Cyclic Change of Fatty Acid Composition in Meibum During the Menstrual Cycle

• Published in: Investigative ophthalmology & visual science Vol. 60; no. 5; pp. 1724 - 1733
• Main Authors: Suzuki, Tomo, Fujiwara, Satoshi, Kinoshita, Shigeru, Butovich, Igor A
• Format: Journal Article
• Language: English
• Published: United States The Association for Research in Vision and Ophthalmology 01.04.2019
• Subjects: Cornea
• ISSN: 1552-5783; 0146-0404; 1552-5783
• DOI: 10.1167/iovs.18-26390

To evaluate the fatty acid (FA) composition in the meibum of pre- and postmenopausal women and age-matched men. This prospective study involved 24 healthy subjects; six premenopausal women in their 30s with a regular menstrual cycle (young-female [yF] group), six postmenopausal women in their 60s (elderly-female [eF] group), and 12 age-matched men (i.e., young-male [yM] and elderly-male [eM] groups, respectively). The menstrual cycle was divided into six phases (phase I-VI). Meibum was obtained from the meibomian gland orifices via a Daviel spoon, and its FA composition was then analyzed via gas chromatography mass spectrometry (GC-MS). Principal component analysis (PCA) was performed on the GC-MS results. The mean FA composition of all subjects was 40% saturated FAs (SFA) and 60% unsaturated FAs (UFAs). The PCA results of all groups indicated two categories (PC1 [77.5%] and PC2 [12.4%]); one consisting of yF-group samples of mainly phase II and III and the other consisting of the yF-group samples of the rest of the cycle, as well as from eF-group, yM-group, and eM-group samples. Each group had a distinctive nature. The FAs that most contributed to PC1 were C14:0, C16:0, and C18:0 in a positive correlation, and C18:1n9 in a negative correlation. FA composition noticeably changes during the menstrual cycle and is somewhat affected by sex and age. The ratio of SFAs (C16:0, C18:0) to mono-UFAs (C18:1n9) in the FA composition might have an impact on the lipid quality of meibum, thus suggesting alteration of its melting temperature and viscosity.