Diabetes, antidiabetic medications, and pancreatic cancer risk: an analysis from the International Pancreatic Cancer Case-Control Consortium.

BACKGROUND: Type 2 diabetes mellitus has been associated with an excess risk of pancreatic cancer, but the magnitude of the risk and the time-risk relationship are unclear, and there is limited information on the role of antidiabetic medications. PATIENTS AND METHODS: We analyzed individual-level data from 15 case-control studies within the Pancreatic Cancer Case-Control Consortium, including 8305 cases and 13 987 controls. Pooled odds ratios (ORs) were estimated from multiple logistic regression models, adjusted for relevant covariates. RESULTS: Overall, 1155 (15%) cases and 1087 (8%) controls reported a diagnosis of diabetes 2 or more years before cancer diagnosis (or interview, for controls), corresponding to an OR of 1.90 (95% confidence interval, CI, 1.72-2.09). Consistent risk estimates were observed across strata of selected covariates, including body mass index and tobacco smoking. Pancreatic cancer risk decreased with duration of diabetes, but a significant excess risk was still evident 20 or more years after diabetes diagnosis (OR 1.30, 95% CI 1.03-1.63). Among diabetics, long duration of oral antidiabetic use was associated with a decreased pancreatic cancer risk (OR 0.31, 95% CI 0.14-0.69, for ≥15 years). Conversely, insulin use was associated with a pancreatic cancer risk in the short term (OR 5.60, 95% CI 3.75-8.35, for <5 years), but not for longer duration of use (OR 0.95, 95% CI 0.53-1.70, for ≥15 years). CONCLUSION: This study provides the most definitive quantification to date of an excess risk of pancreatic cancer among diabetics. It also shows that a 30% excess risk persists for more than two decades after diabetes diagnosis, thus supporting a causal role of diabetes in pancreatic cancer. Oral antidiabetics may decrease the risk of pancreatic cancer, whereas insulin showed an inconsistent duration-risk relationship.

Ulcer, gastric surgery and pancreatic cancer risk: an analysis from the International Pancreatic Cancer Case-Control Consortium (PanC4).

BACKGROUND: Peptic ulcer and its treatments have been associated to pancreatic cancer risk, although the evidence is inconsistent. METHODS: We pooled 10 case-control studies within the Pancreatic Cancer Case-control Consortium (PanC4), including 4717 pancreatic cancer cases and 9374 controls, and estimated summary odds ratios (OR) using multivariable logistic regression models. RESULTS: The OR for pancreatic cancer was 1.10 [95% confidence interval (CI) 0.98-1.23] for history of ulcer (OR = 1.08 for gastric and 0.97 for duodenal ulcer). The association was stronger for a diagnosis within 2 years before cancer diagnosis (OR = 2.43 for peptic, 1.75 for gastric, and 1.98 for duodenal ulcer). The OR was 1.53 (95% CI 1.15-2.03) for history of gastrectomy; however, the excess risk was limited to a gastrectomy within 2 years before cancer diagnosis (OR = 6.18, 95% CI 1.82-20.96), while no significant increased risk was observed for longer time since gastrectomy. No associations were observed for pharmacological treatments for ulcer, such as antacids, H2-receptor antagonists, or proton-pump inhibitors. CONCLUSIONS: This uniquely large collaborative study does not support the hypothesis that peptic ulcer and its treatment materially affect pancreatic cancer risk. The increased risk for short-term history of ulcer and gastrectomy suggests that any such association is due to increased cancer surveillance.

Vitamin B12 and homocysteine status during pregnancy in the metformin in gestational diabetes trial: responses to maternal metformin compared with insulin treatment.

