Details of a Researcher - Ikaga, Toshiharu

Papers - Ikaga, Toshiharu

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Are cold extremities an issue in women’s health? Eepidemiological evaluation of cold extremities among Japanese women

Tsuboi S, Mine T, Tomioka Y, Sshiraishi S, Fukushima F, Ikaga T

International Journal of Women's Health (International Journal of Women's Health) 11 31 - 39 2019

Research paper (scientific journal), Joint Work, ISSN 1179-1411

© 2019 Tsuboi et al. Background: Unlike traditional East Asian medicine, the necessity of health care services for cold extremities is yet to be acknowledged in Western medicine. In this study, we aimed to conduct an epidemiological evaluation of this unremarkable symptom among women in Japan. Materials and methods: A cross-sectional study was conducted from February 2016 to April 2017, and data of 238 women throughout Japan were analyzed. Questionnaires were used to examine participants’ demographics, health-related behaviors, health status, and frequency of subjective symptoms over the past 1 year. The association between cold extremities and other subjective symptoms was examined by the multiple logistic regression analysis. Results: The prevalences of mild and severe cold extremities were 49.6% and 35.3%, respectively. Temperature and utilization of health care services were not significantly different by the severity of cold extremities. The accompanying symptoms that were significantly associated with the cold extremities were shoulder stiffness, fatigue, low back pain, headache, nasal congestion, itching, injury, and difficulty hearing. After multiple logistic regression analysis, low back pain (OR: 4.91) and difficulty hearing (OR: 4.84) kept the significance. Factors related to cold extremities including mental quality of life, sleep quality, and habitual drinking were significantly associated with other accompanying symptoms. Conclusion: Women with cold extremities have various accompanying symptoms and health-risk behaviors. Symptomatic treatment for cold extremities may not be sufficient, and comprehensive care would be required.

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Incidence and characteristics of bath-related accidents

Suzuki M, Shimbo T, Ikaga T, Hori S

Internal Medicine (Internal Medicine) 58 ( 1 ) 53 - 62 2019

Research paper (scientific journal), Joint Work, ISSN 09182918

© 2019 The Japanese Society of Internal Medicine. Objective Bath-related sudden cardiac arrests frequently occur in Japan. This study aimed to describe the actual incidence and characteristics of bath-related accidents, including non-fatal events, and to establish the etiology of bath-related sudden cardiac arrest. Methods This prospective cross-sectional observational study was conducted in Tokyo Metropolis and Saga and Yamagata Prefectures between October 2012 and March 2013. Emergency personnel enrolled events in this study when they recognized that activation of the emergency medical system was related to bathing. Surveillance cards were delivered and collected from the emergency personnel and attending physicians. Results In total, 4,593 events were enrolled (1,528 cardiac arrests, 935 survivors in need of help, 1,553 patients with acute illnesses, and 577 patients with injuries) in this study. In the group of survivors in need of help and with acute illness, consciousness disturbance and lethargy without any organic disease were recognized as the main symptoms. Acute coronary syndrome and stroke were infrequently diagnosed. Of the survivors, 30% had a body temperature above 38°C. Their consciousness level significantly correlated with their body temperature. Emergency personnel reported that 79% of sudden cardiac arrests were from victims whose faces were submerged in the tub water, while 18% of survivors had their faces submerged in the tub water. Conclusion This study revealed that accidents, including non-lethal events, frequently occur. The key symptoms were consciousness disturbance and lethargy characterized as a functional disorder and accompanied by an elevated body temperature. Those findings suggest that heat illness during hot water immersion causes drowning.

