CARDIA data links cadmium exposure, diabetes in young adults
CHICAGO — Data presented here at the ADA Scientific Sessions suggest a relationship may exist between cadmium exposure and the incidence of diabetes in young adults, according to researchers.
“Cadmium (Cd) can be accumulated in almost all organs and tissues and it’s not easy to be eliminated from the body. That’s why the half-life is very long, from 10 to 30 years depending on the tissue types,” Ka He, MD, ScD, of the departments of nutrition and epidemiology at Indiana University School of Public Health, said during a presentation. “Animal studies suggest that beta cells accumulate Cd in a dose and time dependent manner over a prolonged time at environmentally relevant concentrations. Cd induces oxidative stress and damages pancreatic islet beta cells in vivo and in vitro; that’s why it has been hypothesized that Cd increases the incidence for diabetes.”
According to He, the CARDIA study was an NIH-funded, multicenter longitudinal study of lifestyle and evolution of CVD risk factors in young adults. He and colleagues conducted a prospective analysis of 3,898 American young adults aged 20 to 32 years in the ongoing study; participants were without diabetes at enrollment in 1987. They were followed six times until 2010.
According to data, median toenail Cd exposure levels were measured by inductively-coupled-plasma mass spectrometry analysis (ICP-MS) in five separate quintiles as: 0.003 parts per million (ppm), 0.005 ppm, 0.008 ppm, 0.015 ppm and 0.047 ppm.
Over 23 years of follow-up, He said they identified 434 incident cases of diabetes and found a threshold relationship for incident diabetes from the lowest to the highest quintiles of toenail Cd (Q1: HR=1; Q2: HR=1.43 [95% CI, 1.02-2.02]; Q3: HR=1.37 [95% CI, 0.97-1.94]; Q4: HR=1.43 [95% CI, 1.004-2.03]; and Q5: HR=1.42 [95% CI, 1.07-1.89]).
The researchers then sought to compare quintile 1 by grouping quintile groups 2 through 5; they observed a positive relationship between Cd exposure and diabetes incidence (HR=1.42; 95% CI, 1.07-1.89), according to data. Further studies are warranted to confirm these findings, He said.
“Our study found a threshold between Cd exposure and diabetes risk. Longitudinal human data demonstrate that Cd exposure in young adulthood, even at a relatively low level, may be associated with an elevated risk for diabetes,” He said. – by Samantha Costa
For more information:
He K. #83-OR. Presented at: ADA Scientific Sessions; June 21-25, 2013; Chicago.
Disclosure: The researchers report no relevant financial disclosures.