How Common Is Hypercortisolism in Patients With Type 2 Diabetes? Risk Factors, Epidemiology, and Making a Diagnosis...

Area of Science:

• Endocrinology
• Metabolic Diseases
• Diabetes Management

Background:

• Hypercortisolism, including mild autonomous cortisol secretion (MACS), is an underdiagnosed contributor to metabolic dysfunction in type 2 diabetes (T2D).
• Overt Cushing syndrome is rare, but MACS is increasingly recognized in high-risk populations.
• Chronic cortisol excess exacerbates insulin resistance, hepatic gluconeogenesis, obesity, hypertension, dyslipidemia, and cardiovascular disease.

Purpose of the Study:

• To highlight the role of hypercortisolism in metabolic dysfunction among patients with T2D.
• To emphasize the utility of targeted case-finding for MACS in specific patient groups.
• To discuss the appropriate use and interpretation of the 1-mg overnight dexamethasone suppression test (DST).

Main Methods:

• Review of emerging evidence on abnormal cortisol suppression in patients with difficult-to-control T2D and resistant hypertension.
• Discussion of current recommendations for targeted case-finding based on clinical phenotypes.
• Emphasis on the 1-mg overnight DST as a practical, inexpensive, and widely available initial screening test.

Main Results:

• Abnormal cortisol suppression on the DST is more frequent in patients with difficult-to-control T2D and resistant hypertension than previously thought.
• High-risk phenotypes for evaluation include persistent hyperglycemia, severe insulin resistance, resistant hypertension, adrenal incidentalomas, and suggestive physical findings.
• Interpretation of the DST requires consideration of confounding factors like obesity, medications, and other medical conditions.

Conclusions:

• Hypercortisolism is a likely contributor to metabolic dysfunction in a subset of T2D patients, especially those with resistant cardiometabolic disease.
• Recognizing high-risk phenotypes and utilizing the DST can improve the identification of patients with treatable cortisol excess.
• Further prospective studies are needed to optimize screening strategies and confirm the benefits of early diagnosis and treatment on long-term cardiometabolic outcomes.