1.Relationship between daily eating habits and occurrence of stroke in the O City Cohort I survey: a 26-year follow-up of residents in rural Japan
Mako TODA ; Koutatsu MARUYAMA ; Isao SAITO ; Shinji TANAKA ; Yutaka TAKEUCHI ; Hirotada OKUBO ; Tadahiro KATO
Journal of Rural Medicine 2025;20(1):28-38
Objective: This study aimed to elucidate the relationship between daily eating habits and stroke risk factors in O City, Ehime Prefecture, Japan, using stroke registry data collected over a 26-year follow-up period based on standardized national criteria.Materials and Methods: Overall, 1,793 middle-aged Japanese participants (446 men and 1,347 women) who completed a 33-item Food Frequency Questionnaire (FFQ) and had no history of stroke were matched to those from O City in a stroke registry from 1996 to 2022. Stroke diagnosis for each person was used to determine whether this was their first documented stroke, and we classified strokes as either a cerebral infarction (CI) or a hemorrhagic stroke (HS), the latter which included an intracerebral hemorrhage (ICH) or a subarachnoid hemorrhage (SAH). A Cox proportional hazard regression model was used to examine the association between habitual dietary intake and the occurrence of stroke, using the following covariates: age, body mass index, elevated blood pressure/hypertension, dyslipidemia, prediabetes/diabetes, alcohol consumption, and smoking.Results: During the 26 years of follow-up, 45 men (10.1%) and 76 women (5.6%) had stroke. The CI rate was 70.2% (n=85; 38 men, 47 women). The HS rate was 29.8% (n=36; 7 men and 29 women); of these patients, 26 and 10 had ICH and SAH, respectively. In men, orange intake showed a significant inverse correlation with CI. In women, fresh fish intake showed a significant inverse correlation with CI, while yogurt intake showed a significant inverse correlation with HS.Conclusion: Our results indicated that fresh fish intake was significantly associated with the prevention of CI among women in a Japanese cohort survey.
2.Patterns of daily ambulatory activity and the onset of metabolic syndrome in middle-aged and older Japanese women: the Toon Health Study.
Naofumi YAMAMOTO ; Koutatsu MARUYAMA ; Isao SAITO ; Kiyohide TOMOOKA ; Takeshi TANIGAWA ; Ryoichi KAWAMURA ; Yasunori TAKATA ; Haruhiko OSAWA
Environmental Health and Preventive Medicine 2025;30():11-11
BACKGROUND:
This cohort study aimed to identify the accumulation patterns of objectively measured ambulatory activity (AA) variables in the middle-aged and older Japanese women and examine the relationship of these derivative patterns with onset of metabolic syndrome (MetS).
METHODS:
A total of 794 women (mean age: 56.2 years) provided objectively assessed AA data using a uniaxial accelerometer. The number of steps, time accumulated in light-intensity AA (LIAA) and moderate-to-vigorous intensity AA (MVAA) and the ratio of MVAA to total AA (LIAA + MVAA) were calculated. Latent profile analysis was used to identify participant groups based on their distinct AA patterns. Logistic regression models were used to assess the association of groups with the onset of MetS after adjusting for age, sex, education, alcohol habit, smoking habit, energy intake, and the number of MetS components present at baseline.
RESULTS:
Four distinct groups were identified: Group A had low levels of the AA variable; group B accumulated a certain number or more steps primarily through MVAA; group C accumulated a certain number or more steps primarily through LIAA; and group D had high level of the AA variables. Over the course of the 5-year follow-up period, 61 participants (7.7%) developed MetS. The multivariate-adjusted odds ratio (95% confidence interval) for onset of MetS in groups B, C, and D relative to group A were 0.416 (0.166-1.218), 0.451 (0.223-0.914), and 0.933 (0.365-2.382), respectively. Group C had a significantly lower odds ratio of MetS onset than group A.
