Researchers analyzed over 2 million heart rate measurements from 245 healthy adults wearing continuous monitors for seven days, finding that each dimension of impaired sleep health increased nighttime heart rate by 1.2 beats per minute while weakening natural circadian rhythm strength. The study also identified that morning heart rate peaks occurring earlier served as a digital biomarker for insomnia with 80% specificity and 74% sensitivity. These findings illuminate how sleep quality directly modulates autonomic nervous system function through measurable changes in heart rate patterns. The work advances precision medicine by demonstrating how consumer wearables can detect subtle cardiovascular disruptions before clinical disease manifests. This represents a significant step toward using digital biomarkers for early cardiometabolic risk assessment, particularly given that sleep disorders affect nearly 30% of adults globally. However, this preprint awaits peer review, and the findings require validation across diverse populations and age groups. The research confirms existing evidence linking sleep and cardiovascular health while providing new quantitative metrics for real-world monitoring.