Lorene M Nelson

Stanford University, Palo Alto, California, United States

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Publications (66)352.56 Total impact

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    ABSTRACT: Recent cross-sectional studies suggest that restless legs syndrome (RLS) may be associated with an increased prevalence of cardiovascular disease (CVD) comorbidity or risk factors. We evaluated whether primary or secondary RLS was associated with an increased risk of incident cardiovascular disease in a retrospective cohort study within Kaiser Permanente Northern California (KPNC). We identified members of KPNC with primary RLS and secondary RLS between 1999 and 2008 by an algorithm that incorporated longitudinal clinical records related to the diagnosis and treatment of RLS and comorbidities. We then matched each RLS case with up to 50 individuals with no clinical records of RLS by age, sex, race/ethnicity, zip code, and membership duration. For the analyses we excluded any individual with coronary artery disease (CAD: angina, acute myocardial infarction, coronary revascularization procedure, CAD death), CVD (CAD plus stroke), and hypertension at baseline. New cardiovascular events were determined from clinical records. Follow-up ended at an outcome event, disenrollment from KPNC, or death, whichever occurred earliest. There were over 473,358 person-y of follow-up in this cohort analysis with a mean follow-up time of 3.91 y and range from 6 mo to 12 y. Survival analysis techniques, including survival curves and proportional hazard regression models, were used to assess the association between RLS status and CVD. There were 7,621 primary RLS and 4,507 secondary RLS cases identified and included in the study. In general, primary RLS cases were younger and had less comorbidity than secondary RLS cases. During the follow-up period, CVD was diagnosed in 478 primary RLS cohort members, CAD was diagnosed in 310, and hypertension events were identified in 1,466. Diagnosis in secondary RLS cohort members was made during the follow-up period with 451, 338, and 598 CVD, CAD, and hypertension events, respectively. Subjects with primary RLS had a similar risk of incident CVD (hazard ratio (HR) = 0.95; 95% confidence interval (CI) 0.86-1.04) and CAD (HR = 0.99; 95%CI 0.89-1.13) to the comparison cohort, with a slight elevation in the risk of hypertension events (HR = 1.19; CI 1.12-1.25), after multivariable adjustment. Individuals classified as secondary RLS had a significant increased risk of CVD (HR = 1.33; CI 1.21-1.46), CAD (HR = 1.40; CI 1.25-1.56), and hypertension (HR = 1.28; CI 1.18-1.40). Primary RLS was not associated with new-onset CVD or CAD but was associated with a slight increased risk of hypertension. In contrast, secondary RLS was associated with an increased risk of CVD, CAD, and hypertension. Copyright © 2015 Associated Professional Sleep Societies, LLC. All rights reserved.
    Sleep 06/2015; · 5.06 Impact Factor
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    ABSTRACT: Objective This study aims to identify risk factors for prolonged postpartum length of stays (LOS) after cesarean delivery (CD). Study Design Patients undergoing CD were sourced from a multicenter registry of 19 academic centers between 1999 and 2002 (n = 57,067). Prolonged postpartum LOS was defined as a hospitalization duration ≥ 90th centile. Maternal, antepartum, perioperative, and neonatal variables were compared between women with and without prolonged postpartum LOS. Results The 90th centile for postpartum LOS was 4 days, with 14,954 women experiencing prolonged postpartum LOS. Women with perioperative complications had the highest independent risk for a prolonged postpartum LOS: ileus (adjusted odds ratio [aOR] = 12.28; 95% confidence interval CI = 8.98-16.8); endometritis (aOR = 10.45; 95% CI = 9.51-11.5), and wound complications (aOR = 5.49; 95% CI = 4.54-6.63). Several antepartum, perioperative, and neonatal variables were associated with a prolonged postpartum LOS. Conclusion Perioperative complications had the highest risk for prolonged LOS after CD. Strategies to reduce perioperative complications are needed to decrease the health care burden of prolonged post-CD LOS. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
    American Journal of Perinatology 01/2015; 210(1). DOI:10.1055/s-0034-1543953 · 1.60 Impact Factor
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    ABSTRACT: OBJECTIVE: Uterine atony is a leading cause of postpartum hemorrhage (PPH). Although most cases of PPH respond to first line therapy with uterine massage and oxytocin administration, second line uterotonics including methylergonovine and carboprost are integral for the management of refractory uterine atony. Despite their ubiquitous use, it is uncertain whether the risk of hemorrhage-related morbidity differs in women exposed to methylergonovine or carboprost at Cesarean delivery (CD). STUDY DESIGN: We performed a secondary analysis using the Maternal-Fetal Medicine Units Network Cesarean Registry. We identified women who underwent CD and received either methylergonovine or carboprost for refractory uterine atony. The primary outcome was hemorrhage-related morbidity defined as intraoperative or postoperative red blood cells (RBC) transfusion or the need for additional surgical interventions including uterine artery ligation, hypogastric artery ligation, or peripartum hysterectomy for atony. We compared the risk of hemorrhage-related morbidity in those exposed to methylergonovine vs. carboprost. Propensity-score matching was used to account for potential confounders. RESULTS: The study cohort comprised 1,335 women; 870 (65.2%) women received methylergonovine and 465 (34.8%) women received carboprost. After accounting for potential confounders, the risk of hemorrhage-related morbidity was higher in the carboprost group than the methylergonovine group (RR = 1.7; 95% CI = 1.2 - 2.6). CONCLUSION: In this propensity-score matched analysis, methylergonovine was associated with reduced risk of hemorrhage-related morbidity during CD compared to carboprost. Based on these results, methylergonovine may be a more effective second line uterotonic.