CONCLUSION
AA patterns accumulating a certain number or more steps, regardless of the intensity of AA, may help reduce the risk of MetS compared to inactive AA patterns.
Humans
;
Metabolic Syndrome/etiology*
;
Female
;
Middle Aged
;
Japan/epidemiology*
;
Aged
;
Exercise
;
Cohort Studies
;
Accelerometry
;
Risk Factors
;
East Asian People
3.Determination of skin-insect repellent icaridin and DEET in human urine using solid-phase extraction and liquid chromatography with tandem mass spectrometry and its application to a sample of Japanese adults.
Nanami NISHIHARA ; Tomohiko ISOBE ; Mai TAKAGI ; Toshiki TAJIMA ; Yugo KITAHARA ; Mai HAYASHI ; Isao SAITO ; Satoru WATANABE ; Miyuki IWAI-SHIMADA ; Jun UEYAMA
Environmental Health and Preventive Medicine 2025;30():18-18
BACKGROUND:
Icaridin and DEET are common insect repellents widely used on human skin and clothing (skin-insect repellents [skin-IR]) to repel common pests, such as mosquitoes and biting flies. Novel analytical methods for urinary skin-IR exposure biomarkers that can be effectively applied in epidemiological studies and provide strong evidence related to risk assessment associated with daily exposure are required. In this study, we aimed to develop a method for analyzing the concentrations of icaridin, DEET, and two DEET metabolites N,N-diethyl-3-(hydroxymethyl) benzamide and 3-(diethylcarbamoyl) benzoic acid in human urine.
METHODS:
In this analysis, after formic acid-induced acidification of the urine sample, exposure biomarkers were extracted using solid-phase extraction composed of a modified polystyrenedivinylbenzene polymer for reversed phase (hydrophobic) retention. Subsequently, high-performance liquid chromatography-tandem mass spectrometry was performed within 10 min for a separation analysis. The present method was applied to five Japanese adults (aged 20-43 years) who used icaridin or DEET-containing products within a week.
RESULTS:
Limits of detection were 0.06-0.11 µg/L. Extraction recoveries were 74%-88%. The intraday and interday variations were 1.5-17.5 and 0.9-15.8% relative standard deviation, respectively. All exposure biomarkers were successfully detected in all five adults. Urinary concentrations of exposure biomarkers reached their maximum values within 15 h after starting to use skin-IR.
CONCLUSIONS
This method was successful in measuring urinary exposure biomarkers of skin-IR, including icaridin and DEET. Moreover, this study presents the first application of biomonitoring of urinary icaridin concentrations after using a commercial product.
Humans
;
Solid Phase Extraction/methods*
;
Tandem Mass Spectrometry/methods*
;
Adult
;
Insect Repellents/urine*
;
DEET/urine*
;
Young Adult
;
Male
;
Japan
;
Female
;
Chromatography, Liquid
;
Biomarkers/urine*
;
Chromatography, High Pressure Liquid
;
East Asian People
4.Cross-sectional biomonitoring of urinary deoxynivalenol, T-2 and HT-2 toxins, and zearalenone in Japanese adults.
Toshiki TAJIMA ; Tomohiko ISOBE ; Isao SAITO ; Takaaki KONDO ; Koji SUZUKI ; Ryosuke FUJII ; Yoshiki TSUBOI ; Yoshiko SUGITA-KONISHI ; Jun UEYAMA
Environmental Health and Preventive Medicine 2025;30():19-19
BACKGROUND:
Among the more than 300 mycotoxins that are known to have toxic effects on animals and humans, Fusarium toxins deoxynivalenol (DON), T-2 and HT-2 toxins (T2/HT2), and zearalenone (ZEN) are frequently detected in domestic agricultural products. This study aimed to assess DON, T2/HT2, and ZEN exposure in Japanese adults by measuring urinary mycotoxins, observing their distributions, and making comparisons with data from other countries.
