Objective: This study was designed to determine how important a novel risk factor of elevated blood pressure variability (BPV) is in the determination of end-organ damage by comparison with the classic risk factor of a high blood pressure (BP) level.
Methods and results: The effects of haemodynamics on cardiovascular morphology were evaluated by univariate and multivariate regression analysis in two different rat models with an enlarged distribution of haemodynamics. In male sham-operated and sinoaortic-denervated Wistar–Kyoto rats and spontaneously hypertensive rats (n = 34), BPV was more important than BP in cardiac and renal damage and aortic hypertrophy. BPV and BP had independent effects, explaining 59.4% of the variation in damage to these organs. In male (n = 44) and female (n = 46) F1 hybrids of Sprague–Dawley rats and spontaneously hypertensive rats, the greater importance of BPV than BP was further demonstrated in left ventricular hypertrophy, glomerular damage and aortic hypertrophy. The phenomenon was more evident in females than males for cardiovascular hypertrophy. BPV and BP or BPV alone had independent effects, explaining 46.9% (male) or 37.5% (female) of the variation in damage to these organs.
Conclusion: BPV is a more critical determinant than BP level for cardiac damage, renal lesions and aortic hypertrophy in rats, strongly suggesting the significance of BPV control for the protection of these organs.
Department of Pharmacology, Second Military Medical University, Shanghai, China
Received 3 May, 2005
Revised 13 November, 2005
Accepted 14 February, 2006
Correspondence and requests for reprints to Chao-Yu Miao and Ding-Feng Su, MD, PhD, Department of Pharmacology, Second Military Medical University, 325 Guo He Road, Shanghai 200433, China Tel: +86 21 25074374; fax: +86 21 65493951; e-mail: firstname.lastname@example.org and email@example.com
Sponsorship: This project was supported by grants from the National Natural Science Foundation of China (30371649 and 30070871) and the Foundation for the National Excellent Doctoral Thesis Author (200369).