M Nagai

Fukuoka University, Hukuoka, Fukuoka, Japan

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Publications (91)147.45 Total impact

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    ABSTRACT: Background: The sentinel surveillance system in Japan provides estimates of nationwide influenza incidence. Although prefectural influenza incidences can be estimated using data from the current surveillance system, such estimates may be imprecise.Methods: We calculated the numbers of sentinel medical institutions (SMIs) needed in the surveillance system to estimate influenza incidences in prefectures, under the assumption that the standard error rates in 75% of influenza epidemic cases are less than 10%. Epidemic cases observed in 47 prefectures during the 2007/2008, 2008/2009, and 2009/2010 seasons, respectively, were used.Results: The present total number of SMIs was 6669. With respect to current standards, the increases required in prefectures ranged from 0 to 59, and the total increase required in the number of SMIs was 1668.Conclusions: We used sentinel surveillance data for Japan to calculate the number of SMIs required to estimate influenza incidence in each prefecture.
    Journal of Epidemiology 03/2014; · 2.11 Impact Factor
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    ABSTRACT: Objectives. To estimate the number of patients with polymyositis/dermatomyositis (PM/DM) in Japan and the prevalence rate and incidence rate of the disease. Methods. The electronic database in the nationwide registration system on intractable diseases from 2003 to 2010 was utilized to identify the number of prevalent and incident cases of PM/DM. The electronic data entry rate was used to establish the total number of registered cases. Results. The estimated total number of patients with PM/DM and the prevalence rate in Japan in 2010 were 17,000 and 13.2 per 100,000 population, respectively. The prevalence of PM/DM ranged from 10 to 13 per 100,000 population with a trend toward increasing over time. The incidence of PM/DM was estimated within the range 10-13 per 1,000,000 person-years, except for 2003. Conclusions. We report the prevalence and incidence of PM/DM recently in Japan for the first time at the nationwide population level. Because the prevalence seems to be increasing recently, continued monitoring of these epidemiologic features is required.
    Modern Rheumatology 10/2013; · 1.72 Impact Factor
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    ABSTRACT: Several genome-wide association studies and case-control studies have investigated the relationships between single nucleotide polymorphisms (SNPs) in the BST1 gene and Parkinson's disease (PD), but the results have been inconsistent. We examined the relationships between SNPs rs11931532, rs12645693, and rs11724635 and the risk of sporadic PD in Japan. Included were 229 cases within 6years of onset of PD as defined according to the UK PD Society Brain Bank clinical diagnostic criteria. Controls were 357 inpatients and outpatients without neurodegenerative disease. SNPs rs11931532 and rs12645693 were not significantly related to sporadic PD. Compared with a reference group of subjects with the CC genotype of SNP rs11724635, those with the AA genotype had a marginally significantly increased risk of sporadic PD: the adjusted OR was 1.57 (95% CI: 0.95-2.61, P=0.08). No significant interactions were found between BST1 SNP rs11724635 and smoking or caffeine intake with respect to sporadic PD. The current study failed to detect significant relationships between BST1 SNPs rs11931532, rs12645693, and rs11724635 and sporadic PD; however, the relationship between SNP rs11724635 and sporadic PD was of borderline significance. We do not find evidence for interactions between smoking or caffeine intake and SNP rs11724635 affecting sporadic PD.
    Journal of the neurological sciences 09/2012; · 2.32 Impact Factor
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    ABSTRACT: It has been suggested that P-glycoprotein (P-gp), the product of multidrug resistance 1 (MDR1) gene, regulates the brain entry of various xenobiotics. Impaired function of P-gp may be associated with an increased risk of Parkinson's disease (PD). The aim of this study was to investigate the impact of a MDR1 C3435T polymorphism on PD risk alone or in combination with environmental factors. A total of 238 patients with PD and 368 controls were genotyped for the MDR1 C3435T polymorphism. Subjects with the TT genotype of the C3435T polymorphism showed a nonsignificantly increased risk of PD (odds ratio (OR) = 1.49, 95% confidence interval (CI) =0.85 - 2.25) compared with those with the CC genotype. A gene-environment interaction was suggested, with a combination of at least one T allele and ever drinking conferring significantly higher risk (OR = 1.83, 95% CI = 1.07 - 3.15, P = 0.029), compared with the CC genotype and never drinking. No significant interaction of smoking or occupational pesticide use with the C3435T polymorphism was observed. Our results suggest that the C3435T polymorphism may not play an important role in PD susceptibility in Japanese. Evidence of an interaction between the C3435T polymorphism and alcohol consumption was suggested.