ANNUAL NATIONWIDE ENVIRONMENTAL IMPACT ASSESSMENT OF JAPANESE MUNICIPALITIES WITHIN THE FRAMEWORK OF ENDPOINT-TYPE LCIA METHOD "LIME2"

YAMASAKI Junya, IKAGA Toshiharu, ITSUBO Norihiro

Journal of Environmental Engineering (Transactions of AIJ) (Architectural Institute of Japan) 84 ( 764 ) 955 - 965 2019

Research paper (scientific journal), Joint Work, Accepted, ISSN 13480685

In Japan, a unified system to measure environmental loads in administrative areas has not been officially established for environmental accounting at the local government level. As a consequence, environmental accounting has not been adopted by local governments as widely as private companies. Life cycle impact assessment (LCIA) is one aspect of research in the field of life-cycle assessment, whereby environmental loads throughout the life cycle of products and services are measured in a quantitative way. Research in which environmental loads are determined according to geographic location has become more and more important. This study therefore focused on Japanese minimum administrative divisions (municipalities) and attempted to quantify the annual environmental loads emitted within each division in the year 2015 using the LCIA method. For this, this study leveraged the assessment theory Life-Cycle Impact Assessment Method Based on Endpoint Modeling 2 (LIME2). This method is able to calculate assessment results in monetary units called the "Eco-index Yen" (unit: Japanese yen) while integrating the environmental loads of several impact categories, such as "Global warming" and "Land use", based on environmental conditions and knowledge unique to Japan. Using statistical information that was reliable, verifiable, and comparable, the environmental damage amount for the whole of Japan was calculated to be 8.53 trillion yen. The top five amounts were "Global warming" (2.82 trillion yen), "Land use" (2.33 trillion yen), "Waste (domestic)" (1.24 trillion yen), "Biological toxicity" (0.63 trillion yen), and "Atmospheric pollution" (0.61 trillion yen). When the damage amounts were divided by the population of each municipality, the average amount per capita for all Japanese municipalities was calculated to be 67,100 yen per capita (population-weighted average). These damage amounts per capita were placed on a map of Japan according to type of impact category and type of business to visualize the regionality of environmental loads nationwide. The values for "Global warming" and "Land use" tended to be lower in the central parts of large urban areas, and the values for "Global warming" and "Atmospheric pollution" tended to be higher in areas where industries are concentrated. The values for "Primary industries" (which include agriculture) as well as "Manufacturing" were particularly indicative of local industrial activity. Tendencies related to population distribution and industrial activity were easy to see from the map. Next, standard deviation and variation coefficient for the damage amounts per capita were calculated for each region in order to statistically capture the disparities of environmental loads according to impact category and type of business. The disparities of environmental loads that were deeply related to housing, such as "Waste (domestic)" and "Land use", tended to be narrow among municipalities whereas disparities for "Manufacturing" were particularly wide because manufacturers are concentrated in certain parts of the country. From these results, this study revealed Japanese environmental impacts from the perspective of several categories, thus providing information useful for making decisions about environmental policies.

MULTIVARIATE ANALYSIS OF PERCEIVED INDOOR TEMPERATURE AND AGE AT NEED FOR LONG-TERM CARE INSURANCE:A field survey on the effect of winter indoor thermal environment on care requirements: Part 2

NAKAJIMA Yukie, IKAGA Toshiharu, ONO Mari, HOSHI Tanji, ANDO Shintaro

Journal of Environmental Engineering (Transactions of AIJ) (Architectural Institute of Japan) 84 ( 763 ) 795 - 803 2019

