PubMed Health⌕ Search

Biomedical subjects

Robert O Wright

Publications and source records attributed to Robert O Wright.

18 recordsLinked to original sources
PubMed2007

Cumulative lead exposure and cognitive performance among elderly men.

BACKGROUND: Recent evidence suggests that cumulative lead exposure among adults in nonoccupational settings can adversely affect cognitive function. Which cognitive domains are affected has not been explored in detail. METHODS: We used nonlinear spline regressions and linear repeated-measures analysis to assess the association between scores on a battery of cognitive tests over time and both blood and bone lead concentrations in the Normative Aging Study, a cohort of community-dwelling elderly men. Bone lead was measured from 1991 through 1999 with K-shell x-ray fluorescence. A total of 1089 men with a mean (+/-standard deviation) age of 68.7 (+/-7.4) years with blood lead measurements, 761 of whom also had valid bone lead measurements, completed at least one of a battery of cognitive tests. Approximately 3.5 years later, 69% of the men had at least one repeat test. Cognitive testing was performed from 1993 through 2001. RESULTS: On a cross-sectional basis, there was little association between blood or bone lead and cognitive test scores. Change in performance over time on virtually all tests worsened as bone lead increased, with the most robust effects on performance and reaction time scores on visuospatial/visuomotor tests. CONCLUSIONS: Low-level cumulative exposure to lead in nonoccupational settings may adversely affect cognitive function, particularly in the visuospatial/visuomotor domain.

Age Factors↗
PubMed2006

HFE genotype, particulate air pollution, and heart rate variability: a gene-environment interaction.

BACKGROUND: Particulate air pollution has been associated with cardiovascular mortality and morbidity. Transition metals such as iron bound to the particles may be responsible for those associations. The protein product of the hemochromatosis (HFE) gene modulates uptake of iron and divalent cations from pulmonary sources and reduces their toxicity. Two HFE polymorphisms (C282Y and H63D) associated with increased iron uptake may modify the effect of metal-rich particles on the cardiovascular system. METHODS AND RESULTS: We investigated the association between particulate matter < or = 2.5 microm in aerodynamic diameter and heart rate variability in 518 older men from the Normative Aging Study who were examined between November 2000 and December 2004. Linear regression models were fit to evaluate interactions between HFE genotype and particulate matter < or = 2.5 microm in aerodynamic diameter in relation to heart rate variability, controlling for potential confounders. A 10-microg/m3 increase in particulate matter < or = 2.5 microm in aerodynamic diameter during the 48 hours before heart rate variability measurement was associated with a 31.7% (95% CI, 10.3% to 48.1%) decrease in the high-frequency component of heart rate variability in persons with the wild-type genotype, whereas no relationship in the high-frequency component was observed in persons with either HFE variant. The difference in effect of particulate matter < or = 2.5 microm in aerodynamic diameter on the high-frequency component between persons with and without HFE variants was significant (P for interaction=0.02). CONCLUSIONS: The effect of particles on cardiac autonomic function was shielded in subjects with at least 1 copy of an HFE variant compared with wild-type subjects. Transition metals, including iron, bound to ambient particles and the related oxidative stress may play an important role in cardiac toxicity of particles.

Adult↗
PubMed2006

Low-level lead exposure, metabolic syndrome, and heart rate variability: the VA Normative Aging Study.

BACKGROUND: Altered heart rate variability (HRV), a marker of poor cardiac autonomic function, has been associated with sudden cardiac death and heart failure. OBJECTIVE: We examined the association of low-level lead exposure measured in bone by K-X-ray fluorescence with alterations in HRV, and whether metabolic syndrome (MetS) or its individual components modify those associations. METHODS: HRV measures [power in high-frequency (HFnorm) and low-frequency (LFnorm) in normalized units, and LF/HF] were taken among 413 elderly men from the Normative Aging Study. MetS was defined as subjects having three or more of the following criteria: abdominal obesity, hypertriglyceridemia, low high-density lipoprotein, high blood pressure, and high fasting glucose. RESULTS: Of the subjects, 32% were identified as having MetS. Inverse but nonstatistically significant associations of both tibia and patella lead levels with HFnorm and nonstatistically significant positive relations with LFnorm and LF/HF were found in the entire cohort. There was a graded, statistically significant reduction in HFnorm and increases in LFnorm and LF/HF in association with an increase in patella lead as the number of metabolic abnormalities increased. We also observed that higher patella lead was consistently associated with lower HFnorm and higher LFnorm and LF/HF among subjects with MetS or its individual components. No statistically significant interaction between MetS and tibia lead was observed. CONCLUSION: The results suggest that elderly men with MetS were more susceptible to autonomic dysfunction in association with chronic lead exposure as measured in patella. The modification by MetS is consistent with a role for oxidative stress in lead toxicity on the cardiovascular system.

