Cadmium-Exposed Population in Mae Sot District, Tak Province: 4 Bone Mineral Density in Persons with High Cadmium Exposure
Pisit Limpatanachote MD*, Witaya Swaddiwudhipong MD**, Muneko Nishijo MD, PhD***, Ryumon Honda PhD****, Pranee Mahasakpan MPH**, Kowit Nambunmee PhD*****, Werawan Ruangyuttikarn PhD******
Affiliation : * Department of Internal Medicine, Mae Sot General Hospital, Tak, Thailand ** Department of Community and Social Medicine, Mae Sot General Hospital, Tak, Thailand *** Department of Public Health, Kanazawa Medical University, Kahoku, Japan ****Department of Social and Environmental Health, Kanazawa Medical University, Kahoku, Japan *****Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand ******Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Objective : To measure bone mineral density in cadmium-exposed persons aged 40 years and older that lived in the 12
contaminated villages in northwestern Thailand.
Material and Method: Five hundred seventy three persons with urinary cadmium levels > 5 μg/g creatinine during the
2004-2006 surveys were screened in 2007 for urinary excretion of cadmium, bone formation and resorption markers, and
renal function markers. Calcaneus bone density was measured in each person by a dual-energy X-ray absorptiometry bone
scanner.
Results : The mean age of the study persons was 57 years old. The geometric mean level of urinary cadmium for women was
significantly higher than that for men. Women had a lower mean of calcaneus bone density than men. The rate of osteoporosis
in women (21.5%) was significantly higher than that for men (14.7%). Calcaneus bone density was negatively correlated with
urinary excretion of calcium (in both genders) and crosslinked N-telopeptide of type I collagen (in women), after adjusting for
other co-variables. Increasing urinary cadmium levels appeared to correlate with reduced bone density in women, but not in
men. In both genders, urinary excretion of β2-microglobulin and N-acetyl-β-D-glucosaminidase was higher in persons with
osteoporosis than those without.
Conclusion : Bone mineral loss is correlated with urinary cadmium levels and renal dysfunction in this female population.
Keywords : Cadmium, Urinary cadmium, Bone mineral density, Osteoporosis, Renal dysfunction
