The ovarian cycle may influence the exhaled volatile organic compound profile analyzed by an electronic nose.

INTRODUCTION: We aimed to investigate whether the sex hormone profile during the ovarian cycle in healthy women could affect the volatile organic compound (VOC) profile analyzed by an electronic nose (e-nose).

METHODS: We enrolled 21 healthy, never-smoking, regularly menstruating women who were not taking any medications. A series of exhaled breath measurements were performed on all subjects at predefined intervals (days 1-6, 7-12, 13-19, 20-25 and 26-31; day 1 was the first day of menstruation) during their ovarian cycle and analyzed by an e-nose (Cyranose 320).

RESULTS: By principal component analysis, significant modifications of the exhaled VOC profile were observed over the cycle for principal component 1 (PC1; p = 0.001). In particular, the PC1 value was significantly higher during the premenstrual period and during menstruation compared with the first third of estrogen phase, mid-cycle and the first third of progestational phase (for all parameters p < 0.05 and p < 0.01, respectively). Subsequent linear discriminant analysis confirmed the above findings.

CONCLUSIONS: The ovarian cycle may alter the exhaled VOC pattern and this should be taken into account during serial measurements of these markers in the female population.