Satoko Iwasawa

Keio University, Edo, Tokyo, Japan

Are you Satoko Iwasawa?

Claim your profile

Publications (27)86.7 Total impact


  • No preview · Article · Sep 2015 · European Respiratory Journal
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Indium was added to the list of substances regulated by the Ordinance on Prevention of Hazards due to Specified Chemical Substances (OPHSCS) in 2013. Indium metal (IM), however, is not regulated by the OPHSCS due to insufficient information on pulmonary effects following exposure. From 2011 to 2013, a cross-sectional study was conducted on 141 IM-exposed workers at 11 factories. Subjective symptoms were assessed, including levels of serum biomarkers, spirometry readings and total and diffuse lung capacity. Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D) were selected as biomarkers of interstitial pneumonia. Indium serum concentration (In-S) and personal air sampling data were used to estimate exposure. Subjects were categorized into 5 groups based on occupation and type of exposure: smelting, soldering, dental technician, bonding and other. The highest level of In-S was 25.4 µg/l, and the mean In-S level was significantly higher in the smelting group than in other groups. In the smelting group, the prevalence of increased In-S levels was 9.1%, while that of abnormal KL-6 was 15.2%. A significant dose-effect relationship was observed between the In-S and KL-6 levels. No marked differences were observed between any of the groups in SP-D values, pulmonary symptoms, or pulmonary function test results. A total of 31% of the subjects worked in an environment with IM levels exceeding 0.3 µg/m(3), which requires a protective mask to be worn. For workers exposed to IM, work environments should be monitored, appropriate protective masks should be worn, and medical monitoring should be conducted according to the OPHSCS.
    Preview · Article · May 2015 · Journal of Occupational Health
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study investigated the health effects of volcanic gas, mainly sulfur dioxide (SO2), exposure on the children of Miyakejima Island. Health checkups were conducted in November from 2006 to 2011. Health effects were evaluated through a self-administered questionnaire on respiratory and irritative symptoms, and spirometry. SO2 was measured continuously from February 2005 onward at six fixed monitoring stations in inhabitable areas. Based on mean SO2 concentration during 3 months before each health checkup, inhabitable areas were classified into three categories: (1) lower (area L); (2) higher (area H-1); and (3) highest (area H-2). Average concentrations (ppb) of SO2 decreased year-by-year and ranged from 11.3 to 2.47 in area L, from 32.2 to 12.2 in area H-1, and from 75.1 to 12.1 in area H-2, respectively. In general, prevalence of respiratory and irritative symptoms was higher in area H-2, and the prevalence decreased year-by-year in all three areas by Cochran-Armitage test for trend. We defined a study population in area L in 2008 as a reference population because we had no unexposed population. Applying a logistic regression model, age-, sex-, and hypersusceptibility-adjusted prevalence odds ratios to the reference population showed clear exposure-dependent increases in some irritative symptoms such as "Irritation and/or pain in throat" and "in eyes," and approximately 30 ppb seemed to be the threshold concentration. Spirometry did not show any significant differences. Though no pulmonary functions were affected, some subjective symptoms were detected dose-dependently by SO2 exposure concentration in child residents during the 6 years after the eruption.