Adult↗
PubMed2006

End-tidal carbon dioxide as a measure of acidosis among children with gastroenteritis.

OBJECTIVES: We aimed to determine the correlation between end-tidal carbon dioxide levels and serum bicarbonate concentrations among patients with gastroenteritis, to compare the end-tidal carbon dioxide with other clinical parameters that might also be associated with the degree of acidosis, and to examine the relationship between end-tidal carbon dioxide levels and return visits. METHODS: Our prospective sample included patients presenting to the emergency department with a chief complaint of vomiting and/or diarrhea. The association between end-tidal carbon dioxides and serum bicarbonate concentrations was determined with simple linear-regression analysis. Receiver operating characteristic curves were computed to determine the predictive ability of the end-tidal carbon dioxide to detect metabolic acidosis. RESULTS: One hundred thirty of 146 subjects who were approached were included in the final analysis. For those for whom laboratory studies were performed, the mean serum bicarbonate concentration was 17.3 +/- 4.3 mmol/L and the mean end-tidal carbon dioxide level was 34.2 +/- 5.2 mm Hg. End-tidal carbon dioxide levels and serum bicarbonate concentrations were correlated linearly in bivariate analysis. Receiver operating characteristic curves were calculated for end-tidal carbon dioxide as a predictor of serum bicarbonate concentrations of < or = 13, < or = 15, and < or = 17 mmol/L, with areas under the curves of 0.94, 0.95, and 0.90, respectively. The relationship between end-tidal carbon dioxide levels and serum bicarbonate concentrations was independent of other potential predictors of acidosis in multivariable analysis. The mean end-tidal carbon dioxide level for patients who required an unanticipated return visit (33.0 +/- 4.0 mm Hg) was lower than the level for those who did not seek reevaluation (36.6 +/- 3.6 mm Hg). CONCLUSIONS: End-tidal carbon dioxide levels were correlated with serum bicarbonate concentrations among children with vomiting and diarrhea, independent of other clinical parameters. Capnography offers an objective noninvasive measure of the severity of acidosis among patients with gastroenteritis.

Acidosis, Respiratory↗
PubMed2006

Longitudinal associations between blood lead concentrations lower than 10 microg/dL and neurobehavioral development in environmentally exposed children in Mexico City.

OBJECTIVE: Increasing evidence suggests that 10 microg/dL, the current Centers for Disease Control and Prevention screening guideline for children's blood lead level, should not be interpreted as a level at which adverse effects do not occur. Using data from a prospective study conducted in Mexico City, Mexico, we evaluated the dose-effect relationship between blood lead levels and neurodevelopment at 12 and 24 months of age. METHODS: The study population consisted of 294 children whose blood lead levels at both 12 and 24 months of age were < 10 microg/dL; blood lead levels were measured by graphite furnace atomic absorption spectroscopy; Bayley Scales of Infant Development II were administered at these ages. The outcomes of interest were the Mental Development Index and the Psychomotor Development Index. RESULTS: Adjusting for covariates, children's blood lead levels at 24 months were significantly associated, in an inverse direction, with both Mental Development Index and Psychomotor Development Index scores at 24 months. Blood lead level at 12 months of age was not associated with concurrent Mental Development Index or Psychomotor Development Index scores or with Mental Development Index at 24 months of age but was significantly associated with Psychomotor Development Index score at 24 months. The relationships were not altered by adjustment for cord blood lead level or, in the analyses of 24-month Mental Development Index and Psychomotor Development Index scores, for the 12-month Mental Development Index and Psychomotor Development Index scores. For both Mental Development Index and Psychomotor Development Index at 24 months of age, the coefficients that were associated with concurrent blood lead level were significantly larger among children with blood lead levels < 10 microg/dL than it was among children with levels > 10 microg/dL. CONCLUSIONS: These analyses indicate that children's neurodevelopment is inversely related to their blood lead levels even in the range of < 10 microg/dL. Our findings were consistent with a supralinear relationship between blood lead levels and neurobehavioral outcomes.

