Visit-to-visit variability in blood pressure among cannabis users participating in the Third National Health and Nutrition Examination Survey.

OBJECTIVE: Blood pressure variability (BPV) has emerged as an important predictor of cardiovascular morbidity and mortality. Plausible biological mechanisms link cannabis use and blood pressure (BP) regulation. Here, we assess the relationship between cannabis use and BPV, measured by the SD and coefficient of variation across three separate study visits. METHODS: Data for individuals (17-59 years, n = 758) participating in the United States Third National Health and Nutrition Examination Survey substudy were used. Associations between cannabis use and mean BP, SBP and DBP variability were estimated. Participants were classified according to recency or lifetime frequency of cannabis use. Generalized linear regressions were used to model BPV as the outcome and cannabis use status as the exposure, adjusting for potential confounding variables. RESULTS: Compared with nonuse, active cannabis use was associated with higher SD (mmHg) of mean BP [ß = 0.97; 95% confidence interval (CI) = 0.22, 1.73], SBP (ß = 0.95; 95% CI = 0.04, 1.85) and DBP (ß = 1.18; 95% CI = 0.28, 2.08). Similar conclusions were obtained when the coefficient of variation was modelled as the outcome. A robust association was not observed for lifetime use frequency. The association between active cannabis use and SBP variability was stronger in the tobacco smoking subgroup, whereas the association between active cannabis use and DBP variability was stronger in the tobacco nonsmoking subgroup. CONCLUSION: Active cannabis use is associated with BPV. Future research is needed to understand the effects of cannabis use on BP regulation.