Development of a validated uv-vis spectrophotometric method to quantify cortisol in saliva samples of young and middle adults

Background: Cortisol quantification is important in clinical practice to measure periods of stress. The cortisol test is used to diagnose adrenal gland disorders. These include Cushing's syndrome, which causes the body to make too much cortisol, and Addison's disease, which causes the body to not make enough cortisol. Objective: In this work was to develop a validated UV/Vis spectrophotometric method to quantify cortisol in saliva samples from subjects whose ages ranged from 18 to 24 (25 women and 10 men) and ranged from 45 to 55 years old (8 women and 7 men). Methods: For the experimental study, a saliva sample was taken in the first hours of the morning (1.5 mL). The sample was homogenized and read at an absorbance of 280 nm using diluted saliva as a control and carrying out an extraction with ethanol and trichloroacetic acid to identify cortisol. Results: This method was linear (r = 0.9999) for an interval of 2.5 to 25 µg/mL, accurate, precise (variation coefficients of repeatability and reproducibility were less than 1.5%, andless than 2%, respectively). it is specific and with limits of detection and quantification of 0.019 µg/mL and 0.16 µg/mL. The concentration in young people was 52.58  8.59 g/dL (women) and 49.75  7.65 g/dL (men); in older adults 38.83  2.82 g/dL (women) and using this method 25.76 g/dL (men). Conclusion: This method shows to be specific and sensitive with limits of detection and quantification of 0.019 µg/mL and 0.16 µg/mL, respectively. Cortisol average concentration found using this method was higher in young people (women= 52.58  8.59 g/dL and men= 49.75  7.65 g/dL) than in older adults (women= 38.83  2.82 and men= 25.76 g/dL).