    American Journal of Obstetrics and Gynecology 01/2015; 212(5). DOI:10.1016/j.ajog.2015.01.008 · 3.97 Impact Factor
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    ABSTRACT: BACKGROUND: Racial and ethnic disparities have been identified in the provision of neuraxial labor analgesia. These disparities may exist in other key aspects of obstetric anesthesia care. We sought to determine whether racial/ethnic disparities exist in mode of anesthesia for cesarean delivery (CD). METHODS: Women who underwent CD between 1999 and 2002 at 19 different obstetric centers in the United States were identified from the Maternal-Fetal Medicine Units Network Cesarean Registry. Race/ethnicity was categorized as: Caucasian, African American, Hispanic, and Non-Hispanic Others (NHOs). Mode of anesthesia was classified as neuraxial anesthesia (spinal, epidural, or combined spinal-epidural anesthesia) or general anesthesia. To account for obstetric and non-obstetric covariates that may have influenced mode of anesthesia, multiple logistic regression analyses were performed by using sequential sets of covariates. RESULTS: The study cohort comprised 50,974 women who underwent CD. Rates of general anesthesia among racial/ethnic groups were as follows: 5.2% for Caucasians, 11.3% for African Americans, 5.8% for Hispanics, and 6.6% for NHOs. After adjustment for obstetric and non-obstetric covariates, African Americans had the highest odds of receiving general anesthesia compared with Caucasians (adjusted odds ratio [aOR] = 1.7; 95% confidence interval [CI], 1.5-1.8; P < 0.001). The odds of receiving general anesthesia were also higher among Hispanics (aOR = 1.1; 95% CI, 1.0-1.3; P = 0.02) and NHOs (aOR = 1.2; 95% CI, 1.0-1.4; P = 0.03) compared with Caucasians, respectively. In our sensitivity analysis, we reconstructed the models after excluding women who underwent neuraxial anesthesia before general anesthesia. The adjusted odds of receiving general anesthesia were similar to those in the main analysis: African Americans (aOR = 1.7; 95% CI, 1.5-1.9; P < 0.001); Hispanics (aOR = 1.2; 95% CI, 1.1-1.4; P = 0.006); and NHOs (aOR = 1.2; 95% CI, 1.0-1.5; P = 0.05). CONCLUSIONS: Based on data from the Cesarean Registry, African American women had the highest odds of undergoing general anesthesia for CD compared with Caucasian women. It is uncertain whether this disparity exists in current obstetric practice.
    Anesthesia & Analgesia 01/2015; DOI:10.1213/ANE.0000000000000679 · 3.42 Impact Factor
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    ABSTRACT: Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease. The current status of the epidemiology, challenges to its study, and novel study design options are discussed in this paper. We focus on recent results from large-scale population based prospective studies, case-control studies and population based registries, risk factors, and neuropathologic findings in chronic traumatic encephalomyelopathy. We identify areas of interest for future research, including time-trends in the incidence and prevalence of ALS; the meaning of lifetime risk; the phenotypic description of ALS; the definition of familial versus sporadic ALS, syndromic aspects of ALS; specific risk factors such as military service, life style factors such as smoking, the use of statins, and the presence of β-N-methylamino-L-alanine (BMAA), an excitotoxic amino acid derivative possibly produced by cyanobacteria found in almost every terrestrial and aquatic habitat; the emergence and disappearance of an endemic ALS in areas of the Pacific; and gene-environment interactions in the etiology of ALS. To move the epidemiology forward, we suggest using well-characterized cohorts of newly diagnosed ALS patients to identify risk and prognostic factors; storing biological material for future studies; building on the National ALS Registry as a resource of future studies; working in multidisciplinary consortia; and addressing the possible early life etiology of ALS.
    Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration 05/2013; 14(S1). DOI:10.3109/21678421.2013.778565 · 2.59 Impact Factor
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    ABSTRACT: Approximately one half of the radiotherapy (RT) prescribed in the United States is delivered with palliative intent. The purpose of this study was to investigate the patterns of delivery of palliative RT across the United States. Using the Surveillance, Epidemiology, and End Results-Medicare linked database, 51,610 patients were identified with incident stage IV breast, prostate, lung, or colorectal cancer diagnosed between 2000 and 2007 and observed through 2009. Multivariate logistic regression determined predictors of palliative RT. Forty-one percent of the study population received palliative RT, including 53% of patients with lung cancer, followed by those with breast (42%), prostate (40%), and colorectal cancers (12%). Multivariate analysis revealed that older patients (P < .001) and those with higher Charlson comorbidity scores (P < .001) were less likely to receive palliative RT. Black patients with prostate cancer were 20% less likely (P < .001), and black patients with colorectal cancer were 28% less likely (P < .001), than white patients to receive palliative RT. Among those treated with RT, 23% of patients with lung cancer died within 2 weeks of completing treatment, followed by those with colorectal (12%), breast (11%), and prostate cancers (8%). In addition to tumor site, significant predictors (P < .05) of death within 2 weeks of receiving RT included increased age, increased comorbidity, and male sex. Inequality in the receipt of palliative RT exists among the elderly and patients with comorbid conditions and varies with race. In addition, a significant number of patients die shortly after receiving RT. Understanding these patterns of care, along with further research into the underlying causes, will improve access and quality of palliative RT.
    Journal of Oncology Practice 04/2013; 9(5). DOI:10.1200/JOP.2012.000835
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    ABSTRACT: There is a broad scientific consensus that amyotrophic lateral sclerosis (ALS) is caused by gene-environment interactions. Mutations in genes underlying familial ALS (fALS) have been discovered in only 5-10% of the total population of ALS patients. Relatively little attention has been paid to environmental and lifestyle factors that may trigger the cascade of motor neuron death leading to the syndrome of ALS, although exposure to chemicals including lead and pesticides, and to agricultural environments, smoking, certain sports, and trauma have all been identified with an increased risk of ALS. There is a need for research to quantify the relative roles of each of the identified risk factors for ALS. Recent evidence has strengthened the theory that chronic environmental exposure to the neurotoxic amino acid β-N-methylamino-L-alanine (BMAA) produced by cyanobacteria may be an environmental risk factor for ALS. Here we describe methods that may be used to assess exposure to cyanobacteria, and hence potentially to BMAA, namely an epidemiologic questionnaire and direct and indirect methods for estimating the cyanobacterial load in ecosystems. Rigorous epidemiologic studies could determine the risks associated with exposure to cyanobacteria, and if combined with genetic analysis of ALS cases and controls could reveal etiologically important gene-environment interactions in genetically vulnerable individuals.
    01/2013; 14(5-6). DOI:10.3109/21678421.2012.750364
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    ABSTRACT: in animal models such as SOD1 transgenic mice, cell based models, autopsy studies and molecular genetic Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease. The current status of the epidemiology, challenges to its study, and novel study design options are discussed in this paper. We focus on recent results from large-scale population based prospective studies, case-control studies and population based registries, risk factors, and neuropathologic fi ndings in chronic traumatic encephalomyelopathy. We identify areas of interest for future research, including time-trends in the incidence and prevalence of ALS; the meaning of lifetime risk; the phenotypic description of ALS; the defi nition of familial versus sporadic ALS, syndromic aspects of ALS; specifi c risk factors such as military service, life style factors such as smoking, the use of statins, and the presence of β -N-methylamino-L-alanine (BMAA), an excitotoxic amino acid derivative possibly produced by cyanobacteria found in almost every terrestrial and aquatic habitat; the emergence and disappearance of an endemic ALS in areas of the Pacifi c; and gene-environment interactions in the etiology of ALS. To move the epidemiology forward, we suggest using well-characterized cohorts of newly diagnosed ALS patients to identify risk and prognostic factors; storing biological material for future studies; building on the National ALS Registry as a resource of future studies; working in multidisciplinary consortia; and addressing the possible early life etiology of ALS.
    Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration 01/2013; 14(Suppl. 1):33-43. · 2.59 Impact Factor
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    ABSTRACT: Background: With the establishment of a national amyotrophic lateral sclerosis (ALS) registry in the United States, methods are needed to ascertain the completeness of case ascertainment, especially in view of the proposal to rely largely on existing data sources. Methods: Data about ALS patients residing in the 5-county metropolitan Atlanta area (within the State of Georgia) from 2001 to 2005 were categorized according to their source - ALS Association, clinical (Emory Healthcare, community neurologist, Veterans Health Administration, Veterans Benefits Administration), Medicare and death certificates. ALS diagnoses were verified using chart review. Capture-recapture analyses were carried out using log-linear modeling, stratified by age and race. Results: The final model (based on 798 cases), which included the 4 main sources and 3 two-way interaction terms, yielded an estimated total population of 880 (95% CI 816-965), indicating that the combination of case-finding methods identified about 90.7% of cases. The estimated 5-year period prevalence is 38.5/100,000 (95% CI 35.66-42.19). Conclusion: This study highlights gaps in data based on existing data sources and illustrates a method for combining data from multiple sources to help facilitate the successful establishment of a US national ALS registry.
    Neuroepidemiology 10/2012; 40(2):133-141. DOI:10.1159/000342156 · 2.48 Impact Factor
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    ABSTRACT: To examine associations of welding and manganese exposure with Parkinson disease (PD) using meta-analyses of data from cohort, case-control, and mortality studies. Epidemiologic studies related to welding or manganese exposure and PD were identified in a PubMed search, article references, published reviews, and abstracts. Inclusion criteria were 1) cohort, case-control, or mortality study with relative risk (RR), odds ratio (OR), or mortality OR (MOR) and 95 confidence intervals (95% CI); 2) RR, OR, and MOR matched or adjusted for age and sex; 3) valid study design and analysis. When participants of a study were a subgroup of those in a larger study, only results of the larger study were included to assure independence of datasets. Pooled RR/OR estimates and 95% CIs were obtained using random effects models; heterogeneity of study effects were evaluated using the Q statistic and I(2) index in fixed effect models. Thirteen studies met inclusion criteria for the welding meta-analysis and 3 studies for the manganese exposure meta-analysis. The pooled RR for the association between welding and PD for all study designs was 0.86 (95% CI 0.80-0.92), with absence of between-study heterogeneity (I(2) = 0.0). Effect measures for cohort, case-control, and mortality studies were similar (0.91, 0.82, 0.87). For the association between manganese exposure and PD, the pooled OR was 0.76 (95% CI 0.41-1.42). Welding and manganese exposure are not associated with increased PD risk. Possible explanations for the inverse association between welding and PD include confounding by smoking, healthy worker effect, and hormesis.
    Neurology 09/2012; 79(11):1174-80. DOI:10.1212/WNL.0b013e3182698ced · 8.30 Impact Factor
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    ABSTRACT: Autoimmune diseases (AID) are a collection of many complex disorders of unknown etiology resulting in immune responses to self-antigens and are thought to result from interactions between genetic and environmental factors. Here we review the epidemiologic evidence for the role of environmental factors in the development of human AID, the conclusions that can be drawn from the existing data, critical knowledge gaps, and research needed to fill these gaps and to resolve uncertainties. We specifically summarize the state of knowledge and our levels of confidence in the role of specific agents in the development of autoimmune diseases, and we define the areas of greatest impact for future investigations. Among our consensus findings we are confident that: 1) crystalline silica exposure can contribute to the development of several AID; 2) solvent exposure can contribute to the development of systemic sclerosis; 3) smoking can contribute to the development of seropositive rheumatoid arthritis; and 4) an inverse association exists between ultraviolet radiation exposure and the risk of development of multiple sclerosis. We suggest that more studies of phenotypes, genotypes, and multiple exposures are needed. Additional knowledge gaps needing investigation include: defining important windows in the timing of exposures and latencies relating to age, developmental state, and hormonal changes; understanding dose-response relationships; and elucidating mechanisms for disease development. Addressing these essential issues will require more resources to support research, particularly of rare AID, but knowledge of the risks conferred by environmental factors in specific genetic contexts could pave the way for prevention of AID in the future.
