Indoor temperature instability linked to home blood pressure variability

Variability in home blood pressure (HBP) appears to be associated with instability in indoor, but not outdoor, temperature, a recent study has found.

“To our knowledge, this is the first epidemiological study to examine the association between diurnal and day-by-day BP variability and indoor temperature instability,” the researchers said. “The present study provides new insight into the effects of improving one’s living environment, rather than simply improving lifestyle, on reducing BP variability.”

The epidemiological investigation included 3,785 participants across 2,162 households. HBP measurements were collected in the morning and evening for 2 weeks during winter, along with simultaneous indoor temperature recording. Indices of variability included standard deviation (SD), coefficient of variation (CV), and morning-evening (ME) difference.

After adjusting for confounders, multiple linear regression analysis revealed a strong and significant association between indoor temperature variability and HBP. For instance, diurnal variability of indoor temperature, as expressed by ME difference, was significantly correlated with the ME differences of both systolic (SBP; β, 0.85, 95 percent confidence interval [CI], 0.71–0.99; p<0.001) and diastolic (DBP; β, 0.53, 95 percent CI, 0.43–0.62; p<0.001) BP.

Similar patterns were reported for day-by-day variability. The SD of indoor temperature was significantly associated with the SD (β, 0.51, 95 percent CI, 0.45–0.75; p<0.001) and CV (β, 0.44, 95 percent CI, 0.34–0.54; p<0.001) of SBP, and with the SD (β, 0.38, 95 percent CI, 0.27–0.48; p<0.001) and CV (β, 0.41, 95 percent CI, 0.29–0.54; p<0.001) of DBP.

However, across all measures of variability, the researchers detected no link between HBP and outdoor temperature.