What are the calculations for Systolic Blood Pressure (SBP)?

From the Guidelines

The target systolic blood pressure (SBP) should be less than 130 mmHg in patients with diabetes, and in older people (aged >65 years), the SBP goal is to a range of 130 - 139 mmHg. Systolic blood pressure calculations are crucial in managing hypertension, particularly in patients with diabetes. To calculate SBP accurately, use a properly sized blood pressure cuff placed at heart level, typically on the upper arm 1. The cuff should be inflated until the pulse disappears, then slowly deflated while listening with a stethoscope over the brachial artery. The first audible sound (Korotkoff phase 1) indicates the systolic pressure.

• Key points to consider when calculating SBP include:
  • Using a properly sized blood pressure cuff
  • Placing the cuff at heart level
  • Inflating the cuff until the pulse disappears
  • Slowly deflating the cuff while listening with a stethoscope
• Normal adult SBP ranges from 90-120 mmHg, with readings above 130 mmHg indicating hypertension 1.
• When tracking SBP over time, measure at consistent times of day, preferably in the morning and evening, and record values to identify patterns.
• SBP calculations are important because systolic hypertension is a significant risk factor for cardiovascular disease, even when diastolic pressure remains normal 1.
• Elevated SBP increases the workload on the heart and can damage blood vessels over time, leading to complications like heart disease and stroke.
• Optimal BP control reduces the risk of micro- and macrovascular complications 1.
• Guidance on lifestyle changes must be provided for patients with diabetes and hypertension, and evidence strongly supports the inclusion of an angiotensin-converting enzyme inhibitor (ACEI), or an angiotensin receptor blocker (ARB) in patients who are intolerant to ACEI 1.

From the Research

Systolic Blood Pressure Calculations

• Systolic blood pressure (SBP) is a crucial factor in determining the risk of cardiovascular disease (CVD) and mortality 2, 3, 4.
• The optimal target for SBP reduction is still a topic of debate, but studies suggest that lowering SBP to levels below currently recommended targets can significantly reduce the risk of CVD and all-cause mortality 4, 5, 6.
• A reduction of 10 mm Hg in SBP can decrease the risk of CVD events by approximately 20% to 30% 2.
• The SPRINT trial found that targeting an SBP of <120 mm Hg compared to <140 mm Hg resulted in a significantly lower risk for CVD outcomes and all-cause mortality in a population of hypertensive persons at high CV risk 6.

SBP Targets

• The American Heart Association recommends an SBP target of <130 mm Hg for adults <65 years and <130 mm Hg for adults ≥65 years 2.
• The SPRINT trial suggests that targeting an SBP of <120 mm Hg may be beneficial for high-risk populations, including the elderly and those with chronic kidney disease (CKD) 6.
• However, the optimal SBP target may vary depending on individual patient characteristics, such as the presence of comorbidities and the risk of CVD events 3, 5.

Treatment Strategies

• Lifestyle modification, including weight loss, dietary sodium reduction, and physical activity, is recommended as first-line therapy for hypertension 2, 3.
• Antihypertensive medication, such as thiazide diuretics, angiotensin-converting enzyme inhibitors, and calcium channel blockers, may be necessary for patients who do not respond to lifestyle modification or have high CVD risk 2, 3, 5.
• Combination therapy, including the use of a calcium channel blocker and an angiotensin-converting enzyme inhibitor, may be effective in preventing composite cardiovascular events in patients with resistant hypertension 5.