Time of Day as a Biological Variable in Cardiovascular and Kidney Disease Research

Updated: August 20, 2026

Two scientists in lab coats looking at monitor
  • Time-of-day is a fundamental biological variable that needs to be considered in preclinical and clinical research as well as clinical practice.
  • Proper experimental design requires deliberate timing of measurements and transparent reporting in order to strengthen rigor and reproducibility.
  • Lack of awareness and lack of standardized circadian metrics are major barriers to progress in understanding fundamental mechanisms of physiology and pathophysiology.