Researchers from Harvard University have identified that high blood pressure measured while lying down is linked to a greater risk of heart attack, stroke, and other serious outcomes. These findings were set to be presented at a scientific session on Hypertension organized by the American Heart Association in 2023.
The autonomic nervous system plays a key role in adjusting blood pressure when the body changes position. Gravity can cause blood to pool in certain areas when sitting or standing, which sometimes hinders the body’s ability to regulate pressure effectively. This means a person might have normal readings in one position but elevated pressures in another, with potential health consequences.
In this study, researchers reviewed health data from 11,369 adults participating in the ARIC study. The first group was followed from 1987 to 1989, and participants were tracked for an average of 25 to 28 years, with the final follow-up occurring in 2011 to 2013. The long-term nature of the research provides a broad view of how position-dependent blood pressure relates to cardiovascular risk over decades.
Compared with participants who did not have high blood pressure in either seated or lying positions, those whose seated blood pressure was 130/80 mmHg or higher and whose lying-down pressure was elevated faced markedly increased risks. Specifically, the likelihood of developing coronary heart disease was about 1.6 times higher, heart failure about 1.83 times higher, and stroke about 1.86 times higher. These elevated risks persisted even after accounting for other common cardiovascular risk factors.
Interestingly, the data showed that the risk rose even for individuals who had normal seated pressures but elevated pressures when lying down. This pattern suggests that evaluating blood pressure in multiple positions could uncover hidden risk factors that standard single-position measurements may miss.
Across the study groups, differences in blood pressure medication use did not negate these elevated risks. This implies that position-dependent blood pressure might add independent information to cardiovascular risk assessment beyond what is captured by usual treatment regimens.
Experts say these results indicate that people with existing cardiovascular risk factors may benefit from measuring blood pressure in a supine position, in addition to the traditional seated readings. Such an approach could improve risk stratification and help clinicians tailor interventions for those at higher risk of heart disease, stroke, and related conditions.
The study focused on middle-aged adults, which means the findings may not directly apply to older populations without further research. The researchers emphasize that gathering more data across diverse age groups is necessary to determine how lying-down blood pressure relates to risk across the life span.
In the broader context, these findings align with growing attention to how blood pressure variability and postural changes influence cardiovascular health. They complement existing guidance that emphasizes regular monitoring, healthy lifestyle choices, and appropriate management of known risk factors such as hypertension, diabetes, and high cholesterol. Clinicians may consider incorporating posture-based measurements into routine assessments to gain a more comprehensive view of a patient’s cardiovascular risk profile, as supported by observational data from long-term studies like ARIC and corroborating evidence presented by larger cardiovascular research programs (Harvard study communications, 2023).