Morning surge in sympathetic nervous activity in the indoor environment during the cold winter season

We addressed to the sympathetic nervous activation of the same people in both their houses and a highly insulated and airtight model house (model house) during the cold winter season. Eight subjects (4 males and 4 females) stayed two nights at each house and were continuously monitored for sympathetic nerve system by calculating LF (low frequency)/HF (high frequency) in the analysis of heart rate variability using a wearable electrocardiography equipment. The room temperatures were kept constant at 20 degrees C or more in model house, but much lower in their houses. In all subjects, the sleeping duration is longer in model house compared with that in the participants' houses. Four subjects showed a morning surge in sympathetic activity that were more intense at their houses. This morning surge in sympathetic activity in a residential setting suggests the importance of the indoor environment in the management of early morning hypertension.

Automated summary

This study investigated sympathetic nervous activation in individuals in their homes and a highly insulated model house during the cold winter season. The results showed that subjects had longer sleep duration in the model house and some participants exhibited a stronger rise in sympathetic activity in their own homes, highlighting the importance of indoor environment in the management of early morning hypertension.