Overview

• A Chinese cohort study of more than 80,000 adults tracked sleep with activity monitors and found that fragmented or irregular patterns were linked to 172 diseases across cardiovascular, metabolic and neurological systems
• A Springer Nature meta-analysis of 79 studies determined that sleeping under seven hours increases premature death risk by 14% while sleeping over nine hours raises it by 34%, although extended sleep may signal underlying illness
• Cardiologist José Abellán highlighted that misalignment with natural light-dark cycles and irregular sleep boosts heart attack and other cardiovascular event risk and that a single poor night elevates blood pressure, insulin resistance and impairs immune function
• New guidance urges prioritizing sleep depth and schedule consistency over total hours and recommends a simple self-assessment indicator—feeling drowsy after a meal—to judge rest adequacy
• Chronic insomnia affects about 10% of adults, especially women and older individuals, compounding risks from both poor sleep quality and erratic sleep patterns