AIM: The aim of the study is to compare the effects of metformin and insulin treatment for gestational diabetes mellitus (GDM) on vitamin B12 and homocysteine (Hcy) status. METHODS: Women with GDM, who met criteria for insulin treatment, were randomly assigned to metformin (n = 89) or insulin (n = 91) in the Adelaide cohort of the metformin in gestational diabetes (MiG) trial. Fasting serum total vitamin B12 (TB12), holotranscobalamin (HoloTC), a marker of functional B12 status and plasma Hcy concentrations were measured at 20-34 weeks (at randomization) and 36 weeks gestation, then at 6-8 weeks postpartum. RESULTS: Circulating TB12, HoloTC and Hcy were similar in both treatment groups at each time point. Women who were taking dietary folate supplements at randomization had higher serum TB12 and HoloTC at randomization than those not taking folate. Overall, serum TB12 fell more between randomization and 36 weeks gestation in the metformin group than in the insulin group (metformin: -19.7 ± 4.7 pmol/l, insulin: -6.4 ± 3.6 pmol/l, p = 0.004). The decrease in serum TB12 during treatment was greater with increasing treatment duration in metformin-treated (p < 0.001), but not in insulin-treated women. CONCLUSIONS: Total, but not bioavailable, vitamin B12 stores were depleted during pregnancy to a greater extent in metformin-treated than in insulin-treated women with GDM, but neither analyte differed between groups at any stage. This adds further evidence supporting metformin as a safe alternative treatment to insulin in GDM. Further investigation is needed to evaluate whether women treated with metformin for longer periods in pregnancy require additional B12 or other supplementation.

Alcohol consumption and pancreatic cancer: a pooled analysis in the International Pancreatic Cancer Case-Control Consortium (PanC4).

BACKGROUND: Heavy alcohol drinking has been related to pancreatic cancer, but the issue is still unsolved. METHODS: To evaluate the role of alcohol consumption in relation to pancreatic cancer, we conducted a pooled analysis of 10 case-control studies (5585 cases and 11,827 controls) participating in the International Pancreatic Cancer Case-Control Consortium. We computed pooled odds ratios (ORs) by estimating study-specific ORs adjusted for selected covariates and pooling them using random effects models. RESULTS: Compared with abstainers and occasional drinkers (< 1 drink per day), we observed no association for light-to-moderate alcohol consumption (≤ 4 drinks per day) and pancreatic cancer risk; however, associations were above unity for higher consumption levels (OR = 1.6, 95% confidence interval 1.2-2.2 for subjects drinking ≥ 9 drinks per day). Results did not change substantially when we evaluated associations by tobacco smoking status, or when we excluded participants who reported a history of pancreatitis, or participants whose data were based upon proxy responses. Further, no notable differences in pooled risk estimates emerged across strata of sex, age, race, study type, and study area. CONCLUSION: This collaborative-pooled analysis provides additional evidence for a positive association between heavy alcohol consumption and the risk of pancreatic cancer.

Cigarette smoking and pancreatic cancer: an analysis from the International Pancreatic Cancer Case-Control Consortium (Panc4).

BACKGROUND: To evaluate the dose-response relationship between cigarette smoking and pancreatic cancer and to examine the effects of temporal variables. METHODS: We analyzed data from 12 case-control studies within the International Pancreatic Cancer Case-Control Consortium (PanC4), including 6507 pancreatic cases and 12 890 controls. We estimated summary odds ratios (ORs) by pooling study-specific ORs using random-effects models. RESULTS: Compared with never smokers, the OR was 1.2 (95% confidence interval [CI] 1.0-1.3) for former smokers and 2.2 (95% CI 1.7-2.8) for current cigarette smokers, with a significant increasing trend in risk with increasing number of cigarettes among current smokers (OR=3.4 for ≥35 cigarettes per day, P for trend<0.0001). Risk increased in relation to duration of cigarette smoking up to 40 years of smoking (OR=2.4). No trend in risk was observed for age at starting cigarette smoking, whereas risk decreased with increasing time since cigarette cessation, the OR being 0.98 after 20 years. CONCLUSIONS: This uniquely large pooled analysis confirms that current cigarette smoking is associated with a twofold increased risk of pancreatic cancer and that the risk increases with the number of cigarettes smoked and duration of smoking. Risk of pancreatic cancer reaches the level of never smokers ∼20 years after quitting.

Cigar and pipe smoking, smokeless tobacco use and pancreatic cancer: an analysis from the International Pancreatic Cancer Case-Control Consortium (PanC4).

