Andrew Phillips of Harvard Medical School and colleagues from Australia, the UK, and the US conducted a prospective cohort study and found that adults exposed to light at night have an increased risk of various cardiovascular diseases. The study used data from 88,905 people over 40 years of age (mean age 62.4 years; 56.9 percent women) from the UK Biobank repository. They wore light sensors in natural living conditions for a week after being turned on (a total of approximately 13 million hours of recording). Disease incidence data for 9.5 years were taken from UK health registries. Statistical analysis of the data was performed using adjusted Cox proportional hazards models. The results were published in JAMA Network Open.
Compared with participants with low nighttime light exposure (0–50th percentiles), participants with maximum nighttime light exposure (91–100th percentiles) had an increased risk of coronary heart disease (adjusted odds ratio 1.32), myocardial infarction (1.47), heart failure (1.56), atrial fibrillation (1.32), and stroke (1.28). These associations remained significant after adjusting for known cardiovascular risk factors, including physical activity, smoking, alcohol intake, diet, sleep duration, socioeconomic status, and a polygenic risk score.