    Journal of Autoimmunity 06/2012; 39(4). DOI:10.1016/j.jaut.2012.05.002 · 7.02 Impact Factor
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    ABSTRACT: Following reports of an increased incidence of amyotrophic lateral sclerosis (ALS) in U.S. veterans, we have conducted a high-density genome-wide association study (GWAS) of ALS outcome and survival time in a sample of U.S. veterans. We tested ∼1.3 million single nucleotide polymorphisms (SNPs) for association with ALS outcome in 442 incident Caucasian veteran cases diagnosed with definite or probable ALS and 348 Caucasian veteran controls. To increase power, we also included genotypes from 5909 publicly-available non-veteran controls in the analysis. In the survival analysis, we tested for association between SNPs and post-diagnosis survival time in 639 Caucasian veteran cases with definite or probable ALS. After this discovery phase, we performed follow-up genotyping of 299 SNPs in an independent replication sample of Caucasian veterans and non-veterans (ALS outcome: 183 cases and 961 controls; survival: 118 cases). Although no SNPs reached genome-wide significance in the discovery phase for either phenotype, three SNPs were statistically significant in the replication analysis of ALS outcome: rs6080539 (177 kb from PCSK2), rs7000234 (4 kb from ZNF704), and rs3113494 (13 kb from LOC100506746). Two SNPs located in genes that were implicated by previous GWA studies of ALS were marginally significant in the pooled analysis of discovery and replication samples: rs17174381 in DPP6 (p = 4.4×10(-4)) and rs6985069 near ELP3 (p = 4.8×10(-4)). Our results underscore the difficulty of identifying and convincingly replicating genetic associations with a rare and genetically heterogeneous disorder such as ALS, and suggest that common SNPs are unlikely to account for a substantial proportion of patients affected by this devastating disorder.
    PLoS ONE 03/2012; 7(3):e32768. DOI:10.1371/journal.pone.0032768 · 3.53 Impact Factor
  • Carmel Armon, Lorene M Nelson
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    ABSTRACT: Our objective was to evaluate the epidemiological literature regarding the association between trauma to the head and ALS, in order to determine if trauma to the head is a risk factor for ALS. A Medline literature search was conducted for the period between 1980 and October 2010 using the search terms: ('head trauma' OR 'head injury') AND (ALS OR 'amyotrophic lateral sclerosis' OR MND OR 'motor neuron disease'). The references of primary articles and reviews were checked to assure completeness of the search. Articles with primary data and reference groups were reviewed. The American Academy of Neurology evidence based method for classification of evidence for inferring causality and assigning level of conclusion was used. Twelve of 14 articles published since 1980 met the inclusion criteria. One class II article and three class III articles showed an association between a single instance of head trauma and ALS that did not exceed what might be seen due to chance alone. Eight class IV evidence articles could not inform conclusions. We concluded that evidence based analysis of the epidemiologic literature does not permit concluding that a single instance of head trauma is a risk factor for, or causes, ALS (Level U conclusion).
    Amyotrophic Lateral Sclerosis 03/2012; 13(4):351-6. DOI:10.3109/17482968.2012.660954 · 2.37 Impact Factor
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    ABSTRACT: Radiotherapy may improve the outcome of patients with pancreatic cancer but at an increased cost. In this study, the authors evaluated the cost-effectiveness of modern radiotherapy techniques in the treatment of locally advanced pancreatic cancer. A Markov decision-analytic model was constructed to compare the cost-effectiveness of 4 treatment regimens: gemcitabine alone, gemcitabine plus conventional radiotherapy, gemcitabine plus intensity-modulated radiotherapy (IMRT); and gemcitabine with stereotactic body radiotherapy (SBRT). Patients transitioned between the following 5 health states: stable disease, local progression, distant failure, local and distant failure, and death. Health utility tolls were assessed for radiotherapy and chemotherapy treatments and for radiation toxicity. SBRT increased life expectancy by 0.20 quality-adjusted life years (QALY) at an increased cost of $13,700 compared with gemcitabine alone (incremental cost-effectiveness ratio [ICER] = $69,500 per QALY). SBRT was more effective and less costly than conventional radiotherapy and IMRT. An analysis that excluded SBRT demonstrated that conventional radiotherapy had an ICER of $126,800 per QALY compared with gemcitabine alone, and IMRT had an ICER of $1,584,100 per QALY compared with conventional radiotherapy. A probabilistic sensitivity analysis demonstrated that the probability of cost-effectiveness at a willingness to pay of $50,000 per QALY was 78% for gemcitabine alone, 21% for SBRT, 1.4% for conventional radiotherapy, and 0.01% for IMRT. At a willingness to pay of $200,000 per QALY, the probability of cost-effectiveness was 73% for SBRT, 20% for conventional radiotherapy, 7% for gemcitabine alone, and 0.7% for IMRT. The current results indicated that IMRT in locally advanced pancreatic cancer exceeds what society considers cost-effective. In contrast, combining gemcitabine with SBRT increased clinical effectiveness beyond that of gemcitabine alone at a cost potentially acceptable by today's standards.
