Effects of angiotensin-converting enzyme gene polymorphism on heart rate and blood pressure variabilities

本研究的目的是探讨，在复杂的区域疼痛综合征和带状疱疹后神经痛患者，这种多态性（DD和II bomozygotes，和ID杂合子）是否与心率和血压的变异性，神经性疼痛的遗传危险因素。研究组DD、ID和II基因型分布分别为33%、33%和33%。ACE DD基因型患者的ACE活性显著高于ID和II基因型患者。ACE基因型间心率、血压变异性、血浆肾素活性、血管紧张素I和血管紧张素II无显著性差异。ACE DD基因型在本人群中的频率（33%）高于以前在同种族其他正常人群中的频率（20%）。3此外，ACE DD基因型在CRPS I型患者中的频率高于CRPS II型患者。DD基因型可能与神经病理性疼痛和心血管疾病的发生有关，这可能是由于ACE浓度升高所致。这些受试者的ACE活性升高可能导致效应部位血管紧张素II水平升高，这可能是ACE缺失多态性与神经性疼痛易感性遗传风险增加之间相关性的机制。因此，ACE I/D基因多态性的分型可能是神经病理性疼痛的一个有用的预测因子。

The aim of this study was to explore, in patients with complex regional pain syndrome and patients with postherpetic neuralgia, whether this polymorphism (DD and II bomozygotes, and ID heterozygotes) associates heart rate and blood pressure variabilities, and the genetic risk factor for neuropathic pain. The distribution of the DD, ID and II genotypes in the study group is 33%, 33% and 33%, respectively. ACE activity was significantly higher in subjects with the ACE DD genotype than subjects with the ID and II genotypes. No significant difference in heart rate and blood pressure variabilities, plasma renin activity, angiotensin I and II was detected among the ACE genotypes. The frequency of the ACE DD genotype in the present population (33%) was higher than those previously described in other normal populations of the same race (2O%).^3 In addition, the frequency of the ACE DD genotype in CRPS type I was higher than those in CRPS type II.It is possible that the DD genotype favors the development of neuropathic pain as well as cardiovascular disease, perhaps through the presence of higher ACE concentrations. Elevated ACE activity in these subjects may result in increased angiotensin II levels in the effector site, and this might be a mechanism underlying the association between the ACE deletion polymorphism and the increased genetic risk for susceptibility to neuropathic pain. Typing for ACE I/D gene poly-morphism, thus, might be a useful predictor of neuropathic pain.