Transition of cord blood lead level, 1985-2002, in the Taipei area and its determinants after the cease of leaded gasoline use.

Lead has long been of concern for its toxicity, impairment of neurobehavioral and cognitive development, and electrophysiological deficits in children, even at levels less than 10 microg/dL. The present study was conducted to elucidate the extent of cord blood lead level decline in the Taipei area from 1985 to 2002 and to explore the factors affecting the cord blood lead level after the cease of leaded gasoline use. In the current study period of 2001-2002, 184 of 1310 newborns delivered in the Taipei Municipal Women and Children Hospital between September 2001 and August 2002 were eligible and randomly selected to participate in this study. Neither of their parents had an occupational lead exposure history. At each delivery, a sample of 5-10 mL umbilical cord blood was collected for lead determination by graphite furnace atomic absorption spectrometry. The cord blood lead level of the newborns in the current study period averaged 2.35 +/- 1.12 microg/dL. Together with the cord blood lead averages of 7.48 +/- 2.25 and 3.28 +/- 1.52 microg/dL obtained from two previous surveys conducted in 1985-1987 and 1990-1992, respectively, the cord blood lead level was significantly decreased (P < 0.005). It is estimated that such a reduction in cord blood lead from 7.48 to 2.35 microg/dL for each year's cohort of 260,000 newborns in Taiwan might benefit the economics, ranging from US$8.9 billion to US$12.1 billion by improving the worker productivity. For the time period from 1985 to 2002, there were consistent transition patterns among the yearly fluctuations of air lead level, leaded gasoline consumption, lead content in gasoline, estimated lead amount emitted from the consumed leaded gasoline, and average cord blood lead levels of the three respective study periods. Additionally, every 0.1-g/L reduction in lead content in gasoline might lead to a lowering of cord blood lead level by 1.78 microg/dL. Furthermore, at low level of around 2 microg/dL, a multiple regression analysis demonstrated that economic status was the most influential factor for cord blood lead variation (P = 0.0061) while the maternal working month during her pregnancy was retained in the model with borderline effect (P = 0.0625). After accounting for the effect of leaded gasoline on the cord blood lead level, future study to differentiate the primary contributors for the low-level cord blood lead variation around 1-2 microg/dL is warranted.

Cord plasma concentrations of adiponectin and leptin in healthy term neonates: positive correlation with birthweight and neonatal adiposity.

OBJECTIVE: Adiponectin is negatively associated with leptin, insulin and obesity in children and adults. Whereas increases in fetal insulin and leptin are associated with increased weight and adiposity at birth, the role of adiponectin in fetal growth has not yet been determined. The aims of this study were to examine the relationships between adiponectin and insulin, leptin, weight and adiposity at birth in healthy term infants. DESIGN AND METHODS: Anthropometric parameters including weight, length, circumferences and skinfold thickness were measured, and plasma lipid profiles, insulin, leptin and adiponectin concentrations in cord blood samples from 226 singleton infants born at term after uncomplicated pregnancies were assayed. RESULTS: Cord plasma adiponectin, leptin and insulin levels correlated significantly and positively with birthweight (P = 0.001, P < 0.001, P < 0.001, respectively) and the sum of skinfold thicknesses (P < 0.001, P < 0.001, P < 0.001, respectively). Mean cord plasma adiponectin and leptin levels, but not insulin level, were significantly higher in large-for-gestational-age (LGA) infants compared with appropriate-for-gestational-age (AGA) infants. Cord plasma leptin concentration, but not adiponectin concentration, was significantly higher in female infants than in male infants (P = 0.003 and P = 0.94, respectively). Cord plasma adiponectin concentration correlated positively with leptin level (P = 0.007) but not with insulin level (P = 0.78). CONCLUSIONS: High adiponectin levels are present in the cord blood. Cord plasma adiponectin and leptin levels are positively correlated with birthweight and adiposity. This suggests that adiponectin may be involved in regulating fetal growth.