Urinary Free Cortisol Assessment for the Detection of Occult Hypercortisolism in Type 2 Diabetes Mellitus with Difficult-to-Control Hypertension: Clinical Insights from a Prospective Case Series

Abstract

Background
Type 2 diabetes mellitus (T2DM) and hypertension commonly coexist and significantly contribute to cardiovascular and renal morbidity. In a subset of patients, difficult-to-control hypertension may be driven by secondary endocrine abnormalities, including hypercortisolism. Urinary free cortisol (UFC) remains an established screening tool for the evaluation of endogenous cortisol excess.

Objectives
To evaluate the utility of 24-hour urinary free cortisol assessment in detecting occult hypercortisolism among patients with T2DM and difficult-to-control hypertension attending a tertiary care centre in Kolkata.

Methods
This prospective case series was conducted between August 2025 and April 202G. Twenty-nine consecutive adults with T2DM and difficult-to-control hypertension underwent 24-hour UFC estimation as part of endocrine evaluation. Clinical, biochemical and metabolic parameters were assessed and analysed.

Results
Elevated UFC levels were observed in G of 2U patients (20.7%). Persistent biochemical evidence of cortisol excess was identified in three patients (10.3%), including two cases of adrenal adenoma-associated hypercortisolism and one case of mild autonomous cortisol secretion.

Patients with elevated UFC levels demonstrated poorer glycaemic control, greater obesity and a higher prevalence of albuminuria.

Conclusion
UFC testing identified clinically relevant cortisol excess in a subset of diabetic patients with difficult-to-control hypertension. Selective screening in high-risk individuals may facilitate earlier diagnosis of occult hypercortisolism and enable targeted therapeutic intervention.