BACKGROUND: Cigarette smoking is the best-characterized risk factor for pancreatic cancer. However, data are limited for other tobacco smoking products and smokeless tobacco. MATERIALS AND METHODS: We conducted a pooled analysis of cigar and pipe smoking and smokeless tobacco use and risk of pancreatic cancer using data from 11 case-control studies (6056 cases and 11,338 controls) within the International Pancreatic Cancer Case-Control Consortium (PanC4). Pooled odds ratios (OR) and the corresponding 95% confidence intervals (CI) were estimated by unconditional multiple logistic regression models adjusted for study center and selected covariates. RESULTS: Compared with never tobacco users, the OR for cigar-only smokers was 1.6 (95% CI: 1.2-2.3), i.e. comparable to that of cigarette-only smokers (OR 1.5; 95% CI 1.4-1.6). The OR was 1.1 (95% CI 0.69-1.6) for pipe-only smokers. There was some evidence of increasing risk with increasing amount of cigar smoked per day (OR 1.82 for ≥ 10 grams of tobacco), although not with duration. The OR for ever smokeless tobacco users as compared with never tobacco users was 0.98 (95% CI 0.75-1.3). CONCLUSION: This collaborative analysis provides evidence that cigar smoking is associated with an excess risk of pancreatic cancer, while no significant association emerged for pipe smoking and smokeless tobacco use.

Consumption of untreated tank rainwater and gastroenteritis among young children in South Australia.

BACKGROUND: Tank rainwater is a source of untreated drinking water in Australia and elsewhere. The aim of this study was to determine whether the risk of gastroenteritis among children who drank tank rainwater differed from that of children who drank treated public mains water. METHODS: A cohort study of 1,016 4- to 6-year old children who drank rainwater or treated mains water in rural South Australia was undertaken in 1999. Parents kept a daily diary of their child's gastrointestinal symptoms and water consumption for a period of 6 weeks. Data on respiratory illness and other risk factors for gastroenteritis were also collected. RESULTS: The incidence of gastroenteritis among children was 3.8-5.3 episodes per child-year, but most episodes (60%) lasted just 1 day. No increase in odds of gastroenteritis was observed among children who drank rainwater compared with treated mains water. The adjusted odds ratio for gastroenteritis associated with rainwater consumption compared with mains consumption was 0.84 (95% confidence interval 0.63-1.13). CONCLUSIONS: Gastroenteritis was found to be a significant cause of morbidity among young children. Young children, who were regular consumers of tank rainwater, were at no greater odds of gastroenteritis than those who drank treated public mains water.

A two-year prospective study of the health-related quality of life of children with chronic illness--the parents' perspective.

The aim of this study was to assess prospectively changes in the health-related quality of life (HRQL) of children and adolescents with diabetes, asthma or cystic fibrosis (CF). One hundred and twenty-two parents of children aged 10-16 years with asthma, diabetes, or CF were recruited from specialist paediatric clinics. Parents described their children's HRQL using the Child Health Questionnaire (PF98) at baseline, 6, 12, 18 and 24 months post-baseline. They reported that the general health of children with CF was significantly worse than that of children with asthma and diabetes at baseline. In other domains there were few differences between the HRQL of children in the three groups. In several domains, the HRQL of children with asthma or diabetes improved over the 2 years of the study. This improvement was less evident for children with CF.

The relationship between health-related quality of life, pain and coping strategies in juvenile idiopathic arthritis.

OBJECTIVES: To investigate the relationship between health-related quality of life (HRQL), experience of pain and pain coping strategies in children with juvenile idiopathic arthritis (JIA). To compare reports describing these variables obtained from children and their parents. METHODS: Participants were 59 children aged 8 to 18 yr with JIA and their parents. Parents and children completed the PedsQL generic core scales and arthritis module, the visual analogue scale of the Varni-Thompson Pediatric Pain Questionnaire, and the Waldron/Varni Pediatric Pain Coping Inventory. Parents rated children's functional disability using the Childhood Health Assessment Questionnaire. RESULTS: Parents reported significantly lower scores (indicating worse HRQL) than children on five of the eight PedsQL scales rating children's HRQL. Parents and children reported a significant negative relationship between pain levels and the PedsQL scores assessing children's physical, emotional and social functioning. They also reported a significant negative relationship between scores on several pain coping scales and scores on the PedsQL scales. However, the pattern of these relationships varied for reports from parents and children. CONCLUSIONS: Pain intensity and pain coping strategies have a significant and independent relationship with several domains that comprise the HRQL of children with JIA. However, parents and children have differing perceptions of the nature of these relationships. The differences emphasize the importance of clinicians obtaining information about children's HRQL, pain levels and pain coping strategies from both parents and children.

Depression among Australian adolescents.

