著者

Fuminari Asada Takuo Nomura Kenichiro Takano Masashi Kubota Motoki Iwasaki Takayuki Oka Ko Matsudaira

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.28, pp.36, 2023 (Released:2023-06-15)

参考文献数

43

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Background: We designed a quick simple exercise program that can be performed in a short period of time in real-world occupational health settings and investigated the effects of three months of program implementation on non-specific low back pain (NSLBP).Methods: Participants were 136 individuals working in the manufacturing industry. The quick simple exercise program was designed to be doable in three minutes and consisted of two exercises: a hamstring stretch and a lumbar spine rotation with forward, backward, and lateral flexion. This was a randomized controlled trial incorporating an intervention group to whom the exercises were recommended within a leaflet, and a control group to whom the exercises were not recommended. NSLBP was evaluated at baseline and after three months using numerical rating scale (NRS) scores, ranging from 0 points (no pain at all) to 10 points (worst pain imaginable). The percentages of cases that improved by a minimal clinically important difference (two points or above) were compared.Results: Overall, 76.1% of the intervention group participants performed the quick simple exercises at least once every one or two days. Three months after baseline, a significantly higher percentage of participants in the intervention group (17 participants: 25%) had NSLBP improvement of two or more points on the NRS compared to that in the control group (8 participants, 12%) (P = 0.047). The average NRS score decreased significantly from 1.87 ± 1.86 to 1.33 ± 1.60 in the intervention group but showed no significant change in the control group, transitioning from 1.46 ± 1.73 to 1.52 ± 1.83. A significant interaction was also observed between the intervention and control groups (F = 6.550, P = 0.012).Conclusions: Three months of a quick simple exercise program among workers in the manufacturing industry increased the percentage of workers with improvement in the NRS scores. This suggests that the program is effective in managing NSLBP in workers in the manufacturing industry.Trial registration: UMIN-CTR UMIN000024117.

著者

Nlandu Roger Ngatu Kazuto Tayama Kanae Kanda Tomohiro Hirao

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.27, pp.41, 2022 (Released:2022-10-21)

参考文献数

32

被引用文献数

2

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Background: COVID-19 pandemic is tremendously impacted by socioeconomic and health determinants worldwide. This study aimed to determine factors associated with COVID-19 fatality among member states and partner countries of the Organization for Economic Cooperation and Development (OECD).Methods: An ecological study was conducted using COVID-19 data of 48 countries for the period between 31 December 2019–31 December 2021. The outcome variables were COVID-19 case fatality rate (CFR) and years of life lost to COVID-19 (YLLs). Countries’ sociodemographics and COVID-19-related data were extracted from OECD website, Our World in Data, John Hopkins Coronavirus Resource Center, Economist Intelligence Unit (EIU) and WHO.Results: In the first year of the pandemic (December 2019–January 2021), highest CFR was observed in Mexico, 8.51%, followed by China, 5.17% and Bulgaria, 4.12%), and highest YLLs was observed in Mexico, 2,055 per 100,000. At regional level, highest CFR was observed in North & central America, 4.25 (3.71) %, followed by South America (2.5 (0.1) %); whereas highest YLLs was observed in South America region 1457.5 (274.8) per 100,000, followed by North & central America, 1207.3 (908.1) per 100,000. As of 31 December 2021, Mexico (7.52%) and Bulgaria (4.78%) had highest CFR; on the other hand, highest YLLs was observed in England, 26.5 per 1,000, followed by the United States, 25.9 per 1,000. At regional level, highest CFR (3.37(3.19) %) and YLLs (16.7 (13) per 1,000) were both observed in North & central America. Globally, the analysis of the 2-year cumulative data showed inverse correlation between CFR and nurse per 10,000 (R = −0.48; p < 0.05) and GDP per capita (R = −0.54; p < 0.001), whereas positive correlation was observed between YLLs and elderly population rate (R = 0.66; p < 0.05) and overweight/obese population rates (R = 0.55; p < 0.05).Conclusion: This study provides insights on COVID-19 burden among OECD states and partner countries. GDP per capita, overweight/obesity and the rate of elderly population emerged as major social and health determinants of COVID-19 related burden and fatality. Findings suggest that a robust economy and interventions designed to promote healthy longevity and prevent weight gain in at-risk individuals might reduce COVID-19 burden and fatality among OECD states and partner countries.

