Cadmium-Exposed Population in Mae Sot District, Tak Province: 3. Associations between Urinary Cadmium and Renal Dysfunction, Hypertension, Diabetes, and Urinary Stones
Witaya Swaddiwudhipong MD*, Pisit Limpatanachote MD**, Muneko Nishijo MD, PhD***, Ryumon Honda PhD****, Pranee Mahasakpan BSc, MPH*, Somyot Krintratun MD**
Affiliation : * Department of Community and Social Medicine, Mae Sot General Hospital, Tak ** Department of Internal Medicine, Mae Sot General Hospital, Tak *** Department of Public Health, Kanazawa Medical University, Japan **** Department of Social and Environmental Health, Kanazawa Medical University, Japan
Objective : To study the associations between urinary cadmium and renal dysfunction, hypertension, diabetes,
and urinary stones in an adult population living in cadmium-contaminated areas in Mae Sot District, Tak
Province, Thailand.
Material and Method: Seven hundred ninety five cadmium-exposed adults were screened for urinary cadmium,
renal dysfunction, hypertension, diabetes, and urinary stones in 2005. Six selected markers of renal function
in the present study were urinary excretion of β2-microglobulin (β2-MG), N-acetyl-β-D-glucosaminidase (NAG),
total protein and calcium, serum creatinine, and glomerular filtration rate (GFR).
Results : The mean age of the study persons was 50 years old. The overall prevalence rates of hypertension,
diabetes, and urinary stones were 33.3%, 6.2%, and 8.9% respectively. The prevalence of increased pro-
teinuria was greatest in those with urinary cadmium levels > 15 μg/g creatinine. Urinary excretion of β2-MG,
NAG, and total protein significantly increased with increasing urinary cadmium levels, after adjusting for
other co-variables by multiple linear regression analysis. However, urinary cadmium was not significantly
associated with urinary calcium, serum creatinine, and GFR. The prevalence rates of hypertension, diabetes,
and urinary stones did not significantly increase with increasing urinary cadmium levels. Hypertension,
diabetes, and urinary stones were also significant predictors of impaired renal function.
Conclusion : In this population, increasing levels of urinary cadmium are associated with increasing urinary
excretion of β2-MG, NAG, and total protein. Risk for hypertension, diabetes, and urinary stones remains
uncertain in relation to cadmium exposure.
Keywords : Cadmium, Renal dysfunction, Hypertension, Diabetes, Urinary stone