    Cancer 02/2012; 118(4):1119-29. DOI:10.1002/cncr.26365 · 4.90 Impact Factor
  • European Journal of Neurology 09/2011; 18(9):e109. DOI:10.1111/j.1468-1331.2011.03461.x · 3.85 Impact Factor
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    ABSTRACT: To examine genetic associations of polymorphisms in the dopamine receptor D2 (DRD2) and D3 (DRD3) genes with risk of Parkinson's disease (PD). The study included 1325 newly diagnosed patients with PD and 1735 controls from a consortium of five North American case-control studies. We collected risk factor information by in-person or telephone interview. Six DRD2 and two DRD3 polymorphisms were genotyped using a common laboratory. Odds ratios were estimated using logistic regression. Among non-Hispanic whites, homozygous carriers of Taq1A DRD2 (rs1800497) polymorphism had an increased risk of PD compared to homozygous wildtype carriers (OR=1.5, 95% CI 1.0-2.3). In contrast, the direction of association for Taq1A polymorphism was opposite for African-Americans, showing an inverse association with PD risk (OR=0.10, 95% CI 0.2-0.7). Among white Hispanics who carried two alleles, the Ser9Gly DRD3 (rs6280) polymorphism was associated with a decreased risk of PD (OR=0.4, 95% CI 0.2-0.8). The inverse association of smoking with PD risk was not modified by any of the DRD2 or DRD3 polymorphisms. DRD2 polymorphisms are unlikely to be true disease-causing variants; however, three DRD2 polymorphisms (including Taq1A) may be in linkage disequilibrium with possible disease associated variants in the DRD2-ANKK1-NCAM1-TTC12 gene cluster.
    Journal of the neurological sciences 06/2011; 307(1-2):22-9. DOI:10.1016/j.jns.2011.05.031 · 2.26 Impact Factor
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    ABSTRACT: In 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine animal models of Parkinson's disease (PD), caffeine protects neurons by blocking the adenosine receptor A2A (ADORA2A). Caffeine is primarily metabolized by cytochrome P450 1A2 (CYP1A2). Our objective was to examine whether ADORA2A and CYP1A2 polymorphisms are associated with PD risk or modify the caffeine-PD association. Parkinson's Epidemiology and Genetic Associations Studies in the United States (PEGASUS) included five population-based case-control studies. One laboratory genotyped four ADORA2A and three CYP1A2 polymorphisms in 1325 PD cases and 1735 age- and sex-matched controls. Information regarding caffeine (coffee) consumption and other lifestyle factors came from structured in-person or telephone interviews. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression. Two ADORA2A polymorphisms were inversely associated with PD risk - rs71651683, a 5' variant (adjusted allelic OR = 0.51, 95% CI 0.33-0.80, permutation-adjusted P = 0.015) and rs5996696, a promoter region variant (adjusted OR for AC and CC genotypes compared with the AA wild-type genotype were 0.76 (95% CI 0.57-1.02) and 0.37 (95% CI 0.13-1.01), respectively (permutation-adjusted P for trend = 0.04). CYP1A2 polymorphisms were not associated with PD risk; however, the coffee-PD association was strongest among subjects homozygous for either variant allele rs762551 (P(interaction) = 0.05) or rs2470890 (P(interaction) = 0.04). In this consortium study, two ADORA2A polymorphisms were inversely associated with PD risk, but there was weak evidence of interaction with coffee consumption. In contrast, the coffee-PD association was strongest among slow metabolizers of caffeine who were homozygous carriers of the CYP1A2 polymorphisms.
