The relation between central aortic pressure and abnormal circadian rhythm of blood pressure in patients with essential hypertension

Objective To investigate the relationship between central arterial pressure(CAP)and circadian blood pressure rhythm abnormities by comparing the differences of CAP indices in essential hypertensives with different circadian rhythm and to explore the factors affecting CAP. Methods One hundred and ninety cases of essential hypertensive patients treated at the First Affiliated Hospital of Xinjiang Medical University from September 2009to February 2011were enrolled. All the subjects were of Han nationality including 96males and 94females,with the average age of(59.7±12.8)years. Circadian blood pressure rhythm was detected and nocturnal BP descending rate was calculated. Nocturnal BP fall was classified as follows:reverse-dipper(n=59),if the rate was0%;nondipper(n=73),if it was≥0% but10%;and dipper(n=58),if it was20%. The differences and interrelations between CAP and reflected wave augmentation index(AI),ankle-brachial pulse wave velocity(baPWV)were analyzed. Results The indices of nSBP,nDBP and nMAP in reverse-dipper subjects were statistically higher than those in non-dipper and dippers cases(P0.05). dDBP and dMAP in reverse-dippers and non-dippers cohort were significantly lower than dipper individuals(P0.05). The risk of non-dipper hypertension increased to 1.13times for every increase of 10mm Hg in central artery pulse pressure(OR1.13,95% CI1.04-1.27,P0.05). And the risk of reverse-dipper hypertension increased to 1.26times(OR1.26,95%CI1.00-1.39,P0.05)for every increase of 10unit in AI corrected for a heart rate of 75beats per minute(AIx75). baPWV was correlated strongly with reverse-dipper hypertension(P0.05). Conclusion Central artery pulse pressure is related to nocturnal BP descending rate and associated to some extent with reverse-dipper hypertension.