Stewart, Laura K.
College of Natural and Health Sciences; Sport and Exercise Science: Exercise Physiology
University of Northern Colorado
Type of Resources
Place of Publication
University of Northern Colorado
Some physically active individuals are now advocating for the use of cannabis with exercise for its potential to optimize the immune response. Yet, it remains to be seen whether the chronic use of cannabis products is linked to alterations in immune characteristics, such as monocyte phenotype and function in physically active individuals. The purpose of this cross-sectional study was to assess resting concentrations of c-reactive protein (CRP) and interleukin-6 (IL-6), monocyte phenotype and lipopolysaccharide (LPS) stimulated production of Interleukin-6 (IL-6) following pre-treated with synthetic cannabinoid 2 (CB2) receptor agonist and antagonist in physically active individuals using cannabis products at least 5-times per week for the past 6-months (CU) compared to physically active individuals who have not used any cannabis products in the past 6-months (NU). Physically active participants (N=23; n=11 CU and n=12 NU) completed medical history, physical activity, and cannabis use surveys prior to assessment of their height, weight, body mass index (BMI), body fat percentage, resting heart rate and V̇O2max in their initial visit. In a subsequent visit, intravenous whole blood was collected following a 12-hour fast and 72-hours removed from last bout of vigorous exercise. Isolated serum was used to determine resting protein concentration of CRP and IL-6. Monocyte phenotype was analyzed using an Attune NxT flow cytometer following co-staining of CD-14 and CD-16. Supernatant from whole blood samples diluted with culture medium and stimulated for 24-hours with LPS following 1-hour pre-treatment with CB2 agonist and antagonist at a concentration of 1μM. Collected supernatant was analyzed for IL-6 using an ELISA. Data are presented as mean ± SD and were analyzed using SPSS using unpaired t-tests and ANOVA (α=0.05). Pearson’s correlations were calculated to determine meaningful relationships between primary outcome variables. There were no differences between CU and NU with respect to age, height, weight, BMI, body fat percentage, resting heart rate, or relative V̇O2max. There were no differences between the groups with respect to resting concentrations of CRP or IL-6. Total monocytes per mL of blood was significantly greater in CU (5.08 x 105 ± 1.63 x 105 cells/mL) when compared to NU (3.23 x 105 ± 1.20 x 105 cells/mL) (p = 0.01). The number of classical (CU: 3.77 x 105 ± 1.36 x 105 cells/mL; NU: 2.56 x 105 ± 0.97 x 105 cells/mL, p=0.02) and intermediate monocytes (CU: 7.29 x 105 ± 5.19 x 105 cells/mL; NU: 2.32 x 105 ± 2.18 x 105 cells/mL, p=0.01) were significantly greater in CU compared to NU. Cannabis users had a significantly greater relative percent of intermediate monocytes (CU: 13.89 ± 8.43%; NU: 6.33 ± 4.91%; p=0.02), but there were no differences in classical (76.92 ± 8.48 %) or non-classical (12.73 ± 7.14 %) monocytes between the groups. There were no significant differences in stimulated production of IL-6 between CU and NU groups. Further, when the covariates of age, body fat percent, or monocytes/mL were used, there were no significant differences present between stimulated IL-6 production. Results from this study suggest that the chronic use of cannabis in physically active individuals may alter monocyte phenotype and count, but this was not related to changes in resting concentrations of inflammatory markers CRP and IL-6, nor does it alter whole blood LPS stimulated IL-6 release.
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