The relationship between brachial-ankle pulse wave velocity, carotid intima-media thickness and 24 hours ambulatory blood pressure circadian rhythm in prehypertensive subjects

Objective To investigate the relationship between brachial-ankle pulse wave velocity(baPWV), carotid intima-media thickness(IMT) and circadian rhythm of 24 hours ambulatory blood pressure monitoring (24hABPM) in prehypertensive subjects. Methods Three hundred and six cases in the rural area of Zhangqiu City, Shandong Province from July 2008 to July 2009 were recruited, including 96 subjects with normotension (120/80 mm Hg) and 210 ones with prehypertension. All the subjects underwent 24hABPM, baPWV and IMT detection, and the prehypertensive participants were subdivided into 2 groups based on 24hABPM results: 92 cases of dipper group and the other 118 ones of non-dipper group. Results The average 24 hours systolic blood pressure (24hSBP) was higher in non-dipper group than in dipper group[(123.55±8.46)vs(119.59±9.51)mm Hg,P0.05]. And a more marked increase of the nocturnal blood pressure parameters could be found in non-dipper group than that in dipper group. BaPWV and IMT in non-dipper group increased obviously than those in dipper group[(1376.65±118.74) vs (1311.92±114.21) cm/s, P0.01; (0.93±0.11) vs (0.81±0.12) mm, P0.05]. Triglyceride, systolic blood pressure fall(SBPF), diastolic blood pressure fall(DBPF) and nocturnal systolic blood pressure (nSBP) were risk factors for baPWV, while total cholesterol, SBPF, DBPF, 24hSBP, daytime systolic blood pressure were risk factors for IMT by multiple regression analysis. Conclusion The prehypertensive subjects had emerged atherosclerosis and decreased aortic elasticity. BaPWV and IMT were closely related to the abnormal circadian rhythm of 24hABPM.