Association between blood lead and blood pressure: Results from the Canadian Health Measures Survey (2007 to 2011).

Background: Hypertension is the leading risk factor for cardiovascular disease, but its cause is not always known. Interest is increasing in the potential role of environmental chemicals, including lead.

Data And Methods: Data are from the first two cycles of the Canadian Health Measures Survey. Lead in whole blood (PbB), and systolic (SBP) and diastolic (DBP) blood pressure were measured and hypertension status was derived for 4,550 respondents aged 40 to 79. Linear regression estimated associations between PbB and SBP and DBP. Logistic regression estimated associations between PbB and hypertension. Adjusted least squares geometric means of PbB were estimated for hypertensive versus non-hypertensive individuals.

Results: Compared with non-hypertensive individuals, those with hypertension had higher average PbB levels, were older, more likely to be male, and more likely to have other hypertension risk factors (diabetes, family history of high blood pressure). In adjusted regression models, a modest association emerged between PbB levels and SBP among 40- to 54-year-olds, and between PbB levels and DBP for the overall population. No association emerged between PbB levels and hypertension prevalence.

Interpretation: A modest association was observed between blood lead levels and blood pressure, but not with hypertension, in Canadian adults aged 40 to 79.