Han, Ashley JAlexander, Louie CHuebner, Janet LReed, Alexander BKraus, Virginia B2024-02-292024-02-292021-121947-60351947-6043https://hdl.handle.net/10161/30201<h4>Objective</h4>To evaluate effects of physical activity and food consumption on plasma concentrations of free and total transforming growth factor beta-1 (TGF-β1), beta-2 (TGF-β2), and beta-3 (TGF-β3) in individuals with knee osteoarthritis (OA).<h4>Methods</h4>Participants (<i>n</i> = 40 in 2 cohorts of 20; mean age 70 years) with radiographic knee OA were admitted overnight for serial blood sampling. Cohorts 1 and 2 assessed the impacts of food intake and activity, respectively, on TGF-β concentrations. Cohort 1 blood draws included 2 hours postprandial the evening of day 1 (T3), fasting before rising on day 2 (T0), nonfasting 1 hour after rising (T1B), and 4 hours after rising (T2). Cohort 2 blood draws included T3, T0, fasting 1 hour after rising and performing activities of daily living (T1A), and nonfasting 2 hours after rising (T1B). By sandwich ELISAs, we quantified plasma free and total TGF-β1 concentrations in all samples, and plasma total TGF-β2 and TGF-β3 in cohort 2.<h4>Results</h4>Free TGF-β1 represented a small fraction of the total systemic concentration (mean 0.026%). In cohort 2, free and total TGF-β1 and total TGF-β2 concentration significantly increased in fasting samples collected after an hour (T1A) of activities of daily living (free TGF-β1: <i>P</i> = 0.006; total TGF-β1: <i>P</i> < 0.001; total TGF-β2: <i>P</i> = 0.001). Total TGF-β3 increased nonsignificantly following activity (<i>P</i> = 0.590) and decreased (<i>P</i> = 0.035) after food consumption while resting (T1B).<h4>Conclusions</h4>Increased plasma concentrations of TGF-β with physical activity suggests activity should be standardized prior to TGF-β1 analyses.HumansOsteoarthritis, KneeExerciseActivities of Daily LivingAgedTransforming Growth Factor beta1Transforming Growth Factor beta3Journal article