hyperglycemia and diabetic ketoacidosis 5.