    Preview · Article · Mar 2015 · International Archives of Occupational and Environmental Health
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Dementia is a new focus of research on improved treatment for Parkinson's disease (PD). In 2007, a screening tool for PD dementia (PD-D) was developed by the Movement Disorder Society (Level I testing), which still requires verification by a large population study. Methods We conducted a cross-sectional and multicenter study including 13 institutions administering the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) to 304 PD patients (mean age: 70.6 ± 8.3 years; mean Hoehn and Yahr stage: 2.7 ± 0.7). Results In all, 34.5% of the patients had MMSE scores <26; 94.3% of these patients had impairments in ≥2 cognitive domains and met the criteria for probable PD-D by Level I testing. Executive dysfunction combined with attention and memory impairment was most common (51.4%). In the Level I subtests of executive function, the score for phonemic fluency declined by <50% in patients with high MoCA scores (24-30 points) and lacked specificity for PD-D. No patient had visuospatial impairment (measured by the pentagon copying subtest) alone, and the score for pentagon copying stayed at ≥70% even in patients with low MMSE scores (12-25 points), therefore lacking sensitivity for PD-D. Conclusions Level I testing with administration of the MMSE and MoCA is a practical and efficient screening tool for PD-D. However, the phonemic fluency and pentagon copying tests should be replaced by more specific/sensitive ones when screening for PD-D.
    Full-text · Article · May 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background The Montreal Cognitive Assessment (MoCA) is the most suitable measure for screening cognitive impairment in Parkinson's disease (PD). However, the utility of the MoCA has not been documented sufficiently, especially in Asian populations. AimThis multicenter study including a large number of Japanese patients compared Mini-Mental State Examination (MMSE) and MoCA scores in PD patients. Methods We performed a cross-sectional study. Idiopathic PD patients (n = 304; age, 70.6 ± 8.3 years; disease duration, 6.6 ± 5.1 years; Hoehn & Yahr stage, 2.7 ± 0.7; mean ± SD) were registered at 13 participating hospitals, and their clinical/neurological/cognitive features were examined using Japanese versions of the MMSE and MoCA. ResultsThe MMSE and MoCA scores were 26.3 ± 3.6 (range, 12-30) and 20.9 ± 5.0 (range, 5-30), respectively, and exhibited a strong correlation (R2 = 0.74, P <0.001) with each other. An MMSE score <26 was observed in 35% of the subjects. A MoCA score <21 had 89% sensitivity and 83% specificity, comparable to an MMSE score <26. The two scores were correlated with age (R2 = 0.12 and 0.20, respectively; P <0.0001), but not with Hoehn & Yahr stage or disease duration. Conclusions One third of the patients met an MMSE score <26, a diagnostic criterion of PD with dementia. A MoCA score <21 seemed comparable to an MMSE score <26. The two scores were correlated with age, rather than severity of motor symptoms, suggesting that cognitive decline might be independent of motor decline in PD.This article is protected by copyright. All rights reserved.
    Full-text · Article · Feb 2014

