RTI uses cookies to offer you the best experience online. By clicking “accept” on this website, you opt in and you agree to the use of cookies. If you would like to know more about how RTI uses cookies and how to manage them please view our Privacy Policy here. You can “opt out” or change your mind by visiting: http://optout.aboutads.info/. Click “accept” to agree.
Dietary intake estimates and urinary cadmium levels in Danish postmenopausal women
Vacchi-Suzzi, C., Eriksen, K. T., Levine, K., McElroy, J., Tjonneland, A., Raaschou-Nielsen, O., Harrington, J. M., & Meliker, J. R. (2015). Dietary intake estimates and urinary cadmium levels in Danish postmenopausal women. PLoS One, 10(9), Article e0138784. https://doi.org/10.1371/journal.pone.0138784
Cadmium is a known carcinogen that can disrupt endocrine signalling. Cigarette smoking and food are the most common routes of non-occupational exposure to cadmium. Cadmium accumulates in the kidney and can be measured in urine, making urine cadmium (U-Cd) a biomarker of long-term exposure. However dietary-cadmium (D-Cd) intake estimates are often used as surrogate indicator of cadmium exposure in non-smoking subjects. It is therefore important to investigate the concordance between D-Cd estimates obtained with Food Frequency Questionnaires and U-Cd.
Methods
U-Cd levels were compared with estimated dietary-cadmium (D-Cd) intake in 1764 postmenopausal women from the Danish Diet, Cancer and Health cohort. For each participant, a food frequency questionnaire, and measures of cadmium content in standard recipes were used to judge the daily intake of cadmium, normalized by daily caloric intake. Cadmium was measured by ICP-MS in spot urine sampled at baseline and normalized by urinary creatinine. Information on diet, socio-demographics and smoking were self-reported at baseline.
Results
Linear regressions between U-Cd and D-Cd alone revealed minimal but significant positive correlation in never smokers (R-2 = 0.0076, beta = 1.5% increase per 1 ng Cd kcal(-1), p = 0.0085, n = 782), and negative correlation in current smokers (R-2 = 0.0184, beta = 7.1% decrease per 1 ng Cd kcal-1 change, p = 0.0006, n = 584). In the full study population, most of the variability in U-Cd was explained by smoking status (R2 = 0.2450, n = 1764). A forward selection model revealed that the strongest predictors of U-Cd were age in never smokers (Delta R-2 = 0.04), smoking duration in former smokers (Delta R-2 = 0.06) and pack-years in current smokers (Delta R-2 = 0.07). Food items that contributed to U-Cd were leafy vegetables and soy-based products, but explained very little of the variance in U-Cd.
Conclusions
Dietary-Cd intake estimated from food frequency questionnaires correlates only minimally with U-Cd biomarker, and its use as a Cd exposure indicator may be of limited utility in epidemiologic studies.
