Mild hypertension in people at low risk

Summary box

• Clinical context—Up to 40% of adults worldwide have hypertension, complications of which may account for up to 9.4 million deaths annually from cardiovascular disease

• Diagnostic change—Recommendations for drug treatment have decreased from diastolic pressure of >115 mm Hg to ≥140/90 mm Hg. A new category, prehypertension (120/80-139/89 mm Hg), has also been introduced

• Rationale for change—Patients with even mildly raised blood pressure may have increased cardiovascular risk

• Leap of faith—Lowering threshold blood pressures will lead to increased diagnosis and treatment, which will decrease mortality

• Impact on prevalence—22% of adults worldwide have mild hypertension (systolic pressure 140-159 mm Hg) and 13.5% have a systolic pressure ≥160 mm Hg

• Evidence of overdiagnosis—Use of a uniform threshold (140 mm Hg) to mark hypertension risk ignores evidence that risk varies by individual and includes many people who will not benefit from drug treatment

• Harms from overdiagnosis—Studies suggest over half of people with mild hypertension are treated with drugs even though this approach has not been proved to decrease mortality or morbidity. Overemphasis on drug treatment risks adverse effects, such as increased risk of falls, and misses opportunities to modify individual lifestyle choices and tackle lifestyle factors at a public health level

• Limitations of evidence — Lack of randomised trials that use hard outcomes and compare drugs with lifestyle interventions and placebo in patients with mild hypertension

• Conclusion—Lowering definitions of hypertension has led to identification and drug treatment of larger populations of patients despite lack of evidence that drugs reduce morbidity or mortality