INFLUENCE OF INDOOR TEMPERATURE DISTRIBUTION ON HEALTH OF ELDERLY PEOPLE IN COLD CLIMATE

Abstract

 Introduction

 In recent years, many researchers research a relationship between indoor environments and health in older people because an aging society is rapidly progressing all over the world. In Japanese cases, the researches mentioned that the strong relationship between cold indoor environments and health problems such as heart disease and brain disease caused by high blood pressure. However, there are still a few previous studies dealing with the correlation between indoor thermal environment and chronic diseases in cold and snowy Hokkaido. The purpose of this study is to analyze the influence of the cold indoor environment on the health of older people in Hokkaido.

 

 Method

 Table 1 shows the outline of the survey. We conducted the questionnaire, medical examinations, and indoor climate measurement on older people who are over 70 years old without a care in the local cities of Hokkaido, such as Tomamae, Otofuke, Higashikawa, Higashi Kagura, Biei, and Yoichi. We conducted a questionnaire survey on personal attributes and a health condition such as current symptoms, drinking, smoking, sleeping habits. Also, we collected the data for housing information to estimates building energy efficiency. At the same time, we measured indoor temperatures and humidity in the living room and the dressing room as an indoor climate for 14 days from December 2017 to March 2018. The number of respondents was 574, but there were 95 respondents with a miss-measurement of temperature and humidity, and seven respondents whose questionnaires were invalidated. Then 472 respondents were eligible for analysis. We calculated the average temperature, the 1/4 temperature, and the average temperature during the sleeping of the living room and dressing room and the average of the temperature difference between the living room and dressing. Three temperature group, a warm group, a semi-cold group, and a cold group were considered for the logistic analysis. The objective variables of the analysis were high blood pressure, stroke, heart disease, and musculoskeletal symptoms.

 

 Discussion

 The adjusted odds ratio (AOR) was 15.23 (p<0.05) in the comparison of the cold group with the warm group on 1/4 temperature of a living room and dressing room when the objective variable is a stroke. It indicates that the lowest temperature during the winter season is an important index on stroke in a cold climate area.

 The AOR was 2.99 (p<0.05) in the comparison of the semi-cold group with the warm group on average temperature during a sleeping time when the objective variable is musculoskeletal symptoms. Also, COR and AOR were 3.17 (p<0.05) and 3.44 (p<0.05), respectively, on sleeping habits. The high odds ratio among musculoskeletal symptoms, sleeping temperature, and sleeping habits indicates that keeping an indoor environment during sleep effects on good health. AOR was 2.84 (p<0.05) in the comparison of the cold group with the warm group on 1/4 temperature of a living room and dressing room when the objective variable is heart disease. Previous researches found the relationship between heart disease and hypertension. But in this research, we are not able to find the relationship. The reason is that the analysis method was insufficiently considered.