Evaluation of renin and angiotensin II levels in pseudoexfoliation syndrome

ABSTRACT Purpose: Pseudoexfoliation syndrome has been linked to impaired function of the heart and blood vessels. We conducted a study to investigate the role of the renin-angiotensin system in the etiopathogenesis of pseudoexfoliation syndrome. Methods: The subjects were 14 patients with pseudoexfoliation syndrome and 14 healthy controls who underwent cataract extraction. Preoperative 5-ml samples of peripheral venous blood and perioperative aqueous humor were collected from the patients in both groups. Plasma and aqueous humor renin levels were analyzed by an immunoradiometric method, and angiotensin II levels were analyzed by radioimmunassay. SPSS version 16.0 was used for statistical analyses. A p-value <0.05 was considered to indicate a statistically significant difference. Results: The mean ages of the patients in pseudoexfoliation and control groups were 71.7 ± 7.1 and 67.4 ± 9.3 years, respectively (p=0.140). The median aqueous humor renin level was 7.73 pg/ml (4.15-21) in the control group and 11.95 pg/ml (3.75-18.54) in pseudoexfoliation group (p=0.022). There were no differences between the two groups in the plasma renin, plasma angiotensin II, or aqueous humor angiotensin II levels. The correlations between plasma and aqueous humor renin levels and between plasma and aqueous humor angiotensin II levels were examined separately for each group; no significant correlations were observed in pseudoexfoliation group (r=-0.440, p=0.115; r=-0.414, p=0.142) or the control group (r=-0.232, p=0.425; r=0.482, p=0.081). Conclusion: Aqueous humor renin levels are higher in pseudoexfoliation syndrome. The results indicate a probable role of renin-angiotensin system in pseudoexfoliation syndrome. Further studies with larger numbers of cases are needed to clarify the precise association of renin-angiotensin system with the etiopathogenesis of pseudoexfoliation syndrome.

摘要 目的：假性剥脱综合征（pseudoexfoliation syndrome）与心脏及血管功能受损存在关联。本研究旨在探讨肾素-血管紧张素系统（renin-angiotensin system）在假性剥脱综合征发病机制中的作用。方法：研究对象为14例假性剥脱综合征患者与14例接受白内障摘除术的健康对照者。采集两组患者术前外周静脉血5ml及围手术期房水样本。采用免疫放射分析法检测血浆及房水肾素水平，放射免疫分析法检测血管紧张素Ⅱ水平。采用SPSS 16.0版本进行统计学分析，以p值<0.05为差异具有统计学意义。结果：假性剥脱综合征组与对照组患者的平均年龄分别为71.7±7.1岁与67.4±9.3岁（p=0.140）。对照组房水肾素水平中位数为7.73 pg/ml（四分位距4.15~21），假性剥脱综合征组为11.95 pg/ml（3.75~18.54），组间差异具有统计学意义（p=0.022）。两组患者的血浆肾素、血浆血管紧张素Ⅱ及房水血管紧张素Ⅱ水平均无显著组间差异。分别对两组患者的血浆与房水肾素水平、血浆与房水血管紧张素Ⅱ水平的相关性进行分析：假性剥脱综合征组中未观察到显著相关性（r=-0.440，p=0.115；r=-0.414，p=0.142），对照组亦未观察到显著相关性（r=-0.232，p=0.425；r=0.482，p=0.081）。结论：假性剥脱综合征患者的房水肾素水平更高。研究结果提示肾素-血管紧张素系统可能参与假性剥脱综合征的发病过程。后续需开展更大样本量的研究，以明确肾素-血管紧张素系统与假性剥脱综合征发病机制间的确切关联。