著者

Watanabe Tomoyuki Miyao Masaru Honda Ryumon Yamada Yuichi

出版者

springer

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.13, pp.264-270, 2008 (Released:2009-02-23)

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Objectives The aim of this study was to compare the risk for cancers of A-bomb survivors in the ongoing life span study (LSS) with unexposed groups consisting of the entire populations of Hiroshima prefecture and neighboring Okayama prefecture. Methods The subjects consisted of the Hiroshima group reported in LSS report 12 (LSS-H group) and a control group (the entire populations of Hiroshima and Okayama-HPCG and OPCG, respectively). We estimated the expected number of deaths due to all causes and to cancers of various causes among the exposed survivors of the Hiroshima bombing in the LSS report 12 who died in the follow-up interval at ages similar to those of people in Hiroshima and Okayama prefectures who were aged 0-34 years at the time of the bombing in 1945. We compared the standardized mortality ratio (SMR) of the LSS-H group to that of the HPCG and OPCG (SMR-H and SMRO, respectively). Results Even at low and very low dose categories, the SMR-H and SMR-O were significantly high for all deaths, all cancers, solid cancers, and liver cancers in male subjects, and for uterus and liver cancers in female subjects, respectively. The results show that, if the dose estimations of the dosimetry system 1986 (DS86) are correct, there are significantly increased risks of cancer among even survivors exposed to the very low dose level. Conclusions The dose assumptions of DS86 have been criticized for underestimating doses in areas distant from the hypocenter. The contribution of residual radiation, ignored in LSS, and that of neutrons, underestimated by DS86, is suggested to be fairly high.

著者

Takashi Yamauchi Takashi Shimazaki Hiroyuki Yanagisawa Machi Suka

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.28, pp.53, 2023 (Released:2023-09-22)

参考文献数

47

被引用文献数

1

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Background: Students and workers have been subjected to increased levels of psychological distress due to the quarantine policy and containment measures during the COVID-19 pandemic. This scoping review aimed to present an overview of published evidence regarding formal and informal help-seeking intentions/behaviors for non-mental health-related issues as well as mental health-related issues among students and workers during the pandemic.Methods: In June 2022, we searched MEDLINE, APA PsycNet, and CINAHL for articles reporting the state of help-seeking intentions/behaviors among students and workers during the pandemic. Peer-reviewed original articles published in English were selected.Results: In total, 150 articles were identified, and 12 articles were selected for final analysis after removing articles that met the exclusion criteria. Three studies targeted university students, and nine targeted healthcare workers. Study settings were restricted to Western countries and China. Of the 12 studies, 11 were observational and predominantly cross-sectional studies. Two longitudinal studies using student samples suggested that university students became more reluctant to seek help from both formal and informal sources during the COVID-19 pandemic compared to before, despite the increased need for support during the pandemic. Among healthcare workers, the proportions of those who sought help from formal sources in person were low (7–26%), even among those with mental health issues, despite the increase in the need for mental health services. One randomized controlled study reported that a brief video-based intervention increased treatment-seeking intentions among healthcare workers in the intervention group compared with the non-intervention group.Conclusions: The present review revealed that, although most studies included in the final analysis were cross-sectional, intentions/behaviors to seek help from both formal and informal sources decreased among university students, even those with mental health issues. Among healthcare workers, while the frequency of help-seeking from formal sources in person was low, a brief online intervention was suggested to be useful for promoting help-seeking from formal sources. During public health crises such as the COVID-19 pandemic, system and infrastructure development of online help-seeking services could potentially promote formal and informal help-seeking intentions/behaviors for diverse issues, including non-mental health-related issues, among university students and healthcare workers/providers.