Research paper (scientific journal), Joint Work, ISSN 13480685

Given the rapid ageing of the Japanese population, it is important to identify strategies to minimise the gap between healthy life expectancy and average life span. Cold-related injuries and symptoms have recently attracted attention, and studies on the relationship between blood pressure, falls, physical performance, and the thermal environment of housing have been reported. Based on previous studies, we hypothesised that people living in cold homes will receive certification for long-term care insurance earlier in life, indicating a shorter healthy life expectancy. This retrospective study involved 205 community-dwelling older adults living in Japan. Participants completed a self-report questionnaire about personal characteristics, housing, and perceived indoor temperature in their home during winter. Participants were divided into a Cold group and a Warm group based on perceived indoor temperature. Mean and minimum living room and bedroom temperatures differed between the Cold group and Warm group. On the other hand, mean, maximum, and minimum temperatures in the dressing room all differed significantly between the Cold group and the Warm group. Air conditioners were the only heating system that contributed to warmer indoor temperature. Maximum temperature was higher but minimum temperature was lower in houses with fan heaters, which may run intermittently and with short running time. Houses in which kotatsu systems or electric blankets were used tended to have colder indoor temperatures in the living room and bedroom. The Kaplan-Meier method was used to analyse the relationship between age at certification for needing long-term care insurance and perceived indoor temperature. Mean age at certification was 77.8 years in the Cold group and 80.6 years in the Warm group (p<0.01, generalised Wilcoxon test). Multivariate analysis by ANCOVA revealed a significant main effect of perceived indoor temperature, with the Cold group having a younger age at certification for needing long-term care (F(1, 197)=9.27, p<0.01). Estimated marginal means indicated that healthy life expectancy was 2.9 years shorter in the Cold group than in the Warm group even after adjusting for participant characteristics. When the relationship between measured indoor temperature and age at certification was tested, people living in houses with low indoor temperature (<14 °C) or high indoor temperature (≥18 °C) had a higher age at long-term care certification. People with low indoor temperature might spend longer time outside and use heating systems for shorter time. Since we could not grasp or control times going-out or using heating system, we conclude that relationship between measured indoor temperature and age at certification can support the previous result though, close investigations of indoor thermal environment in where older people lives are still needed. Our findings suggest that maintaining an appropriate indoor thermal environment could help prevent the need for long-term care.

Quantitative improvement in workplace performance through biophilic design: A pilot experiment case study

Ayuso Sanchez J, Ikaga T, Vega Sanchez S

Energy and Buildings (Energy and Buildings) 177 316 - 328 2018.10

Research paper (scientific journal), Joint Work, ISSN 03787788

© 2018 Elsevier B.V. Numerous studies endorsed by the scientific community affirm that biophilic design in the workplace improves productivity and user well-being. However, it is necessary to go a step further and objectify the design criteria serving as an operator for productivity and well-being in design practice. In response to the challenges of how to measure the improvement of productivity and well-being through biophilic architecture design, the main contribution of this article is the development of a tool that allows to measure the predicted feature that improve productivity and well-being, based on a scientific method, which is tested by conducting a pilot experiment. A scheduled pilot experiment, as a small-scale version done in preparation for a major study, has been conducted to test a tool that quantifies the impact of biophilic design features on performance and well-being, to evaluate the influence of variables such as greenery and daylight on improving workplace performance, and look at biophilic design knowledge in greater depth. The role of natural indoor environments - understood as spaces within buildings provided with elements of nature - has received relatively little attention, compared to the number of studies evaluating occupant impact related to other characteristics of indoor environments derived from mechanical and electrical systems such as thermal factors, noise and vibration, ergonomics and office design. The present study is one of the first studies evaluating and measuring the combination of greenery and daylight into a biophilic design proposal. The results highlight an improvement in well-being, performance, creativity and health by introducing daylight and greenery into workplace design such as biophilic design features. The tool developed and tested in this pilot experiment opens a way to improve measured workplace performance to a much greater extent in contrast to the existing practice.