Child Behavior Disorders↗
PubMed2005

Neuropsychological correlates of hair arsenic, manganese, and cadmium levels in school-age children residing near a hazardous waste site.

A pilot study was conducted to explore the potential associations between hair metal levels and the neuropsychological function and behavior of school-aged children. Thirty-two children, 11-13 years old, were administered a battery of tests that assessed general intelligence, visual-motor skills, receptive language, verbal memory, nonverbal problem-solving, and behavior problems. Parents and teachers rated the children's attention, executive functions, and behavior problems. The concentrations of manganese (Mn), arsenic (As), and cadmium (Cd) were measured in hair samples provided by 31 of the children. The mean hair metal levels were: Mn, 471.5 parts per billion (ppb); As, 17.8 ppb; Cd, 57.7 ppb. Children's general intelligence scores, particularly verbal IQ scores, were significantly related, inversely, to hair Mn and As levels, as were scores on tests of memory for stories and a word list. In some cases, a significant Mn-by-As interaction was found. It appeared that it was the low scores of children for whom both Mn and As levels were above the median values in the sample that were responsible for the main effects observed for each metal. No other significant relationships were found. These results suggest the need to study further the neuropsychological correlates of developmental exposure to Mn and As, particularly as a mixture.

Arsenic↗
PubMed2005

Bispectral analysis during deep sedation of pediatric oral surgery patients.

PURPOSE: Bispectral (BIS) analysis uses electroencephalogram information from a forehead electrode to calculate an index score (0 to 100; 0 = coma; 90 to 100 = awake). This index score correlates with the level of alertness in anesthetized patients. Classically, sedation has been monitored with clinical sedation scales such as the Observers Assessment of Alertness Sedation Scale (OAA/S), Modified Ramsey Scale, or a Visual Analog Scale (VAS). Our objective was to determine the correlation between clinical sedation scales and BIS index in pediatric patients undergoing sedation in an outpatient oral surgery setting. MATERIALS AND METHODS: Prospective cohort study of patients aged 2 to 17 years undergoing sedation in an outpatient oral surgery office. Sedation was performed in the customary manner with the addition of BIS monitoring. Three clinical sedation scores (OAA/S: 5 to 1; 5 = awake, 1 = unresponsive; Modified Ramsey: 1 to 6; 1-2 = awake, 6 = unresponsive; VAS: 0 to 10; 0 = awake, 10 = unresponsive) were assigned every 5 minutes by an investigator blinded to the BIS index. Data were analyzed using a repeated measures linear regression model. RESULTS: Sixteen subjects undergoing oral surgery, ages 4.5 years to 17 years, were enrolled, mean age 12.6 years +/- 4.3 years (standard deviation). Patients received methohexital in addition to 1 or more of the following: nitrous oxide, fentanyl, or midazolam. The results of the longitudinal regression analysis showed a highly significant association between the sedation scales and the BIS index. CONCLUSION: The BIS monitor may be a useful adjunct in monitoring pediatric patients receiving sedation in the outpatient setting.

Adolescent↗
PubMed2005

Bispectral analysis during pediatric procedural sedation.

OBJECTIVE: Bispectral analysis (BIS) is a technology using EEG information from a forehead electrode to calculate an index (0-100; 0 = coma, 90-100 = awake). Our objective was to determine the degree of agreement between sedation scales and BIS values in pediatric patients undergoing sedation. METHODS: Patients ages 2 to 17 years, undergoing procedural sedation, were enrolled. Sedation was performed in the customary manner with the addition of BIS monitoring and assessment of a clinical sedation scale: the Observer's Assessment of Alertness/Sedation (OAA/S), every 5 minutes during the sedation procedure. Clinical scales were performed by an investigator blinded to the BIS index. The association between a clinical scale and BIS scores was analyzed using longitudinal regression analysis. RESULTS: We enrolled 47 subjects; 55% were sedated with ketamine and midazolam and the remaining 45% received methohexital, propofol or midazolam and a narcotic. The results of the regression analysis demonstrated a highly significant association between the OAA/S score and BIS value (beta = 5.0, 95% CI 4.3 to 5.7, P < 0.0001). Patients were divided into 2 groups, those sedated with ketamine and those sedated with nonketamine medications. The association between OAA/S score and BIS value was not statistically significant for the ketamine population (beta = 0.809, 95% CI -0.1 to 1.7, P = 0.09), but remained significant for the nonketamine subjects (beta = 8.6, 95% CI 7.7 to 9.4, P < 0.0001). CONCLUSIONS: The OAA/S sedation scale predicts the BIS value for pediatric patients undergoing procedural sedation when sedated with certain medications, excluding ketamine.