著者

Hiroyuki Hayashida Akiko Matsumoto Hinako Nanri Yuichiro Nishida Yusuke Takagi Megumi Hara

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.28, pp.29, 2023 (Released:2023-05-11)

参考文献数

62

被引用文献数

3

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Background: According to recent reports, individuals with reduced aldehyde dehydrogenase activity may require more energy for the detoxification of aldehydes. Aldehyde dehydrogenase 2 (ALDH2), an ALDH isozyme, is responsible for detoxifying acetaldehyde, an intermediate metabolite of ethanol. Because the variant allele of the rs671 polymorphism of ALDH2 results in a substantial reduction in enzymatic activity, carriers of this variant allele may have a higher energy demand when consuming alcohol than non-carriers. However, no studies have evaluated this phenomenon to date.Method: To test the hypothesis, we statistically examined the interactive effects between the rs671 and ethanol consumption on energy intake using cross-sectional data from a population-based cohort study, the Japan Multi-Institutional Collaborative Cohort Study, which was conducted in Saga city between 2005–2007 (N = 12,068).Results: General linear regression models adjusted for age, sex, ethanol consumption, current smoking status, years of education, dietary restriction, medical history, and physical activity level revealed that energy intake was higher in variant allele carriers than in non-carriers among individuals with alcohol drinking habits, whereas no such correlation was observed among those without drinking habits (≤2 g ethanol/day) (p = 0.03 for interaction between rs671 and ethanol consumption). Energy intake excluding energy from alcoholic beverages, carbohydrate intake, protein intake, and fat intake, showed similar tendencies (p for interaction = 0.01, 0.01, 0.04, and 0.07, respectively).Conclusions: These findings support the hypothesis that increased energy intake is required for the detoxification of aldehydes in individuals with low ALDH activity. This epidemiological evidence provides a possible scientific basis for understanding aldehyde detoxification mechanisms and suggests a novel phenotype of the ALDH2 rs671 polymorphism.

著者

Mami Wakabayashi Hirono Ishikawa Yoshiharu Fukuda Hiroyasu Iso Takahiro Tabuchi

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.28, pp.24, 2023 (Released:2023-04-18)

参考文献数

41

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Background: Little is known about the vulnerable populations and problem drinking in terms of health inequality. This study aimed to investigate the relationship between health indifference estimated by Health Interest Scale (HIS) and problem drinking identified by the Alcohol Use Disorder Identification Test (AUDIT).Methods: A cross-sectional study was conducted utilizing data from a nationwide internet survey in Japan in 2022. The number of total participants was 29,377, with 49% of them being male, and the mean age was 47.9 (±17.9) years. The participants were categorized into the following groups based on the quintiles of HIS score: health indifference (0–16), low health interest (17–20), middle health interest (21–22), middle-high interest (23–26) and high health interest (27–36) groups. Problem drinking was identified as AUDIT score of ≥8 points.Results: The association between health indifference and problem drinking was explored through logistic regression with adjustment for various socioeconomic status, such as education, income level, and occupation; the adjusted odds ratio (aOR) was 1.72 [95% confidence interval (CI): 1.51–1.95].Conclusion: Health indifferent or lower health interest groups were a vulnerable population for problem drinking, regardless of their socioeconomic status. It could be useful to identify the health indifferent group through HIS and to monitor the impact of health intervention for this group for the reduction of health inequality.

著者

Aya Sugiyama Fumie Okada Kanon Abe Hirohito Imada Serge Ouoba Bunthen E Md Razeen Ashraf Hussain Masayuki Ohisa Ko Ko Shintaro Nagashima Tomoyuki Akita Shinichi Yamazaki Michiya Yokozaki Eisaku Kishita Junko Tanaka

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.27, pp.30, 2022 (Released:2022-07-07)