OBJECTIVES: To examine the prevalence and factors associated with depression in Australian adolescents. DESIGN: A representative, multistage probability sample of Australian households conducted in 1998 (part of the National Survey of Mental Health and Well-being). Adolescents completed self-report questionnaires and parents were interviewed using a lay-administered, structured psychiatric interview and several questionnaires. PARTICIPANTS: 1,490 adolescents aged 13-17 years and their parent or main caregiver. MAIN OUTCOME MEASURES: Prevalence of depression in adolescents, as reported by parents and by adolescents themselves; demographic factors; health-risk behaviours; and rate of use of support services. RESULTS: Of the 1,490 adolescents originally sampled, 150 (10%) did not complete responses to questions on depression and were excluded from the analysis. Seventy of the remaining 1340 adolescents (5.2%; 95% CI, 4.0%-6.4%) met criteria for self-reported depression. Agreement between parent- and adolescent-reported depression was poor (kappa=0.27). Adolescent-reported depression was associated with increased suicide plans (odds ratio [OR], 2.83; 95% CI, 1.19-6.70) and attempts (OR, 9.05; 95% CI, 3.49-23.50) in the previous year, use of marijuana 10 or more times in the previous month (OR, 2.88; 95% CI, 1.25-6.64), having conduct disorder (OR, 4.09; 95% CI, 1.23-13.63) and use of school support services (OR, 4.71; 95% CI, 1.82-12.22). Those who used any kind of support service (24/70; 34%) used a mean of 2.9 services (mode, 2; range, 1-5). Three per cent (2/70) of depressed adolescents had been treated with antidepressants. CONCLUSIONS: Depressed adolescents exhibit higher rates of health-risk behaviours and psychosocial impairment than non-depressed adolescents, but only a small number receive appropriate treatment. Staff working in school-based services should be trained to identify adolescents with depression and facilitate referral for treatment.

Efficacy of once-daily tobramycin monotherapy for acute pulmonary exacerbations of cystic fibrosis: a preliminary study.

Our objective was to compare the efficacy, safety, and microbiology of once-daily intravenous (IV) tobramycin with conventional 8-hourly tobramycin/ceftazidime IV therapy for acute Pseudomonas aeruginosa (PA) pulmonary exacerbations in cystic fibrosis (CF). CF patients with PA-induced pulmonary exacerbations were allocated to receive either once-daily tobramycin (Mono) or conventional therapy with tobramycin/ceftazidime given 8-hourly (Conv). The two longitudinal groups received therapy in a double-blind, randomized manner over a period of 2 years. Tobramycin doses were adjusted to achieve a daily area under the time-concentration curve of 100 mg x hr/L in both groups. Results were assessed for both short-term changes (efficacy and safety after 10 days of IV antibiotics during acute exacerbations) and long-term changes (efficacy, safety, and sputum microbiology between study entry and exit). Pulmonary function tests (PFTs) on admission were similar in both groups. After 10 days of IV antibiotics, absolute mean improvements in percent of predicted PFTs were 12.8, 12.1, and 13.7 for forced expiratory volume in 1 sec (FEV(1)), forced vital capacity (FVC), and forced expired flow between 25--75% of FVC (FEF(25--75%)) in the Conv group (n = 51 admissions) compared to 10.6, 9.9, and 10.6 in the Mono group (n = 47)(P<0.05 for all). Sixteen percent in the Conv group and 15% of patients in the Mono group did not respond to therapy by day 10. Long-term PFT patterns were similar for the Conv and Mono groups. The time between admissions did not differ. The Mono group showed a significant increase in tobramycin minimum inhibitory concentrations (MICs) against PA from study entry to study exit (P = 0.02, n = 27 strains); this failed to reach significance in the Conv group (P = 0.08, n = 25). There was no significant increase in the number of isolates, with MIC> or =8 mg/L in both groups. No short- or long-term changes in audiology or serum creatinine were found in either group. After 10 days of IV therapy, the urinary enzyme N-acetyl-beta-d-glucosaminidase/creatinine ratios increased in both groups (P0.05). This increase was greater in the Conv compared to the Mono group (P < 0.05). We conclude that this pilot study indicates once-daily tobramycin therapy to be as effective and safe as conventional 8-hourly tobramycin/ceftazidime therapy. Combination antibacterial therapy appears to offer no clinical advantage over once-daily tobramycin monotherapy. Tobramycin once-daily monotherapy is a potential alternative to conventional IV antibacterial therapy which deserves further investigation, including the impact on susceptibility of PA to tobramycin.