Adolescent↗
PubMed2005

Maternal fish consumption, hair mercury, and infant cognition in a U.S. Cohort.

Fish and other seafood may contain organic mercury but also beneficial nutrients such as n-3 polyunsaturated fatty acids. We endeavored to study whether maternal fish consumption during pregnancy harms or benefits fetal brain development. We examined associations of maternal fish intake during pregnancy and maternal hair mercury at delivery with infant cognition among 135 mother-infant pairs in Project Viva, a prospective U.S. pregnancy and child cohort study. We assessed infant cognition by the percent novelty preference on visual recognition memory (VRM) testing at 6 months of age. Mothers consumed an average of 1.2 fish servings per week during the second trimester. Mean maternal hair mercury was 0.55 ppm, with 10% of samples > 1.2 ppm. Mean VRM score was 59.8 (range, 10.9-92.5). After adjusting for participant characteristics using linear regression, higher fish intake was associated with higher infant cognition. This association strengthened after adjustment for hair mercury level: For each additional weekly fish serving, offspring VRM score was 4.0 points higher [95% confidence interval (CI), 1.3 to 6.7]. However, an increase of 1 ppm in mercury was associated with a decrement in VRM score of 7.5 (95% CI, -13.7 to -1.2) points. VRM scores were highest among infants of women who consumed > 2 weekly fish servings but had mercury levels </= 1.2 ppm. Higher fish consumption in pregnancy was associated with better infant cognition, but higher mercury levels were associated with lower cognition. Women should continue to eat fish during pregnancy but choose varieties with lower mercury contamination.

Adult↗
PubMed2004

Cumulative lead exposure and prospective change in cognition among elderly men: the VA Normative Aging Study.

Lead exposure has been found to affect cognitive function in several different populations. Whether chronic low-level environmental exposure to lead results in cognitive decline among adults has not been examined. The authors assessed the relation between biomarkers of lead exposure and change in Mini-Mental State Examination (MMSE) scores in the Normative Aging Study, a cohort of elderly US men. Bone lead was measured with K-shell x-ray fluorescence. A total of 466 men aged 67.4 (standard deviation, 6.6) years took the MMSE on two occasions that were an average of 3.5 (standard deviation, 1.1) years apart during the period 1993-2001 and had bone lead concentrations measured during the period 1991-2002. A one-interquartile range (20 microg/g of bone mineral) higher patella bone lead concentration was associated with a change in MMSE score of -0.24 (95% confidence interval: -0.44, -0.05) after adjustment for age, education, smoking, alcohol intake, and time between MMSE tests. This effect is approximately equivalent to that of aging 5 years in relation to the baseline MMSE score in study data. The association with tibia lead was weaker and that with blood lead was absent. The data suggest that higher patella bone lead levels, a marker of mobilizable accumulated lead burden, are associated with a steeper decline over time in performance on the MMSE test among nonoccupationally exposed elderly men.

Adult↗
PubMed2004

Chronic caregiver stress and IgE expression, allergen-induced proliferation, and cytokine profiles in a birth cohort predisposed to atopy.

BACKGROUND: Psychologic stress modifies immune function and cytokine production. OBJECTIVE: We examined relationships between caregiver stress on the following markers of early childhood immune response: (1) IgE expression (n=215); (2) mitogen-induced and allergen-specific (Dermatophagoides farinae [Der f 1] and cockroach [Bla g 2]) proliferative response (n=114); and (3) subsequent cytokine expression (INF-gamma, TNF-alpha, IL-10, and IL-13) in a prospective birth cohort predisposed to atopy. METHODS: Caregiver stress was measured at 2-month intervals for the first 2 years of life and yearly thereafter by using the Perceived Stress Scale. A subsequent blood sample obtained from the children (median age, 2.1 years; range, 18-32 months) was analyzed for total serum IgE level and allergen-induced proliferation quantified as the stimulation index (SI; mean thymidine incorporation of the stimulated sample divided by that of the unstimulated sample). The relationship between stress and the proliferative response (SI >3 vs SI < or =3), and total IgE level (< or =100 IU/mL vs >100 IU/mL) was examined by using logistic regression. The relationship between cytokine levels and stress was analyzed by using linear regression. RESULTS: In adjusted analyses higher caregiver stress in the first 6 months after birth was associated with a Der f 1 SI of greater than 3 (odds ratio [OR], 1.5; 95% CI, 1.0-2.3) and nominally associated with a Bla g 2 SI of greater than 3 (OR, 1.13; 95% CI, 0.7-1.8). Higher stress between ages 6 and 18 months was associated with a high total IgE level (OR, 2.03; 95% CI, 1.1-3.6). Higher stress was significantly associated with increased production of TNF-alpha, with a suggested trend between higher stress and reduced INF-gamma production. CONCLUSION: Increased stress in early childhood was associated with an atopic immune profile in these children predisposed to atopy-asthma.

