Blood mercury levels and neurobehavioral function

Context  Due to its cardiovascular benefits, fish consumption is widely encouraged among older Americans. However, this fast-growing population is at increased risk of cognitive impairment and may be particularly sensitive to methylmercury, a neurotoxicant found in fish. Objective  To describe associations of blood mercury levels with neurobehavioral test scores in an urban adult population. Design, Setting, and Participants  Cross-sectional analysis to determine the effect of mercury levels on neurobehavior in 474 randomly selected participants in the Baltimore Memory Study, a longitudinal study of cognitive decline involving 1140 Baltimore residents aged 50 to 70 years. We measured total mercury in whole blood samples and used multiple linear regression to examine its associations with neurobehavioral test scores. First-visit data were obtained in 2001-2002. Main Outcome Measures  Twenty scores from 12 neurobehavioral tests. Results  The median blood mercury level was 2.1 µg/L (range, 0-16 µg/L). After adjustment for covariates, increasing blood mercury was associated with worse performance on Rey complex figure delayed recall, a test of visual memory (, –0.224; 95% confidence interval, –0.402 to –0.047). However, increasing blood mercury levels were associated with better performance on finger tapping, a test of manual dexterity ( for dominant hand, 0.351; 95% confidence interval, 0.017-0.686). Conclusion  Overall, the data do not provide strong evidence that blood mercury levels are associated with worse neurobehavioral performance in this population of older urban adults.      

Heavy metal content of ayurvedic herbal medicine products

Context  Lead, mercury, and arsenic intoxication have been associated with the use of Ayurvedic herbal medicine product (HMPs). Objectives  To determine the prevalence and concentration of heavy metals in Ayurvedic HMPs manufactured in South Asia and sold in Boston-area stores and to compare estimated daily metal ingestion with regulatory standards. Design and Setting  Systematic search strategy to identify all stores 20 miles or less from Boston City Hall that sold Ayurvedic HMPs from South Asia by searching online Yellow Pages using the categories markets, supermarkets, and convenience stores, and business names containing the word India, Indian cities, and Indian words. An online national directory of Indian grocery stores, a South Asian community business directory, and a newspaper were also searched. We visited each store and purchased all unique Ayurvedic HMPs between April 25 and October 24, 2003. Main Outcome Measures  Concentrations (µg/g) of lead, mercury, and arsenic in each HMP as measured by x-ray fluorescence spectroscopy. Estimates of daily metal ingestion for adults and children estimated using manufacturers’ dosage recommendations with comparisons to US Pharmacopeia and US Environmental Protection Agency regulatory standards. Results  A total of 14 (20%) of 70 HMPs (95% confidence interval, 11%-31%) contained heavy metals: lead (n = 13; median concentration, 40 µg/g; range, 5-37 000), mercury (n = 6; median concentration, 20 225 µg/g; range, 28-104 000), and/or arsenic (n = 6; median concentration, 430 µg/g; range, 37-8130). If taken as recommended by the manufacturers, each of these 14 could result in heavy metal intakes above published regulatory standards. Conclusions  One of 5 Ayurvedic HMPs produced in South Asia and available in Boston South Asian grocery stores contains potentially harmful levels of lead, mercury, and/or arsenic. Users of Ayurvedic medicine may be at risk for heavy metal toxicity, and testing of Ayurvedic HMPs for toxic heavy metals should be mandatory.      

Distribution of and factors associated with serum homocysteine levels in children: Child and Adolescent Trial for Cardiovascular Health

Context  Although evidence suggests that homocysteine is a risk factor for cardiovascular disease in adults, little information exists on homocysteine levels in children. Objectives  To describe the distribution of serum homocysteine concentrations among children and to examine the association between homocysteine levels and several characteristics, including serum levels of folic acid and vitamins B₁₂ and B₆. Design  Cross-sectional analysis. Setting  School-based cohort from California, Louisiana, Minnesota, and Texas. Participants  A total of 3524 US schoolchildren, aged 13 and 14 years, from the Child and Adolescent Trial for Cardiovascular Health (completed in 1994). Measurement was conducted in 1997. Main Outcome Measure  Nonfasting serum total homocysteine concentration. Results  The distribution of homocysteine values ranged from 0.1 to 25.7 µmol/L (median, 4.9 µmol/L). Geometric mean homocysteine concentration was significantly higher in boys (5.22 µmol/L) than girls (4.84 µmol/L); blacks (5.51 µmol/L) than whites (4.96 µmol/L) or Hispanics (4.93 µmol/L); nonusers of multivitamins (5.09 µmol/L) than users (4.82 µmol/L); and smokers (5.19 µmol/L) than nonsmokers (5.00 µmol/L). Serum homocysteine was significantly inversely correlated with serum levels of folic acid (r=-0.36; P=.001), vitamin B₁₂ (r=-0.21; P=.001), and vitamin B₆ (r=-0.18; P=.001). Serum homocysteine was not significantly associated with serum lipid levels or family history of cardiovascular disease and was only weakly related to body mass index and systolic blood pressure. After multivariate adjustment, homocysteine remained independently associated with sex, race, serum folic acid and vitamin B₁₂ levels, and systolic blood pressure. Conclusions  The distribution of homocysteine levels in children is substantially lower than that observed for adults; however, a small percentage of children are still potentially at elevated risk for future cardiovascular disease. Serum folic acid may be an important determinant of homocysteine levels in children.      

