Screening for Cushing's syndrome using early morning urine samples

Area of Science:

• Endocrinology
• Metabolic Disorders
• Clinical Chemistry

Background:

• Obesity is a prevalent condition often associated with metabolic and endocrine dysregulation.
• The hypothalamic-pituitary-adrenal (HPA) axis plays a crucial role in stress response and metabolism.
• Assessing urinary free cortisol is a common method for evaluating HPA axis activity.

Purpose of the Study:

• To determine urinary free 11-hydroxycorticosteroid/creatinine ratios (UFC/Cr) in obese subjects.
• To investigate the prevalence of elevated UFC/Cr and its association with endocrine disorders.
• To identify potential cases of Cushing's syndrome among obese patients.

Main Methods:

• Collection of early morning urine samples from 138 obese patients attending endocrine clinics.
• Measurement of urinary free 11-hydroxycorticosteroid/creatinine ratios (UFC/Cr).
• Further investigation of the hypothalamic-pituitary-adrenal axis for patients with abnormal UFC/Cr levels.

Main Results:

• The majority of obese subjects (128/138) exhibited UFC/Cr ratios within the normal non-obese range (5-55 mumol/mol).
• Elevated UFC/Cr ratios were detected in a subset of patients, prompting further HPA axis evaluation.
• Investigations confirmed Cushing's syndrome in 8 patients (6 with bilateral adrenal hyperplasia, 2 with adrenal tumors) and suggested intermittent adrenal hyperactivity in 2 others.

Conclusions:

• While most obese individuals have normal UFC/Cr, elevated ratios warrant further investigation for Cushing's syndrome.
• Urinary free corticosteroid measurements are valuable in diagnosing adrenal hyperactivity in obese populations.
• Early detection of Cushing's syndrome in obese patients is crucial for appropriate management and treatment.