Arsenic exposure increases risk for LV hypertrophy, wall thickness
American Indian patients with minimal CV risk factors who were exposed to arsenic had an increase in left ventricular hypertrophy and LV wall thickness, according to a study published in Circulation: Cardiovascular Imaging.
“People drinking water from private wells, which are not regulated, need to be aware that arsenic may increase the risk for cardiovascular disease,” Gernot Pichler, MD, PhD, MSc, medical specialist for internal medicine in the department of cardiology at Hospital Hietzing/Heart Center Clinic Floridsdorf in Vienna, scientific collaborator at INCLIVA Health Research Institute in Valencia, Spain, and a visiting scholar in the department of environmental health sciences at Columbia University, said in a press release. “Testing those wells is a critical first step to take action and prevent exposure.”
Strong Heart Family Study data
Researchers analyzed data from 1,337 American Indians (mean age, 31 years; 61% women) from the Strong Heart Family Study who were free from CVD and diabetes.
Urine samples were collected to measure concentrations of methylarsonate, arsenobetaine, dimethylarsinate and inorganic arsenic. Concentrations of inorganic and methylated arsenic served as a biomarker for the exposure to inorganic arsenic from food and water.
Participants also underwent transthoracic echocardiograms to assess cardiac function and geometry. Questionnaires were completed to collect information on physical activity, smoking history, socioeconomic data and medical history. Trained nurses and medical assistants measured weight, height and BP.
Follow-up was conducted for a mean of 5.6 years. At baseline, the median urine arsenic measurement was 4.24 µg/g creatinine.
There was a twofold increase in prevalent LV hypertrophy with each increase in urinary arsenic levels for all participants (OR = 1.47; 95% CI, 1.05-2.08) and in those with prehypertension or hypertension (OR = 1.58; 95% CI, 1.04-2.41). This association was not seen for incident LV hypertrophy.
In cross-sectional and prospective analyses, continuous measures of LV geometry including left atrial systolic diameter, LV mass index, LV posterior wall thickness and interventricular septum were positively and significantly linked to arsenic exposure. Isovolumic relaxation time and stroke volume were also significantly associated with arsenic exposure.
“While reported findings provide insights to the association between arsenic exposure with LV geometry and functioning, further research is needed to elucidate the causal pathways underlying this relationship and whether these associations are reversible after arsenic exposure is removed from drinking water,” Pichler and colleagues wrote.
Recent arsenic exposure
“Although commonly used as a biomarker, urinary arsenic reflects recent exposure generally from the previous day,” Rajiv Chowdhury, MBBS, PhD, scientific director, university lecturer in global health, senior research associate in global cardiovascular health and a cardiovascular epidemiologist at University of Cambridge, U.K., and Kim van Daalen, BSc, MPhil, PhD student of global public health at University of Cambridge, wrote in a related editorial. “Due to a single measurement of arsenic in this study at baseline, statistical analysis cannot account for changes of arsenic exposure over time nor can a temporal relationship (short-term, long-term) between arsenic exposure and outcome be conclusively established.” – by Darlene Dobkowski
Disclosures: The authors and van Daalen report no relevant financial disclosures. Chowdhury reports he is a co-principal investigator of a Research Council UK project.