Neurobehavioral effects of dental amalgam in children: a randomized clinical trial

Context  Dental (silver) amalgam is a widely used restorative material containing 50% elemental mercury that emits small amounts of mercury vapor. No randomized clinical trials have determined whether there are significant health risks associated with this low-level mercury exposure. Objective  To assess the safety of dental amalgam restorations in children. Design  A randomized clinical trial in which children requiring dental restorative treatment were randomized to either amalgam for posterior restorations or resin composite instead of amalgam. Enrollment commenced February 1997, with annual follow-up for 7 years concluding in July 2005. Setting and Participants  A total of 507 children in Lisbon, Portugal, aged 8 to 10 years with at least 1 carious lesion on a permanent tooth, no previous exposure to amalgam, urinary mercury level <10 µg/L, blood lead level <15 µg/dL, Comprehensive Test of Nonverbal Intelligence IQ 67, and with no interfering health conditions. Intervention  Routine, standard-of-care dental treatment, with one group receiving amalgam restorations for posterior lesions (n = 253) and the other group receiving resin composite restorations instead of amalgam (n = 254). Main Outcome Measures  Neurobehavioral assessments of memory, attention/concentration, and motor/visuomotor domains, as well as nerve conduction velocities. Results  During the 7-year trial period, children had a mean of 18.7 tooth surfaces (median, 16) restored in the amalgam group and 21.3 (median, 18) restored in the composite group. Baseline mean creatinine-adjusted urinary mercury levels were 1.8 µg/g in the amalgam group and 1.9 µg/g in the composite group, but during follow-up were 1.0 to 1.5 µg/g higher in the amalgam group than in the composite group (P<.001). There were no statistically significant differences in measures of memory, attention, visuomotor function, or nerve conduction velocities (average z scores were very similar, near zero) for the amalgam and composite groups over all 7 years of follow-up, with no statistically significant differences observed at any time point (P values from .29 to .91). Starting at 5 years after initial treatment, the need for additional restorative treatment was approximately 50% higher in the composite group. Conclusions  In this study, children who received dental restorative treatment with amalgam did not, on average, have statistically significant differences in neurobehavioral assessments or in nerve conduction velocity when compared with children who received resin composite materials without amalgam. These findings, combined with the trend of higher treatment need later among those receiving composite, suggest that amalgam should remain a viable dental restorative option for children. Trial Registration  clinicaltrials.gov Identifier: NCT00066118      

Fish intake, contaminants, and human health: evaluating the risks and the benefits

Context  Fish (finfish or shellfish) may have health benefits and also contain contaminants, resulting in confusion over the role of fish consumption in a healthy diet. Evidence Acquisition  We searched MEDLINE, governmental reports, and meta-analyses, supplemented by hand reviews of references and direct investigator contacts, to identify reports published through April 2006 evaluating (1) intake of fish or fish oil and cardiovascular risk, (2) effects of methylmercury and fish oil on early neurodevelopment, (3) risks of methylmercury for cardiovascular and neurologic outcomes in adults, and (4) health risks of dioxins and polychlorinated biphenyls in fish. We concentrated on studies evaluating risk in humans, focusing on evidence, when available, from randomized trials and large prospective studies. When possible, meta-analyses were performed to characterize benefits and risks most precisely. Evidence Synthesis  Modest consumption of fish (eg, 1-2 servings/wk), especially species higher in the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), reduces risk of coronary death by 36% (95% confidence interval, 20%-50%; P<.001) and total mortality by 17% (95% confidence interval, 0%-32%; P = .046) and may favorably affect other clinical outcomes. Intake of 250 mg/d of EPA and DHA appears sufficient for primary prevention. DHA appears beneficial for, and low-level methylmercury may adversely affect, early neurodevelopment. Women of childbearing age and nursing mothers should consume 2 seafood servings/wk, limiting intake of selected species. Health effects of low-level methylmercury in adults are not clearly established; methylmercury may modestly decrease the cardiovascular benefits of fish intake. A variety of seafood should be consumed; individuals with very high consumption (5 servings/wk) should limit intake of species highest in mercury levels. Levels of dioxins and polychlorinated biphenyls in fish are low, and potential carcinogenic and other effects are outweighed by potential benefits of fish intake and should have little impact on choices or consumption of seafood (women of childbearing age should consult regional advisories for locally caught freshwater fish). Conclusions  For major health outcomes among adults, based on both the strength of the evidence and the potential magnitudes of effect, the benefits of fish intake exceed the potential risks. For women of childbearing age, benefits of modest fish intake, excepting a few selected species, also outweigh risks.      

Incidence of cervical squamous intraepithelial lesions associated with HIV serostatus, CD4 cell counts, and human papillomavirus test results