  • No preview · Article · Oct 2013 · Sangyo eiseigaku zasshi Journal of occupational health

  • No preview · Article · Oct 2013 · Journal of the Neurological Sciences
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background. Accumulated evidence shows how important spinal posture is for aged populations in maintaining independence in everyday life. However, the cross-sectional designs of most previous studies prevent elucidation of the relationship between spinal posture and future dependence in activities of daily living (ADL). We tried to clarify the association by measuring spinal posture noninvasively in a community-based prospective cohort study of older adults, paying particular attention to thoracic curvature, lumbar curvature, sacral hip angle, and inclination to determine which parameter is most strongly associated with dependence in ADL.Methods. Spinal posture was evaluated in 804 participants (338 men, 466 women, age range: 65-94 years) who were independent in ADL at baseline. We defined dependence in ADL as admission to a nursing home or need of home assistance. During the 4.5-year follow-up period, 126 (15.7%) participants became dependent in ADL. The relationship between the spinal posture parameters and outcome was assessed by dividing the participants into sex-specific quartiles of the parameters.Results. Only inclination (angle subtended between the vertical and a line joining C7 to the sacrum) was associated with outcome, although lumbar curvature also showed a marginal association. The age- and sex-adjusted odds ratio for a 1 unit increase in the quartiles of inclination was 1.79 (confidence interval: 1.44, 2.23). After mutual adjustment for the 4 parameters, statistical significance for inclination still remained, with no substantial changes in the association estimates.Conclusions. This study indicates that spinal inclination is associated with future dependence in ADL among older adults. © 2013 © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: [email protected] /* */
    No preview · Article · Jan 2013 · The Journals of Gerontology Series A Biological Sciences and Medical Sciences
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE:: Dehydroepiandrosterone sulfate (DHEAS) appears to have a protective effect against depression, but evidence from prospective cohort studies is sparse. Therefore, we examined the association between serum DHEAS levels and depressive symptoms in older community-dwelling Japanese. DESIGN:: A community-based cohort study. SETTING:: Kurabuchi Town, Gunma Prefecture, Japan. PARTICIPANTS:: A total of 554 residents (248 men and 306 women) age 65 years or older without depressive symptoms at baseline. MEASUREMENTS:: We performed a baseline examination of the subjects between 2005 and 2006 to determine serum DHEAS levels. The subjects were categorized into three groups based on age strata- and sex-specific tertiles of DHEAS. Depressive symptoms were assessed with the Geriatric Depression Scale 15-item version (GDS-15) in face-to-face home visit interviews carried out once in 2007 and once in 2008. The association of DHEAS with depressive symptoms (GDS-15 ≥ 6) was analyzed with the use of logistic regression models. RESULTS:: The incidence of depressive symptoms was 12.1% in men and 19.6% in women. In men, the multiadjusted odds ratio of depressive symptoms was 0.24 (95% confidence interval: 0.06-0.94, Wald χ = 4.20, degrees of freedom = 1, p = 0.04) for the highest tertile compared with the lowest. The association observed for the highest versus the lowest remained significant even after adjustment for physical performance and cognitive function. In women, DHEAS was not associated with depressive symptoms. CONCLUSIONS:: In this study, higher serum DHEAS levels were found to be protectively and independently associated with the risk of developing depressive symptoms in men, but not in women.
    No preview · Article · Oct 2012 · The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: This multicenter cross-sectional study aimed to investigate the clinical features and varieties of non-motor fluctuation in Parkinson's disease (PD). Methods: To identify motor and non-motor fluctuation, we employed the wearing-off questionnaire of 19 symptoms (WOQ-19) in 464 PD patients. We compared the frequency of levodopa-related fluctuation as identified by the WOQ-19 with recognition by neurologists. We compared patients with both motor and non-motor fluctuations with those who only had motor fluctuations. Non-motor fluctuations were separated into psychiatric, autonomic, and sensory categories for further analysis. Results: The patients' average age was 70.8 ± 8.4 years (mean ± SD) and disease duration was 6.6 ± 5.0 years. The frequency of motor fluctuations was 69% and for non-motor fluctuation 40%. Fifty-three percent of patients with motor fluctuations also had non-motor fluctuations, whereas 93% of patients with non-motor fluctuations also had motor fluctuations. The WOQ-19 showed a sensitivity of 82% but a specificity of only 40%. The patients with both non-motor and motor fluctuations exhibited more severe motor symptoms, more non-motor symptoms and higher levodopa daily doses (p < 0.05). Patients had significantly higher fluctuation rates if they had psychiatric (49%) and sensory (45%) symptoms than patients with autonomic symptoms (32%, p < 0.01). Forty-eight percent of patients with non-motor fluctuations exhibited more than one type of non-motor fluctuation. Conclusion: Forty percent of PD patients presented with non-motor fluctuations, and almost half of these exhibited more than one type. Appropriate recognition of levodopa-related fluctuations, both motor and non-motor, can lead to treatment modifications in PD patients.
    No preview · Article · Sep 2012 · Parkinsonism & Related Disorders