参考文献数

49

被引用文献数

3

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Background: This longitudinal study aimed to determine chronological changes in the seroprevalence of prior SARS-CoV-2 infection, including asymptomatic infections in Hiroshima Prefecture, Japan.Methods: A stratified random sample of 7,500 residents from five cities of Hiroshima Prefecture was selected to participate in a three-round survey from late 2020 to early 2021, before the introduction of the COVID-19 vaccine. The seroprevalence of anti–SARS-CoV-2 antibodies was calculated if at least two of four commercially available immunoassays were positive. Then, the ratio between seroprevalence and the prevalence of confirmed COVID-19 cases in Hiroshima was calculated and compared to the results from other prefectures where the Ministry of Health, Labour and Welfare conducted a survey by using the same reagents at almost the same period.Results: The numbers of participants in the first, second, and third rounds of the survey were 3025, 2396, and 2351, respectively and their anti-SARS-CoV-2 antibodies seroprevalences were 0.03% (95% confidence interval: 0.00–0.10%), 0.08% (0.00–0.20%), and 0.30% (0.08–0.52%), respectively. The ratio between the seroprevalence and the prevalence of confirmed COVID-19 cases in Hiroshima was 1.2, which was smaller than that in similar studies in other prefectures.Conclusions: The seroprevalence of anti–SARS-CoV-2 antibodies in Hiroshima increased tenfold in a half year. The difference between seroprevalence and the prevalence of confirmed COVID-19 cases in Hiroshima was smaller than that in other prefectures, suggesting that asymptomatic patients were more actively detected in Hiroshima.

著者

Ananya Roy Md Ashraful Alam Yoonhee Kim Masahiro Hashizume

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.27, pp.36, 2022 (Released:2022-09-28)

参考文献数

50

被引用文献数

2

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Background: Previous studies have reported that high ambient temperature is associated with increased risk of suicide; however, the association has not been extensively investigated with drug overdose which is the most common method of unsuccessful suicidal behavior in Japan. Therefore, this study aims to examine the short-term association between daily mean temperature and the incidence of self-harm attempts by drug overdose in Tokyo, Japan.Methods: We collected the emergency ambulance dispatch data and daily meteorological data in Tokyo from 2010 to 2014. A quasi-Poisson regression model incorporating a distributed lag non-linear function was applied to estimate the non-linear and delayed association between temperature and drug overdose, adjusting for relative humidity, seasonal and long-term trends, and days of the week. Sex, age and location-specific associations of ambient temperature with drug overdose was also estimated.Results: 12,937 drug overdose cases were recorded during the study period, 73.9% of which were female. We observed a non-linear association between temperature and drug overdose, with the highest risk observed at 21 °C. The highest relative risk (RR) was 1.30 (95% Confidence Interval (CI): 1.10–1.67) compared with the risk at the first percentile of daily mean temperature (2.9 °C) over 0–4 days lag period. In subgroup analyses, the RR of a drug overdose at 21 °C was 1.36 (95% CI: 1.02–1.81) for females and 1.07 (95% CI: 0.66–1.75) for males. Also, we observed that the risk was highest among those aged ≥65 years (RR = 2.54; 95% CI: 0.94–6.90), followed by those aged 15–34 years (RR = 1.25; 95% CI: 0.89–1.77) and those aged 35–64 years (RR = 1.15; 95% CI: 0.78–1.68). There was no evidence for the difference in RRs between urban (23 special wards) and sub-urban areas in Tokyo.Conclusions: An increase in daily mean temperature was associated with increased drug overdose risk. This study indicated the positive non-linear association between temperature and incomplete attempts by drug overdose. The findings of this study may add further evidence of the association of temperature on suicidal behavior and suggests increasing more research and investigation of other modifying factors.

著者

Daisuke Hori Yuichi Oi Shotaro Doki Tsukasa Takahashi Tomohiko Ikeda Yu Ikeda Yo Arai Kei Muroi Hiroaki Sasaki Mami Ishitsuka Asako Matsuura Wyi Go Ichiyo Matsuzaki Shinichiro Sasahara

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.27, pp.17, 2022 (Released:2022-04-16)