Context  Recent cervical cancer screening guidelines state that the interval between screenings can be safely extended to 3 years in healthy women 30 years or older who have normal cytology results and have negative test results for oncogenic human papillomavirus (HPV) DNA. Objective  To determine the incidence of squamous intraepithelial lesions (SILs) in HIV-seropositive women with normal cytology results, by baseline HPV DNA results. Design, Setting, and Patients  Participants were HIV-seropositive (n = 855; mean age, 36 years) and HIV-seronegative (n = 343; mean age, 34 years) US women with normal baseline cervical cytology who were enrolled in the Women’s Interagency HIV Study (WIHS), a large, multi-institutional prospective cohort study. Since their recruitment during 1994-1995, WIHS participants have been followed up semi-annually with repeated Pap smears for a median of 7 years. Main Outcome Measure  The cumulative incidence of any SIL and high-grade SIL or cancer (HSIL+) was estimated according to baseline HPV DNA results, stratified by HIV serostatus and CD4 T-cell count. Results  Development of any SIL in women with negative HPV results (both oncogenic and nononcogenic) at 2 years was as follows: in HIV-seropositive women with CD4 counts less than 200/µL, 9% (95% CI, 1%-18%); with CD4 counts between 200/µL and 500/µL, 9% (95% CI, 4%-13%); and with CD4 counts greater than 500/µL, 4% (95% CI, 1%-7%). The CIs for these estimates overlapped with those for HIV-seronegative women with normal baseline cytology who were HPV-negative (3%; 95% CI, 1%-5%), indicating that at 2 years, there were no large absolute differences in the cumulative incidence of any SIL between groups. Furthermore, no HPV-negative participants in any group developed HSIL+ lesions within 3 years. Multivariate Cox models showed that on a relative scale, the incidence of any SIL among HIV-seropositive women with CD4 counts greater than 500/µL (hazard ratio [HR], 1.2; 95% CI, 0.5-3.0), but not those with CD4 counts less than or equal to 500/µL (HR, 2.9; 95% CI, 1.2-7.1), was similar to that in HIV-seronegative women. Conclusion  The similar low cumulative incidence of any SIL among HIV-seronegative and HIV-seropositive women with CD4 counts greater than 500/µL and who had normal cervical cytology and HPV-negative test results suggests that similar cervical cancer screening practices may be applicable to both groups, although this strategy warrants evaluation in an appropriate clinical trial.      

Vitamin A Intake and Hip Fractures Among Postmenopausal Women

Context  Ingestion of toxic amounts of vitamin A affects bone remodeling and can have adverse skeletal effects in animals. The possibility has been raised that long-term high vitamin A intake could contribute to fracture risk in humans. Objective  To assess the relationship between high vitamin A intake from foods and supplements and risk of hip fracture among postmenopausal women. Design  Prospective analysis begun in 1980 with 18 years of follow-up within the Nurses' Health Study. Setting  General community of registered nurses within 11 US states. Participants  A total of 72 337 postmenopausal women aged 34 to 77 years. Main Outcome Measures  Incident hip fractures resulting from low or moderate trauma, analyzed by quintiles of vitamin A intake and by use of multivitamins and vitamin A supplements, assessed at baseline and updated during follow-up. Results  From 1980 to 1998, 603 incident hip fractures resulting from low or moderate trauma were identified. After controlling for confounding factors, women in the highest quintile of total vitamin A intake (3000 µg/d of retinol equivalents [RE]) had a significantly elevated relative risk (RR) of hip fracture (RR, 1.48; 95% confidence interval [CI], 1.05-2.07; P for trend = .003) compared with women in the lowest quintile of intake (<1250 µg/d of RE). This increased risk was attributable primarily to retinol (RR, 1.89; 95% CI, 1.33-2.68; P for trend <.001 comparing 2000 µg/d vs <500 µg/d). The association of high retinol intake with hip fracture was attenuated among women using postmenopausal estrogens. Beta carotene did not contribute significantly to fracture risk (RR, 1.22; 95% CI, 0.90-1.66; P for trend = .10 comparing 6300 µg/d vs <2550 µg/d). Women currently taking a specific vitamin A supplement had a nonsignificant 40% increased risk of hip fracture (RR, 1.40; 95% CI, 0.99-1.99) compared with those not taking that supplement, and, among women not taking supplemental vitamin A, retinol from food was significantly associated with fracture risk (RR, 1.69; 95% CI, 1.05-2.74; P for trend = .05 comparing 1000 µg/d vs <400 µg/d). Conclusions  Long-term intake of a diet high in retinol may promote the development of osteoporotic hip fractures in women. The amounts of retinol in fortified foods and vitamin supplements may need to be reassessed.      

Folate intake and the risk of incident hypertension among US women

Context  Folate has important beneficial effects on endothelial function, but there is limited information about folate intake and risk of incident hypertension. Objective  To determine whether higher folate intake is associated with a lower risk of incident hypertension. Design, Setting, and Participants  Two prospective cohort studies of 93 803 younger women aged 27 to 44 years in the Nurses’ Health Study II (1991-1999) and 62 260 older women aged 43 to 70 years in the Nurses’ Health Study I (1990-1998), who did not have a history of hypertension. Baseline information on dietary folate and supplemental folic acid intake was derived from semiquantitative food frequency questionnaires and was updated every 4 years. Main Outcome Measure  Relative risk of incident self-reported hypertension during 8 years of follow-up. Results  We identified 7373 incident cases of hypertension in younger women and 12 347 cases in older women. After adjusting for multiple potential confounders, younger women who consumed at least 1000 µg/d of total folate (dietary plus supplemental) had a decreased risk of hypertension (relative risk [RR], 0.54; 95% confidence interval [CI], 0.45-0.66; P for trend <.001) compared with those who consumed less than 200 µg/d. Younger women’s absolute risk reduction (ARR) was approximately 8 cases per 1000 person-years (6.7 vs 14.8 cases). The multivariable RR for the same comparison in older women was 0.82 (95% CI, 0.69-0.97; P for trend = .05). Older women’s ARR was approximately 6 cases per 1000 person-years (34.7 vs 40.4 cases). When the analysis was restricted to women with low dietary folate intake (<200 µg/d), the multivariable RR for younger women with total folate intake at least 800 µg/d compared with less than 200 µg/d was 0.55 (95% CI, 0.32-0.94; P for trend = .03), and 0.61 (95% CI, 0.34-1.11; P for trend = .05) in the older cohort. Among women who did not take folic acid–containing supplements, dietary folate intake of 400 µg/d or more was not significantly associated with risk of hypertension. Conclusion  Higher total folate intake was associated with a decreased risk of incident hypertension, particularly in younger women.      

