(P18-049-24) Tai Chi Exercise of Short Duration Alters Circulating Oxylipins in Post-menopausal Women With Knee Osteoarthritis

Objectives: Tai Chi (TC) exercise after 56 days alters blood levels of oxylipins (OxL) and endocannabinoids (eCB) in postmenopausal women with knee osteoarthritis. TC also changes brain connectivity in these women. It is not clear if 4 exercise sessions of TC affects inflammatory OxL and eCB which was the study objective in these women.

Methods: Post-menopausal women completed 4 TC sessions on non-consecutive days within 10 days, 60 min/session including 5 min of warmup, 50 min practicing TC, and 5 min of cooldown. Participants learned 10 selected moves from 24-form Yang-style TC in sections designed to allow self-practicing in a short time. Plasma isolated from non-fasting blood draws at baseline and immediately after the 4^th session of TC were analyzed for eCB (e.g., AEA and 2-AG) and OxL using targeted metabolomic methods that preserve 2-AG. Specifically, OxL were isolated by solid phase extraction on 10 mg Oasis-HLB sorbent beds (Waters Corp, Milford, MA), modified for use in a 96 well plate format. Partial least squares discriminant analysis highlighted changes between pre- and post-intervention samples. Paired t-tests with false discovery rate corrections were performed to examine the differences in plasma eCB and OxL.

Results: 19 women (58.9±5.2 years old, BMI: 33.6±5.4 kg/m²) completed the study. After the 4th TC session compared to baseline, several OxL values showed important PLS scores greater than 1.0. Further, the pre- and post-sessions values revealed a shift towards positive X Scores post-sessions. Generally, 1-AG and 12-HETE were lower, and 18:2n6 and 18-HETE higher post-sessions, with PLS scores above 1.0.

Conclusions: In contrast to 8 wk TC, 4 sessions of TC in post-menopausal women had modest impact on AEA and 2-AG, however, effects on OxL were significant. Our findings with TC in self-reported healthy post-menopausal women should now focus on how TC affects 1-AG metabolism (phospholipase C, DAGL-alpha, MGL, FAAH, and the LOX pathways) and roles of substrate dietary PUFA. We report that TC exercise is one approach to minimize pain and improve brain plasticity related to OxL and eCB and dietary PUFA.

Funding Sources: Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock. NIH grant R01NS038261.