    Drug Metabolism and Pharmacokinetics 09/2012; · 2.07 Impact Factor
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    ABSTRACT: OBJECTIVES: The aim of this study was to describe age, gender distribution, and age at onset of systemic lupus erythematosus (SLE), polymyositis/dermatomyositis (PM/DM), and systemic sclerosis (SSc) in Japan. METHODS: We used epidemiological information on 21,405, 6,327, and 10,058 patients with SLE, PM/DM, and SSc, respectively, in a Japanese nationwide registration database of patients with intractable diseases. RESULTS: All three diseases occur predominantly in women, with the female-to-male ratio being 8.2:1, 2.6:1, and 7.7:1 for SLE, PM/DM, and SSc, respectively. The most susceptible age for SLE is 15-44 and 20-39 years for males and females, respectively. For PM/DM it is 45-64 and 40-64 years and for SSc, 50-69 and 40-59 for men and women, respectively. CONCLUSIONS: The basic descriptive epidemiological characteristics of SLE, PM/DM, and SSc in Japan, such as gender distribution, present age, and age at onset, were surveyed nationwide for fiscal 2007. It was found that these characteristics were similar to those in Western populations. Our finding provides new information on the natural history of disease development.
    Modern Rheumatology 08/2012; · 1.72 Impact Factor
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    ABSTRACT: BACKGROUND: A recent meta-analysis on the UCHL1 S18Y variant and Parkinson's disease (PD) showed a significant inverse association between the Y allele and PD; the individual studies included in that meta-analysis, however, have produced conflicting results. We examined the relationship between UCHL1 S18Y single nucleotide polymorphism (SNP) and sporadic PD in Japan. METHODS: Included were 229 cases within 6 years of onset of PD, defined according to the UK PD Society Brain Bank clinical diagnostic criteria. Controls were 357 inpatients and outpatients without neurodegenerative disease. Adjustment was made for sex, age, region of residence, smoking, and caffeine intake. RESULTS: Compared with subjects with the CC or CA genotype of UCHL1 S18Y SNP, those with the AA genotype had a significantly increased risk of sporadic PD: the adjusted OR was 1.57 (95% CI: 1.06 to 2.31). Compared with subjects with the CC or CA genotype of UCHL1 S18Y and the CC or CT genotype of SNCA SNP rs356220, those with the AA genotype of UCHL1 S18Y and the TT genotype of SNP rs356220 had a significantly increased risk of sporadic PD; the interaction, however, was not significant. Our previous investigation found significant inverse relationships between smoking and caffeine intake and PD in this population. There were no significant interactions between UCHL1 S18Y and smoking or caffeine intake affecting sporadic PD. CONCLUSIONS: This study reveals that the UCHL1 S18Y variant is a risk factor for sporadic PD. We could not find evidence for interactions affecting sporadic PD between UCHL1 S18Y and SNCA SNP rs356220, smoking, or caffeine intake.
    BMC Neurology 07/2012; 12(1):62. · 2.56 Impact Factor
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    ABSTRACT: Several case-control studies and genome-wide association studies have examined the relationships between single nucleotide polymorphisms (SNPs) in the SNCA gene and Parkinson's disease (PD), and have provided inconsistent results. We investigated the relationships between SNPs rs356229, rs356219, rs356220, rs7684318, and rs2736990 and the risk of sporadic PD in Japan using data from a multicenter hospital-based case-control study. Included were 229 cases within 6 years of onset of PD as defined according to the UK PD Society Brain Bank clinical diagnostic criteria. Controls were 357 inpatients and outpatients without neurodegenerative disease. Adjustment was made for sex, age, region of residence, and smoking. Based on the recessive model, compared with subjects with the CC or CT genotype of SNP rs356220, those with the TT genotype had a significantly increased risk of sporadic PD: the adjusted OR was 1.42 (95% CI: 1.002-2.02). In the additive model, SNP rs2736990 was significantly related to the risk of sporadic PD: the adjusted OR was 1.30 (95% CI: 1.002-1.68). There were no significant relationships between SNP rs356229, rs356219, or rs7684318 and the risk of sporadic PD in any genetic model. The additive interactions between SNPs rs356219 and rs356220 and smoking with respect to sporadic PD were significant although the multiplicative interactions were not significant. This study suggests that SNCA SNPs rs356220 and rs2736990 are significantly associated with the risk of sporadic PD in Japanese. We also present new evidence for biological interactions between SNPs rs356219 and rs356220 and smoking that affect sporadic PD.