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Sustainability assessment of cities: SDGs and GHG emissions

Shun Kawakubo, Shuzo Murakami, Toshiharu Ikaga, Yasushi Asami

Building Research & Information (Informa UK Limited) 46 ( 5 ) 528 - 539 2018.07

Research paper (scientific journal), Joint Work, ISSN 09613218

The United Nations' (UN) sustainable development goals (SDGs), the core of the 2030 Agenda for Sustainable Development and the UN Paris Agreement, were adopted in 2015. Involvement of not only national governments but also all other stakeholders including local governments is important to promote sustainable development and to achieve the goals. The question arises, therefore, of what methods should be used to best implement and assess sustainability issues at a local level. In this light, a new version of Comprehensive Assessment System for Built Environment Efficiency (CASBEE), CASBEE for Cities, is introduced for assessing the sustainability of cities and communities around the world based on SDG indicators and greenhouse gas (GHG) emissions. The tool allows users to understand the sustainability of cities and communities based on quality (Q) and environmental load (L) perspectives. The sustainability assessments show that cities in developed countries tend to have good grades for Q, but bad grades for L, while cities in developing countries tend to have the opposite trend. This will assist cities and communities in both developed and developing countries to understand urgent problems and to identify effective solutions for sustainable development.

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EVALUATION OF RELATIONSHIP BETWEEN RESIDENCE RESILIENCY AND RESIDENTS' AWARENESS OF DISASTER PREVENTION

SATO Ryota, IKAGA Toshiharu, MURAKAMI Shuzo, SEIKE Tsuyoshi, OTSUKA Kaichi

Journal of Environmental Engineering (Transactions of AIJ) (Architectural Institute of Japan) 83 ( 749 ) 615 - 623 2018.07

Research paper (scientific journal), Joint Work, ISSN 13480685

The severe damage caused by the Great East Japan Earthquake in 2011 highlighted the shortcomings in disaster reduction. Therefore, the concept of resilience has drawn much attention to reduce damage and to achieve restoration of services in addition to preventing damage; thus, new policy guidelines in various fields have been published.  To improve residence resiliency, it is important not only to prepare for physical needs, but to understand the risks during disasters, to take appropriate action, and to make homes safe to avoid injuries and accidents in everyday life. However, the actual extent to which residents have made these preparations is not properly understood. Factors affecting residence resiliency is unclear, and it is necessary to clarify this and to consider measures to promote resident preparation.  In this research, we conducted a questionnaire survey on residents’ disaster preparation and awareness to evaluate residence resiliency and analyze the factors affecting residence resiliency. The questionnaire survey results show that the higher the household income and the higher the age of the resident, the higher the residence resiliency. Residents living in areas affected by the Great East Japan Earthquake showed a relatively high resilience. In addition, factor analysis was conducted, and we extracted elements describing residence resiliency. Eight factors were extracted from questionnaires on resilience, and the factors were classified as “Risk understand 1”, “Risk understand 2”, “Life continuity”, “Action plan”, “Links with region”, “Equipment preparation”, “Daily safety”, and “Information”. Evaluating the resilience for each factor indicated that the “Links with region” and “Equipment preparation” factors are inadequate, and that information is provided according to these factors.  We analyzed the relationship between residents' awareness and residence resiliency by structural equation modeling. The results showed that concerns about primary damage and mutual help awareness affect disaster prevention awareness, and that disaster prevention awareness affects residence resiliency. Therefore, to improve residence resiliency, activities to improve mutual help awareness should be promoted and residents should be encouraged to recognize the risk of disaster and the possibility of damage. However, in the model we created, disaster prevention awareness only accounts for 26% of residence resiliency, and the effect of household income and age is large. Therefore, measures for promoting preparation among those with low income and among young people are important.

Influence of residential performance on residents’ health status: Nationwide survey of environmental performance of detached houses and residents’ health status

Shun Kawakubo, Toshiharu Ikaga, Shuzo Murakami, Tanji Hoshi, Shintaro Ando

International Journal of Japan Architectural Review for Engineering and Design (JAR) (Wiley) 1 ( 2 ) 271 - 279 2018.01

Research paper (scientific journal), Joint Work, Accepted, ISSN 2475-8876

Previous studies have revealed the relationships between specific residential environmental factors and residents' health status. However, no study has considered the comprehensive health risk due to the overall residential environment. Therefore, a large-scale nationwide questionnaire survey was conducted using the CASBEE Health Checklist to examine the residential environment of detached houses and residents' health status. This analysis indicated that the overall residential environment is likely an important determinant of health and was associated with disease prevalence among residents.

