Insight

E. Shyam P. Reddy: Brighter Nights Showed Dose-Response Associations with Higher Risk

E. Shyam P. Reddy/LinkedIn

Jul 6, 2025, 16:56

E. Shyam P. Reddy: Brighter Nights Showed Dose-Response Associations with Higher Risk

E. Shyam P. Reddy, Professor and Director of the Cancer Biology Program at Morehouse School of Medicine, shared a post on LinkedIn:

“Brighter nights showed dose-response associations with higher risk across all five outcomes. Participants classified in the 90–100th percentile of night-time light exposure experienced 23–32% higher hazard for coronary artery disease, 42–47% for myocardial infarction, 45–56% for heart failure, 28–32% for atrial fibrillation, and 28–30% for stroke compared with those in the 0-50th percentile.

Relationships persisted after controlling for physical activity, smoking, alcohol, diet, sleep duration, socioeconomic status, and genetic risk. Women displayed stronger associations for heart failure and coronary artery disease whereas younger participants showed stronger associations for heart failure and atrial fibrillation.

Authors propose circadian misalignment induced by unnatural light may trigger metabolic and vascular perturbations that elevate cardiovascular risk. Impaired glucose tolerance and heightened diabetes susceptibility may foster endothelial dysfunction and atherosclerosis.

Light-driven hypercoagulability could increase thromboembolic events, while sustained elevation of 24-hour blood pressure may damage vascular endothelium and provoke myocardial hypertrophy. Conflicting timing signals to sinoatrial and atrioventricular nodes may amplify arrhythmic vulnerability.

Avoiding bright light during habitual sleep times may serve as a practical addition to established cardiovascular prevention strategies, according to the authors, who call for circadian-informed lighting guidance in homes, hospitals, and urban planning.”

Read further.

E. Shyam P. Reddy: Brighter Nights Showed Dose-Response Associations with Higher Risk