| Urinary Cadmium and Osteoporosis in U.S. Women ≥ 50 Years of Age: NHANES 1988–1994 and 1999–2004 Carolyn M. Gallagher,1 John S. Kovach,2 and Jaymie R. Meliker1 1Graduate Program in Public Health, and 2Department of Preventive Medicine, Stony Brook University Medical Center, Stony Brook, New York, USA Abstract
Background: Urinary cadmium (U-Cd) has been associated with decreased peripheral bone mineral density (BMD) and osteoporosis. This association, however, has not been confirmed using femoral BMD, the international standard for diagnosing osteoporosis, at levels < 1.0 µg Cd/g creatinine. Objectives: Our goal was to investigate the statistical association between U-Cd, at levels ≤ 1 µg/g creatinine, and osteoporosis, as indicated by hip BMD and self-report in a population-based sample of U.S. women ≥ 50 years of age. Methods: We drew data from the National Health and Nutrition Examination Surveys for 1988–1994 (n = 3,207) and 1999–2004 (n = 1,051) . Osteoporosis was indicated by hip BMD cutoffs based on the international standard and self-report of physician diagnosis. We analyzed U-Cd levels for association with osteoporosis using multiple logistic regression. Results: Women ≥ 50 years of age with U-Cd levels between 0.50 and 1.00 µg/g creatinine were at 43% greater risk for hip-BMD–defined osteoporosis, relative to those with levels ≤ 0.50 µg/g (odds ratio = 1.43 ; 95% confidence interval, 1.02–2.00 ; p = 0.04) . We observed similar effect estimates using self-report of physician-diagnosed osteoporosis. Smokers did not show a statistically increased risk. Conclusions: Results suggest that U.S. women are at risk for osteoporosis at U-Cd levels below the U.S. Occupational Safety and Health Administration's 3-µg/g safety standard. Given null findings among smokers, dietary Cd, rather than tobacco, is the likely source of Cd-related osteoporosis risk for the U.S. female population ≥ 50 years of age. Key words: bone mineral density, cadmium, femur, hip, osteoporosis, women. Environ Health Perspect 116: 1338–1343 (2008) . doi:10.1289/ehp.11452 available via http://dx.doi.org/ [Online 13 June 2008]
Address correspondence to C.M. Gallagher, Graduate Program in Public Health, Stony Brook University Medical Center, Health Sciences Center, L3, Room 071, State University of New York at Stony Brook, Stony Brook, NY 11790 USA. Telephone: (631) 675-0278. Fax: (631) 444-3480. E-mail: 2crgallagher@optonline.net We gratefully acknowledge the reviewers for their thorough and insightful comments. The authors declare they have no competing financial interests. Received 6 March 2008 ; accepted 12 June 2008.
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