Coexistence of PM<sub>2.5</sub> and low temperature is associated with morning hypertension in hypertensives

<div><p></p><p>We tested the hypothesis that concentration of PM<sub>2.5</sub> is associated with home BP level. We analyzed home BP data for 91 consecutive days in 40 hypertensives. PM<sub>2.5</sub> solely was not correlated with home BP levels, but low temperature was associated with a 1.6-fold increased likelihood of morning hypertension (<i>p</i> < 0.001) under the condition of high PM<sub>2.5</sub> concentration. In addition, coexistence of low temperature and high PM<sub>2.5</sub> was associated with a 2.3-fold increased likelihood of morning hypertension (<i>p</i> < 0.001) compared with high temperature and low PM<sub>2.5</sub> condition. Environmental and meteorological factors could be important causes of enhanced home BP elevation.</p></div>