RESUMEN
Food-borne cadmium was the principal source of exposure for persons living in the 12 cadmium-contaminated villages in Mae Sot District, Tak Province, northwestern Thailand. This report presents progress in cadmium-related health effects among persons with high cadmium exposure. The study included 436 persons who had urinary cadmium levels ≥5 µg/g creatinine and were screened for urinary cadmium, renal function, hypertension, diabetes and urinary stones in 2005 (baseline) and 2010 (5-year follow-up). Study renal biomarkers included urinary excretion of ß(2)-microglobulin (ß(2)-MG), total protein and calcium, serum creatinine and glomerular filtration rate (GFR). The geometric mean level of urinary cadmium statistically significantly reduced from 9.5±1.6 µg/g creatinine in 2005 to 8.8±1.6 µg/g creatinine in 2010. Compared to baseline, the follow-up examination revealed significant increases in urinary ß(2)-MG (tubular effect), urinary total protein and serum creatinine, and a decrease in GFR (glomerular effects). Progressive renal dysfunctions were similarly observed in persons both with and without reduction in cadmium intake. Significant increases in prevalence of hypertension, diabetes and urinary stones were also detected at follow-up. These three disorders were found to markedly impair renal functions in the study persons. Our study indicates that in persons with prolonged excessive cadmium exposure, toxic health effects may progress even after exposure reduction. Renal damage from cadmium can be due to its direct nephrotoxic effect and also through the related disorders causing nephropathy.
Asunto(s)
Cadmio/toxicidad , Diabetes Mellitus/inducido químicamente , Exposición a Riesgos Ambientales/análisis , Contaminantes Ambientales/toxicidad , Hipertensión/inducido químicamente , Enfermedades Renales/inducido químicamente , Cadmio/orina , Diabetes Mellitus/epidemiología , Diabetes Mellitus/orina , Exposición a Riesgos Ambientales/efectos adversos , Contaminantes Ambientales/orina , Femenino , Estudios de Seguimiento , Humanos , Hipertensión/epidemiología , Hipertensión/orina , Enfermedades Renales/epidemiología , Enfermedades Renales/orina , Masculino , Persona de Mediana Edad , Tailandia/epidemiologíaRESUMEN
Excessive urinary calcium excretion is the major risk of urinary stone formation. Very few population studies have been performed to determine the relationship between environmental cadmium exposure and urinary stone disease. This population-based study examined an association between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and prevalence of urinary stones in persons aged 15 years and older, who lived in the 12 cadmium-contaminated villages in the Mae Sot District, Tak Province, northwestern Thailand. A total of 6748 persons were interviewed and screened for urinary cadmium and urinary stone disease in 2009. To test a correlation between urinary excretion of cadmium and calcium, we measured urinary calcium content in 1492 persons, who lived in 3 villages randomly selected from the 12 contaminated villages. The rate of urinary stones significantly increased from 4.3% among persons in the lowest quartile of urinary cadmium to 11.3% in the highest quartile. An increase in stone prevalence with increasing urinary cadmium levels was similarly observed in both genders. Multiple logistic regression analysis revealed a positive association between urinary cadmium levels and stone prevalence, after adjusting for other co-variables. The urinary calcium excretion significantly increased with increasing urinary cadmium levels in both genders, after adjusting for other co-variables. Elevated calciuria induced by cadmium might increase the risk of urinary stone formation in this environmentally exposed population.