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Effect of Office and Housing Environment on Mental and Physical Health and Workplace Productivity (part1) Statistical analysis based on questionnaire survey

四方路慶樹, 伊香賀俊治, 藤野善久, 平岡雅哉, 佐藤正章, 鈴木雄介, 権藤尚, 海塩渉, 関紅美花

Techinical Papers of Annual Meeting the Society of Heating,Air-conditioning and Sanitary Engineers of Japan (The Society of Heating,Air-Conditioning and Sanitary Engineers of Japan) 2018 ( 0 ) 185 - 188 2018

Research paper (scientific journal), Joint Work, Accepted, ISSN 1880-3806

執務者が長い時間を過ごす執務環境が心身の健康に影響を及ぼす可能性が既往研究により報告されているが、執務者の生活に大きく関わっている住環境や、メンテナンス・企業経営等の管理方法を考慮した包括的な検証は不十分である。そこで、執務環境と住環境が心身の健康と知的生産性に与える影響の包括的な検証を目的とした実態調査を実施した。結果として、良質な執務環境と住環境が心身の健康改善と知的生産性向上に寄与する可能性が示された。

AN EXAMPLE OF CLUSTER ENERGY MANAGEMENT SYSTEM IN AGING SOCIETY

Terashima Kohei, Akada Hiroyasu, Kobayashi Yuriko, Sato Haruki, Ikaga Toshiharu

グランド再生可能エネルギー国際会議論文集 (特定非営利活動法人再生可能エネルギー協議会) 1 ( 0 ) 2018

Research paper (scientific journal), Joint Work, Accepted

Under the Paris Agreement, Japan promises reducing 26 % from greenhouse gas emissions in 2013 by 2030. We have proposed a concept of Cluster Energy Management System, CEMS, which can design a highly saving-energy network based on demand simulation of communities consisting various different residents. As an example of CEMS designing a good thermal and electricity demand-balance among a network of residential houses, commercial and nursing facilities is introduced. The network can use almost whole exhaust heat from distributed power plant such as fuel cell with solar power and thermal utilization. We can simulated saving about 40 % in prime-energy consumption and about 45 % reduction of CO2 emission by designing an example case of the CEMS, which combines fuel cells and electric vehicles in a community, where 200 families including elderly people are living. We concluded that it would be possible to reduce primary energy consumption and CO2 emission by nearly a half amount or more by introducing the CEMS.

Relationship between indoor temperature in winter and Brain Healthcare Quotient

Matsumoto M., Ikaga T., Yamakawa Y., Uchida Y., Murakami S., Ando S., Mitsukura Y., Hayashi Y.

15th Conference of the International Society of Indoor Air Quality and Climate, INDOOR AIR 2018 (15th Conference of the International Society of Indoor Air Quality and Climate, INDOOR AIR 2018) 2018

Research paper (scientific journal), Accepted, ISSN 9781713826514

In Japan, where the population is aging, it is necessary to maintain mental and physical health over the long term in order to solve social problems such as increasing medical expenses. It has been suggested that exposure to cold adversely affects brain health. Thus, we hypothesized that the brain health of residents in cold houses would be worse than that of residents in warm houses. In the winter season from 2016 to 2017, we measured indoor temperature, conducted brain health tests using MRI examination, and administered questionnaire surveys for 59 residents of a town in northern Japan. The results of multiple regression analysis show that residents who had a cold living room had lower indexes representing the quality of cranial nerve fibers than residents who had a warm living room in winter.

