Person:

Weuve, Jennifer Lynn

Background: Pulse pressure increases with age in industrialized societies as a manifestation of arterial stiffening. Lead accumulates in the vasculature and is associated with vascular oxidative stress, which can promote functional and structural vascular disease. Objectives: We tested the hypothesis that cumulative community-level lead exposure, measured with K-X-ray fluorescence, is associated with pulse pressure in a cohort of adult men. Methods and results: In a cross-sectional analysis of 593 men not treated with antihypertensive medication, tibia lead was positively associated with pulse pressure (p < 0.001). Adjusting for age, race, diabetes, family history of hypertension, education, waist circumference, alcohol intake, smoking history, height, heart rate, fasting glucose, and total cholesterol-to-HDL ratio, increasing quintiles of tibia lead remained associated with increased pulse pressure (ptrend = 0.02). Men with tibia lead above the median (19.0 μg/g) had, on average, a 4.2-mmHg (95% confidence interval, 1.9–6.5) higher pulse pressure than men with tibia lead level below the median. In contrast, blood lead level was not associated with pulse pressure. Conclusions: These data indicate that lead exposure may contribute to the observed increase in pulse pressure that occurs with aging in industrialized societies. Lead accumulation may contribute to arterial aging, perhaps providing mechanistic insight into the observed association of low-level lead exposure with cardiovascular mortality.

Background: Individuals previously exposed to lead remain at risk because of endogenous release of lead stored in their skeletal compartments. However, it is not known if long-term cumulative lead exposure is a risk factor for tooth loss. Objectives: We examined the association of bone lead concentrations with loss of natural teeth. Methods: We examined 333 men enrolled in the Veterans Affairs Normative Aging Study. We used a validated K-shell X-ray fluorescence (KXRF) method to measure lead concentrations in the tibial midshaft and patella. A dentist recorded the number of teeth remaining, and tooth loss was categorized as 0, 1–8 or ≥ 9 missing teeth. We used proportional odds models to estimate the association of bone lead biomarkers with tooth loss, adjusting for age, smoking, diabetes, and other putative confounders. Results: Participants with ≥ 9 missing teeth had significantly higher bone lead concentrations than those who had not experienced tooth loss. In multivariable-adjusted analyses, men in the highest tertile of tibia lead (> 23 μg/g) and patella lead (> 36 μg/g) had approximately three times the odds of having experienced an elevated degree of tooth loss (≥ 9 vs. 0–8 missing teeth or ≥ 1 vs. 0 missing teeth) as those in the lowest tertile [prevalence odds ratio (OR) = 3.03; 95% confidence interval (CI), 1.60–5.76 and OR = 2.41; 95% CI, 1.30–4.49, respectively]. Associations between bone lead biomarkers and tooth loss were similar in magnitude to the increased odds observed in participants who were current smokers. Conclusion: Long-term cumulative lead exposure is associated with increased odds of tooth loss.

Background: Recent data indicate that chronic low-level exposure to lead is associated with accelerated declines in cognition in older age, but this has not been examined in women. Objective: We examined biomarkers of lead exposure in relation to performance on a battery of cognitive tests among older women. Methods: Patella and tibia bone lead—measures of cumulative exposure over many years—and blood lead, a measure of recent exposure, were assessed in 587 women 47–74 years of age. We assessed their cognitive function 5 years later using validated telephone interviews. Results: Mean ± SD lead levels in tibia, patella, and blood were 10.5 ± 9.7 μg/g bone, 12.6 ± 11.6 μg/g bone, and 2.9 ± 1.9 μg/dL, respectively, consistent with community-level exposures. In multivariable-adjusted analyses of all cognitive tests combined, levels of all three lead biomarkers were associated with worse cognitive performance. The association between bone lead and letter fluency score differed dramatically from the other bone lead-cognitive score associations, and exclusion of this particular score from the combined analyses strengthened the associations between bone lead and cognitive performance. Results were statistically significant only for tibia lead: one SD increase in tibia lead corresponded to a 0.051-unit lower standardized summary cognitive score (95% confidence interval: −0.099 to −0.003; p = 0.04), similar to the difference in cognitive scores we observed between women who were 3 years apart in age. Conclusions: These findings suggest that cumulative exposure to lead, even at low levels experienced in community settings, may have adverse consequences for women’s cognition in older age.