The mental health of young people in Australia: key findings from the child and adolescent component of the national survey of mental health and well-being.

OBJECTIVE: To identify the prevalence of three mental disorders (Depressive Disorder, Conduct Disorder and Attention-Deficit/Hyperactivity Disorder), the prevalence of mental health problems, the health-related quality of life of those with problems, and patterns of service utilisation of those with and without mental health problems, among 4-17-year-olds in Australia. To identify rates of health-risk behaviours among adolescents with mental health problems. METHOD: The mental disorders were assessed using the parent-version of the Diagnostic Interview Schedule for Children Version IV. Parents completed the Child Behaviour Checklist to identify mental health problems and standard questionnaires to assess health-related quality of life and service use. The Youth Risk Behaviour Questionnaire completed by adolescents was employed to identify health-risk behaviours. RESULTS: Fourteen percent of children and adolescents were identified as having mental health problems. Many of those with mental health problems had problems in other areas of their lives and were at increased risk for suicidal behaviour. Only 25% of those with mental health problems had attended a professional service during the six months prior to the survey. CONCLUSION: Child and adolescent mental health problems are an important public health problem in Australia. The appropriate balance between funding provided for clinical interventions focusing on individual children and families and funding for interventions that focus on populations, requires careful study. The latter are an essential component of any strategy to reduce mental health problems as the high prevalence of problems makes it unlikely that individual care will ever be available for all those needing help. Clinical and population health interventions must take into account the comorbid problems experienced by children with mental disorders.

Interactions between environmental lead exposure and sociodemographic factors on cognitive development.

A total of 375 children who lived in Port Pirie, South Australia, and surrounding towns were followed from birth to ages 11-13 y. Possible interactions between lifetime average blood lead concentration and sociodemographic factors (including gender, parents' occupational prestige [as a surrogate of socioeconomic status], quality of home environment, and maternal intelligence quotient) on children's intelligence quotients were examined. Although no statistically significant interaction between blood lead concentration and any of these covariates was found, the results suggested that-after adjustment for a wide range of covariates--children from socially disadvantaged backgrounds (adjusted regression coefficient = -9.6 intelligence quotient points per log unit of blood lead concentration; 95% confidence interval = -2.5, -17.7) were more sensitive to the effects of lead than those of a higher socioeconomic status (adjusted regression coefficient = -2.9; 95% confidence interval = 3.8, -9.6). In addition, girls (adjusted regression coefficient = -7.4; 95% confidence interval = -1.7, -13.1) were more sensitive to the effects of lead than boys (adjusted regression coefficient = -2.6; 95% confidence interval = 2.9, -8.0). These results were basically consistent with our findings observed at ages 2 y, 4 y, and 7 y.

Otoacoustic emissions in 28 young adults exposed to amplified music.

Popular concern about widespread damage to the hearing from exposure to amplified music continues, although there has been little firm evidence of permanent effects in casual listeners. Measurement of transient evoked otoacoustic emissions (TEOAEs) provides a sensitive technique for testing outer hair cell (OHC) function, and was used in this study of 28 young adults aged 18-25 years, whose only significant source of noise exposure was loud music, to look for evidence of poorer cochlear function in those of greater exposure; they provided 27 right ears and 27 left ears suitable for measurement of TEOAE strength. Estimates of subjects' total noise dose were obtained from self-reports of the duration and intensity of their exposure to music and other sources of noise. Ears with greater exposure to loud music showed significantly weaker TEOAEs than less exposed ears in response to a 4 kHz tone burst, or in response to a saturating (82 dBSPL) click if the response was treated with a high-frequency bandpass filter (2-4 kHz) (p<0.05). Differences between more exposed and less exposed groups of ears were most marked in the 2 kHz half-octave band for right ears, and in the 2.8 kHz half-octave band for left ears. A hypothesis is proposed that weakness in TEOAEs as a result of exposure to loud music is seen first in the 2 kHz region of the emission spectrum, and later at higher frequencies; and that for a given amount of exposure, TEOAE weakness (or OHC damage) is more advanced in left ears than in right.

Lifetime low-level exposure to environmental lead and children's emotional and behavioral development at ages 11-13 years. The Port Pirie Cohort Study.