  • No preview · Article · Jul 2012 · Alzheimer's and Dementia
  • [Show abstract] [Hide abstract]
    ABSTRACT: REM sleep behavior disorder (RBD) is known to be observed more frequently in patients with an α-synucleinopathy such as Parkinson's disease (PD) than in the general population. The precise prevalence of RBD in Japanese PD patients is not known. Therefore, we investigated the prevalence and the clinical characteristics of patients with RBD in a large population of Japanese patients with PD. We investigated various clinical features and employed the Japanese version of the RBD screening questionnaire on 469 non-demented Japanese PD patients in this multicenter study. Probable or possible RBD was detected in 146 patients (31.1%) and was significantly associated with longer PD duration, higher Hoehn and Yahr stage, higher Unified Parkinson's Disease Rating Scale part III subscale (7 items), more motor fluctuations, and a higher levodopa-equivalent daily dose (p < 0.01). As to the major autonomic dysfunctions, severe constipation was significantly more frequent in PD patients with RBD than in those without it (p < 0.01). The RBD symptoms of 53 patients (39.0%) preceded the onset of PD motor symptoms. The median interval from the onset of RBD symptoms to PD motor symptoms was 17.5 years, and 3 patients had intervals of over 50 years. This large-scale multicenter study revealed that RBD is a frequent non-motor symptom in Japanese patients with PD, which may precede the onset of motor symptoms. Moreover, RBD that increases with the duration and severity of PD may be associated with autonomic dysfunction.
    No preview · Article · Jan 2012 · Journal of Neurology
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this work was to investigate the prevalence of camptocormia and the clinical characteristics of patients with camptocormia in a large population of PD patients. Although camptocormia has been recognized as a prominent phenomenon in PD, the previous epidemiological reports were limited, especially in terms of sample size. We evaluated 531 PD patients (disease duration: 7.0 ± 5.5 years, mean ± standard deviation). We examined their clinical features and the prevalence of camptocormia. Camptocormia was detected in 22 patients (4.1%) and found in patients who were older and had more severe motor symptoms and a higher levodopa (L-dopa) dose (P < 0.05), compared to the patients without camptocormia. Patients with camptocormia showed significantly higher frequencies of autonomic symptoms, such as constipation and urinary incontinence (P < 0.05). Camptocormia is uncommon in PD and is associated with disease severity, higher L-dopa dose and higher frequencies of autonomic symptoms.
    No preview · Article · Dec 2011 · Movement Disorders
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objectives Mount Oyama on Miyakejima Island, Tokyo, erupted in June, 2000. All Miyake village citizens were forced to evacuate from the island in September, 2000, due to continuous eruptions and emissions of unsafe amounts of volcanic gas, mainly SO2. From February, 2005, residents started to return to the island despite the fact that volcanic gas was still being emitted. This study examines changes in respiratory function over 4 years from autumn 2004 to November 2008. Methods The study population comprised 276 adults (122 male, 154 female) who each underwent an examination for respiratory health just before returning to the island (2004) and another examination 4 years after their return (2008). Exposure was approximated by monitoring data across 7 monitoring stations. Mean SO2 concentration from February 2005 to November 2008 was 0.022 ppm. Effects were evaluated by spirometry. Results Study subjects showed no reduction in lung function between 2004 and 2008. Conclusions No change was observed in respiratory function in adult Miyakejima residents due to 4 years of residence in an environment with an average SO2 concentration of 0.022 ppm. However, to truly shed light on the effects of SO2 on respiratory function in adults, it is important to continue this study and conduct further analysis.
    Preview · Article · Oct 2011 · Occupational and Environmental Medicine

  • No preview · Article · Oct 2011 · Occupational and Environmental Medicine
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mt. Oyama on Miyakejima Island erupted in June 2000 and all Miyake village citizens were forced to evacuate the island in the September, due to continuous eruptions and emission of unsafe amounts of volcanic gas, mainly sulfur dioxide (SO2). Beginning in February 2005, residents returned to live on the island despite the fact that volcanic gas was still being emitted. To examine changes in the respiratory systems of included children from February 2006 to November 2006. The study population was 141 children who participated in health checkups in November 2006, including 33 SO2 hypersusceptible children who had a current or past history of asthma, obstructive lung function, current symptoms of whistling and wheezing, and/or deterioration of respiratory symptoms. Respiratory effects were evaluated by a questionnaire for respiratory symptoms and by spirometry. SO2 was monitored at 7 sampling points within inhabited areas, and the mean SO2 concentration from February 2005 to November 2006 was 0.031 ppm. The area was categorized into four areas by average SO2 concentration, namely, areas L, H-1, H-2, and H-3, where the average SO2 levels were 0.019, 0.026, 0.032, and 0.045 ppm, respectively. Compared to children in area L, the frequencies of "phlegm" and "irritation of the nose" were significantly greater in the children in areas H-2 and H-3. %FVC and %FEV1 in hypersusceptible children were significantly reduced in November 2006 as compared to February 2006 (P = 0.047, 0.027), though no reduction observed in normosusceptible children. Respiratory functions in hypersusceptible Miyakejima children may be affected by SO2 exposure, and further follow-up observation is necessary.
    No preview · Article · Jan 2010 · [Nippon kōshū eisei zasshi] Japanese journal of public health

