Aortic SBP (aSBP) associates with arterial damage more consistently than brachial SBP (bSBP). However, it is unknown how often aSBP is normal in the presence of elevated bSBP, and vice versa; if SBP phenotyping on the basis of bSBP and aSBP cut-off values improves cardiovascular risk stratification. We tested the frequency of four office SBP phenotypes: type I (both normal bSBP and aSBP); type II (high bSBP but normal aSBP); type III (normal bSBP but high aSBP), and type IV (both high bSBP and aSBP), the probability of each phenotype to be associated with increased arterial damage, using type Ia (i.e. normal bSBP and low-normal aSBP) as reference.
In 1861 participants (age: 54 years, 49.1% men), we measured simultaneously bSBP, aSBP, and carotid cross-sectional wall area with ultrasound.
Depending on the applied cut-off values, type II and type III phenotypes represented together 5-11% of the population (0.9-3.4 and 1.8-10.3%, respectively) and type IV around 20%. Subgroups with phenotypes, Ib (i.e. normal bSBP and high-normal aSBP), II, III, and IV had gradually significantly higher probability (by 1.37-1.91, 2.3-3.3, 3.3-8.9 times, and 4.18-6.25, respectively) to present elevated carotid artery cross-sectional wall area compared with the reference group, even after adjustment for DBP and other confounders.
Type II (i.e. isolated high bSBP) and type III (i.e. isolated high aSBP) office SBP phenotypes were common and had intermediate level (between types I and IV) of arterial damage.