| Objective: Previous studies suggest that aldosterone has effects of promoting inflammation and collagen formation, inducing degeneration and necrosis of fibrin; however, the effect of aldosterone itself on the target organ in hypertension remains controversy. Arterial stiffness has been adopted as one of target organ damages by the latest version of guidelines for management of hypertension proposed by European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). Among the index evaluating large artery stiffness, pulse wave velocity (PWV) is the one most commonly used and widely recognized. It has recently been proposed that there is limited value if aldosterone is measured alone, or its increase in level alone would not give rise to any unfavorable consequences, which require the synergistic reaction between aldosterone and high level of sodium. It has been showed by a study published in N Eng J Med that the risk of an increase by one blood-pressure category or the development of hypertension in normotensive subjects was only in those who were in the highest quartile of serum aldosterone and only among participants with a level above the median of urine sodium index, an index calculated as the number of millimoles of sodium per gram of creatinine in a spot urine sample for assessing dietary salt intake. Under the normal condition, there is a negative reciprocal relationship between the level of plasma aldosterone and urine sodium index, and a condition that the level of plasma aldosterone is inappropriate for that of sodium, if occurs, could be a reflection of disorder in internal homeostasis, and might play a role in developing and worsening hypertension; however, there have been few related studies especially when its effect on stiffness of large arteries is concerned. In the present study, the possible effect of plasma aldosterone levels and urinary sodium levels on brachial—anklearterv PWV (baPWV) was observed in order to provide a novel way for understanding the mechanisms for increased arterial stiffness in hypertensive patients.Methods: Essential hypertensive subjects referred for outpatient department of cardiology, the Second Hospital of Hebei Medical University from November 2009 to May 2010 were considered eligible if they met the diagnostic criteria for hypertension defined in Chinese Hypertension Prevention Guide proposed in 2004, antihypertensive medication had not been taken or had been taken but stopped for more than 2 weeks, free of diabetes or obvious cardiac, cerebral or renal comorbidities and no history of smoking or alcohol. A total of 80 patients were enrolled (male 41, 51.3%; 47.15±14.49 years). Measurements of blood pressure, baPWV, plasma aldosterone and urine sodium and creatinine (for calculation of urine sodium index) were all performed under standardized conditions or as described by the manufactures. Data were analyzed using SPSS, version 13.0. Measurement data were expressed as x±s. For testing the data of plasma aldosterone, urine sodium index and baPWV, which were not normally distributed, both rank regression analysis and rank sum test were used, separately.Results:1 Comparison between the right side and left side of baPWV: because the data for baPWV were not normally distributed and could not be corrected by transformation into natural log terms, a two related samples rank sum test was used. The result showed that there was no significant difference between the both side of baPWV (P = 0.221).2 Effect of plasma aldosterone level and urine sodium index level on baPWV——regression analysis: because the three parameters are all not normally distributed and could not be corrected by transformation into natural log terms a rank regression analysis was used. The result showed that the rank correlation for both aldosterone (P = 0.447) and urine sodium index (P = 0.356) with baPWV was not significant.3 According to the median of plasma aldosterone level and urine sodium index level, patients were divided into four groups and did Comparison among the four groups(p=0.04), There are differences between the groups。Then did Pairwise comparisons among the four groups, The first group compared with other groups, there was significant difference (p<0.05).4 In the first group, we did Correlation Analysis between baPWV and plasma aldosterone level, r=0.613, p=0.001; there were Significant correlation between them.We also did Correlation Analysis between baPWV and urine sodium index, r=0.209, p=0.175; there were not Significant correlation between them.Conclusions:1 In essential hypertensive patient, baPWV is not significantly affected by the level of either plasma aldosterone or that of urine sodium index alone.2 Only in plasma aldosterone levels and urinary sodium index were higher than the median level of the two conditions, arterial stiffness appeared increased significantly.3 Higher levels of urinary sodium index, is a large incidence of atherosclerosis of aldosterone to promote the development of the condition... |