    Parkinsonism & Related Disorders 03/2012; 18(5):557-61. · 3.27 Impact Factor
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    ABSTRACT: Nearly all epidemiologic studies examining the association between the risk of Parkinson's disease (PD) and diet have focused on single foods and specific nutrients. However, epidemiologic evidence for the association of dietary pattern with PD, namely the measurement of overall diet by considering the cumulative effects of nutrients is extremely limited. We conducted a hospital-based case-control study in Japan to examine the relationship between dietary patterns and the risk of PD. Patients with PD diagnosed using the UK PD Society Brain Bank criteria (n = 249) and controls without neurodegenerative diseases (n = 368) were recruited. At the time of recruitment, dietary intake during the preceding 1 month was assessed using a validated, self-administered diet history questionnaire. Dietary patterns from 33 predefined food groups (energy-adjusted food g/day) were extracted by factor analysis. Three dietary patterns were identified: 'Healthy', 'Western' and 'Light meal' patterns. After adjustment for potential non-dietary confounding factors, the Healthy pattern, characterized by a high intake of vegetables, seaweed, pulses, mushrooms, fruits and fish, was inversely associated with the risk of PD with a border-line significance (P for trend = 0.06). Multivariate Odds ratio (95% confidence intervals) for PD in the highest quartile of the Healthy pattern was 0.54 (0.32-0.92) compared with the lowest quartile. No associations with PD were detected for the other two dietary patterns. In this case-control study in Japan, a dietary pattern consisting of high intakes of vegetables, fruits and fish may be associated with a decreased risk of PD.
    European Journal of Neurology 12/2011; 19(5):681-8. · 4.16 Impact Factor
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    ABSTRACT: Parkinson's disease (PD) is characterized by alterations in dopaminergic neurotransmission. Genetic polymorphisms involved in dopaminergic neurotransmission may influence susceptibility to PD. We investigated the relationship of catechol-O-methyltransferase (COMT), monoamine oxidase B (MAOB), dopamine receptor (DR) D2 and DRD4 polymorphisms and PD risk with special attention to the interaction with cigarette smoking among 238 patients with PD and 369 controls in a Japanese population. Subjects with the AA genotype of MAOB rs1799836 showed a significantly increased risk of PD (odds ratio (OR) = 1.70, 95% confidence interval (CI) = 1.12 - 2.58) compared with the AG and GG genotypes combined. The AA genotype of COMT rs4680 was marginally associated with an increased risk of PD (OR = 1.86, 95% CI = 0.98 - 3.50) compared with the GG genotype. The DRD2 rs1800497 and DRD4 rs1800955 polymorphisms showed no association with PD. A COMT -smoking interaction was suggested, with the combined GA and AA genotypes of rs4680 and non-smoking conferring significantly higher risk (OR = 3.97, 95% CI = 2.13 - 7.41) than the AA genotype and a history of smoking (P for interaction = 0.061). No interactions of smoking with other polymorphisms were observed. The COMT rs4680 and MAOB rs1799836 polymorphisms may increase susceptibility to PD risk among Japanese. Future studies involving larger control and case populations and better pesticide exposure histories will undoubtedly lead to a more thorough understanding of the role of the polymorphisms involved in the dopamine pathway in PD.
    BMC Neurology 07/2011; 11:89. · 2.56 Impact Factor
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    ABSTRACT: Metals are involved in several important functions in the nervous system. Zinc and iron are increased and copper is decreased in the substantia nigra in Parkinson's disease (PD). However, epidemiological evidence for the association of dietary intake of metals with the risk of PD is limited. We investigated the relationship between metal consumption and the risk of PD in Japan using data from a multicenter hospital-based case-control study. Included were 249 cases within 6 years of onset of PD based on the UK PD Society Brain Bank clinical diagnostic criteria. Controls were 368 inpatients and outpatients without a neurodegenerative disease. Information on dietary factors was collected using a self-administered diet history questionnaire. Higher intake of iron, magnesium, and zinc was independently associated with a reduced risk of PD: the adjusted OR in the highest quartile was 0.24 (95% CI: 0.10-0.57, P for trend=0.0003) for iron, 0.33 (95% CI: 0.13-0.81, P for trend=0.007) for magnesium and 0.50 (95% CI: 0.26-0.95, P for trend=0.055) for zinc. There were no relationships between the intake of copper or manganese and the risk of PD. Higher intake of iron, magnesium, and zinc may be protective against PD.
