Chronic Cannabis Use and Circulating Bio‐Markers of Neural Health, Stress, and Inflammation in Physically Active Individuals

Abstract

PurposeThe purpose of this cross‐sectional study is to compare measures of general health, circulating concentrations of nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), c‐reactive protein (CRP), interleukin‐6 (IL‐6) and cortisol in physically active cannabis users (CU) and physically active non‐cannabis users (NU).MethodsParticipants (N=30; n=20 male) were defined as CU (n=15; n=10 male) if they were using cannabis products at least once a week for the past 6‐months or NU (n=15; n=10 male) if they had not used any cannabis products in the past 6‐months. Age, height, weight, and body composition were assessed. Resting heart rate (HR) was obtained using a Polar heart rate monitor and VO2max, as a measure of cardiovascular fitness, was assessed with a ParvoMedics metabolic cart using a graded treadmill protocol. Fasted and rested intravenous blood samples were collected and ELISAs were used to obtain NGF, BDNF, CRP, IL‐6, and cortisol concentrations. Data are presented as mean ± SD and analyzed with a student's t‐test (alpha=0.05).ResultsCU used cannabis products an average of 4.5±2.5 times per week. There were no significant differences between CU and NU age (23.4±4.4 yrs), height (177.6±8.2 cm), weight (75.7±15.5 kg), body composition, or VO2max (50.3±7.4 ml/kg/min). HR was significantly higher in CU (72.7±15.9 bpm) compared to NU (62.5±7.9 bpm) (p=0.04). Concentrations of BDNF were significantly lower in CU (5.6±0.8 ng/mL) compared to NU (6.3±0.8 ng/mL) (p=0.02). There were no differences in concentration of NGF (193.7±71.6 pg/mL), CRP (CU=1.0± 1.83; NU=0.5±0.4 mg/L), IL‐6 (1.28±0.6 pg/mL), or cortisol (19.8±7.0 ng/mL).ConclusionsAlthough aspects of general health appeared to be similar between NU and CU groups, this study revealed elevated resting HR and reduced BDNF concentrations in CU compared to NU. Although there were no differences between groups with respect to bio‐markers of stress (IL‐6, CRP and cortisol); CU were classified as moderate risk for cardiovascular disease (CVD) compared to low CVD risk for NU as defined by CRP concentrations. This study suggests that chronic cannabis use is associated with altered central and peripheral synaptic plasticity, as well as the potential for increased CVD risk classification in physically active individuals.Support or Funding InformationThis research was funded by the University of Northern Colorado New Projects Program Grant, University of Northern Colorado Graduate Student Association and Natural and Health Sciences Student Grants.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.