Lead, mercury, and arsenic in US- and Indian-manufactured Ayurvedic medicines sold via the Internet

Robert B. Saper, MD, MPH; Russell S. Phillips, MD; Anusha Sehgal, MD(Ayurveda); Nadia Khouri, MPH; Roger B. Davis, ScD; Janet Paquin, PhD; Venkatesh Thuppil, PhD; Stefanos N. Kales, MD, MPH

JAMA. 2008;300(8):915-923.

Context  Lead, mercury, and arsenic have been detected in a substantial proportion of Indian-manufactured traditional Ayurvedic medicines. Metals may be present due to the practice of rasa shastra (combining herbs with metals, minerals, and gems). Whether toxic metals are present in both US- and Indian-manufactured Ayurvedic medicines is unknown.

Objectives  To determine the prevalence of Ayurvedic medicines available via the Internet containing detectable lead, mercury, or arsenic and to compare the prevalence of toxic metals in US- vs Indian-manufactured medicines and between rasa shastra and non–rasa shastra medicines.

Design  A search using 5 Internet search engines and the search terms Ayurveda and Ayurvedic medicine identified 25 Web sites offering traditional Ayurvedic herbs, formulas, or ingredients commonly used in Ayurveda, indicated for oral use, and available for sale. From 673 identified products, 230 Ayurvedic medicines were randomly selected for purchase in August-October 2005. Country of manufacturer/Web site supplier, rasa shastra status, and claims of Good Manufacturing Practices were recorded. Metal concentrations were measured using x-ray fluorescence spectroscopy.

Main Outcome Measures  Prevalence of medicines with detectable toxic metals in the entire sample and stratified by country of manufacture and rasa shastra status.

Results  One hundred ninety-three of the 230 requested medicines were received and analyzed. The prevalence of metal-containing products was 20.7% (95% confidence interval [CI], 15.2%-27.1%). The prevalence of metals in US-manufactured products was 21.7% (95% CI, 14.6%-30.4%) compared with 19.5% (95% CI, 11.3%-30.1%) in Indian products (P = .86). Rasa shastra compared with non–rasa shastra medicines had a greater prevalence of metals (40.6% vs 17.1%; P = .007) and higher median concentrations of lead (11.5 µg/g vs 7.0 µg/g; P = .03) and mercury (20 800 µg/g vs 34.5 µg/g; P = .04). Among the metal-containing products, 95% were sold by US Web sites and 75% claimed Good Manufacturing Practices. All metal-containing products exceeded 1 or more standards for acceptable daily intake of toxic metals.

Conclusion  One-fifth of both US-manufactured and Indian-manufactured Ayurvedic medicines purchased via the Internet contain detectable lead, mercury, or arsenic.

     

Safety and immunogenicity of a baculovirus-expressed hemagglutinin influenza vaccine: a randomized controlled trial

Context  A high priority in vaccine research is the development of influenza vaccines that do not use embryonated eggs as the substrate for vaccine production. Objective  To determine the dose-related safety, immunogenicity, and protective efficacy of an experimental trivalent influenza virus hemagglutinin (rHA0) vaccine produced in insect cells using recombinant baculoviruses. Design, Setting, and Participants  Randomized, double-blind, placebo-controlled clinical trial at 3 US academic medical centers during the 2004-2005 influenza season among 460 healthy adults without high-risk indications for influenza vaccine. Interventions  Participants were randomly assigned to receive a single injection of saline placebo (n = 154); 75 µg of an rHA0 vaccine containing 15 µg of hemagglutinin from influenza A/New Caledonia/20/99(H1N1) and influenza B/Jiangsu/10/03 virus and 45 µg of hemagglutinin from influenza A/Wyoming/3/03(H3N2) virus (n = 153); or 135 µg of rHA0 containing 45 µg of hemagglutinin each from all 3 components (n = 153). Serum samples were taken before and 30 days following immunization. Main Outcome Measures  Primary safety end points were the rates and severity of solicited and unsolicited adverse events. Primary immunogenicity end points were the rates of 4-fold or greater increases in serum hemagglutinin inhibition antibody to each of the 3 vaccine strains before and 28 days after inoculation. The prespecified primary efficacy end point was culture-documented influenza illness, defined as development of influenza-like illness associated with influenza virus on a nasopharyngeal swab. Results  Rates of local and systemic adverse effects were low, and the rates of systemic adverse effects were not different in either vaccine group than in the placebo group. Hemagglutinin inhibition antibody responses to the H1 component were seen in 3% of placebo, 51% of 75-µg vaccine, and 67% of 135-µg vaccine recipients, while responses to B were seen in 4% of placebo, 65% of 75-µg vaccine, and 92% of 135-µg vaccine recipients. Responses to the H3 component occurred in 11% of placebo, 81% of 75-µg vaccine, and 77% of 135-µg vaccine recipients. Influenza infections in the study population were due to influenza B and A(H3N2), and influenza A infections were A/California/7/2004–like viruses, an antigenically drifted strain. Seven cases of culture-confirmed CDC-defined influenza-like illness occurred in 153 placebo recipients (4.6%) compared with 2 cases (1.3%) in 150 recipients of 75 µg of vaccine, and 0 cases in recipients of 135 µg of vaccine. Conclusions  In this study, a trivalent rHA0 vaccine was safe and immunogenic in a healthy adult population. Preliminary evidence of protection against a drifted influenza A(H3N2) virus was obtained, but the sample size was small. Inclusion of a neuraminidase component did not appear to be required for protection. Trial Registration  clinicaltrials.gov Identifier: NCT00328107      

