Circadian Timekeeping in Health and Disease

Abstract

THE study of circadian (approximately 24-hour) rhythms has within the past decade evolved from a biologic curiosity to a science with enormous implications for clinical medicine. The concurrent maturation of circadian oscillator theory, the anatomic definition of circadian pacemakers in mammals, and the identification of a considerable number of persons with malfunctions of the circadian timing system have formed the basis of a new medical discipline.¹ Circadian rhythms relate to clinical medicine in two major ways. First, circadian rhythmicity is such a pervasive element of human physiology that its recognition has required a reassessment of many clinical diagnostic and therapeutic . . .