    Journal of the neurological sciences 07/2011; 306(1-2):98-102. · 2.32 Impact Factor
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    ABSTRACT: The evidence for associations between occupational factors and the risk of Parkinson's disease (PD) is inconsistent. We assessed the risk of PD associated with various occupational factors in Japan. We examined 249 cases within 6 years of onset of PD. Control subjects were 369 inpatients and outpatients without neurodegenerative disease. Information on occupational factors was obtained from a self-administered questionnaire. Relative risks of PD were estimated using odds ratios (ORs) and 95% confidence intervals (CIs) based on logistic regression. Adjustments were made for gender, age, region of residence, educational level, and pack-years of smoking. Working in a professional or technical occupation tended to be inversely related to the risk of PD: adjusted OR was 0.59 (95% CI: 0.32-1.06, P = 0.08). According to a stratified analysis by gender, the decreased risk of PD for persons in professional or technical occupations was statistically significant only for men. Adjusted ORs for a professional or technical occupation among men and women were 0.22 (95% CI: 0.06-0.67) and 0.99 (0.47-2.07), respectively, and significant interaction was observed (P = 0.048 for homogeneity of OR). In contrast, risk estimates for protective service occupations and transport or communications were increased, although the results were not statistically significant: adjusted ORs were 2.73 (95% CI: 0.56-14.86) and 1.74 (95% CI: 0.65-4.74), respectively. No statistical significance was seen in data concerning exposure to occupational agents and the risk of PD, although roughly a 2-fold increase in OR was observed for workers exposed to stone or sand. The results of our study suggest that occupational factors do not play a substantial etiologic role in this population. However, among men, professional or technical occupations may decrease the risk of PD.
    BMC Neurology 07/2011; 11:83. · 2.56 Impact Factor
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    ABSTRACT: Apolipoprotein E (APOE) is associated with increased oxidative stress, which is caused by reactive oxygen species (ROS). Enhanced cytochrome P450 2E1 (CYP2E1) activity may also increase formation of neurotoxins such as ROS. As Parkinson's disease (PD) is a neurodegenerative disorder, both the APOE and CYP2E1 genes that are involved in neurodegeneration by oxidative stress may be associated with PD risk. We investigated the relationship of the APOE and CYP2E1 rs2864987 polymorphisms and PD risk with special attention to the interaction with alcohol consumption among 238 patients with PD and 296 controls in a Japanese population. The frequencies of the ɛ2, ɛ3, and ɛ4 alleles of the APOE polymorphism among controls were 3.72, 86.7, and 9.63%, respectively. As compared with the APOE ε3/ε3 genotype, the 2/ε4 genotype was associated with an increased risk of PD (adjusted odds ratio (OR) = 9.50, 95% (confidence interval) CI = 1.12-80.6). The presence of the ε3 allele was associated with a decreased risk of PD. Meanwhile, CYP2E1 rs2864987 was not associated with PD risk. Although CYP2E1 is involved in the metabolism of alcohol, there was no evidence of interaction between alcohol consumption and CYP2E1 rs2864987. Our results suggested that the APOE polymorphism might play an important role in PD susceptibility in our Japanese population. Future studies involving larger control and case populations and better alcohol consumption histories will undoubtedly lead to a more thorough understanding of the role of polymorphisms of genes related to the generation of ROS in PD development.
