Home blood pressure (HBP) variability is an important factor for cardiovascular events. While several studies have examined the effects of individual attributes and lifestyle factors on reducing HBP variability, the effects of living environment remain unknown. We hypothesized that a stable home thermal environment contributes to reducing HBP variability. We conducted an epidemiological survey on HBP and indoor temperature in 3785 participants (2162 households) planning to have their houses retrofitted with insulation. HBP was measured twice in the morning and evening for 2 weeks in winter. Indoor temperature was recorded with each HBP observation. We calculated the morning-evening (ME) difference as an index of diurnal variability and the standard deviation (SD), coefficient of variation (CV), average real variability (ARV) and variability independent of the mean (VIM) as indices of day-by-day variability. The association between BP variability and temperature instability was analyzed using multiple linear regression models. The mean ME difference in indoor/outdoor temperature (a decrease in temperature overnight) was 3.2/1.5 °C, and the mean SD of indoor/outdoor temperature was 1.6/2.5 °C. Linear regression analyses showed that the ME difference in indoor temperature was closely correlated with the ME difference in systolic BP (0.85 mmHg/°C, p < 0.001). The SD of indoor temperature was also associated with the SD of systolic BP (0.61 mmHg/°C, p < 0.001). The CV, ARV, and VIM showed similar trends as the SD of BP. In contrast, outdoor temperature instability was not associated with either diurnal or day-by-day HBP variability. Therefore, residents should keep the indoor temperature stable to reduce BP variability.

家庭血压 (HBP) 变异性是心血管事件的重要因素。虽然几项研究已经检查了个体属性和生活方式因素对降低 HBP 变异性的影响，但生活环境的影响仍然未知。我们假设稳定的家庭热环境有助于降低 HBP 变异性。我们对 3785 名参与者（2162 户）进行了一项关于 HBP 和室内温度的流行病学调查，这些参与者（2162 户）计划对他们的房屋进行保温改造。在冬季，HBP 在早上和晚上测量两次，持续 2 周。每次 HBP 观察记录室内温度。我们计算了早晚 (ME) 差异作为昼夜变异性指数和标准差 (SD)、变异系数 (CV)、平均实际变异性 (ARV) 和独立于平均值的变异性 (VIM) 作为每日变异性的指标。使用多元线性回归模型分析了 BP 变异性和温度不稳定性之间的关联。室内外温度的平均ME差（夜间温度下降）为3.2/1.5°C，室内外温度的平均SD为1.6/2.5°C。线性回归分析表明，室内温度的 ME 差异与收缩压的 ME 差异（0.85 mmHg/°C，室内外温度的平均 SD 为 1.6/2.5 °C。线性回归分析表明，室内温度的 ME 差异与收缩压的 ME 差异（0.85 mmHg/°C，室内外温度的平均 SD 为 1.6/2.5 °C。线性回归分析表明，室内温度的 ME 差异与收缩压的 ME 差异（0.85 mmHg/°C，p  < 0.001)。室内温度的 SD 也与收缩压的 SD 相关（0.61 mmHg/°C，p  < 0.001）。CV、ARV 和 VIM 显示出与 BP 的 SD 相似的趋势。相比之下，室外温度不稳定性与昼夜或每天的 HBP 变化无关。因此，居民应保持室内温度稳定，以减少血压波动。