title: Incidence of nephrolithiasis in relation to environmental exposure to lead and cadmium in a population study.
abstract: Whether environmental exposure to nephrotoxic agents that potentially interfere with calcium homeostasis, such as lead and cadmium, contribute to the incidence of nephrolithiasis needs further clarification. We investigated the relation between nephrolithiasis incidence and environmental lead and cadmium exposure in a general population. In 1302 participants randomly recruited from a Flemish population (50.9% women; mean age, 47.9 years), we obtained baseline measurements (1985-2005) of blood lead (BPb), blood cadmium (BCd), 24-h urinary cadmium (UCd) and covariables. We monitored the incidence of kidney stones until October 6, 2014. We used Cox regression to calculate multivariable-adjusted hazard ratios for nephrolithiasis. At baseline, geometric mean BPb, BCd and UCd was 0.29µmol/L, 9.0nmol/L, and 8.5nmol per 24h, respectively. Over 11.5 years (median), nephrolithiasis occurred in 40 people. Contrasting the low and top tertiles of the distributions, the sex- and age-standardized rates of nephrolithiasis expressed as events per 1000 person-years were 0.68 vs. 3.36 (p=0.0016) for BPb, 1.80 vs. 3.28 (p=0.11) for BCd, and 1.65 vs. 2.95 (p=0.28) for UCd. In continuous analysis, with adjustments applied for sex, age, serum magnesium, and 24-h urinary volume and calcium, the hazard ratios expressing the risk associated with a doubling of the exposure biomarkers were 1.35 (p=0.015) for BPb, 1.13 (p=0.22) for BCd, and 1.23 (p=0.070) for UCd. In conclusion, our results suggest that environmental lead exposure is a risk factor for nephrolithiasis in the general population.
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Azusa
authors.initials: A
authors.lastname: Hara
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Wen-Yi
authors.initials: WY
authors.lastname: Yang
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Thibault
authors.initials: T
authors.lastname: Petit
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Zhang
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Yu-Mei
authors.initials: YM
authors.lastname: Gu
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Fang-Fei
authors.initials: FF
authors.lastname: Wei
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Lotte
authors.initials: L
authors.lastname: Jacobs
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium; Department of Internal Medicine, Faculty of Clinical Sciences, College of Health Sciences University of Abuja, Nigeria.
authors.forename: Augustine N
authors.initials: AN
authors.lastname: Odili
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
authors.forename: Lutgarde
authors.initials: L
authors.lastname: Thijs
authors.affiliation: Centre for Environmental Sciences, University of Hasselt, Belgium.
authors.forename: Tim S
authors.initials: TS
authors.lastname: Nawrot
authors.affiliation: Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium; R&D Group VitaK, Maastricht University, Maastricht, The Netherlands. Electronic address: jan.staessen@med.kuleuven.be.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Staessen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001530:Belgium / Q000453:epidemiology; D002104:Cadmium / Q000097:blood* / Q000633:toxicity; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D004785:Environmental Pollutants / Q000097:blood* / Q000633:toxicity; D005260:Female; D006801:Humans; D015994:Incidence; D007854:Lead / Q000097:blood* / Q000633:toxicity; D008297:Male; D008875:Middle Aged; D053040:Nephrolithiasis / Q000097:blood / Q000139:chemically induced / Q000453:epidemiology*; D011159:Population Surveillance; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D002104:Cadmium; D007854:Lead
keywords: Cadmium; Lead; Nephrolithiasis; Population science; Risk stratification