METHODS:
A total of 201 individuals participated in the study. Twenty-four-hour urine samples were collected from young adults (34 men and 35 women) in the Tokai region (urban area) and spot urine samples were collected from middle-aged and elderly adults (64 men and 68 women) in the Donan area of Hokkaido Prefecture (rural area). Urinary DON, T2/HT2, and ZEN levels were measured using a validated liquid chromatography-tandem mass spectrometry method.
RESULTS:
For DON, T2/HT2, and ZEN, the detection frequencies above the limit of detection (LOD) level (0.15, 0.13, and 0.01 µg/L, respectively) in all the samples were 53%, 26%, and 71%, respectively. The median concentrations (95th percentile) of urinary DON, HT2, and ZEN were 0.19 (3.93),
Humans
;
Zearalenone/urine*
;
Japan
;
Male
;
Female
;
Trichothecenes/urine*
;
T-2 Toxin/urine*
;
Biological Monitoring
;
Adult
;
Middle Aged
;
Aged
;
Cross-Sectional Studies
;
Young Adult
;
Mycotoxins/urine*
;
Environmental Exposure/analysis*
;
East Asian People
5.The association between masticatory ability and lower Timed Up & Go Test performance among community-dwelling Japanese aging men and women: The Toon Health Study
Saori MIYAZAKI ; Koutatsu MARUYAMA ; Kiyohide TOMOOKA ; Shinji NISHIOKA ; Noriko MIYOSHI ; Ryoichi KAWAMURA ; Yasunori TAKATA ; Haruhiko OSAWA ; Takeshi TANIGAWA ; Isao SAITO
Osteoporosis and Sarcopenia 2023;9(3):94-98
Objectives:
Few studies examined the association between deterioration of masticatory ability assessed by objective marker and physical function. Therefore, we examined the association between salivary flow rate which is one of the objective and surrogate marker of masticatory ability and lower Timed Up & Go (TUG) performance which is one of major measurement of physical function among aging Japanese.
Methods:
This cross-sectional study enrolled 464 Japanese aged 60e84 years old. Participants chewed tasteless and odorless gum for 5 min, calculated stimulated salivary flow rate (g/min) during all chews.The 3 m TUG was conducted, and 75th percentile value (6.8 s for men and 7.0 s for women) or higher was defined as lower TUG performance. Logistic regression analysis was used to examine the association between stimulated salivary flow rate and lower TUG performance.
Results:
We found that the stimulated salivary flow rate tended to be negatively associated with the TUG time. We also observed significant negative association between stimulated salivary flow rate and lower TUG performance; the multivariable-adjusted OR (95% confidence interval, CIs) of lower TUG performance for the highest quartile of stimulated salivary flow rate compared with the lowest quartile was0.34 (0.16e0.69, P for trend ¼ 0.02). Further adjusting for BMI, the association was attenuated but remaind significant; the OR (95% CIs) in highest quartile was 0.37 (0.18e0.76, P for trend ¼ 0.04).
Conclusions
Higher stimulated salivary flow, which means well masticatory ability, was inversely associated with lower TUG performance in the aging Japanese population.
6.Preventive role of community-level social capital in the need for long-term care and impairment in instrumental activities of daily living: a multilevel analysis.
Hitomi MATSUURA ; Yoko HATONO ; Isao SAITO
Environmental Health and Preventive Medicine 2023;28():15-15
BACKGROUND:
Individual-level social capital is an important determinant of older adults' long-term care needs; however, there is scant evidence regarding community-level social capital. Therefore, we investigated the association between community-level social capital and the prevalence of the need for long-term care among older adults.
METHODS:
Between January and February 2018, a cross-sectional survey was conducted among all older adults (n = 13,558) aged 65 to 74 years in a rural municipality in Japan (total population, n = 72,833). A self-reported questionnaire was used to identify community-level social capital, comprising civic participation, social cohesion, and reciprocity. A multilevel logistic regression analysis was performed to estimate the odds ratios of the need for long-term care and a decline in social activity competence as assessed by instrumental activities of daily living. For the analysis, the community levels were divided into 76 voting districts and adjusted for daily life, lifestyle, socioeconomic status, health conditions, and the three social capital subscale scores at the individual level.
