This article is more than 5 years old. Information may no longer be current.
Environmental mercury from fish linked with increased hypertension in Nunavik Inuit adults
Click Here to Manage Email Alerts
Higher concentrations of mercury in the blood are associated with an increase in systolic BP, new study results suggested.
Researchers included data from 732 Nunavik Inuit adults (50.4% female) who completed the Qanuippitaa? health survey. Anthropometric blood samples, as well as systolic and diastolic BP, were also collected. The researchers used mercury blood concentration as a biomarker of recent mercury exposure.
Mean BP was 117 mm Hg/ 73 mm Hg. The mean mercury level in the study population was 50.2 nmol/L (95% CI, 46.6-54.1). Both simple and multiple analyses between mercury and BP parameters were performed. After adjusting for confounding variables, the results suggested an association between higher mercury concentration and increased systolic BP (P= .0004). Diastolic BP tended to increase with elevations in blood mercury concentration (P= .069). The n-3 fatty acid EPA (P= .049) and selenium (P = .025) were negatively associated with systolic BP. The n-3 fatty acid EPA was also negatively associated with diastolic BP (P= .005). Differences in mean pulse pressure between the second and fourth quartiles of mercury concentration were also reported (P= .0017).
“The results of the present study obtained in a highly mercury-exposed population help us to better understand the CV mercury toxicity and to assess the risks/benefits of fish consumption,” the researchers concluded. “Moreover, this study constitutes the baseline of a cohort study that will allow us to determining whether mercury is associated with the development of hypertension.”
Valera B. Hypertension. 2009;54:981-986.
[This study] seems to indicate that fish consumption in the Nunavik Inuit population is somewhat of a Pandora’s Box. Although the omega fatty acids may exert their well known beneficial CV effects, the mercury content of fish could abolish these beneficial effects by raising BP. The association between mercury exposure or blood mercury levels and BP has been documented in several cohorts, among them the National Health and Nutrition Examination Survey. Acute mercury poisoning may actually result in a clinical picture that resembles pheochromocytoma with tachycardia and acute elevation of BP. However, there are some distinct limitations to the mercury and BP story. First of all, such a connection has not been shown to hold true in all populations. Second, we do not know whether the findings from the Nunavik Inuit adults can be extrapolated to other populations as well. Third, also given that 90% of this population drank, it seems to be very difficult to correct for alcohol intake as a confounding variable. Clearly, this is a complex issue and we need more evidence before we can make any recommendations to our patients.
Cardiology Today Editorial Board member