Lysophosphatidic Acid as a Potential Biomarker for Ovarian and Other Gynecologic Cancers

Context.— Lysophosphatidic acid (LPA) has been shown to stimulate proliferation of ovarian cancer cells and is present in the ascitic fluid of patients with ovarian cancer. Objectives.— To determine whether elevated levels of LPA are present in plasma from patients with ovarian cancer and other gynecologic malignancies compared with healthy controls and to evaluate whether an elevated LPA plasma level may be a biomarker for these diseases. Design.— A research assay was used to measure total LPA levels in plasma from healthy women and women with different diseases. All LPA assays and comparison of LPA levels and CA125 (an ovarian cancer biomarker) levels were performed by observers blinded to patient status or group. Setting.— The Cleveland Clinic Foundation. Participants.— A convenience sample of 48 healthy control women, 48 women with ovarian cancer, 36 women with other gynecologic cancers, 17 women with benign gynecologic diseases, 11 women with breast cancer, and 5 women with leukemias. Main Outcome Measures.— Total LPA levels in plasma samples from patients and controls. Results.— Patients in the ovarian cancer group had significantly higher plasma LPA levels (mean, 8.6 µmol/L; range, 1.0-43.1 µmol/L) compared with the healthy control group (mean, 0.6 µmol/L; range, <0.1-6.3 µmol/L) (P<.001). Elevated plasma LPA levels were detected in 9 of 10 patients with stage I ovarian cancer, 24 of 24 patients with stage II, III, and IV ovarian cancer, and 14 of 14 patients with recurrent ovarian cancer. Of 36 patients with other gynecologic cancers, 33 also showed higher LPA levels (mean, 14.9 µmol/L; range, <0.1-63.2 µmol/L), compared with healthy controls (P<.001). Elevated plasma LPA levels were detected in 5 of 48 controls and 4 of 17 patients with benign gynecologic diseases and in no women with breast cancer or leukemia. In comparison, among a subset of patients with ovarian cancer, 28 of 47 had elevated CA125 levels, including 2 of 9 patients with stage I disease. Conclusions.— Plasma LPA levels may represent a potential biomarker for ovarian cancer and other gynecologic cancers. However, these findings are preliminary and require confirmation in larger studies.      

Blood lead,blood pressure,and hypertension in perimenopausal and postmenopausal women

Context  Lead exposures have been shown to be associated with increased blood pressure and risk of hypertension in older men. In perimenopausal women, skeletal lead stores are an important source of endogenous lead exposure due to increased bone demineralization. Objective  To examine the relationship of blood lead level with blood pressure and hypertension prevalence in a population-based sample of perimenopausal and postmenopausal women in the United States. Design, Setting, and Participants  Cross-sectional sample of 2165 women aged 40 to 59 years, who participated in a household interview and physical examination, from the Third National Health and Nutrition Examination Survey conducted from 1988 to 1994. Main Outcome Measures  Associations of blood lead with blood pressure and hypertension, with age, race and ethnicity, cigarette smoking status, body mass index, alcohol use, and kidney function as covariates. Results  A change in blood lead levels from the lowest (quartile 1: range, 0.5-1.6 µg/dL) to the highest (quartile 4: range, 4.0-31.1 µg/dL) was associated with small statistically significant adjusted changes in systolic and diastolic blood pressures. Women in quartile 4 had increased risks of diastolic (>90 mm Hg) hypertension (adjusted odds ratio [OR], 3.4; 95% confidence interval [CI], 1.3-8.7), as well as moderately increased risks for general hypertension (adjusted OR, 1.4; 95% CI, 0.92-2.0) and systolic (>140 mm Hg) hypertension (adjusted OR, 1.5; 95% CI, 0.72-3.2). This association was strongest in postmenopausal women, in whom adjusted ORs for diastolic hypertension increased with increasing quartile of blood lead level compared with quartile 1 (adjusted OR, 4.6; 95% CI, 1.1-19.2 for quartile 2; adjusted OR, 5.9; 95% CI, 1.5-23.1 for quartile 3; adjusted OR, 8.1; 95% CI, 2.6-24.7 for quartile 4). Conclusions  At levels well below the current US occupational exposure limit guidelines (40 µg/dL), blood lead level is positively associated with both systolic and diastolic blood pressure and risks of both systolic and diastolic hypertension among women aged 40 to 59 years. The relationship between blood lead level and systolic and diastolic hypertension is most pronounced in postmenopausal women. These results provide support for continued efforts to reduce lead levels in the general population, especially women.      

