日前,，美國(guó)哈佛大學(xué)公共衛(wèi)生學(xué)院的研究者報(bào)告說(shuō),，夏季最高溫度與最低溫度之差如果顯著拉大，有可能提高老年慢性病患者的死亡率,。相關(guān)論文發(fā)表在美國(guó)《國(guó)家科學(xué)院院刊》（PNAS）上,。
報(bào)告指出，研究人員利用美國(guó)“醫(yī)療保健”系統(tǒng)在1985年至2006年間收集的數(shù)據(jù),，追蹤研究約370萬(wàn)名65歲以上慢性病患者的長(zhǎng)期健康狀況,。排除其他影響因素后，研究人員發(fā)現(xiàn),，在這些老人居住的135個(gè)城市中,，如遇上夏季溫差變化較大的年份，老人的死亡率會(huì)隨之升高,。
總體而言,，夏季溫差每升高1攝氏度，老年慢性病患者的死亡率平均增加2.8%至4%,，其中糖尿病患者死亡率增加4%,，心臟病患者的死亡率增加3.8%，這一幾率在慢性肺病和心衰患者中則分別增加3.7%和2.8%,。
科學(xué)界近年來(lái)預(yù)測(cè),，氣候變化不僅會(huì)提升全球氣溫，而且會(huì)擴(kuò)大夏季氣溫變化幅度,，特別是在中緯度地區(qū),。這項(xiàng)新研究結(jié)果說(shuō)明，這種溫差變化可能引起公共衛(wèi)生問(wèn)題,。
報(bào)告作者之一,、哈佛大學(xué)教授喬爾·施瓦茨說(shuō)，人們不容易適應(yīng)異常的氣溫變化,，隨著人口老化,，糖尿病等慢性病的患病比例逐漸增高，氣候變化導(dǎo)致更多異常氣溫波動(dòng),，這類公共衛(wèi)生問(wèn)題可能變得越發(fā)突出,。（生物谷Bioon.com）
doi:10.1073/pnas.1113070109
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Summer temperature variability and long-term survival among elderly people with chronic disease
Zanobetti, Antonella; O'Neill, Marie S.; Gronlund, Carina J.; Schwartz, Joel D.
Time series studies show that hot temperatures are associated with increased death rates in the short term. In light of evidence of adaptation to usual temperature but higher deaths at unusual temperatures, a long-term exposure relevant to mortality might be summertime temperature variability, which is expected to increase with climate change. We investigated whether the standard deviation (SD) of summer (June–August) temperatures was associated with survival in four cohorts of persons over age 65 y with predisposing diseases in 135 US cities. Using Medicare data (1985–2006), we constructed cohorts of persons hospitalized with chronic obstructive pulmonary disease, diabetes, congestive heart failure, and myocardial infarction. City-specific yearly summer temperature variance was linked to the individuals during follow-up in each city and was treated as a time-varying exposure. We applied a Cox proportional hazard model for each cohort within each city, adjusting for individual risk factors, wintertime temperature variance, yearly ozone levels, and long-term trends, to estimate the chronic effects on mortality of long-term exposure to summer temperature SD, and then pooled results across cities. Mortality hazard ratios ranged from 1.028 (95% confidence interval, 1.013– 1.042) per 1 °C increase in summer temperature SD for persons with congestive heart failure to 1.040 (95% confidence interval, 1.022–1.059) per 1 °C increase for those with diabetes. Associations were higher in elderly persons and lower in cities with a higher percentage of land with green surface. Our data suggest that long-term increases in temperature variability may increase the risk of mortality in different subgroups of susceptible older populations.
