Hair mercury level in smokers and its influence on blood pressure and lipid metabolism.

Abstract

OBJECT: Smoking is a major risk factor for the development and progression of cardiovascular disease and cigarettes contain a slight amount of mercury. Mercury has been causally linked to cardiovascular diseases. This study evaluated the mercury content in hair according to smoking exposure status and the influence of the mercury level on blood pressure and lipid metabolism.

METHODS: We examined mercury concentration in the hair samples from 236 healthy people 16-75-years-of-age who had visited the health promotion center of a university hospital from January 2004 to January 2007. Self-reported cigarette smoking status and baseline health information were obtained using a questionnaire. Blood pressure and serum lipid level according to the mercury concentration were assessed.

RESULTS: The mean systolic blood pressure in the smoking exposure group and non-exposure group were 123.2±15.4mmHg and 117.2±15.9mmHg, respectively (p=0.005). The mean diastolic pressure in the smoking exposure group and non-exposed group were 80.2±10.9mmHg and 75.1±11.3mmHg, respectively (p<0.001). Mercury concentration had a positive relationship with systolic and diastolic blood pressure. Compared with the normal and high mercury groups, the normal mercury group demonstrated lower blood pressure, lower triglyceride, and lower smoking amount, but higher high density lipoprotein cholesterol than the high mercury group. There was an increase of mercury concentration in the smoking exposure group. The 20-29 packyear group showed significantly increased odds ratio of mercury content, compared with the non-exposure group (14.00, 95% confidence interval, 5.03-38.96).

CONCLUSIONS: Smoking is positively associated with mercury accumulation, and high mercury concentration is associated with increased blood pressure and abnormal lipid metabolism.