Allergens↗
PubMed2004

Evaluation of promotility agents to limit the gut bioavailability of extended-release acetaminophen.

BACKGROUND: Erythromycin and neostigmine have both been shown to act as gastrointestinal promotility agents. OBJECTIVES: The purpose of this study was to determine whether either erythromycin or neostigmine, administered parenterally, would result in lower serum levels of a recently ingested drug, when compared with placebo. METHODS: Ten volunteers ingested 1300 mg of extended-release acetaminophen on each of three occasions. They were then given an intravenous dose of erythromycin (200 mg), neostigmine (2 mg), or placebo. Each volunteer received all three treatments in a counterbalanced fashion, each separated from the next by at least two weeks. Blood for serum acetaminophen concentration was drawn at 1, 2, 4, 6 and 8 h after treatment, and the serum acetaminophen elimination curves were compared for the three treatments. RESULTS: The elimination phase of the curves did not differ among the treatments as a result of administration of the prokinetic agents. CONCLUSIONS: Under the present conditions, administration of erythromycin and neostigmine as prokinetic agents failed to alter the kinetics of an ingested dose of sustained-release acetaminophen.

Acetaminophen↗
PubMed2004

Association between hemochromatosis genotype and lead exposure among elderly men: the normative aging study.

Because body iron burden is inversely associated with lead absorption, genes associated with hemochromatosis may modify body lead burden. Our objective was to determine whether the C282Y and/or H63D hemochromatosis gene (HFE) is associated with body lead burden. Patella and tibia lead levels were measured by K X-ray fluorescence in subjects from the Normative Aging Study. DNA samples were genotyped for C282Y and H63D using polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP). A series of multivariate linear regression models were constructed with bone or blood lead as dependent variables; age, smoking, and education as independent variables; and C282Y or H63D as independent risk factors and/or effect modifiers. Of 730 subjects, 94 (13%) carried the C282Y variant and 183 (25%) carried the H63D variant. In the crude analysis, mean tibia, patella, and blood lead levels were consistently lower in carriers of either HFE variant compared with levels in subjects with wild-type genotypes. In multivariate analyses that adjusted for age, smoking, and education, having an HFE variant allele was an independent predictor of significantly lower patella lead levels (p < 0.05). These data suggest that HFE variants have altered kinetics of lead accumulation after exposure. Among elderly men, subjects with HFE variants had lower patella lead levels. These effects may be mediated by alterations in lead toxicokinetics via iron metabolic pathways regulated by the HFE gene product and body iron stores.

Aged↗
PubMed2004

Cognitive deficits and magnetic resonance spectroscopy in adult monozygotic twins with lead poisoning.

Seventy-one-year-old identical twin brothers with chronic lead poisoning were identified from an occupational medicine clinic roster. Both were retired painters, but one brother (J.G.) primarily removed paint and had a history of higher chronic lead exposure. Patella and tibia bone lead concentrations measured by K-X-ray fluorescence in each brother were 5-10 times those of the general population and about 2.5 times higher in J.G. than in his brother (E.G.). Magnetic resonance spectroscopy (MRS) studies examined N-acetylaspartate:creatine ratios, a marker of neuronal density. Ratios were lower in J.G. than in his brother. Scores on neurocognitive tests that assess working memory/executive function were below expectation in both twins. Short-term memory function was dramatically worse in J.G. than in his brother. These results demonstrate some of the more subtle long-term neurologic effects of chronic lead poisoning in adults. In particular, they suggest the presence of frontal lobe dysfunction in both twins, but more dramatic hippocampal dysfunction in the brother with higher lead exposure. The MRS findings are consistent with the hypothesis that chronic lead exposure caused neuronal loss, which may contribute to the impairment in cognitive function. Although a causal relation cannot be inferred, the brothers were genetically identical, with similar life experiences. Although these results are promising, further study is necessary to determine whether MRS findings correlate both with markers of lead exposure and tests of cognitive function. Nevertheless, the results point to the potential utility of MRS in determining mechanisms of neurotoxicity not only for lead but also for other neurotoxicants as well.

