Endocrine Abstracts

Introduction: Alternative biofluids such as sweat, which can be obtained non-invasively and present a simpler matrix composition than serum/plasma or urine, may be useful for monitoring biomarkers. The long-term sampling with patches either on the chest or back can be conveniently used under both rest and exercise conditions to provide an integrated response of free biomarkers over the course of a day. The smaller sample volumes generated by sweat collection can be conveniently handled using modern sensitive LC-MS/MS methods (1).

Methods: Sweat samples were collected using 5 x 5 cm non woven patches attached to the subject’s back with Tegaderm patches and left in place for 24 hours. Sweat was extracted from the swab using centrifugation and the filtrate was extracted using liquid liquid extraction. The extract was analysed for cortisol and cortisone using LC-MS/MS. (Waters TQ-XS) and was based on our routine validated salivary cortisol/cortisone method.

Results: The weight of sweat collected ranged from 200-500 mg, in keeping with published sedentary sweat production rates. Cortisone exceeded cortisol concentration by at least 4:1 in agreement with typical results seen in saliva samples.

Conclusions: Sweat contains measurable concentrations of cortisol and cortisone and may provide a convenient non invasive means of monitoring these steroids.

Reference: (1) Nunes MJ. Evaluation of Sweat-Sampling Procedures for Human Stress-Biomarker Detection. Analytica 2022, 3, 178–194.