Figure 4.

Cross-sectional association between nighttime aircraft noise and sleep–wake cycle using UK Biobank cohort ($n=\mathrm{18,399}$). Note: Sleep–wake cycle outcomes including RA, IV, and IS, all unitless. A higher RA value indicates greater activity during the day and reduced activity during sleep. A high IV suggests a more fragmented rhythm indicative of circadian dysfunction. A higher IS score indicates a strong alignment with light and other environmental cues that regulate the biological clock. The figures display the point estimate ($\mathrm{\beta }$) and 95% CIs. $\mathrm{\beta }$ represents the increment in the absolute value of the outcome when exposed to higher aircraft noise categories, in comparison with those exposed to $<45$ dB. ${\mathrm{L}}_{\text{night}}$ refers to the A-weighted equivalent noise level (${\mathrm{L}}_{\text{eq}}$) measured in decibels (dB) over the 8-h night period from 23:00 hours to 07:00 hours. All models have been adjusted for sex; ethnicity; age in 2006; BMI; ever seen a psychiatrist or doctor (GP) for nerves, anxiety, tension, or depression; smoking status; alcohol consumption; total number of vigorous or moderate physical activities (in days) a participant typically reported doing in a week; average yearly household income before tax; Townsend deprivation index at the time of recruitment from the national census output areas associated with the participant’s place of residence; nighttime road traffic noise; nighttime rail traffic noise; ${\mathrm{NO}}_2$ concentration; ${\mathrm{PM}}_{2.5}$ concentration; and greenspace percentage within a buffer of $\mathrm{1,000}\mathrm{m}$. The numeric results can be found in Excel Tables S3, S4, and S5. BMI, body mass index; CI, confidence interval; GP, general practitioner; IS, interdaily stability; IV, intradaily variability; RA, relative amplitude.