Aged↗
PubMed2003

Apolipoprotein E genotype predicts 24-month bayley scales infant development score.

Apolipoprotein E (APOE) regulates cholesterol and fatty acid metabolism, and may mediate synaptogenesis during neurodevelopment. To our knowledge, the effects of APOE4 isoforms on infant development have not been studied. This study was nested within a cohort of mother-infant pairs living in and around Mexico City. A multiple linear regression model was constructed using the 24-mo Mental Development Index (MDI) of the Bayley Scale as the primary outcome and infant APOE genotype as the primary risk factor of interest. Regression models stratified on APOE genotype were constructed to explore effect modification. Of 311 subjects, 53 (17%) carried at least one copy of the APOE4 allele. Mean (SD) MDI scores among carriers with at least one copy of APOE4 were 94.1 (14.3) and among E3/E2 carriers were 91.2 (14.0). After adjustment for covariates, APOE4 carrier status was associated with a 4.4 point (95% confidence interval: 0.1-8.7; p = 0.04) higher 24-mo MDI. In the stratified regression models, the negative effects for umbilical cord blood lead level on 24-mo MDI score was approximately 4-fold greater among APOE3/APOE2 carriers than among APOE4 carriers. These results suggest that subjects with the E4 isoform of APOE may have advantages over those with the E2 or E3 isoforms with respect to early life neuronal/brain development.

Apolipoprotein E2↗
PubMed2003

Association between iron deficiency and blood lead level in a longitudinal analysis of children followed in an urban primary care clinic.

OBJECTIVE: To determine if iron deficiency (ID) is longitudinally associated with lead poisoning. STUDY DESIGN: Blood lead levels, hemoglobin, mean corpuscular volume (MCV), red cell distribution width (RDW), insurance status, and age were determined for 1,275 children. ID was defined as MCV <70 fl and RDW >14.5 if age was <2 years and MCV <73 fl and RDW >14.5 if age was >/=2 years. Logistic regression models were constructed by using the second-visit blood lead levels dichotomized at >/=0.48 microm/L (10 microg/dL) as the outcome. RESULTS: The odds ratio (OR) for baseline ID predicting lead poisoning at the second visit was 4.12 (95% CI, 1.96-8.65). In the second model, using children who were iron-replete at both visits as the referent group, for children with ID at both visits, the OR for predicting lead poisoning at the second visit was 5.54 (95% CI, 2.25-13.62). For children with ID at the first visit and iron-replete at the second visit, the OR was 2.73 (95% CI, 0.90-8.27), and for children iron-replete at the first visit and ID at the second visit, the OR was 0.81 (95% CI, 0.10-6.30). CONCLUSIONS: ID is associated with subsequent lead poisoning. These data are consistent with a biological mechanism of increased lead absorption among iron deficient children.

Anemia, Iron-Deficiency↗
PubMed2003

Lead exposure biomarkers and mini-mental status exam scores in older men.

BACKGROUND: Lead is neurotoxic; yet, whether cognitive decline in older persons is associated with lead exposure is unknown. We studied whether lead exposure biomarkers are associated with cognitive test scores, as well as the modifying effects of age on the lead-cognition relationship. METHODS: Lead exposure biomarkers and Mini-Mental Status Exam (MMSE) scores were measured among subjects in the Normative Aging Study. Multiple linear and logistic regression analyses were performed to examine the cross-sectional association of these 2 variables. RESULTS: We found an odds ratio (OR) of 2.1 for MMSE <24 with an increase from the lowest to the highest quartile of patella lead levels (95% confidence interval [CI] = 1.1 to 4.1). From the lowest to the highest quartile of blood lead the OR for low MMSE was 3.4 (CI = 1.6 to 6.2). There was an interaction between lead biomarkers and age. Among subjects in the lowest quartile of patella lead levels, MMSE score decreased by 0.03 points per year (CI = -0.07 to 0.005), whereas in the highest quartile, MMSE score decreased by 0.13 points per year (CI = -0.19 to -0.07). Similar interactions were found between blood lead levels and age. CONCLUSIONS: Increased levels of lead in bone and blood are inversely associated with cognitive performance among older men. Lead exposure might accelerate age-associated cognitive decline.

Aged↗