AN EXAMPLE OF CLUSTER ENERGY MANAGEMENT SYSTEM IN AGING SOCIETY

Terashima Kohei, Akada Hiroyasu, Kobayashi Yuriko, Sato Haruki, Ikaga Toshiharu

グランド再生可能エネルギー国際会議論文集 (特定非営利活動法人再生可能エネルギー協議会) 1 2018

Research paper (scientific journal), Joint Work, Accepted

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Influence of environmental humidity on oral dryness among nursing home residents in Japan

Yukie Nakajima, Toshiharu Ikaga, Shintaro Ando, Tanji Hoshi

15th Conference of the International Society of Indoor Air Quality and Climate, INDOOR AIR 2018 (15th Conference of the International Society of Indoor Air Quality and Climate, INDOOR AIR 2018) 2018

Research paper (scientific journal), Joint Work, Accepted

Maintaining good quality of life among elderly residents of nursing homes is becoming more important as their numbers increase with the ageing of society. Dry mouth, or xerostomia, is one condition that must be prevented, as it can lead to various serious diseases. However, older people are susceptible to dry mouth due to reduced lip closing force. In this study, a field survey of the indoor environment of nursing homes and oral dryness among nursing home residents was conducted in winter 2015. Twenty-seven facilities were classified as dry or moist based on measured indoor humidity. Ordered logistic regression analysis showed that the likelihood of dry mouth was significantly lower among patients residing in the moist group compared with the dry group.

Relationship between Bath-related Deaths and Low Air Temperature.

Masaru Suzuki, Toshiharu Ikaga, Shingo Hori

Internal medicine (Tokyo, Japan) (JAPAN SOC INTERNAL MEDICINE) 56 ( 23 ) 3173 - 3177 2017.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 0918-2918

Objective Bath-related sudden cardiac arrests occur frequently in Japan. Although previous studies have reported that most fatal events occurr in winter, the reason why such events exhibit a seasonal variation has not been elucidated. In this study, we hypothesized that the occurrence of bath-related deaths was correlated with a low air temperature. Methods This prospective cross-sectional observational study was conducted in the Tokyo Metropolitan area between October 2012 and March 2013. Data were collected for all cases involving the activation of the emergency medical system because of an accident or acute illness related to bathing that occurred in Tokyo during the study period. In particular, elderly (≥65 years) cardiac arrest victims who had been found in a bathtub filled with water were enrolled. The relationship between the daily number of cardiac arrest events and the lowest daily air temperature in Tokyo was studied using a nonlinear regression model. Results A total of 3,624 bath-related events were registered in this study. Among these events, 1,081 deaths of elderly individuals who had been found in a bathtub filled with water were recorded. A close correlation was observed between the daily number of events and the lowest daily air temperature. This correlation was described by the following equation: y=8.38e-0.07x, where y was the daily number of cardiac arrests and x was the lowest daily air temperature. Conclusion A low air temperature was closely correlated with the occurrence of bath-related cardiac arrest.

Life Cycle Assessment for Commercial Buildings

SATO Masaaki, IKAGA Toshiharu

Journal of Life Cycle Assessment, Japan (The Institute of Life Cycle Assessment, Japan) 13 ( 2 ) 111 - 117 2017

Research paper (scientific journal), Joint Work, Accepted, ISSN 18802761

Current Situation of LCA for Buildings used by National / Local Governments and Private Companies, and Development for Health Impact Assessment

IKAGA Toshiharu

Journal of Life Cycle Assessment, Japan (The Institute of Life Cycle Assessment, Japan) 13 ( 2 ) 104 - 110 2017

Research paper (scientific journal), Joint Work, Accepted, ISSN 18802761

This article introduces the current situation of LCA for buildings. The research and development on LCA method of buildings started in 1990 as an activity of the Architectural Institute of Japan, and it became LCA guideline of buildings. By using of this guideline, the cost effectiveness evaluation tool to mitigate climate change was developed and applied by national and local government, and widely used by many private companies. As well as simplified LCA method was developed and introduced into the comprehensive assessment system for built environment efficiency named “CASBEE: Comprehensive Assessment System for Built Environment Efficiency” for all kind of buildings such as detached houses and large-scale commercial buildings. Furthermore, the human health impact assessment methods associated with indoor environment including indoor air pollution are conducted.

