Adult Mortality Attributable to Preventable Risk Factors for Non-Communicable Diseases and Injuries in Japan: A Comparative Risk Assessment

BackgroundThe population of Japan has achieved the longest life expectancy in the world. To further improve population health, consistent and comparative evidence on mortality attributable to preventable risk factors is necessary for setting priorities for health policies and programs. Although several past studies have quantified the impact of individual risk factors in Japan, to our knowledge no study has assessed and compared the effects of multiple modifiable risk factors for non-communicable diseases and injuries using a standard framework. We estimated the effects of 16 risk factors on cause-specific deaths and life expectancy in Japan. Methods and FindingsWe obtained data on risk factor exposures from the National Health and Nutrition Survey and epidemiological studies, data on the number of cause-specific deaths from vital records adjusted for ill-defined codes, and data on relative risks from epidemiological studies and meta-analyses. We applied a comparative risk assessment framework to estimate effects of excess risks on deaths and life expectancy at age 40 y. In 2007, tobacco smoking and high blood pressure accounted for 129,000 deaths (95% CI: 115,000–154,000) and 104,000 deaths (95% CI: 86,000–119,000), respectively, followed by physical inactivity (52,000 deaths, 95% CI: 47,000–58,000), high blood glucose (34,000 deaths, 95% CI: 26,000–43,000), high dietary salt intake (34,000 deaths, 95% CI: 27,000–39,000), and alcohol use (31,000 deaths, 95% CI: 28,000–35,000). In recent decades, cancer mortality attributable to tobacco smoking has increased in the elderly, while stroke mortality attributable to high blood pressure has declined. Life expectancy at age 40 y in 2007 would have been extended by 1.4 y for both sexes (men, 95% CI: 1.3–1.6; women, 95% CI: 1.2–1.7) if exposures to multiple cardiovascular risk factors had been reduced to their optimal levels as determined by a theoretical-minimum-risk exposure distribution. ConclusionsTobacco smoking and high blood pressure are the two major risk factors for adult mortality from non-communicable diseases and injuries in Japan. There is a large potential population health gain if multiple risk factors are jointly controlled. Please see later in the article for the Editors' Summary

研究背景
日本国民平均预期寿命位居全球首位。为进一步提升国民整体健康水平，需获取可归因于可预防危险因素的死亡率相关一致且可比的证据，以此为健康政策与项目制定优先级提供依据。尽管既往已有多项研究量化了日本境内单个危险因素的影响，但据我们所知，目前尚无研究采用标准分析框架，对多种可改变的非传染性疾病及损伤相关危险因素的效应进行评估与比较。本研究针对日本人群，评估了16种危险因素对不同病因死亡及预期寿命的影响。

研究方法与结果
本研究从国民健康与营养调查（National Health and Nutrition Survey）及流行病学研究中获取危险因素暴露数据，从经不明原因编码校正后的生命登记数据中获取不同病因死亡人数数据，并从流行病学研究及荟萃分析（meta-analyses）中获取相对风险数据。我们采用比较风险评估框架（comparative risk assessment framework），估算了超额风险对40岁人群死亡及预期寿命的影响。
2007年，吸烟与高血压分别导致129000例死亡（95%置信区间（95% CI）：115000~154000）与104000例死亡（95%置信区间：86000~119000）；紧随其后的依次为身体活动不足（52000例死亡，95%置信区间：47000~58000）、高血糖（34000例死亡，95%置信区间：26000~43000）、膳食高盐摄入（34000例死亡，95%置信区间：27000~39000）与饮酒（31000例死亡，95%置信区间：28000~35000）。
近数十年来，老年人群中归因于吸烟的癌症死亡率呈上升趋势，而归因于高血压的脑卒中死亡率则有所下降。若将多种心血管危险因素的暴露水平降至理论最低风险暴露分布（theoretical-minimum-risk exposure distribution）所确定的最优水平，2007年男女两性的40岁人群预期寿命均可延长1.4年（男性：95%置信区间1.3~1.6年；女性：95%置信区间1.2~1.7年）。

研究结论
在日本，吸烟与高血压是导致成人因非传染性疾病及损伤死亡的两大主要危险因素。若能联合管控多种危险因素，可大幅提升国民整体健康水平。
请参阅本文后文的编辑摘要。