The effects of arsenic exposure on blood pressure and early risk markers of cardiovascular disease: Evidence for population differences.

Exposure to inorganic arsenic has been identified as a risk factor for elevated blood pressure and cardiovascular disease. Our aim with this study was to elucidate effects of arsenic on blood pressure and early risk markers of cardiovascular disease in a population with efficient arsenic metabolism that can modify other arsenic-related health effects. The study included 225 women in the northern Argentinean Andes. Exposure to arsenic was assessed by the sum of arsenic metabolite concentrations in urine. Blood pressure was measured in the supine position. Blood samples were collected for measurement of hemoglobin, homocysteine, triglycerides, apolipoproteins A and B, and cytokines in separated plasma. The median arsenic concentration in urine was 200 µg/L (range 22-545 µg/L). Unexpectedly, urinary arsenic concentrations were inversely associated with both systolic (p=0.081), and diastolic (p=0.002) blood pressure, and with the ratio of apolipoproteins B/A (p<0.001). There was no clear sign of increased inflammation, measured as cytokine concentrations, in relation to arsenic. Furthermore, urinary arsenic was associated with low hemoglobin concentrations (p<0.001). Our results show that arsenic exposure was not associated with elevated levels of early risk markers for cardiovascular disease in this population. This provides evidence that the effects of arsenic on risk of cardiovascular disease differ between populations, which needs to be taken into account in risk assessment.