全国二次医療圏を対象とした傷病別入院患者割合と都市・住環境因子の比較

鈴木健太郎, 伊香賀俊治, 村上周三, 川久保俊

環境工学I (Architectural Institute of Japan) ( 2016 ) 1195 - 1196 2016.08

Research paper (scientific journal), Joint Work, Accepted

CiNii Research

A STUDY ON ECONOMIC IMPACT OF ENVIRONMENTAL EFFICIENCY AND INTELLECTUAL PRODUCTIVITY CONTRIBUTION ON RENTS

ITO Masato, MURAKAMI Shuzo, IKAGA Toshiharu, HAYASHI Tatsuya, TAKAI Hiroaki, MATSUNAGA Koichi

AIJ Journal of Technology and Design (Architectural Institute of Japan) 22 ( 52 ) 1053 - 1056 2016

Research paper (scientific journal), Joint Work, Accepted, ISSN 18818188 13419463

EVENT HISTORY ANALYSIS OF INDOOR THERMAL ENVIRONMENT AND CARE PREVENTION OF RESIDENTS:A field survey on the effect of winter indoor thermal environment on care requirements

HAYASHI Yukie, IKAGA Toshiharu, HOSHI Tanji, ANDO Shintaro

Journal of Environmental Engineering (Transactions of AIJ) (Architectural Institute of Japan) 81 ( 729 ) 901 - 908 2016

Research paper (scientific journal), Joint Work, Accepted, ISSN 1881817X 13480685

As ageing of the population progresses, long-term care becomes a more pressing health issue. In Japan, the gap between healthy life expectancy and average life span is expected to grow; therefore, it is necessary to extend healthy life expectancy while minimising the need for long-term care. The effect of indoor air temperature on the health of the elderly has recently attracted attention. Thus, in this study, we clarify the relationship between the indoor thermal environment and the care requirements of the elderly.  This research was conducted as a field study comprising actual measurements of indoor thermal environment, questionnaire surveys, and data collection from face sheets in 2014. The study area was Senri New Town, Osaka Prefecture, Japan. Participants were elderly residents (65-91 years) who were using a day service facility. The indoor air temperature 1.1 m above the floor was measured over approximately 2 weeks in the living room, bedroom, corridor, and dressing room at 5-min intervals. Relative humidity was also measured in the living room and bedroom concurrently. Questionnaire surveys regarding personal factors and housing were distributed. Data about health conditions and diseases requiring care were also collected. Data about care level, date of care certification, and care certification period were collected from long-term care insurance cards.  Regarding the frequency of feeling cold in each of the rooms, participants who answered “1) Frequently” and “2) Sometimes” were assigned to the high-frequency group, whereas those who answered “3) Seldom” and “4) Never” were assigned to the low-frequency group. Mean living room and dressing room temperatures were significantly lower in the high-frequency group than in the low-frequency group (p < 0.01). Mean room temperatures were also compared between houses with different insulation performance. The mean room temperatures in the corridors and dressing rooms were lowest for “Pre-1980 standards” households, and highest for “Over 1992 standards”.  The results describe the differences in room temperature between the frequency of feeling cold in dressing rooms, which is affected by low insulation performance, and verifies the association between indoor thermal environment and long-term care through subjective evaluation. The Kaplan-Meier (KM) method was used to analyse the speed of certification for the participants' long-term care needs. The age at which half of the group was certificated was 76 years in the high-frequency group and 80 years in the low-frequency group (p < 0.05). The chi-square test showed that there were no significant differences in personal factors between the two groups, confirming that the result in KM method could be explained by the difference in the thermal environment in the dressing rooms.  Our results suggest that it is necessary to maintain an appropriate indoor thermal environment to prevent the need for long-term care, especially the indoor thermal environment in rooms other than the living room, such as the dressing room. The results of this study are expected to promote improvements in the indoor thermal environment, thereby contributing to care prevention among frail elderly people.