    Journal of Neural Transmission 03/2011; 118(9):1335-44. · 3.05 Impact Factor
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    ABSTRACT: Studies that have addressed the association between the intake of coffee or caffeine and Parkinson's disease (PD) were conducted mainly in Western countries. Little is known about this relationship in an Asian population. Therefore, we performed an assessment of the association of the intake of coffee, other caffeine-containing beverages, and caffeine with the risk of PD in Japan. The study involved 249 PD cases and 368 control subjects. Information on dietary factors was obtained through a self-administered diet history questionnaire. Adjustment was made for sex, age, region of residence, educational level, pack-years of smoking, body mass index, the dietary glycemic index, and intake of cholesterol, vitamin E, β-carotene, vitamin B(6,) alcohol, and iron. Intake of coffee, black tea, and Japanese and Chinese teas was significantly inversely associated with the risk of PD: the adjusted odds ratios in comparison of the highest with the lowest quartile were 0.52, 0.58, and 0.59, respectively (95% confidence intervals = 0.30-0.90, 0.35-0.97, and 0.35-0.995, respectively). A clear inverse dose-response relationship between total caffeine intake and PD risk was observed. We confirmed that the intake of coffee and caffeine reduced the risk of PD. Furthermore, this is the first study to show a significant inverse relationship between the intake of Japanese and Chinese teas and the risk of PD.
    Parkinsonism & Related Disorders 03/2011; 17(6):446-50. · 3.27 Impact Factor
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    ABSTRACT: Three previous cohort studies in the USA reported that dairy product consumption was significantly associated with an increased risk of Parkinson's disease (PD) in men, but not in women. We examined the relationship between consumption of dairy products, calcium, and vitamin D and the risk of PD using data from a multicenter hospital-based case-control study in Japan. Included were 249 cases within 6 years of onset of PD based on the UK PD Society Brain Bank clinical diagnostic criteria. Controls were 368 inpatients and outpatients without a neurodegenerative disease. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for sex, age, region of residence, pack-years of smoking, years of education, body mass index, and dietary factors including cholesterol, dietary glycemic index, vitamin E, β-carotene, vitamin B(6), caffeine, iron, and alcohol. Total dairy product consumption was not materially associated with the risk of PD (P for trend = 0.62). No evident relationships were observed between intake of milk, yogurt, cheese, or ice cream and the risk of PD (P for trend = 0.75, 0.63, 0.59, and 0.35, respectively). There were no measurable associations between consumption of calcium or vitamin D and PD (P for trend = 0.37 and 0.69, respectively). No significant interactions were observed between the dietary exposures and sex regarding PD. Our results suggest that intake of dairy products, calcium, and vitamin D was not related to PD, regardless of sex. However, such null relationships might be a consequence of PD.
    Parkinsonism & Related Disorders 02/2011; 17(2):112-6. · 3.27 Impact Factor
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    ABSTRACT: antioxidant vitamins are expected to protect cells from oxidative damage by neutralizing the effects of reactive oxygen species. However, epidemiological evidence regarding the associations between antioxidant vitamin intake and Parkinson's disease (PD) is limited and inconsistent. We investigated the relationship between dietary intake of selected antioxidant vitamins, vegetables and fruit and the risk of PD in Japan using data from a multicenter hospital-based case-control study. included were 249 patients within 6 years of onset of PD. Controls were 368 inpatients and outpatients without a neurodegenerative disease. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for sex, age, region of residence, pack-years of smoking, years of education, body mass index, dietary intake of cholesterol, alcohol, total dairy products, and coffee and the dietary glycemic index. higher consumption of vitamin E and β-carotene was significantly associated with a reduced risk of PD after adjustment for confounders under study: the adjusted odds ratio in the highest quartile was 0.45 (95% confidence interval [CI]: 0.25-0.79, P for trend = 0.009) for vitamin E and 0.56 (95% CI: 0.33-0.97, P for trend = 0.03) for β-carotene. Stratified by sex, such inverse associations were significant only in women. No material relationships were shown between intake of vitamin C, α-carotene, cryptoxanthin, green and yellow vegetables, other vegetables, or fruit and the risk of PD. higher intake of vitamin E and β-carotene may be associated with a decreased risk of PD.
