The longitudinal relationship between cannabis use and hypertension.

INTRODUCTION: The relationship between cannabis use and hypertension is not clear based on prior epidemiological studies. Thus, we examined this relationship over a 3-year follow-up period using a large population-based sample from the USA.

METHODS: Self-reported longitudinal data were obtained from the National Epidemiologic Survey on Alcohol and Related Conditions Wave 1 (2001/2002) and Wave 2 (2004/2005). The sample was restricted to participants who did not report hypertension at baseline (n = 26 844; 51% 40 years and older, 51% female, 71% white). χ -tests were used to examine the distributions of confounders stratified by the incidence of hypertension. Thereafter, multiple logistic regression analyses were conducted to quantify the relationships between lifetime cannabis use, 12-month cannabis use and 12-month cannabis use frequency and incidence of hypertension while adjusting for confounders.

RESULTS: Cannabis use was associated with a decreased incidence of hypertension in the unadjusted analyses. However, the relationships were confounded by age. After adjustment for all confounders, neither lifetime cannabis use (odds ratio, 95% confidence interval 0.89, 0.77 to 1.02), 12-month cannabis use (0.78, 0.56 to 1.09) nor 12-month cannabis use frequency [at least monthly use (0.85, 0.57 to 1.28) and less than monthly use (0.67, 0.40 to 1.11)] were associated above chance with the incidence of hypertension.

DISCUSSION AND CONCLUSIONS: Lifetime cannabis use, 12-month cannabis use and 12-month cannabis use frequency were not associated with the incidence of hypertension.