Annals of Internal Medicine
Summaries for Patients Does Exposure to Low or Moderate Levels of Arsenic Increase the Risk for Cardiovascular Disease?
The full report is titled “Association Between Exposure to Low to Moderate Arsenic Levels and Incident Cardiovascular Disease. A Prospective Cohort Study.” It is in the 19 November 2013 issue of Annals of Internal Medicine (volume 159, pages 649-659). The authors are K.A. Moon, E. Guallar, J.G. Umans, R.B. Devereux, L.G. Best, K.A. Francesconi, W. Goessler, J. Pollak, E.K. Silbergeld, B.V. Howard, and A. Navas-Acien.
What is the problem and what is known about it so far? Inorganic arsenic is a poisonous substance that occurs when arsenic is combined with elements other than carbon. It can be released into the air and deposited into water and soil during events, such as forest fires, or through industrial operations, such as ore mining. Humans may be exposed to it by eating foods, such as rice, flour, and other grains, that were grown in contaminated soil or water. They may also be exposed to it through drinking water, particularly in areas where the groundwater is in contact with arsenic-containing minerals. Although the maximum level allowed in water is 10 g/L in the United States, arsenic levels are commonly greater in some rural communities in the Southwest, Midwest, and Northeast. Long-term exposure to high levels of inorganic arsenic, such as through drinking water with greater than 100 g/L, is known to increase the risk for cardiovascular disease. Less is known about the cardiovascular effects of long-term exposure to low to moderate levels (⬎ 10 g/L but ⬍100 g/L). Why did the researchers do this particular study? To find out whether long-term exposure to low to moderate levels of inorganic arsenic increased the risk for cardiovascular disease. Who was studied? 3575 American Indian men and women aged 45 to 74 years living in Arizona, Oklahoma, North Dakota, and South Dakota. Most were born in their communities and had lived there for their entire lives. How was the study done? Between 1989 and 1991, the researchers measured the amount of inorganic and methylated arsenic in participants’ urine. They then tracked the incidence of fatal and nonfatal cardiovascular disease through 2008 and related it to levels of urinary arsenic. What did the researchers find? A total of 1184 participants developed fatal and nonfatal cardiovascular disease, and 439 participants died of cardiovascular disease. Participants with greater concentrations of arsenic were more likely to have cardiovascular disease than participants with lower concentrations, even after adjusting for other factors, such as smoking, body mass index, and lipid levels. The association between greater urinary arsenic levels and cardiovascular disease was stronger among women, people who never smoked, participants with diabetes, and participants from Arizona.
Summaries for Patients are a service provided by Annals to help patients better understand the complicated and often mystifying language of modern medicine. Summaries for Patients are presented for informational purposes only. These summaries are not a substitute for advice from your own medical provider. If you have questions about this material, or need medical advice about your own health or situation, please contact your physician. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians.
What were the limitations of the study? The results are based on a single measurement of urine arsenic levels. It is unknown whether participants’ levels remained the same over time. The researchers could not clearly establish a causal relationship between arsenic exposure and cardiovascular disease. They did not directly measure arsenic levels in drinking water. What are the implications of the study? Exposure to even low levels of inorganic arsenic may increase the risk for cardiovascular disease.
I-20 © 2013 American College of Physicians
Downloaded From: http://annals.org/ on 10/31/2016
Summaries for Patients Does Exposure to Low or Moderate Levels of Arsenic Increase the Risk for Cardiovascular Disease?
The full report is titled “Association Between Exposure to Low to Moderate Arsenic Levels and Incident Cardiovascular Disease. A Prospective Cohort Study.” It is in the 19 November 2013 issue of Annals of Internal Medicine (volume 159, pages 649-659). The authors are K.A. Moon, E. Guallar, J.G. Umans, R.B. Devereux, L.G. Best, K.A. Francesconi, W. Goessler, J. Pollak, E.K. Silbergeld, B.V. Howard, and A. Navas-Acien.
What is the problem and what is known about it so far? Inorganic arsenic is a poisonous substance that occurs when arsenic is combined with elements other than carbon. It can be released into the air and deposited into water and soil during events, such as forest fires, or through industrial operations, such as ore mining. Humans may be exposed to it by eating foods, such as rice, flour, and other grains, that were grown in contaminated soil or water. They may also be exposed to it through drinking water, particularly in areas where the groundwater is in contact with arsenic-containing minerals. Although the maximum level allowed in water is 10 g/L in the United States, arsenic levels are commonly greater in some rural communities in the Southwest, Midwest, and Northeast. Long-term exposure to high levels of inorganic arsenic, such as through drinking water with greater than 100 g/L, is known to increase the risk for cardiovascular disease. Less is known about the cardiovascular effects of long-term exposure to low to moderate levels (⬎ 10 g/L but ⬍100 g/L). Why did the researchers do this particular study? To find out whether long-term exposure to low to moderate levels of inorganic arsenic increased the risk for cardiovascular disease. Who was studied? 3575 American Indian men and women aged 45 to 74 years living in Arizona, Oklahoma, North Dakota, and South Dakota. Most were born in their communities and had lived there for their entire lives. How was the study done? Between 1989 and 1991, the researchers measured the amount of inorganic and methylated arsenic in participants’ urine. They then tracked the incidence of fatal and nonfatal cardiovascular disease through 2008 and related it to levels of urinary arsenic. What did the researchers find? A total of 1184 participants developed fatal and nonfatal cardiovascular disease, and 439 participants died of cardiovascular disease. Participants with greater concentrations of arsenic were more likely to have cardiovascular disease than participants with lower concentrations, even after adjusting for other factors, such as smoking, body mass index, and lipid levels. The association between greater urinary arsenic levels and cardiovascular disease was stronger among women, people who never smoked, participants with diabetes, and participants from Arizona.
Summaries for Patients are a service provided by Annals to help patients better understand the complicated and often mystifying language of modern medicine. Summaries for Patients are presented for informational purposes only. These summaries are not a substitute for advice from your own medical provider. If you have questions about this material, or need medical advice about your own health or situation, please contact your physician. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians.
What were the limitations of the study? The results are based on a single measurement of urine arsenic levels. It is unknown whether participants’ levels remained the same over time. The researchers could not clearly establish a causal relationship between arsenic exposure and cardiovascular disease. They did not directly measure arsenic levels in drinking water. What are the implications of the study? Exposure to even low levels of inorganic arsenic may increase the risk for cardiovascular disease.
I-20 © 2013 American College of Physicians
Downloaded From: http://annals.org/ on 10/31/2016
