Sleep - All posts

In 88,905 adults followed with wrist light sensors, brighter nights were tied to higher future risks of coronary disease, heart attack, heart failure, atrial fibrillation, and stroke under the paper's primary model 3 (demographics, socioeconomic factors, physical activity, smoking, alcohol, diet, and urbanicity). That pattern is association, not proof that your bedroom lamp causes disease. A lab study in healthy young adults found one night of moderate room light during sleep caused a higher nighttime heart rate and lower heart-rate variability and showed higher HOMA-IR, higher 30-minute insulin area under the curve, and a lower Matsuda index the next morning versus very dim light. For everyday sleep space habits, the CDC recommends a cool, dark, quiet bedroom and limiting bright artificial light before bed.