Effect of calcium carbonate on the absorption of levothyroxine

Context  The effect of calcium carbonate on the absorption of levothyroxine has not been studied systematically. Such a potential drug interaction merits investigation because concurrent treatment with both drugs is common, particularly in postmenopausal women. Objective  To investigate the potential interference of calcium carbonate in the absorption of levothyroxine. Design  Prospective cohort study conducted from November 1998 to June 1999, supplemented with an in vitro study of thyroxine (T₄) binding to calcium carbonate. Setting  Veterans Affairs Medical Center in West Los Angeles, Calif. Patients  Twenty patients (age range, 27-78 years; n=11 men) with hypothyroidism who were taking a stable long-term regimen of levothyroxine were included in the study. All patients had serum free T₄ and thyrotropin values in the normal range before beginning the study. Intervention  Subjects were instructed to take 1200 mg/d of elemental calcium as calcium carbonate, ingested with their levothyroxine, for 3 months. Main Outcome Measures  Levels of free T₄, total T₄, total triiodothyronine (T₃), and thyrotropin, measured in all subjects at baseline (while taking levothyroxine alone), at 2 and 3 months (while taking calcium carbonate and levothyroxine), and 2 months after calcium carbonate discontinuation (while continuing to take levothyroxine). Results  Mean free T₄ and total T₄ levels were significantly reduced during the calcium period and increased after calcium discontinuation. Mean free T₄ levels were 17 pmol/L (1.3 ng/dL) at baseline, 15 pmol/L (1.2 ng/dL) during the calcium period, and 18 pmol/L (1.4 ng/dL) after calcium discontinuation (overall P<.001); mean total T₄ levels were 118 nmol/L (9.2 µg/dL) at baseline, 111 nmol/L (8.6 µg/dL) during the calcium period, and 120 nmol/L (9.3 µg/dL) after calcium discontinuation (overall P=.03). Mean thyrotropin levels increased significantly, from 1.6 mIU/L at baseline to 2.7 mIU/L during the calcium period, and decreased to 1.4 mIU/L after calcium discontinuation (P=.008). Twenty percent of patients had serum thyrotropin levels higher than the normal range during the calcium period; the highest observed level was 7.8 mIU/L. Mean T₃ levels did not change during the calcium period. The in vitro study of T₄ binding to calcium showed that adsorption of T₄ to calcium carbonate occurs at acidic pH levels. Conclusions  This study of 20 patients receiving long-term levothyroxine replacement therapy indicates that calcium carbonate reduces T₄ absorption and increases serum thyrotropin levels. Levothyroxine adsorbs to calcium carbonate in an acidic environment, which may reduce its bioavailability.      

Rapid scale-up of antiretroviral therapy at primary care sites in Zambia: feasibility and early outcomes

Context  The Zambian Ministry of Health has scaled-up human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) care and treatment services at primary care clinics in Lusaka, using predominately nonphysician clinicians. Objective  To report on the feasibility and early outcomes of the program. Design, Setting, and Patients  Open cohort evaluation of antiretroviral-naive adults treated at 18 primary care facilities between April 26, 2004, and November 5, 2005. Data were entered in real time into an electronic patient tracking system. Intervention  Those meeting criteria for antiretroviral therapy (ART) received drugs according to Zambian national guidelines. Main Outcome Measures  Survival, regimen failure rates, and CD4 cell response. Results  We enrolled 21 755 adults into HIV care, and 16 198 (75%) started ART. Among those starting ART, 9864 (61%) were women. Of 15 866 patients with documented World Health Organization (WHO) staging, 11 573 (73%) were stage III or IV, and the mean (SD) entry CD4 cell count among the 15 336 patients with a baseline result was 143/µL (123/µL). Of 1142 patients receiving ART who died, 1120 had a reliable date of death. Of these patients, 792 (71%) died within 90 days of starting therapy (early mortality rate: 26 per 100 patient-years), and 328 (29%) died after 90 days (post-90-day mortality rate: 5.0 per 100 patient-years). In multivariable analysis, mortality was strongly associated with CD4 cell count between 50/µL and 199/µL (adjusted hazard ratio [AHR], 1.4; 95% confidence interval [CI], 1.0-2.0), CD4 cell count less than 50/µL (AHR, 2.2; 95% CI, 1.5-3.1), WHO stage III disease (AHR, 1.8; 95% CI, 1.3-2.4), WHO stage IV disease (AHR, 2.9; 95% CI, 2.0-4.3), low body mass index (<16; AHR,2.4; 95% CI, 1.8-3.2), severe anemia (<8.0 g/dL; AHR, 3.1; 95% CI, 2.3-4.0), and poor adherence to therapy (AHR, 2.9; 95% CI, 2.2-3.9). Of 11 714 patients at risk, 861 failed therapy by clinical criteria (rate, 13 per 100 patient-years). The mean (SD) CD4 cell count increase was 175/µL (174/µL) in 1361 of 1519 patients (90%) receiving treatment long enough to have a 12-month repeat. Conclusion  Massive scale-up of HIV and AIDS treatment services with good clinical outcomes is feasible in primary care settings in sub-Saharan Africa. Most mortality occurs early, suggesting that earlier diagnosis and treatment may improve outcomes.      