    European Journal of Neurology 05/2011; 18(5):756-65. DOI:10.1111/j.1468-1331.2011.03353.x · 3.85 Impact Factor
  • European Journal of Neurology 01/2011; 18(9). · 3.85 Impact Factor
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    ABSTRACT: To assess the familial aggregation of Parkinson's disease (PD), we compared the cumulative incidence of PD among first-degree relatives of PD cases and controls. We identified newly diagnosed patients with PD (n = 573) during 1994 to 1995 within Kaiser Permanente Medical Care Program of Northern California and recruited 496 cases (87%) for the case-control study. Of 720 eligible controls matched by birth year and sex to cases, 541 (75%) agreed to participate. Information on family history of PD and other neurodegenerative diseases was obtained by in-person structured interview. We used the reconstructed cohort approach that provides a better estimate of the risk. The cumulative incidence of PD was significantly higher among relatives of PD patients compared with relatives of controls (2.0 vs. 0.7%; relative risk (RR) = 3.4, 95% confidence interval (CI) 1.9-5.9; P = 0.0001). The degree of familial aggregation was higher among first-degree relatives of Hispanic PD cases compared with Hispanic controls (3.7% vs. 0.4%; RR = 8.5, 95% CI 1.0-68.9) than it was among non-Hispanic Caucasian cases and controls (2.0% vs. 0.8%; RR = 2.7, 95% CI 1.5-5.1; P = 0.02). The familial aggregation of PD was stronger among the siblings of PD cases (RR = 5.4, 95% CI 1.8-16.0) than among parents (RR = 2.7, 95% CI 1.3-5.2). The incidence and familial aggregation of PD is highest among Hispanics, warranting further studies of genetic and environmental risk factors in the Hispanic population.
    Movement Disorders 11/2010; 25(15):2587-94. DOI:10.1002/mds.23361 · 5.63 Impact Factor
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    ABSTRACT: To determine whether low levels of 25-hydroxyvitamin D (25[OH]D) contribute to the increased risk of postpartum multiple sclerosis (MS) relapses. Prospective cohort study. Outpatients identified through membership records of Kaiser Permanente Northern California or Stanford University outpatient neurology clinics. Twenty-eight pregnant women with MS. We prospectively followed up patients through the postpartum year and assessed exposures and symptoms through structured interviews. Total serum 25(OH)D levels were measured using the DiaSorin Liaison Assay during the third trimester and 2, 4, and 6 months after giving birth. The data were analyzed using longitudinal multivariable methods. Levels of 25(OH)D and relapse rate. Fourteen (50%) women breastfed exclusively, and 12 women (43%) relapsed within 6 months after giving birth. During pregnancy, the average 25(OH)D levels were 25.4 ng/mL (range, 13.7-42.6) and were affected only by season (P=.009). In contrast, in the postpartum period, 25(OH)D levels were significantly affected by breastfeeding and relapse status. Levels of 25(OH)D remained low in the exclusive breastfeeding group, yet rose significantly in the nonexclusive breastfeeding group regardless of season (P=.007, unadjusted; P=.02, adjusted for season). By 4 and 6 months after childbirth, 25(OH)D levels were, on average, 5 ng/mL lower in the women who breastfed exclusively compared with the nonbreastfeeding group (P=.001). Pregnancy and exclusive breastfeeding are strongly associated with low 25(OH)D levels in women with MS. However, these lower vitamin D levels were not associated with an increased risk of postpartum MS relapses. These data suggest that low vitamin D in isolation is not an important risk factor for postpartum MS relapses.
    Archives of neurology 11/2010; 68(3):310-3. DOI:10.1001/archneurol.2010.291 · 7.01 Impact Factor

Publication Stats

3k Citations
352.56 Total Impact Points

Institutions

  • 2001–2015
    • Stanford University
      • • Department of Health Research and Policy
      • • Department of Medicine
      Palo Alto, California, United States
  • 1998–2012
    • Stanford Medicine
      • • Division of Epidemiology
      • • Department of Health Research and Policy
      Stanford, California, United States
  • 1990–1997
    • University of Washington Seattle
      • • Department of Epidemiology
      • • Department of Medicine
      Seattle, WA, United States
  • 1991
    • Swedish Medical Center Seattle
      Seattle, Washington, United States