Disruption of circadian rhythms and health: Sleep, social jetlag, and cardiometabolic risk

The circadian system is a 24-hour internal clock that functions as the body’s sleep/wake cycle. This biological clock affects the daily rhythms of the different physiological processes and synchronizes with the cycles of light and dark or the solar clock. ‘Social jetlag’ occurs when circadian clock timing does not match solar clock timing, and this is correlated with depression, metabolic problems, obesity and higher body mass index (BMI). It also increases the likelihood of alcohol or caffeine intake and tobacco use. About half of the population in an industrialized society may have out-of-sync circadian rhythms, and this can influence cardiometabolic risk. Technology, behavior and shift work has been associated with the shift in the sleep-wake pattern, and several studies suggest the relationship between shift work and increased incidence of diabetes, CAD, CVD, coronary heart disease, acute myocardial infarctions, and cerebrovascular accident.