Distribution of metals exposure and associations with cardiometabolic risk factors in the "Modeling the Epidemiologic Transition Study".
BACKGROUND
Metals are known endocrine disruptors and have been linked to cardiometabolic diseases via multiple potential mechanisms, yet few human studies have both the exposure variability and biologically-relevant phenotype data available. We sought to examine the distribution of metals exposure and potential associations with cardiometabolic risk factors in the "Modeling the Epidemiologic Transition Study" (METS), a prospective cohort study designed to assess energy balance and change in body weight, diabetes and cardiovascular disease risk in five countries at different stages of social and economic development.


METHODS
Young adults (25-45 years) of African descent were enrolled (N = 500 from each site) in: Ghana, South Africa, Seychelles, Jamaica and the U.S.A. We randomly selected 150 blood samples (N = 30 from each site) to determine concentrations of selected metals (arsenic, cadmium, lead, mercury) in a subset of participants at baseline and to examine associations with cardiometabolic risk factors.


RESULTS
Median (interquartile range) metal concentrations (μg/L) were: arsenic 8.5 (7.7); cadmium 0.01 (0.8); lead 16.6 (16.1); and mercury 1.5 (5.0). There were significant differences in metals concentrations by: site location, paid employment status, education, marital status, smoking, alcohol use, and fish intake. After adjusting for these covariates plus age and sex, arsenic (OR 4.1, 95% C.I. 1.2, 14.6) and lead (OR 4.0, 95% C.I. 1.6, 9.6) above the median values were significantly associated with elevated fasting glucose. These associations increased when models were further adjusted for percent body fat: arsenic (OR 5.6, 95% C.I. 1.5, 21.2) and lead (OR 5.0, 95% C.I. 2.0, 12.7). Cadmium and mercury were also related with increased odds of elevated fasting glucose, but the associations were not statistically significant. Arsenic was significantly associated with increased odds of low HDL cholesterol both with (OR 8.0, 95% C.I. 1.8, 35.0) and without (OR 5.9, 95% C.I. 1.5, 23.1) adjustment for percent body fat.


CONCLUSIONS
While not consistent for all cardiometabolic disease markers, these results are suggestive of potentially important associations between metals exposure and cardiometabolic risk. Future studies will examine these associations in the larger cohort over time.
Yale Center for Perinatal, Pediatric & Environmental Epidemiology, Department of Chronic Disease Epidemiology, Yale School of Public Health, 1 Church St, New Haven, CT 06510, USA. adrienne.ettinger@yale.edu.
Adrienne S
AS
Ettinger
Pascal
P
Bovet
Jacob
J
Plange-Rhule
Terrence E
TE
Forrester
Estelle V
EV
Lambert
Nicola
N
Lupoli
James
J
Shine
Lara R
LR
Dugas
David
D
Shoham
Ramon A
RA
Durazo-Arvizu
Richard S
RS
Cooper
Amy
A
Luke
D000328:Adult; D000349:Africa / Q000453:epidemiology; D001151:Arsenic / Q000097:blood*; D015415:Biomarkers; D001835:Body Weight / Q000187:drug effects*; D002318:Cardiovascular Diseases / Q000139:chemically induced / Q000453:epidemiology*; D002641:Chicago / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000139:chemically induced / Q000453:epidemiology*; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D006801:Humans; D007563:Jamaica / Q000453:epidemiology; D008297:Male; D019216:Metals, Heavy / Q000097:blood*; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
D015415:Biomarkers; D004785:Environmental Pollutants; D019216:Metals, Heavy; D001151:Arsenic