Asunto(s)
Cadmio/orina , Contaminantes Ambientales/orina , Cálculos Urinarios/epidemiología , Adolescente , Adulto , Anciano , Exposición a Riesgos Ambientales/estadística & datos numéricos , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Tailandia/epidemiología , Cálculos Urinarios/orina , Adulto JovenRESUMEN
Risk for hypertension and diabetes has not been conclusively found to be a result of cadmium exposure. A population-based study was conducted in 2009 to examine the correlations of urinary cadmium, a good biomarker of long-term cadmium exposure, with hypertension and diabetes in persons aged 35 years and older who lived in the 12 cadmium-contaminated rural villages in northwestern Thailand. A total of 5273 persons were interviewed and screened for urinary cadmium, hypertension, and diabetes. The geometric mean level of urinary cadmium for women (2.4+/-2.3 microg/g creatinine) was significantly greater than that for men (2.0+/-2.2 microg/g creatinine). Hypertension was presented in 29.8% of the study population and diabetes was detected in 6.6%. The prevalence of hypertension significantly increased from 25.0% among persons in the lowest tertile of urinary cadmium to 35.0% in the highest tertile. In women, the rate of hypertension significantly increased with increasing urinary cadmium levels in both ever and never smokers, after adjusting for age, alcohol consumption, body mass index, and diabetes. In men, such association was less significantly found in never smokers. The study revealed no significant association between urinary cadmium and diabetes in either gender. Our study supports the hypothesis that environmental exposure to cadmium may increase the risk of hypertension. Risk for diabetes in relation to cadmium exposure remains uncertain in this exposed population.
Asunto(s)
Cadmio/orina , Diabetes Mellitus/epidemiología , Contaminantes Ambientales/orina , Hipertensión/epidemiología , Adulto , Cadmio/toxicidad , Diabetes Mellitus/orina , Monitoreo del Ambiente , Contaminantes Ambientales/toxicidad , Contaminación Ambiental/estadística & datos numéricos , Monitoreo Epidemiológico , Femenino , Humanos , Hipertensión/orina , Masculino , Persona de Mediana Edad , Tailandia/epidemiologíaRESUMEN
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 beta2-microglobulin (beta2-MG), N-acetyl-beta-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 proteinuria was greatest in those with urinary cadmium levels > or = 15 microg/g creatinine. Urinary excretion of beta2-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 beta2-MG, NAG, and total protein. Risk for hypertension, diabetes, and urinary stones remains uncertain in relation to cadmium exposure.
Asunto(s)
Cadmio/toxicidad , Diabetes Mellitus/epidemiología , Exposición a Riesgos Ambientales/efectos adversos , Hipertensión/epidemiología , Enfermedades Renales/epidemiología , Cálculos Urinarios/epidemiología , Acetilglucosaminidasa/orina , Biomarcadores , Cadmio/orina , Calcio/orina , Intervalos de Confianza , Creatinina/orina , Diabetes Mellitus/inducido químicamente , Diabetes Mellitus/diagnóstico , Femenino , Tasa de Filtración Glomerular , Humanos , Hipertensión/inducido químicamente , Hipertensión/diagnóstico , Enfermedades Renales/inducido químicamente , Enfermedades Renales/diagnóstico , Modelos Logísticos , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Prevalencia , Factores de Riesgo , Tailandia/epidemiología , Cálculos Urinarios/inducido químicamente , Cálculos Urinarios/diagnóstico , Microglobulina beta-2/orinaRESUMEN
BACKGROUND: In 2004, 7,697 cadmium-exposed persons aged 15 years and older in Mae Sot District, Tak Province, Thailand, were screened for urinary cadmium levels and 554 cases (7.2%) had > or = 5 microg/g creatinine. OBJECTIVE: The present study reported the prevalence of renal dysfunction among those with high urinary cadmium (> or = 5 microg/g creatinine). MATERIAL AND METHOD: The study persons were interviewed and examined for detection of renal dysfunction. Venous blood and second morning urine were obtained from each subject for microscopic analysis and biochemistry measurements. RESULTS: Of the 527 examined persons, 14.2% had urinary beta2-microglobulin excretion between 300 and 999 microg/g creatinine, and 19.9% contained > or = 1,000 microg/g creatinine. About 21.1% had serum creatinine concentrations between 1.1 and 1.4 mg/dl and 4.2% contained > or = 1.5 mg/dl. Low glomerular filtration rate (GFR < 60 ml/min/1.73 m2 body surface area) was present in 16.9% of the study persons. Of the persons surveyed, 75.3% had the fractional excretion of phosphate > 5% and 24.7% contained the fractional excretion of potassium > 10%. The overall prevalence rates of hypertension and urinary stones in the study population were 31.3% and 8.9%, respectively. Excretion of urinary beta2-microglobulin significantly increased with increasing urinary cadmium levels. Both increased serum creatinine and decreased GFR appeared to be associated with increasing urinary cadmium although the difference was not statistically significant. There were no significant associations between urinary cadmium levels and excretion of urinary protein, urinary calcium, hypertension, and urinary stones. CONCLUSION: Excessive exposure to cadmium might produce renal dysfunction among the present study population. Increased urinary excretion of beta2-microglobulin is a good indicator of renal tubular dysfunction among persons with excessive cadmium exposure.
