Mercury Exposure and Risk of Hypertension in US Men and Women in 2 Prospective Cohorts
Hypertension, 08/08/2012
Clinical Article
Mozaffarian D et al. – The findings from 2 separate large prospective cohort studies do not support any clinically apparent adverse effects of methylmercury exposure on the risk of hypertension in men or women, including at levels ≤2.5–fold higher than the reference dose.
Methods- The authors measured toenail mercury, a valid biomarker of long–term methylmercury exposure, among 6045 US men and women free of hypertension at baseline.
- Geometric mean toenail mercury concentrations were 0.08 μg/g in the lowest quintile and 0.74 μg/g in the highest quintile, the latter corresponding with exposures =2.0–fold higher than the US Environmental Protection Agency reference dose.
- Participants were followed prospectively (mean±SD follow–up, 14.9±7.9 years) for a new self–report of physician–diagnosed hypertension (3540 cases), shown to be >95% sensitive and specific for diagnosing hypertension in these cohorts as compared with review of medical charts and direct blood pressure measurement, respectively.
- After adjustment for demographic, clinical, and lifestyle risk factors, the hazard ratio (95% CI) for incident hypertension in the highest versus lowest quintile of mercury exposure was 0.96 (0.84–1.09) in women, 0.82 (0.62–1.08) in men, and 0.94 (0.84–1.06) in both cohorts combined.
- Findings were similar when more extreme categories of mercury were compared (across deciles, with geometric mean levels in highest decile =2.9–fold higher than the reference dose) and in analyses stratified by fish or omega–3 consumption, selenium levels, body mass index, and age.
