Inclusion Criteria- Male patients
- Age of 18 years or older.
Exclusion Criteria- Female sex.
- Patients for whom a hair sample of at least 3cm from vertex posterior cannot be obtained.
- Hemorrhagic stroke.
- Documented atrial fibrillation or flutter during admission or at any time in the past.
- Use of inhaled, systemic or topical corticosteroids at study initiation, or during the previous 12 months.
- Disorders associated with disruption of HPA axis (Cushing syndrome, Addison syndrome).
- Bleaching or use of artificial hair color.
- Inability to sign informed consent.
- Morbid obesity (BMI > 35).