Circadian health influences cardiometabolic disease

Editor's Note

Circadian health plays a role in cardiometabolic disease risk and clinicians should take note of this, according to a new scientific statement from the American Heart Association described in a November 14 news story in JAMA. Circadian disruptions are associated with increased risk of cardiovascular disease and mortality. Extreme circadian disruptions can disproportionately affect people who are employed on nontraditional schedules, such as shift work, the statement summary described.

The circadian system includes multiple 24-hour rhythms involving parts of the body such as the brain, heart, lungs, and liver. When these rhythms are disrupted, more than sleep can be impacted. For example, as described in the statement, a desynchronized circadian system can adversely influence digestion, lipid processing, body temperature, and hormone release, and it may increase the risk of obesity, type 2 diabetes, hypertension, and cardiovascular disease. A demonstration of these disruptions and timing can be seen in the circadian pattern of health effects such as myocardial infarctions that occur largely in the morning, or insulin sensitivity and glucose tolerance which are usually lower in the evening, per the summary.

Several best practices for healthy circadian rhythms, as well as interventions to address circadian disruptions were described, including morning light therapy and wearable tracking devices that record sleep quality. The statement authors cited in the summary noted that factors such as irregular light exposure and activity patterns are “likely often overlooked by health care clinicians,” despite the importance to patient well-being.