Asunto(s)
Enfermedades Renales/epidemiología , Adolescente , Adulto , Cadmio/orina , Creatinina/sangre , Exposición a Riesgos Ambientales , Femenino , Humanos , Enfermedades Renales/orina , Masculino , Persona de Mediana Edad , Tailandia/epidemiología , Adulto Joven , Microglobulina beta-2/orinaRESUMEN
BACKGROUND: In Mae Sot District, Tak Province, Thailand, the paddy fields receiving irrigation from the two creeks and crops grown in the areas were found to contain markedly elevated cadmium levels during the surveys in 2001-2004. OBJECTIVE: The present report carried out a survey in 2004 to determine urinary cadmium, a good index of excessive cadmium exposure and body burden, among the exposed residents aged 15 years and older in these contaminated areas. MATERIAL AND METHOD: Morning urine samples were collected from the subjects and then kept frozen until cadmium analysis. Urinary cadmium was determined using the atomic absorption spectrometry and urinary creatinine was determined using a method of reaction with picric acid at alkaline pH and colorimetry. RESULTS: Of the 7,697 persons surveyed, only 45.6% had urinary cadmium levels < 2 microg/g creatinine. About 4.9% were between 5 and 10 microg/g creatinine and 2.3% had cadmium concentrations > 10. The urinary cadmium level was greater among women than men and increased with increasing age. Smokers were more likely to have high urinary cadmium than non-smokers. Persons who mainly consumed rice grown locally in the contaminated areas had higher urinary cadmium than those who did not. CONCLUSION: Persons who had high urinary cadmium levels and might have cadmium-induced toxic effects should be screened for early detection of chronic cadmium toxicity. Smoking cessation programs should be one component of preventive action beneficial for the study population. The production of rice and other crops for human consumption should be prohibited to prevent further accumulation of cadmium in the body of the exposed population.
Asunto(s)
Cadmio/orina , Exposición a Riesgos Ambientales , Adolescente , Adulto , Carga Corporal (Radioterapia) , Exposición a Riesgos Ambientales/estadística & datos numéricos , Femenino , Humanos , Masculino , Cese del Hábito de Fumar , TailandiaRESUMEN
BACKGROUND: Sequestration of infected red blood cells (iRBCs) in the microcirculation is central to the pathophysiology of falciparum malaria. It is caused by cytoadhesion of iRBCs to vascular endothelium, mediated through the binding of Plasmodium falciparum erythrocyte membrane protein-1 to several endothelial receptors. Binding to CD36, the major vascular receptor, is stabilized through dephosphorylation of CD36 by an alkaline phosphatase. This is inhibited by the alkaline phosphatase-inhibitor levamisole, resulting in decreased cytoadhesion. METHODS: Patients with uncomplicated falciparum malaria were randomized to receive either quinine treatment alone or treatment with a single 150-mg dose of levamisole as an adjunct to quinine. Peripheral blood parasitemia and parasite stage distribution were monitored closely over time. RESULTS: Compared with those in control subjects, peripheral blood parasitemias of mature P. falciparum parasites increased during the 24 h after levamisole administration (n=21; P=.006). The sequestration ratio (between observed and expected peripheral blood parasitemia) of early trophozoite and midtrophozoite parasites increased after levamisole treatment, with near complete prevention of early trophozoite sequestration and >65% prevention of midtrophozoite sequestration. CONCLUSION: These findings strongly suggest that levamisole decreases iRBC sequestration in falciparum malaria in vivo and should be considered as a potential adjunctive treatment for severe falciparum malaria. TRIAL REGISTRATION: Current Controlled Trials identifier: 15314870.