Bedroom noise exposure and nighttime blood pressure in older adults: Cross-sectional analysis from HEIJO-KYO study.

BACKGROUND

Previous large-scale studies have identified outdoor noise as a cardiovascular risk factor. Compared to outdoor noise, indoor noise, particularly bedroom noise, may provide a more direct assessment of individual nighttime exposure within the home. However, indoor nighttime exposure remains insufficiently investigated. This study aimed to investigate the association between bedroom noise and nighttime blood pressure (BP) in older populations.

METHODS

A cross-sectional analysis of 1072 older people (mean age, 71.8 years; standard deviation, 7.1) from the HEIJO-KYO cohort utilized repeated measurements of ambulatory BP and bedroom noise (A-weighted equivalent continuous sound pressure level [LAeq, dBA] from bedtime to rising time) over 48-h. BP was measured at 30-min intervals. Bedroom noise was sampled and recorded at 1-min intervals at bedside.

RESULTS

Adjusted linear mixed-effects models revealed a significant association between average bedroom noise (per 1 dBA, LAeq) and nighttime systolic BP (SBP) (Coefficient = 0.13 mmHg, 95% confidence interval: 0.03 to 0.22; P = 0.008) and pre-awake SBP (Coefficient = 0.17 mmHg, 95% confidence interval: 0.04 to 0.29; P = 0.009). Nighttime SBP (mean [standard deviation]) increased across noise tertile groups (low, middle, and high: 113.7 [16.5], 115.3 [15.2], and 117.8 [16.2] mmHg, respectively; P for trend <0.001). Prevalence of nocturnal hypertension significantly increased in the higher noise group (P for trend = 0.027). Similar associations were observed for daytime and 24-h hypertension.

CONCLUSIONS

Bedroom noise was significantly associated with nighttime SBP, pre-awake SBP, and the prevalence of hypertension.