参考文献数

7

被引用文献数

1

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Background: Ibaraki’s Amabie-chan is a COVID-19 infection control system unique to Ibaraki prefecture, Japan. It requires residents to register each time they visit events, commercial facilities, and restaurants. The number of registrations has been limited, and its function alerting about people positive for COVID-19 infection seems not to be working. Nevertheless, registration with the system might have some impact on the user’s behavior. In the current preliminary survey, the possible impact of Ibaraki’s Amabie-chan on infection prevention behavior and fear of COVID-19 was investigated.Methods: A cross-sectional, web-based, anonymous, and self-administered survey was conducted at two workplaces in Tsukuba Science City, Ibaraki, Japan. The first survey was conducted at one of the workplaces in November 2020, and the second survey, at the other workplace in February 2021. Variables of interest were sex, age group, marital status, employment status, Ibaraki’s Amabie-chan use, COVID-19 Contact-Confirming Application use, ten items of infection prevention behaviors, and fear of COVID-19. Hierarchical linear regression analysis was performed.Results: In both surveys, use of Ibaraki’s Amabie-chan was significantly associated with COCOA use and with “physical condition management such as body temperature measurement.” No association was found with other infection prevention behaviors or with fear of COVID-19.Conclusions: Our findings did not provide sufficient evidence for the effectiveness of Ibaraki’s Amabie-chan in regard to users’ infection control behavior. Further detailed study is needed to investigate the effectiveness in terms of infection prevention and the cost-effectiveness of Ibaraki’s Amabie-chan.

著者

Miyako Kimura Kazushige Ide Kazuki Kimura Toshiyuki Ojima

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.27, pp.14, 2022 (Released:2022-03-26)

参考文献数

36

被引用文献数

4

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Background: Happiness may help to prevent negative physiological outcomes in response to life events; however, factors contributing to happiness during the COVID-19 pandemic have not been longitudinally investigated. This study explored the predictors of happiness in mothers of young children in Japan using comparable data that were obtained before and during the COVID-19 pandemic.Methods: We conducted the baseline survey in February 2020, and 4 months later, we also conducted the follow-up survey. Throughout all 47 prefectures in Japan, 4,700 (100 respondents/prefecture) mothers of infants and/or preschoolers (0–6 years) participated in the baseline online survey; 2,489 of these also participated in the follow-up survey.Results: We performed hierarchical multiple regression analysis and our final model indicated that maternal happiness during COVID-19 pandemic was positively related to employment status (homemaker, β = 0.052, p = 0.014), levels of available social support (average, β = 0.052, p = 0.012, high, β = 0.055, p = 0.010) and happiness score before the pandemic (β = 0.467, p < 0.001), and satisfaction toward the measures against the COVID-19 at partners’ workplace (average, β = 0.129, p < 0.001; high, β = 0.279, p < 0.001), preventive behavior against COVID-19 (average, β = 0.055, p = 0.002; high, β = 0.045, p = 0.015) and positive attitudes/thinking (β = 0.087, p < 0.001) during the pandemic. In contrast, poor mental health (K6 ≥5, β = −0.042, p = 0.011) before the pandemic and negative changes during the pandemic (≥3, β = −0.085, p < 0.001) were negatively related to maternal happiness during the pandemic. Our final model explained 44.9% of the variance in mothers’ happiness during the COVID-19 pandemic.Conclusions: Satisfaction toward the measures against the COVID-19 at partners’ workplace, preventive behavior, and positive attitudes/thinking were especially important for maternal happiness during the COVID-19 pandemic. Future study is needed to consider measures against infectious diseases in the workplace that are desirable for the well-being of parents with young children, taking into account the gender perspective.

著者

Nomura Kyoko Minamizono Sachiko Maeda Eri Kim Roseline Iwata Toyoto Hirayama Junko Ono Kyoichi Fushimi Masahito Goto Takeshi Mishima Kazuo Yamamoto Fumio

出版者

BioMed Central

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.26, no.30, 2021-03-05

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Background We aimed to estimate the prevalence of depressive symptoms as well as suicide-related ideation among Japanese university students during the stay-home order necessitated by the coronavirus disease 2019 pandemic in Japan, and offer evidence in support of future intervention to depression and suicide prevention strategies among college and university students. Methods The data for this cross-sectional study were derived from the Student Mental Health Survey conducted from May 20 to June 16, 2020 at a national university in Akita prefecture. Among the 5111 students recruited, 2712 participated in this study (response rate, 53%; mean age ± standard deviation, 20.5 ±3.5 years; men, 53.8%). Depressive symptoms were identified by using the Patient Health Questionnaire-9 (PHQ-9). Results The prevalence of moderate depressive symptoms based on a PHQ-9 score ≥10 and suicide-related ideation based on question 9 of PHQ-9 ≥1, which encompasses thoughts of both suicide and self-harm, was 11.7% and 6.7%, respectively. Multivariable logistic regression analyses showed that risk factors for depression included being a woman, smoking, alcohol consumption, and social network communication using either video or voice. For suicide-related ideation, alcohol consumption was the only risk factor. Exercise and having someone to consult about worries were associated with decreased risk of both depressive symptoms and suicide-related ideation. Conclusions Negative lifestyles of smoking and drinking, and being a woman, may be important risk factors for depressive symptoms, whereas exercise and having someone to consult about worries may be protective factors.

