Influence of sex on the accuracy of oscillometric-derived blood pressures.

The effect of sex on the correlation between oscillometric and central aortic blood pressures (BP) is largely unknown. BP was simultaneously measured in the brachial artery using an oscillometric device and in the aorta using a fluid-filled catheter in 98 patients undergoing coronary angiography. Mean age (± standard deviation) was 58 ± 12 years, with 55% of the patients being male. Mean BP (MBP) measured by the oscillometric device and in the aorta were similar when the group was examined as a whole, but the oscillometric device overestimated MBP in men and underestimated MBP in women. Oscillometric pressures accurately estimated diastolic BP in women but overestimated diastolic BP in men and underestimated systolic BP in both sexes. The oscillometric device underestimated aortic pulse pressure in both sexes but less in men than in women. The accuracy of oscillometric MBP and diastolic BP varied as a function of aortic MBP, but sex-related differences in the accuracy of oscillometric pressures remained significant after adjusting for MBP, body mass index, height, age, race, heart rate, diabetes, smoking status, and BP-lowering therapies using a multivariate logistic regression model. Sex is an important determinant of the accuracy of oscillometric BP.