    European Journal of Neurology 01/2011; 18(1):106-13. · 4.16 Impact Factor
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    ABSTRACT: Although some epidemiologic studies found inverse associations between alcohol drinking and Parkinson's disease (PD), the majority of studies found no such significant associations. Additionally, there is only limited research into the possible interactions of alcohol intake with aldehyde dehydrogenase (ALDH) 2 activity with respect to PD risk. We examined the relationship between alcohol intake and PD among Japanese subjects using data from a case-control study. From 214 cases within 6 years of PD onset and 327 controls without neurodegenerative disease, we collected information on "peak", as opposed to average, alcohol drinking frequency and peak drinking amounts during a subject's lifetime. Alcohol flushing status was evaluated via questions, as a means of detecting inactive ALHD2. The multivariate model included adjustments for sex, age, region of residence, smoking, years of education, body mass index, alcohol flushing status, presence of selected medication histories, and several dietary factors. Alcohol intake during peak drinking periods, regardless of frequency or amount, was not associated with PD. However, when we assessed daily ethanol intake separately for each type of alcohol, only Japanese sake (rice wine) was significantly associated with PD (adjusted odds ratio of ≥66.0 g ethanol per day: 3.39, 95% confidence interval: 1.10-11.0, P for trend = 0.001). There was no significant interaction of alcohol intake with flushing status in relation to PD risk. We did not find significant associations between alcohol intake and PD, except for the daily amount of Japanese sake. Effect modifications by alcohol flushing status were not observed.
    BMC Neurology 11/2010; 10:111. · 2.56 Impact Factor
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    ABSTRACT: Previous case-control studies in Japanese and ethnic Chinese populations reported that the LRRK2 Gly2385Arg variant is a risk factor for Parkinson's disease (PD). We aimed to validate the previous findings and investigate whether cigarette smoking influences the relationship between the Gly2385Arg variant and PD. Included were 229 cases within 6years of onset of sporadic PD. Controls were 358 inpatients and outpatients without a neurodegenerative disease. The frequency of the heterozygous genotype was 13.1% of cases and 6.4% of controls: adjusted OR for the GA genotype was 2.06 (95% CI: 1.15-3.69). Compared with subjects with the GG genotype who had ever smoked, those with the GA genotype who had never smoked had a 5.8-fold increased risk of sporadic PD. The multiplicative interaction between the SNP and smoking was not statistically significant. With respect to the additive interaction, the estimated attributable proportion due to interaction (AP), but not relative excess risk due to interaction or the synergy index, was statistically significant (AP=0.50, 95% CI: 0.05-0.94), suggesting the presence of a biological interaction. The present study confirms that the LRRK2 Gly2385Arg variant is a risk factor for sporadic PD. In addition, we provide new evidence for the biological interaction between the polymorphism and smoking with regard to the risk of sporadic PD.
    Journal of the neurological sciences 10/2010; 297(1-2):15-8. · 2.32 Impact Factor
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    ABSTRACT: Patients with idiopathic Parkinson's disease (PD) appear to have reduced capacity for detoxification of certain environmental compounds. The glutathione S-transferases (GSTs) are candidate genes for PD because they are involved in the metabolism of pesticides and cigarette smoke. We investigated the relationship of the seven GST polymorphisms (GSTM1 deletion, GSTT1 deletion, GSTP1 rs1695, GSTO1 rs4925, GSTO1 rs11191972, GSTO2 rs156697 and GSTO2 rs2297235) and PD risk with special reference to the interaction with pesticide use or cigarette smoking among 238 patients with PD cases and 370 controls in a Japanese population. None of the GST polymorphisms were associated with PD. GSTO1 rs4925 and GSTO2 rs2297235 were found to be in strong linkage disequilibrium (D' = 0.98). Cigarette smoking was significantly associated with decreased risk of PD. However, no interaction of smoking with any of the GST polymorphisms was observed. Self-reported pesticide use was not associated with increased risk of PD. There was no evidence of interaction between self-reported pesticide use and either GST polymorphism. Our results suggest that the tested GST polymorphisms did not play an important role in PD susceptibility in our Japanese population. Our study does not give evidence of interaction between the GST polymorphisms and smoking may although this study provided sufficient statistical power to detect modest interaction. As for interaction between GSTP polymorphisms and pesticide use, the power of this study to detect an interactive effect was low due to a small number of pesticide users. Future studies involving larger control and case populations and better pesticide exposure histories will undoubtedly lead to a more thorough understanding of the role of the GST polymorphisms in PD development.
