A study from Harvard University, published in _JAMA Cardiology_, found that patients who had elevated blood pressure while lying down (supine position) were at a higher risk for heart disease, stroke, and death—even if their seated blood pressure readings were normal.
To determine which method of blood pressure measurement can more accurately predict future cardiovascular disease and mortality risks, researchers tracked 11,369 participants (mean age 53.9 years; 55.7 per cent women) who were free of heart disease at the outset and had both supine and seated blood pressure measurements. Among participants without seated hypertension, 16.4 per cent showed supine hypertension, while 73.5 per cent of those with seated hypertension also had supine hypertension.
Over a 25-year follow-up period, supine hypertension was associated with a 60 per cent higher risk of coronary heart disease; 83 per cent higher risk of heart failure; 86 per cent higher risk of stroke; more than twice the risk of fatal coronary heart disease; and 43 per cent higher risk of all-cause mortality, irrespective of seated hypertension. Having hypertension only while lying down carried a similar level of risk as having hypertension in both the supine and seated positions but posed a significantly greater risk compared with seated hypertension alone for all outcomes, except fatal coronary heart disease.
“Our conclusion was that not only is supine blood pressure an important risk factor for cardiovascular disease, but also it’s possible we could be missing a high-risk state by simply focusing on the seated position,” the study author said.