title: Assessment of bone metabolism in cadmium-induced renal tubular dysfunction by measurements of biochemical markers.
abstract: Bone metabolism related to the severity of cadmium (Cd)-induced renal tubular dysfunction (RTD) was assessed by measuring several bone biochemical markers. Fifty-three female subjects with RTD aged 65-76 years (mean 70.0+/-3.3 years) and who lived in the Cd-polluted Jinzu River basin in Toyama, Japan were studied. Bone alkaline phosphatase (bone-ALP), intact bone Gla-protein (intact-BGP) and carboxy-terminal propeptide of type I collagen (PICP) in serum as bone formation markers and pyridinoline (Pyr) and deoxypyridinoline (Dpyr) in urine as bone resorption markers were measured. All markers of bone turnover were increased and significantly correlated with each other, suggesting that bone formation and resorption were coupled and increased in Cd-induced RTD. Fractional excretion of beta(2)-microglobulin (beta(2)-m, FE(beta 2-m)) as an index of severity of Cd-induced RTD was extremely varied ranging from 0.45 to 53%. There were no significant correlations between FE(beta 2-m) and each of the five bone biochemical markers. The bone turnover in Cd-induced RTD appeared to be determined by the glomerular filtration rate (GFR): in subjects with GFRs above 50 ml/min, the levels of bone-ALP or intact-BGP tended to be inversely related to the GFRs, whereas in subjects with GFRs below 40 ml/min, those levels tended to decrease. These results suggest that the bone turnover, in particular the bone formation, was influenced by renal tubular function as assessed by the levels of GFR in Cd-induced RTD.
authors.affiliation: Department of Public Health, Faculty of Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan. aoshima@ms.toyama-mpu.ac.jp
authors.forename: Keiko
authors.initials: K
authors.lastname: Aoshima
authors.forename: Jianjun
authors.initials: J
authors.lastname: Fan
authors.forename: Yunqing
authors.initials: Y
authors.lastname: Cai
authors.forename: Terutaka
authors.initials: T
authors.lastname: Katoh
authors.forename: Hidetoyo
authors.initials: H
authors.lastname: Teranishi
authors.forename: Minoru
authors.initials: M
authors.lastname: Kasuya
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D015415:Biomarkers; D001842:Bone and Bones / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D002105:Cadmium Poisoning / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000139:chemically induced* / Q000378:metabolism* / Q000503:physiopathology; D007677:Kidney Function Tests; D007684:Kidney Tubules / Q000378:metabolism* / Q000503:physiopathology*; D009929:Organ Size / Q000502:physiology; D015675:Osteocalcin / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000378:metabolism
chemical_list: D015415:Biomarkers; D001613:beta 2-Microglobulin; D015675:Osteocalcin; D000469:Alkaline Phosphatase