Background: Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic.
Objective: We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania.
Methods: Unexposed (n = 16) and exposed (n = 19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (<10 μg/l). Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (>20 mmHg) and DBP (>15 mmHg).
Results: Drinking water inorganic arsenic averaged 40.2 ± 30.4 and 1.0 ± 0.2 μg/l for the exposed and unexposed groups, respectively (P < 0.001). Compared to the unexposed group, the exposed group expressed a greater probability of blood pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P = 0.035) and cold stress (73.7 vs. 37.5%; P = 0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P = 0.035).
Conclusions: Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk.
aYale School of Public Health, Yale University School of Medicine, New Haven, Connecticut, USA
bEnvironmental Health Center, Cluj-Napoca, Romania
cInstitut fuer Chemie: Analytische Chemie, Karl-Franzens-Universitaet, Graz, Austria
dThe John B. Pierce Laboratory, New Haven, Connecticut, USA
*Equal contribution as senior authors.
Correspondence to Catherine W. Yeckel, PhD, The John B. Pierce Laboratory, 290 Congress Ave., New Haven, CT 06519-1403, USA.Tel: +1 203 562 9901 x267; fax: +1 203 624 4950; e-mail: firstname.lastname@example.org
Abbreviations: ASHRAM, Arsenic Health Risk Assessment and Molecular Epidemiology; CPT, cold pressor test; DMAV, dimethylarsinic acid; iAs, inorganic arsenic; LVH, left-ventricular hypertrophy; MMAV, monomethylarsonic acid; PMI, primary methylation index; SMI, secondary methylation index
Received 11 April, 2012
Revised 10 August, 2012
Accepted 30 October, 2012