Serum uric acid and cardiovascular mortality the NHANES I epidemiologic follow-up study, 1971-1992. National Health and Nutrition Examination Survey

Context  Although many epidemiological studies have suggested that increased serum uric acid levels are a risk factor for cardiovascular mortality, this relationship remains uncertain. Objective  To determine the association of serum uric acid levels with cardiovascular mortality. Design and Setting  Cross-sectional population-based study of epidemiological follow-up data from the First National Health and Nutrition Examination Survey (NHANES I) from 1971-1975 (baseline) and data from NHANES I Epidemiologic Follow-up Study (NHEFS). Participants  A total of 5926 subjects who were aged 25 to 74 years and had serum uric acid level measurements at baseline. Main Outcome Measures  Ischemic heart disease mortality, total cardiovascular mortality, and all-cause mortality, compared by quartiles of serum uric acid level. Results  In an average of 16.4 years of follow-up, 1593 deaths occurred, of which 731 (45.9%) were ascribed to cardiovascular disease. Increased serum uric acid levels had a positive relationship to cardiovascular mortality in men and women and in black and white persons. Deaths due to ischemic heart disease in both men and women increased when serum uric acid levels were in the highest quartile compared with the lowest quartile (men, >416 vs <321 µmol/L; risk ratio, 1.77 [95% confidence interval {CI}, 1.08-3.98]; women, >333 vs <238 µmol/L; risk ratio, 3.00 [95% CI, 1.45-6.28]). Cox regression analysis showed that for each 59.48-µmol/L increase in uric acid level, cardiovascular mortality and ischemic heart disease mortality increased. Hazard ratios for men were 1.09 (95% CI, 1.02-1.18) and 1.17 (95% CI, 1.06-1.28), and for women were 1.26 (95% CI, 1.16-1.36) and 1.30 (95% CI, 1.17-1.45), respectively, after adjustment for age, race, body mass index, smoking status, alcohol consumption, cholesterol level, history of hypertension and diabetes, and diuretic use. Further analysis, stratifying by cardiovascular risk status, diuretic use, and menopausal status, confirmed a significant association of uric acid and cardiovascular mortality in all subgroups except among men using diuretics (n=79) and men with 1 or more cardiovascular risk factors (n=1140). Conclusion  Our data suggest that increased serum uric acid levels are independently and significantly associated with risk of cardiovascular mortality.      

Cost-effectiveness of vitamin therapy to lower plasma homocysteine levels for the prevention of coronary heart disease: effect of grain fortification and beyond

Context  A high homocysteine level has been identified as an independent modifiable risk factor for coronary heart disease (CHD) events and death. Since January 1998, the US Food and Drug Administration has required that all enriched grain products contain 140 µg of folic acid per 100 g, a level considered to decrease homocysteine levels. Objectives  To examine the potential effect of grain fortification with folic acid on CHD events and to estimate the cost-effectiveness of additional vitamin supplementation (folic acid and cyanocobalamin) for CHD prevention. Design and Setting  Cost-effectiveness analysis using the Coronary Heart Disease Policy Model, a validated, state-transition model of CHD events in adults aged 35 through 84 years. Data from the third National Health and Nutrition Examination Survey (NHANES III) were used to estimate age- and sex-specific differences in homocysteine levels. Intervention  Hypothetical comparison between a diet that includes enriched grain products projected to increase folic acid intake by 100 µg/d with the same diet without folic acid fortification; and a comparison between vitamin therapy that consists of 1 mg of folic acid and 0.5 mg of cyanocobalamin and the diet that includes grains fortified with folic acid. Main Outcome Measures  Incidence of myocardial infarction and death from CHD, quality-adjusted life-years (QALYs) saved, and medical costs. Results  Grain fortification with folic acid was predicted to decrease CHD events by 8% in women and 13% in men, with comparable reductions in CHD mortality. The model projected that, compared with grain fortification alone, treating all patients with known CHD with folic acid and cyanocobalamin over a 10-year period would result in 310 000 fewer deaths and lower costs. Over the same 10-year period, providing vitamin supplementation in addition to grain fortification to all men aged 45 years or older without known CHD was projected to save more than 300 000 QALYs, to save more than US $2 billion, and to be the preferred strategy. For women without CHD, the preferred vitamin supplementation strategy would be to treat all women older than 55 years, a strategy projected to save more than 140 000 QALYs over 10 years. Conclusions  Folic acid and cyanocobalamin supplementation may be cost-effective among many population subgroups and could have a major epidemiologic benefit for primary and secondary prevention of CHD if ongoing clinical trials confirm that homocysteine-lowering therapy decreases CHD event rates.      

Effect of homocysteine lowering on mortality and vascular disease in advanced chronic kidney disease and end-stage renal disease: a randomized controlled trial

Context  High plasma homocysteine levels are a risk factor for mortality and vascular disease in observational studies of patients with chronic kidney disease. Folic acid and B vitamins decrease homocysteine levels in this population but whether they lower mortality is unknown. Objective  To determine whether high doses of folic acid and B vitamins administered daily reduce mortality in patients with chronic kidney disease. Design, Setting, and Participants  Double-blind randomized controlled trial (2001-2006) in 36 US Department of Veterans Affairs medical centers. Median follow-up was 3.2 years for 2056 participants aged 21 years or older with advanced chronic kidney disease (estimated creatinine clearance 30 mL/min) (n = 1305) or end-stage renal disease (n = 751) and high homocysteine levels ( 15 µmol/L). Intervention  Participants received a daily capsule containing 40 mg of folic acid, 100 mg of pyridoxine hydrochloride (vitamin B₆), and 2 mg of cyanocobalamin (vitamin B₁₂) or a placebo. Main Outcome Measures  The primary outcome was all-cause mortality. Secondary outcomes included myocardial infarction (MI), stroke, amputation of all or part of a lower extremity, a composite of these 3 plus all-cause mortality, time to initiation of dialysis, and time to thrombosis of arteriovenous access in hemodialysis patients. Results  Mean baseline homocysteine level was 24.0 µmol/L in the vitamin group and 24.2 µmol/L in the placebo group. It was lowered 6.3 µmol/L (25.8%; P < .001) in the vitamin group and 0.4 µmol/L (1.7%; P = .14) in the placebo group at 3 months, but there was no significant effect on mortality (448 vitamin group deaths vs 436 placebo group deaths) (hazard ratio [HR], 1.04; 95% CI, 0.91-1.18). No significant effects were demonstrated for secondary outcomes or adverse events: there were 129 MIs in the vitamin group vs 150 for placebo (HR, 0.86; 95% CI, 0.67-1.08), 37 strokes in the vitamin group vs 41 for placebo (HR, 0.90; 95% CI, 0.58-1.40), and 60 amputations in the vitamin group vs 53 for placebo (HR, 1.14; 95% CI, 0.79-1.64). In addition, the composite of MI, stroke, and amputations plus mortality (P = .85), time to dialysis (P = .38), and time to thrombosis in hemodialysis patients (P = .97) did not differ between the vitamin and placebo groups. Conclusion  Treatment with high doses of folic acid and B vitamins did not improve survival or reduce the incidence of vascular disease in patients with advanced chronic kidney disease or end-stage renal disease. Trial Registration  clinicaltrials.gov Identifier: NCT00032435      

