Lying Down With High Blood Pressure Linked To Higher Risk Of Heart Complications

The analysis of 11,369 adults with an average age of 54 years old who were followed by an average of 25-28 years from four diverse communities in America (the longitudinal Atherosclerosis Risk in Communities (ARIC) study) found that those with high blood pressure, while seated upright and lying flat on their backs (supine), had a higher risk of stroke, heart failure, premature death, and heart disease compared to adults without high blood pressure while upright or supine. 

Additionally, those with high blood pressure while lying supine but not while seated upright had similar levels of elevated risks as those with high blood pressure in both positions, and the increased risks did not differ by the type of blood pressure medication used among the participants.

Blood pressure in different parts of the body is regulated by the autonomic nervous system, but gravity may cause blood to pool when seated upright and the body is sometimes unable to properly regulate blood pressure while a person is lying down, seated, or in standing positions. 

“If blood pressure is only measured while people are seated upright, cardiovascular disease risk may be missed if not measured also while they are lying supine on their backs,” said lead study author Duc M. Giao, a researcher and a 4th-year M.D. student at Harvard Medical School in Boston.

The researchers' findings revealed that 16% of the participants who did not have high blood pressure while seated had high blood pressure while lying supine compared to 74% of those with seated high blood pressure who also had supine high blood pressure. Those who had high blood pressure while seated and supine had a 1.6 times higher risk of developing coronary heart disease, 1.83 times higher risk of developing heart failure, 1.85 times higher risk of stroke, 1.43 times higher risk of overall premature death, and 2.18 times higher risk of dying from coronary heart disease compared to those with high blood pressure in both positions. 

“Our findings suggest people with known risk factors for heart disease and stroke may benefit from having their blood pressure checked while lying flat on their backs,” Giao said. “Efforts to manage blood pressure during daily life may help lower blood pressure while sleeping. Future research should compare supine blood pressure measurements in the clinic with overnight measurements.”