RESULTS:
After adjusting for the covariates, we observed a tendency that a higher community level of reciprocity was associated with a lower prevalence of long-term care needs (OR: 0.86, 95% confidence interval: 0.75-1.00), whereas a high community level of social cohesion was associated with a significantly reduced decline in instrumental activities of daily living (OR per standard deviation increase: 0.87, 95% confidence interval: 0.79-0.96). No significant association was found with civic participation. Similarly, individual-level social capital was associated with the need for long-term care and decline in instrumental activities of daily living.
CONCLUSIONS
Our findings suggest that good community-level reciprocity or social cohesion as well as good individual social capital status may help prevent the need for long-term care among older adults.
Humans
;
Aged
;
Interpersonal Relations
;
Activities of Daily Living
;
Social Participation
;
Social Capital
;
Multilevel Analysis
;
Cross-Sectional Studies
;
Long-Term Care
;
Japan/epidemiology*
;
Social Support
7.A three‑dimensional investigation of mandibular deviation in patients with mandibular prognathism
Kazuaki OSAWA ; Jun NIHARA ; Hideyoshi NISHIYAMA ; Kojiro TAKAHASHI ; Ayako HONDA ; Chihiro ATARASHI ; Ritsuo TAKAGI ; Tadaharu KOBAYASHI ; Isao SAITO
Maxillofacial Plastic and Reconstructive Surgery 2023;45(1):4-
Background:
Craniofacial disharmony in cases of jaw deformity associated with abnormal lateral deviation of the jaw mostly involves both the maxilla and mandible. However, it has been still difficult to capture the jaw deviation aspect in a 3-dimensional and quantitative techniques. In this study, we focused on 3-dimensional mandibular morphology and position of the condylar head in relation to the base of the skull in patients with mandibular prognathism, one of the most common jaw deformities. We used cluster analysis to quantify and classify deviation and clarified its characteristics. We also investigated the degree of correlation between those findings and menton (Me) deviation measured on frontal cephalograms, which is a conventional indicator of jaw deformity.
Results:
Findings obtained from 100 patients (35 men, 65 women) were classified into the following three groups based on mandibular morphology and condylar position relative to the skull base. Then, reclassification using these parameters enabled classification of cluster analysis findings into seven groups based on abnormal jaw deviation characteristics. Comparison among these seven groups showed that the classification criteria were ramus height, mandibular body length, distance from the gonion to the apex of the coronoid process, and the lateral and vertical positions of the mandible. Weak correlation was also found between Me deviation on frontal cephalograms and each of the above parameters measured on 3D images.
Conclusions
Focusing on mandibular morphology and condylar position relative to the skull base in patients with mandibular prognathism, we used cluster analysis to quantify and classify jaw deviation. The present results showed that the 3D characteristics of the mandible based on mandibular morphology and condylar position relative to the skull base can be classified into seven groups. Further, we clarified that Me deviation on frontal cephalograms, which has been used to date, is inadequate for capturing jaw deviation characteristics.
8.Relationship between mortality risk and health-related factors and sense of coherence in residents ofa rural area in Japan
Kanako YAMAUCHI ; Tadahiro KATO ; Isao SAITO ; Masamitsu YAMAIZUMI
Journal of Rural Medicine 2020;15(1):38-43
Objective: This study aimed to examine the relationship between mortality risk and health-related factors and sense of coherence (SOC) in a cohort study of residents from a rural area of Japan.Materials and Methods: We followed-up with 3,416 baseline respondents over 3.76 years. Residents were subdivided into three groups based on SOC score: low, middle, and high. We used the total SOC score of the low-level SOC group as the standard, and calculated the standardized mortality ratio (SMR) for the middle- and high-level SOC groups. For all three SOC groups, health-related factors were analyzed by one-way analysis of variance, and lifestyle and history were analyzed using the χ2 test. Results were also analyzed by gender and age.Results: For men in the low-level SOC group, the SMR value was defined as 1, and for men in the high-level SOC group (0.44; 95% confidence interval: 0.11–0.77), the SMR value was significantly lower. There was a statistically significant reduction in the percentage of smokers in the men in the high-level SOC group.Conclusion: In this study, high-level SOC was associated with low mortality risk. This finding was particularly pronounced in the men.
