- Intra-arterial systolic BP measurements taken at the wrist can run much higher than brachial values, by 15 mmHg in 14% of cases.
- These authors say that radial measures are not a good representation of brachial values.
Why this matters
- Wearables that measure BP at the wrist are a growing market, raising concerns about these differences.
- Some have eyed purported differences skeptically, calling it a “fictional Popeye phenomenon,” which these authors say their findings demonstrate actually exists.
- Average increase in systolic BP with wrist vs brachial measurement was 5.5 mmHg.
- 57% had wrist values that were not within 5 mmHg of brachial measures.
- Of these, 14% had wrist values >15 mmHg higher (mean radial, 163.9±22.0 vs mean brachial, 142.4±20.5 mmHg; P<.001>
- 11% had wrist values >5 mmHg lower than brachial (mean radial, 133.3±26.6 vs mean brachial, 143.9±26.5; P<.001>
- Intra-arterial BP measures taken in 180 people having coronary angiography (mean age, 61 years; 69% men).
- Funding: Grant support for authors.
- Mostly older, overweight men with self-reported cardiovascular disease.