    Parkinsonism & Related Disorders 08/2010; 16(7):447-52. · 3.27 Impact Factor
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    ABSTRACT: Although numerous studies describe the clinical characteristics of idiopathic osteonecrosis of the femoral head (ONFH) in specific study populations, these have not been confirmed in countrywide studies. We therefore determined: (1) the annual number of patients seeking medical care and number of patients newly diagnosed; and (2) the distribution of the age and gender of the patients, potential causative factors, severity of the disease, and operative procedures performed. We conducted a nationwide epidemiologic survey in 2005. The survey included all orthopaedic departments in Japan by stratified random sampling according to the number of beds. The number of patients who sought medical care for idiopathic ONFH during 2004 was estimated to be 11,400 (95% confidence interval, 10,100-12,800). We obtained clinical information from 1502 of these patients. The peak in age distribution occurred in the 40s. Potential causative factors were systemic steroid administration (51%) and habitual alcohol use (31%). Hip replacement was the most frequently performed procedure (65%). Among patients with a history of systemic steroid administration, systemic lupus erythematosus was reported most frequently (31%) as the underlying disease. Among patients younger than 40 years, steroid use was the most prominent potential causative factor (60%), and hip replacement frequently was performed (45%). A greater proportion of patients with no history of steroid or alcohol use was observed among patients 65 years or older (41%). In addition to the disease burden of idiopathic ONFH in Japan, our results confirmed the importance of developing preventive and treatment strategies, especially among the younger population. Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 03/2010; 468(10):2715-24. · 2.79 Impact Factor
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    ABSTRACT: This case-control study investigated the associations of a history of hypertension, hypercholesterolemia, and diabetes mellitus with the risk of Parkinson's disease (PD) in Japan. Included were 249 cases within 6 years of onset of PD. Controls were 368 inpatients and outpatients without a neurodegenerative disease. Data on the vascular risk factors and confounders were obtained from a self-administered questionnaire. The vascular risk factors were defined based on drug treatment. Adjustment was made for sex, age, region of residence, pack-years of smoking, years of education, leisure-time exercise, body mass index, dietary intake of energy, cholesterol, vitamin E, alcohol, and coffee and the dietary glycemic index. The proportions of hypertension, hypercholesterolemia, and diabetes mellitus prior to the onset of PD were 23.7%, 9.6%, and 4.0%, respectively, in cases. Hypertension, hypercholesterolemia, and diabetes mellitus were significantly associated with a decreased risk of PD: the adjusted ORs were 0.43 (95% CI: 0.29-0.64), 0.58 (95% CI: 0.33-0.97), and 0.38 (95% CI: 0.17-0.79), respectively. No significant differences were observed in the association of vascular risk factors with the risk of PD between men and women. We found evidence of significant inverse associations of hypertension, hypercholesterolemia, and diabetes mellitus with the risk of PD in Japan. Further well-designed investigations of the association of vascular risk factors with the risk of PD are needed, particularly large-scale prospective studies in Asia.
    Journal of the neurological sciences 03/2010; 293(1-2):82-6. · 2.32 Impact Factor

Publication Stats

854 Citations
147.45 Total Impact Points

Institutions

  • 2009–2012
    • Fukuoka University
      • • Faculty of Medicine
      • • Department of Public Health
      Hukuoka, Fukuoka, Japan
  • 2010–2011
    • Kyushu University
      • Department of Neurology
      Fukuoka-shi, Fukuoka-ken, Japan
  • 1997–2011
    • Saitama Medical University
      • Department of Public Health
      Saitama, Saitama-ken, Japan
  • 1996–2011
    • The University of Tokyo
      • • School of Public Health
      • • Department of Health Science and Nursing
      Tokyo, Tokyo-to, Japan
  • 2007–2009
    • Aichi Prefectural College of Nursing & Health
      • Department of Public Health, Aichi Prefectural College of Nursing and Health
      Nagoya, Aichi, Japan
  • 2008
    • National Institute of Infectious Diseases, Tokyo
      Edo, Tōkyō, Japan
    • Shiga University of Medical Science
      • Department of Health Science
      Ōtu, Shiga, Japan
  • 2003–2008
    • Fujita Health University
      • Department of Hygiene
      Nagoya, Aichi, Japan
  • 2006
    • Sapporo Medical University
      Sapporo, Hokkaidō, Japan
  • 2004
    • National Institute for Environmental Studies
      • Center for Environmental Health Sciences
      Tsukuba, Ibaraki, Japan
    • Kanazawa Medical University
      • Department of Epidemiology and Public Health
      Kanazawa-shi, Ishikawa-ken, Japan
  • 2000
    • Oita University of Nursing and Health Sciences
      Ōita, Ōita, Japan
  • 1995
    • Jichi Medical University
      • Department of Public Health
      Totigi, Tochigi, Japan