著者

Suka Machi Yamauchi Takashi Yanagisawa Hiroyuki

出版者

Springer Science and Business Media LLC

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.24, no.1, 2019-05-08

著者

Wolfgang Gerhard LOCHER

出版者

The Japanese Society for Hygiene

雑誌

Environmental Health and Preventive Medicine (ISSN:1342078X)

巻号頁・発行日

vol.12, no.6, pp.238-245, 2007 (Released:2007-12-01)

参考文献数

48

被引用文献数

2

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Max von Pettenkofer (1818–1901) belonged to the scientific elite of the 19th century. With his stringent search for the laws of nature and his fight for scientific truth, Pettenkofer was the prototype of a modern researcher. In the field of hygiene, he sought ways and means of preserving health and preventing sickness. With his consistent application of the experimental method to the field of public health, Pettenkofer helped the discipline of hygiene to provide precise and reliable answers to sanitary questions. In his experimental work on hygiene, Pettenkofer sought an answer to every imaginable question concerning the connection between the human organism and its environment. To proceed in this direction, Pettenkofer combined medical expertise with physics, chemistry, technique and statistics. This even today modern “crossover-thinking” made hygiene to the first interdisciplinary medical field. With his Institute of Hygiene, Pettenkofer established 1879 the first centre of competence for hygiene and environment in the world, opening a new era of environmental observation. In the framework of hygiene, Pettenkofer turned also to questions of nutrition and the quality of foodstuff. The science of hygiene owes to Max von Pettenkofer not only its development and cartography, but also its introduction as an academic discipline. Finally he regarded hygiene also as an economic and cultural feature. His idea about a clean soil in the cities and his promotion of adequate water supply and sufficient sewage networks are linked to his theory of the cholera. Pettenkofer believed that a battle against this epidemic could be won.

著者

NAKAGI Yoshihiko ITO Toshihiro HIROOKA Kenzo SUGIOKA Yoshihiko ENDO Hitoshi SAIJO Yasuaki IMAI Hirohisa TAKEDA Hidekatsu KAYAMA Fujio SASAKI Satoshi YOSHIDA Takahiko

雑誌

Environmental health and preventive medicine (ISSN:1342078X)

巻号頁・発行日

vol.15, no.4, pp.222-228, 2010-07-01

参考文献数

37

被引用文献数

16

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http://dx.doi.org/10.1007/s12199-009-0131-8Objectives : We explored the relationship between bone mineral density (BMD) and lifestyle in juveniles to identify factors leading to higher peak bone mass and prevention of osteoporosis in later life. Methods : Juveniles (1,364 students: 770 boys and 594 girls, aged 6–18 years) attending school in Hokkaido prefecture, Japan, were asked to complete a brief self-administered diet history questionnaire for 10-year-olds (BDHQ10y) providing information about personal history, lifestyle, and intake of nutritional elements. In addition, BMD and grip strength were measured. We analyzed the relationship between BMD and lifestyle factors. Results : The difference in BMD for boys was larger among the junior and senior high school groups. The difference in BMD for girls was larger among older elementary and later school children. Anthropometric variables and grip strength were strongly correlated with BMD. Having a nap-time routine was significantly correlated with BMD, but sleep time and sports club activities were not. BMD among juveniles who attained secondary sexual characteristics was significantly higher than that of juveniles of the same age who had not attained these characteristics. Calcium intake was significantly lower in senior high school students compared with other grades. Consumption of milk by senior high school boys and junior high school girls was weakly correlated with BMD. Conclusions : Our findings encourage educational interventions to counsel students to avoid weight loss and calcium deficiency. This effective intervention should begin before the higher elementary school, when juveniles have the greatest likelihood for preventing lower peak bone mass and osteoporosis.