Prenatal lead exposure and childhood blood pressure and kidney function.
BACKGROUND
Exposure to lead, a common environmental pollutant, is known to cause cardiovascular and nephrotoxic effects in adults. Potential effects of early-life lead exposure on these functions are, however, less well characterized.


OBJECTIVE
To assess blood pressure and kidney function in preschool-aged children in relation to prenatal lead exposure.


METHODS
This prospective study in rural Bangladesh measured children's systolic and diastolic blood pressure in triplicate at the follow-up at 4.5±0.11 years. Their kidney function was assessed by the estimated glomerular filtration rate (eGFR), calculated based on serum cystatin C concentrations, and by kidney volume, measured by sonography. Exposure to lead was assessed by concentrations in the mothers' blood (erythrocyte fraction; Ery-Pb) in gestational weeks (GW) 14 and 30, the effects of which were evaluated separately in multivariable-adjusted linear regression analyses.


RESULTS
We found no associations between maternal exposure to lead [n~1500 for GW14 and 700 for GW30] and children's blood pressure or eGFR. However, we found an inverse association between late gestation lead and kidney volume, although the sample size was limited (n=117), but not with early gestation lead (n=573). An increase of 85µg/kg in Ery-Pb (median concentration at GW30) was associated with a 6.0cm3/m2decrease in kidney volume (=0.4SD; p=0.041). After stratifying on gender, there seemed to be a somewhat stronger association in girls.


CONCLUSIONS
Prenatal lead exposure may cause long-lasting effects on the kidney. This warrants follow-up studies in older children, as well as additional studies in other populations.
Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Helena
H
Skröder
London School of Hygiene and Tropical Medicine, London, UK.
Sophie
S
Hawkesworth
MRC Human Nutrition Research, Cambridge, UK.
Sophie E
SE
Moore
Department of Clinical Trial and Clinical Epidemiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
Yukiko
Y
Wagatsuma
Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Maria
M
Kippler
Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. Electronic address: marie.vahter@ki.se.
Marie
M
Vahter
D001459:Bangladesh; D001794:Blood Pressure / Q000187:drug effects*; D002675:Child, Preschool; D004785:Environmental Pollutants / Q000097:blood / Q000633:toxicity*; D005260:Female; D005865:Gestational Age; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D006801:Humans; D007668:Kidney / Q000187:drug effects* / Q000503:physiopathology; D007854:Lead / Q000097:blood / Q000633:toxicity*; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000097:blood / Q000139:chemically induced* / Q000503:physiopathology; D012423:Rural Health; D012737:Sex Factors
D004785:Environmental Pollutants; D007854:Lead
Blood pressure; Children; Kidney function; Lead; Prenatal exposure