Department of Health and Social Behaviour, The University of Tokyo School of Public Health, Tokyo, Japan.
Eur J Public Health. 2019 Oct 1;29(5):826-832. doi: 10.1093/eurpub/ckz038.
Epidemiological evidence has shown that lower salt intake reduces hypertension-related disease mortality. Japan has experienced a drastic decrease in cardiovascular mortality, although this varies across regions. This regional variation does not necessarily match the local patterns of reported average salt intake. In this study, we examined population-level risk factors for hypertension-related disease mortality, focussing on the average household dietary consumption of salt intake sources.
We prepared an ecological panel dataset, with prefecture as the unit of analysis, by referring to public statistics and market research data from 2012 to 2015. We collected prefectural averages of household dietary consumption related to salt intake and other nutrients that may affect hypertension control. We used demographic characteristics, medical care availability and local economy indices as covariates. Panel data analysis with fixed-effects modelling was performed, regressing prefectural-level mortality from ischaemic heart diseases, subarachnoid and intracerebral haemorrhage and cerebral infarction on dietary consumption and the selected covariates.
We confirmed the average household consumption of salt equivalents of discretional salt intake sources to be positively but only weakly associated with mortality from ischaemic heart diseases and cerebral infarction. Household expenditure on processed foods was positively associated with ischaemic heart disease mortality.
These findings may suggest that the reduction of salt in processed foods, in addition to individual behavioural change, could be useful for decreasing mortality from ischaemic heart diseases in the Japanese population. Ecological factors related to decreasing cerebrovascular disease mortality in the context of the ageing Japanese population require further investigation.
流行病学证据表明，减少盐的摄入量可降低与高血压相关的疾病死亡率。尽管日本各地的心血管死亡率都有所下降，但这种情况因地区而异。这种地域差异并不一定与报告的平均盐摄入量的当地模式相匹配。在这项研究中，我们研究了与高血压相关的疾病死亡率的人群水平风险因素，重点关注家庭饮食中盐摄入量来源的平均摄入量。
我们通过参考 2012 年至 2015 年的公共统计数据和市场研究数据，以县为分析单位，准备了一个生态面板数据集。我们收集了与盐摄入量和其他可能影响高血压控制的营养素有关的家庭饮食消费的县平均数据。我们使用人口统计学特征、医疗保健可及性和当地经济指数作为协变量。使用固定效应模型进行面板数据分析，回归县一级缺血性心脏病、蛛网膜下腔和脑出血以及脑梗死死亡率与饮食消费和所选协变量的关系。
我们证实离散盐摄入源的家庭平均盐摄入量与缺血性心脏病和脑梗死死亡率呈正相关，但相关性较弱。家庭在加工食品上的支出与缺血性心脏病死亡率呈正相关。
这些发现可能表明，除了个人行为改变外，减少加工食品中的盐含量可能有助于降低日本人口的缺血性心脏病死亡率。需要进一步研究与日本人口老龄化相关的降低脑血管病死亡率的生态因素。
