From the Faculty of Science and Technology, Keio University, Yokohama, Japan (W.U.).
Department of System Design Engineering, Faculty of Science and Technology, Keio University, Yokohama, Japan (T.I.).
Hypertension. 2019 Oct;74(4):756-766. doi: 10.1161/HYPERTENSIONAHA.119.12914. Epub 2019 Aug 26.
Mortality due to cardiovascular disease rises sharply in winter. Known as excess winter mortality, this phenomenon is partially explained by cold exposure-induced high blood pressure. Home blood pressure, especially in the morning, is closely associated with cardiovascular disease risk. We conducted the first large nationwide survey on home blood pressure and indoor temperature in 3775 participants (2095 households) who intended to conduct insulation retrofitting and were recruited by construction companies. Home blood pressure was measured twice in the morning and evening for 2 weeks. The relationship between home blood pressure and indoor temperature in winter was analyzed using a multilevel model with 3 levels: repeatedly measured day-level variables (eg, indoor ambient temperature and quality of sleep), nested within individual-level (eg, age and sex), and nested within household level. Cross-sectional analyses involving about 2900 participants (1840 households) showed that systolic blood pressure in the morning had significantly higher sensitivity to changes in indoor temperature (8.2 mm Hg increase/10°C decrease) than that in the evening (6.5 mm Hg increase/10°C decrease) in participants aged 57 years (mean age in this survey). We also found a nonlinear relationship between morning systolic blood pressure and indoor temperature, suggesting that the effect of indoor temperature on blood pressure varied depending on room temperature range. Interaction terms between age/women and indoor temperature were significant, indicating that systolic blood pressure in older residents and women was vulnerable to indoor temperature change. We expect that these results will be useful in determining optimum home temperature recommendations for men and women of each age group. Clinical Trial Registration- URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: UMIN000030601.
心血管疾病导致的死亡率在冬季急剧上升。这种现象被称为冬季超额死亡率，部分原因是寒冷暴露引起的高血压。家庭血压，尤其是清晨的血压，与心血管疾病风险密切相关。我们对 3775 名（2095 户）计划进行隔热改造的参与者进行了首次全国范围内的家庭血压和室内温度调查，这些参与者是由建筑公司招募的。家庭血压在两周内早晚各测量两次。使用具有 3 个层次的多层次模型分析冬季家庭血压与室内温度之间的关系：反复测量的日水平变量（例如室内环境温度和睡眠质量）嵌套在个体水平（例如年龄和性别）内，嵌套在家庭水平内。涉及约 2900 名参与者（1840 户）的横断面分析表明，在 57 岁的参与者中，清晨收缩压对室内温度变化的敏感性明显高于傍晚收缩压（每 10°C 降低 8.2mmHg，每 10°C 降低 6.5mmHg）。我们还发现清晨收缩压与室内温度之间存在非线性关系，这表明室内温度对血压的影响取决于室温范围。年龄/女性与室内温度之间的交互项具有统计学意义，这表明老年居民和女性的收缩压易受室内温度变化的影响。我们期望这些结果将有助于确定每个年龄组男性和女性的最佳家庭温度建议。临床试验注册- URL：http://www.umin.ac.jp/ctr/index.htm。独特标识符：UMIN000030601。