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 µmol/L (21.2 µg/dL) at age 2 years to 0.38 µmol/L (7.9 µg/dL) at age 11 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.      

Respiratory symptoms, pulmonary function, and markers of inflammation among bar workers before and after a legislative ban on smoking in public places

Context  Scotland prohibited smoking in confined public places on March 26, 2006. Objective  To investigate the association of smoke-free legislation with symptoms, pulmonary function, and markers of inflammation of bar workers. Design, Setting, and Participants  This prospective observational study was conducted in Tayside, Scotland from February-June 2006. One hundred five nonasthmatic and asthmatic nonsmoking bar workers were initially enrolled, of whom 77 completed the study per protocol. Main Outcome Measures  Respiratory and sensory symptoms, spirometry measurements, serum cotinine levels, peripheral inflammatory cell count, asthma quality-of-life scores, and exhaled nitric oxide levels were evaluated before and after introduction of the smoking ban. Results  For the per-protocol analysis, the percentage of bar workers with respiratory and sensory symptoms decreased from 79.2% (n = 61) before the smoke-free policy to 53.2% (n = 41) (total change, –26%; 95% confidence interval [CI], –13.8% to –38.1%; P<.001) and 46.8% (n = 38) (–32.5%; 95% CI, –19.8% to –45.2%; P<.001) 1 and 2 months afterward. Forced expiratory volume in the first second increased from 96.6% predicted to 104.8% (change, 8.2%; 95% CI, 3.9% to 12.4%; P<.001) and then 101.7% (change, 5.1%; 95% CI, 2.1% to 8.0%; P = .002), and serum cotinine levels decreased from 5.15 ng/mL to 3.22 ng/mL (change, –1.93 ng/mL; 95% CI, –2.83 to –1.03 ng/mL; P<.001) and then 2.93 ng/mL (–2.22 ng/mL; 95% CI, –3.10 to –1.34 ng/mL; P<.001). The total white blood cell and neutrophil count was reduced from 7610 to 6980 cells/µL at 2 months (–630 cells/µL; 95% CI, –1010 to –260 cells/µL; P = .002) and from 4440 to 4030 cells/µL (–410 cells/µL; 95% CI, –740 to –90 cells/µL; P = .03), respectively. Asthmatic bar workers also had less airway inflammation, with a reduction in exhaled nitric oxide from 34.3 parts per billion (ppb) to 27.4 ppb 1 month after the ban (0.8-fold change; 95% CI, 0.67 to 0.96 ppb; P = .04), and Juniper quality-of-life scores increased from 80.2 to 87.5 points (7.3 points; 95% CI, 0.1 to 14.6 points; P = .049). Conclusions  Smoke-free legislation was associated with significant early improvements in symptoms, spirometry measurements, and systemic inflammation of bar workers. Asthmatic bar workers also had reduced airway inflammation and improved quality of life.      

Effects of Prenatal and Postnatal Methylmercury Exposure From Fish Consumption on Neurodevelopment: Outcomes at 66 Months of Age in the Seychelles Child Development Study

Context.— Human neurodevelopmental consequences of exposure to methylmercury (MeHg) from eating fish remain a question of public health concern. Objective.— To study the association between MeHg exposure and the developmental outcomes of children in the Republic of Seychelles at 66 months of age. Design.— A prospective longitudinal cohort study. Participants.— A total of 711 of 779 cohort mother-child pairs initially enrolled in the Seychelles Child Development Study in 1989. Setting.— The Republic of Seychelles, an archipelago in the Indian Ocean where 85% of the population consumes ocean fish daily. Main Outcome Measures.— Prenatal and postnatal MeHg exposure and 6 age-appropriate neurodevelopmental tests: the McCarthy Scales of Children's Abilities, the Preschool Language Scale, the Woodcock-Johnson Applied Problems and Letter and Word Recognition Tests of Achievement, the Bender Gestalt test, and the Child Behavior Checklist. Results.— The mean maternal hair total mercury level was 6.8 ppm and the mean child hair total mercury level at age 66 months was 6.5 ppm. No adverse outcomes at 66 months were associated with either prenatal or postnatal MeHg exposure. Conclusion.— In the population studied, consumption of a diet high in ocean fish appears to pose no threat to developmental outcomes through 66 months of age.