Systolic blood pressure key for older patients, EU researchers say
Contrary to the conventional method of using both systolic blood pressure and diastolic blood pressure to measure and diagnose hypertension, a team of European scientists now proposes that only systolic pressure readings should be used in patients aged over 50. Their proposal will be published in an upcoming edition of The Lancet. The experts, Bryan Williams of the University of Leicester and Leicester Royal Infirmary, UK, Lars H. Lindholm of the Umeå University Hospital, Sweden, and Peter Sever of the International Centre for Circulatory Health, Imperial College London, UK, say that diastolic hypertension has started to take a back seat when compared to systolic hypertension because the latter has gained prevalence in patients aged over 50. Systolic pressure is the blood pressure when the heart contracts. More explicitly, it is the maximum arterial pressure during contraction of the heart's left ventricle. The first number recorded in a patient's blood pressure is the systolic pressure. A normal reading is 120 mm Hg (millimetres of mercury), and the recommended goal for this pressure is less than 140 mm Hg. Diastolic blood pressure is the minimum pressure in the cycle's rest phase, i.e. the pressure in the arteries between beats when the heart relaxes to fill with blood. A normal diastolic blood pressure reading is 80 mm Hg. While ageing brings on increases in systolic blood pressure, diastolic blood pressure only increases until 50 years of age and then drops. It is critical because cardiovascular disease typically rears its ugly head around this age. In a nutshell, systolic hypertension rises, while diastolic hypertension falls, or almost disappears. 'Since more than 75% of people with hypertension are aged over 50 years, the burden of disease is mainly due to systolic pressure,' the scientists explain. 'The use of diastolic pressure for diagnosis and risk analysis in our ageing populations has thus become illogical.' The scientists argue that four factors come into play when determining that only systolic blood pressure be measured for patients over 50: (1) measurements of systolic blood pressure are easier and more accurate than diastolic blood pressure, as well as a better predictor of risk; (2) patients would gain more understanding; (3) systolic blood pressure measurement would simplify treatment decisions for doctors; and (4) targeting a public health campaign on a single number for people over 50 would prove positive in improving treatment outcomes for people with systolic hypertension and curtail related diseases or death rates. It should be noted that the scientists recognise that both systolic and diastolic blood pressures should be used for people under 50. 'However, this much smaller group of patients should not dilute the key message regarding the overwhelming importance of systolic blood pressure for most patients with hypertension,' the scientists comment. Assessments of these two groups show that up to 40% of patients under 40 years old with hypertension have isolated diastolic hypertension, while some 30% of people aged between 40 and 50 have it. A focus on only systolic blood pressure in younger people will typically result in an adequate control of diastolic blood pressure, they say. But if diastolic blood pressure is the sole focus, people who are at risk will be left with uncontrolled systolic blood pressure, they add. The British and Swedish scientists remark that systolic blood pressure should 'become the sole defining feature of hypertension and key treatment target for people over age 50'. At the end of the day, both doctors and patients will have the capacity to better deal with hypertension and will have better treatment options. 'Such an initiative would have major public health implications for the prevention of blood pressure-related cardiovascular disease,' the team contends.