A Study Over The Mechanism Of Heat Wave’s Impact On Coronary Artery Heart Diseases

With the global warming of climate and the influence of local climate, such as urban heat island effect, heat wave, one of the extreme weather events, occurred frequently in summer all over the world, which had an enormous damage to national economy and people’s lives. Coronary heart disease (CHD) was not the most common type of the organ lesion caused by atherosclerosis, but a most common disease which was serious harm to human body. As its dramatic effects, the research between heat wave and CHD was confined to epidemiological study. The mechanism research, which needed the experimental sound proof and deep discussion, was quite necessary.Nanjing was selected as the research region in this article. To begin with, the environmental background value was established by national comfort index of human body (ICHB) analysis. Then comparing the ICHB of different high temperature weather process, the heat wave was confirmed as the most uncomfortable weather of all. Finally, the animal experiment was carried out on the mechanism research. The results are as follows:(1) The average annual ICHB in China and each partition showed ascendant trend which reached an extremely significant level during the past30years, and the linear increasing trend of ICHB in China was0.08/a. Comparing the ICHB of four seasons, the uptrend of ICHB in spring, autumn and winter revealed more palpable than summer. Increasing was the most prominent in winter, and next in spring. According to the results of path analysis, there was an enormously significant positive(negative) correlation between temperature (relative humidity and wind speed) and ICHB, furthermore, the temperature had the biggest impact on ICHB while the influence of humidity and wind speed on ICHB mainly indirect effected by temperature. Over the past three decades, the hotter days in July were almost equal in August, and that in June were less. What’s more, there were a largest number of hotter days in Southern China, but the northwest region was the most comfortable one.(2) The high temperature weather in summer could divide into different types according to the high-temperature-lasting days and the relative humidity. Nanjing was a typical high sweltering temperature type city in summer. Comparing the ICHB of three different high-temperature-lasting types in Nanjing, heat wave process was the most uncomfortable weather, which also had a great damage to CHD patients.(3) ApoE-/-mice were more vulnerable when suffering the heat wave, which might be one of the mechanisms of the phenomenon that coronary artery disease patients were more vulnerable to heat wave weather. BH4could promote the NO releasing, which could increase the heat loss of the mice, during heat wave, especially the ApoE-/-mice. More care should be taken about the CHD patients during the heat wave in summer.