The Port Pirie Cohort Study is the first study to monitor prospectively the association between lifetime blood lead exposure and the prevalence of emotional and behavioral problems experienced by children. Lead exposure data along with ratings on the Child Behavior Checklist were obtained for 322 11-13-year-old children from the lead smelting community of Port Pirie, Australia. Mean total behavior problem score (95% confidence interval (CI)) for boys whose lifetime average blood lead concentration was above 15 microg/dl was 28.7 (24.6-32.8) compared with 21.1 (17.5-24.8) in boys with lower exposure levels. The corresponding mean scores (95% CI) for girls were 29.7 (25.3-34.2) and 18.0 (14.7-21.3). After controlling for a number of confounding variables, including the quality of the child's HOME environment (assessed by Home Observation for Measurement of the Environment), maternal psychopathology, and the child's IQ, regression modeling predicted that for a hypothetical increase in lifetime blood lead exposure from 10 to 30 microg/dl, the externalizing behavior problem score would increase by 3.5 in boys (95% CI 1.6-5.4), and by 1.8 (95% CI -0.1 to 11.1) in girls. Internalizing behavior problem scores were predicted to rise by 2.1 (95% CI 0.0-4.2) in girls but by only 0.8 (95% CI -0.9 to 2.4) in boys.

Sociodemographic and behavioural determinants of blood lead concentrations in children aged 11-13 years. The Port Pirie Cohort Study.

OBJECTIVE: To describe the determinants of blood lead concentration in children with long term environmental exposure to lead. DESIGN: Prospective cohort study. SETTING: The lead smelting town of Port Pirie, South Australia, and surrounding townships. PARTICIPANTS: 326 children born in and around Port Pirie, 1979-1982, followed up until age 11-13 years in 1993-1994. MAIN OUTCOME MEASURES: Blood lead concentrations assessed at birth and at multiple ages up to 11-13 years; average lifetime blood lead concentration. RESULTS: Mean blood lead concentration rose sharply over the ages 6 to 15 months, reached a maximum around 2 years of age, and declined steadily as the children grew older. There was no difference in blood lead concentration between boys and girls until they reached the age of 11-13 years, when mean blood lead concentration in boys (8.4 micrograms/dL [0.41 mumol/L]) was slightly higher than in girls (7.5 micrograms/dL [0.36 mumol/L]). Residential area and father's employment site were the two variables most strongly predictive of a child's blood lead concentration at the end of primary school. Poorer-quality home environment was also found to be an independent contributor to blood lead concentrations. CONCLUSIONS: Age-related factors, and possibly recent concerted efforts to decrease entry or re-entrainment of lead into the environment at Port Pirie, have resulted in most children in our study having blood lead concentrations below 10 micrograms/dL (0.48 mumol/L) at the end of their primary school years. Lead exposure during a child's early years remains an important contributor to average lifetime exposure.

Declining blood lead levels and changes in cognitive function during childhood: the Port Pirie Cohort Study.

CONTEXT: Many studies have found a significant inverse association between early exposure to environmental lead and cognitive function in childhood. Whether these effects are reversible when exposure is reduced is not clear. OBJECTIVE: To assess the reversibility of the apparent effects of lead on cognitive abilities in early childhood by testing whether declines in blood lead concentrations beyond the age of 2 years are associated with improvements in cognition. SETTING: Urban and rural communities surrounding a large lead smelter in Port Pirie, South Australia. PARTICIPANTS: A total of 375 children followed up from birth to the age of 11 to 13 years. DESIGN: Long-term prospective cohort study. MAIN OUTCOME MEASURES: The Bayley Mental Development Index at age 2 years, the McCarthy General Cognitive Index at age 4 years, and IQs from the Wechsler Intelligence Scale (revised version) at ages 7 and 11 to 13 years. RESULTS: Mean blood lead concentrations in the children decreased from 1.02 pmol/L (21 .2 microg/dL) at age 2 years to 0.38 micromol/L (7.9 microg/dL) at age 1 1 to 13 years, but cognitive scores in children whose blood lead concentration declined most were generally not improved relative to the scores of children whose blood lead levels declined least. Changes in IQ and declines in blood lead levels that occurred between the ages of 7 and 11 to 13 years (r= 0.12, P= .09) suggested slightly better cognition among children whose blood lead levels declined most. CONCLUSION: The cognitive deficits associated with exposure to environmental lead in early childhood appear to be only partially reversed by a subsequent decline in blood lead level.