COMPARISON OF HOME BLOOD PRESSURE BEFORE-AND-AFTER MOVING TO HIGH THERMAL INSULATION PERFORMANCE HOUSES:A field survey on the effect of indoor thermal environment on blood pressure in winter (Part III)

UMISHIO Wataru, IKAGA Toshiharu, ANDO Shintaro, OTSUKA Kuniaki

Journal of Environmental Engineering (Transactions of AIJ) (Architectural Institute of Japan) 81 ( 722 ) 357 - 366 2016

Research paper (scientific journal), Joint Work, Accepted, ISSN 1881817X 13480685

A cardiac disease is the second most common cause of death and a cerebrovascular disease is the fourth, a major cause of which is hypertension. Hypertension is an asymptomatic disease, which is called “silent killer”, affecting one-third of the population. Therefore, it is essential not only “high risk approaches” which are measures for hypertensive individuals such as treatment with an antihypertensive drug but also “population approaches” which are measures to reduce blood pressure (BP) of entire nation toward prevention of Hypertension.  Against this background, the effects of the indoor thermal environment on BP have attracted attention because it affects asymptomatic individuals. Now some studies on the relationship between BP and indoor thermal environment are accumulated. But most of the studies are cross-sectional studies, so there is a real need for follow-up studies and actual proof of causal correlation between BP and indoor thermal environment. This study aimed to demonstrate antihypertensive effects by moving to high thermal insulation performance houses.  Follow-up studies on home BP and indoor temperature was conducted before and after moving in winter 2014 and 2015. Home BP was measured by participants twice daily: before getting into bed in the evening and after getting out of bed in the morning for two weeks. Indoor temperature at 1.1 m above the floor was measured in the living room, bedroom, bathroom, and dressing room at 10-min intervals. During the survey periods, participants recorded the wake time and bedtime each day in a diary. Questionnaire surveys on personal factors and housing were also carried out. Besides, questionnaire surveys on housing were distributed to building contractor to get a reliable answer.  Thermal insulation performance of houses before moving was either “pre-1980 standards” or “1980 standards.” While thermal insulation performance of houses after moving satisfied “1999 standards”: heat loss coefficient (Q value) of houses after moving was 1.9 W/m2K, corresponding gap area (C value) was 0.4 cm2/m2 on average. Average daily outdoor temperature of before moving survey periods (5.7 °C) was nearly equal to average daily outdoor temperature of after moving survey periods (5.1 °C). The living room temperature gap between before and after moving was the largest at a wake-up time. At 6 o'clock, living room temperature after moving was higher by 2.0 °C than living room temperature before moving. In addition, the lowest temperature had increased and the highest temperature had decreased in each room. So, stabilizing effects of indoor temperature by moving were recognized.  Systolic BP (SBP) decreased by 1.5 mmHg per 1 °C increase in indoor air temperature and standard deviation (SD) of SBP improved by 2.3 mmHg per 1 °C improvement in SD of indoor air temperature in a group over 125 mmHg. Therefore, stabilization of indoor temperature has stabilizing effects on BP. However, there were several participants whose houses got colder and more unstable after moving. To examine factors related to indoor temperature changes, a comparison of indoor temperature between before and after moving by patterns of moving was carried out. As a result, moving from a single-family house to a single-family house and from a wooden house to a wooden house became warmer and improved SD of indoor temperature. On the other hand, moving from a condominium to a single-family house and from a reinforced concrete house to a wooden house became colder. Moreover, not heating a room after moving caused a sharp decrease in indoor temperature. So, it is not satisfied only by moving to high thermal insulation performance houses but paying attention to house form and structure and adequately heating a room to improve BP value and stability of BP.

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