  • No preview · Article · Nov 2009 · Epidemiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Several epidemiological studies have shown that self-reported vision and hearing impairments are associated with adverse health outcomes (AHOs) in older populations; however, few studies have used objective sensory measurements or investigated the role of gender in this association. Therefore, we examined the association of vision and hearing impairments (as measured by objective methods) with AHOs (dependence in activities of daily living or death), and whether this association differed by gender. From 2005 to 2006, a total of 801 residents (337 men and 464 women) aged 65 years or older of Kurabuchi Town, Gunma, Japan, participated in a baseline examination that included vision and hearing assessments; they were followed up through September 2008. Vision impairment was defined as a corrected visual acuity of worse than 0.5 (logMAR = 0.3) in the better eye, and hearing impairment was defined as a failure to hear a 30 dB hearing level signal at 1 kHz in the better ear. Information on outcomes was obtained from the town hall and through face-to-face home visit interviews. We calculated the risk ratios (RRs) of AHOs for vision and hearing impairments according to gender. During a mean follow-up period of 3 years, 34 men (10.1%) and 52 women (11.3%) had AHOs. In both genders, vision impairment was related to an elevated risk of AHOs (multi-adjusted RR for men and women together = 1.60, 95% CI = 1.05-2.44), with no statistically significant interaction between the genders. In contrast, a significant association between hearing impairment and AHOs (multi-adjusted RR = 3.10, 95% CI = 1.43-6.72) was found only in the men. In this older Japanese population, sensory impairments were clearly associated with AHOs, and the association appeared to vary according to gender. Gender-specific associations between sensory impairments and AHOs warrant further investigation.
    Full-text · Article · Nov 2009 · BMC Geriatrics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The number of studies that use objective and quantitative methods to evaluate facial skin aging in elderly people is extremely limited, especially in Japan. Therefore, in this cross-sectional study we attempted to characterize the condition of facial skin (hyperpigmentation, pores, texture, and wrinkling) in Japanese adults aged 65 years or older by using objective and quantitative imaging methods. In addition, we aimed to identify lifestyle factors significantly associated with these visible signs of aging. The study subjects were 802 community-dwelling Japanese men and women aged at least 65 years and living in the town of Kurabuchi (Takasaki City, Gunma Prefecture, Japan), a mountain community with a population of approximately 4800. The facial skin condition of subjects was assessed quantitatively using a standardized facial imaging system and subsequent computer image analysis. Lifestyle information was collected using a structured questionnaire. The association between skin condition and lifestyle factors was examined using multivariable regression analysis. Among women, the mean values for facial texture, hyperpigmentation, and pores were generally lower than those among age-matched men. There was no significant difference between sexes in the severity of facial wrinkling. Older age was associated with worse skin condition among women only. After adjusting for age, smoking status and topical sun protection were significantly associated with skin condition among both men and women. Our study revealed significant differences between sexes in the severity of hyperpigmentation, texture, and pores, but not wrinkling. Smoking status and topical sun protection were significantly associated with signs of visible skin aging in this study population.
    Full-text · Article · Sep 2009 · Journal of Epidemiology
  • [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this study was to assess the relation between serum levels of retinol and other antioxidants and hearing impairment in Japanese older adults. This is a community-based cross-sectional study comprising 762 residents aged 65 years or older in Kurabuchi, Gumma, Japan. We measured serum retinol and other antioxidants (alpha- and gamma-tocopherols, and carotenoids including beta-cryptoxanthin, alpha- and beta-carotenes, lycopene, and lutein plus zeaxanthin) by high-performance liquid chromatography and divided each measurement into quartiles. Hearing impairment was defined as a failure to hear a 30-dB hearing level (HL) signal at 1 kHz and a 40-dB HL signal at 4 kHz in the better ear in pure-tone audiometric tests. The odds ratios (OR) for hearing impairment were calculated for each of the upper three quartiles of retinol and other antioxidant levels relative to the lowest quartile. Crude analysis showed that serum levels of retinol and provitamin A carotenoids (beta-cryptoxanthin, and alpha- and beta-carotenes) were inversely related to the prevalence of hearing impairment. The multiadjusted ORs (95% confidence intervals) for the highest quartile of retinol and the provitamin A family (combinations of provitamin A carotenoids) compared with the lowest were 0.51 (0.26-1.00) and 0.53 (0.27-1.02), respectively. A dose-response relationship was observed for retinol (p = .03) and provitamin A (p = .09). Increased serum levels of retinol and provitamin A carotenoids were clearly associated with a decreased prevalence of hearing impairment.
    No preview · Article · May 2009 · The Journals of Gerontology Series A Biological Sciences and Medical Sciences