9.Optimization and validation of a highly sensitive method for determining glyphosate in human urine by solid-phase extraction and liquid chromatography with tandem mass spectrometry: a methodological study.
Hiroshi NOMURA ; Risa HAMADA ; Isao SAITO ; Kunihiko NAKANE ; Ritsuko SAWA ; Miwa UKAI ; Eiji SHIBATA ; Mitsuo SATO ; Michihiro KAMIJIMA ; Jun UEYAMA
Environmental Health and Preventive Medicine 2020;25(1):83-83
BACKGROUND:
Glyphosate and its salt formulations are nonselective herbicides that have been extensively used worldwide, both for residential and agricultural purposes. The possible carcinogenicity and teratogenicity of glyphosate remain to be elucidated. We developed a sensitive and high-throughput analytical method for urinary glyphosate using liquid chromatography-tandem mass spectrometry with the aim of contributing to glyphosate exposure assessment in epidemiological studies.
METHODS:
After urine dilution (creatinine matching dilution to 0.05 g creatinine/L), glyphosate was extracted using two types of solid phase extraction columns (SCX and NH2) with automated sample preparation instruments. The eluate was dried and dissolved in the mobile phase, followed by liquid chromatography-tandem mass spectrometry analysis. The optimized method was applied to urine samples obtained from 54 Japanese adults and children.
RESULTS:
The results from the validation study demonstrated good recoveries (91.0-99.6%), within- and between-run precisions (< 15%), low detection limits (0.1 μg/L), and lower limit of quantification (0.3 μg/L). The detection frequency and median concentration of the urinary glyphosate in Japanese subjects were 59% and 0.25 μg/L (0.34 μg/g creatinine).
CONCLUSIONS
Our reliable determination method was successful in measuring urinary glyphosate concentration. Moreover, this is the first biomonitoring report of urinary glyphosate levels in the Japanese general population.
Adult
;
Aged
;
Chromatography, Liquid/methods*
;
Female
;
Glycine/urine*
;
Humans
;
Male
;
Middle Aged
;
Solid Phase Extraction/methods*
;
Tandem Mass Spectrometry/methods*
10.Chronological Endoscopic and Pathological Observations in Russell Body Duodenitis.
Atsushi GOTO ; Takeshi OKAMOTO ; Masaharu MATSUMOTO ; Hiroyuki SAITO ; Hideo YANAI ; Hiroshi ITOH ; Isao SAKAIDA
Clinical Endoscopy 2016;49(4):387-390
A 64-year-old man was found to have a nodule in his right lung. He also complained of nausea and abdominal pain during the clinical course. Esophagogastroduodenoscopy revealed a duodenal ulcer associated with severe stenosis and a suspicion of malignancy. However, three subsequent biopsies revealed no evidence of malignancy. The fourth biopsy showed scattered large eosinophilic cells with an eccentric nucleus, leading to a diagnosis of Russell body duodenitis (RBD). RBD is an extremely rare disease, and little is known about its etiology and clinical course. The pathogenesis of RBD is discussed based on our experience with this case.
Abdominal Pain
;
Biopsy
;
Constriction, Pathologic
;
Diagnosis
;
Duodenal Ulcer
;
Duodenitis*
;
Endoscopy, Digestive System
;
Eosinophils
;
Humans
;
Lung
;
Middle Aged
;
Nausea
;
Rare Diseases


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