<International Circulation>: Why does hyperkalemia often occur in hypertensive patients?
　　Prof.Ruilope: Hypertension is a very common condition and probably 40% of the global population are hypertensives. The prevalence of hypertension is increasing and it is doing so for two reasons. One is the ageing population and the other is increasing body weight. I say this as an introduction because the higher the number of people with hypertension， the more difficult it will be to get good control of hypertension. If hypertension is not well-controlled then cardiovascular (cardiac， brain and great arteries) damage can appear and this is followed very frequently by renal damage. Hyperkalemia correlates in 99.9% of cases with renal damage and a low renal function. In general， an estimated glomerular filtration rate <30ml/min/1.73m2 body surface area is the level at which the risk is higher. Renal protection and cardiovascular protection requires suppression of the renin-angiotensin system and that in turn causes suppression of aldosterone directly through aldosterone blockers or indirectly through ACEs or ARBs. If aldosterone goes down then the capacity to excrete potassium decreases so hyperkalemia can be seen. This is also facilitated by other circumstances that exist in clinical diseases such as acidosis or overall and more frequently， the capacity for patients to have an adequate diet with a low amount of potassium is not perfect at all.

　　《国际循环网》：为什么高血压患者经常发生高钾血症？
　　Ruilope教授：高血压是非常常见的疾病，全球约40%的人患有高血压。高血压的患病率逐渐增加是由于下述两个原因：一个是人口的老龄化，另一个是体重的不断增加。我介绍这个背景是因为患高血压的人越多，控制高血压就越难。如果高血压控制不好，那么患者就会出现心血管损害（心、脑和大动脉），之后通常会发生肾损害。99.9%的肾损害且肾功能下降的患者会出现高钾血症。总体上来讲，估算肾小球滤过率<30 ml/min·1.73 m2体表面积时风险增加。肾脏保护和心血管保护需要抑制肾素-血管紧张素-醛固酮系统，通过应用醛固酮拮抗剂可直接抑制醛固酮的作用或通过ACEI或ARB间接抑制醛固酮的作用。如果醛固酮水平下降的话，肾脏分泌钾的能力下降，会导致高钾血症的发生。酸中毒等临床疾病存在也会促进高钾血症的发生，患者进食低钾、足量的饮食并不能完全防止高钾血症的发生。

　　<International Circulation>: There are other reasons for hyperkalemia to be present?
　　Prof.Ruilope: There is a monogenic form of hypertension that in the presence of normal renal function patients present with hyperkalemia， but that is really very rare. There is another alteration that occurs in the presence of normal renal function but with hyperkalemia and this is the so-called hyporenin hypoaldosteronism that is seen particularly in diabetics. This means that their renin-angiotensin system which causes the secretion of aldosterone is decreased so aldosterone production is small so there is a situation of hypoaldosteronism which facilitates this. The third situation would be a certain type of renal acidosis which is an effect in the renal tubules， promoting acidosis and acidosis promotes hyperkalemia because there is an interchange between potassium ions and hydrogen ions into the cell to avoid this acidosis and the potassium in the serum rises.

　　《国际循环网》：高钾血症还有其他原因吗？
　　Ruilope教授：有一种单基因遗传的高血压，患者表现为高钾血症，肾功能正常，但是这一疾病非常罕见。肾功能正常的高钾血症患者还会出现另一个改变，就是常见于糖尿病患者的低肾素低醛固酮血症。这意味着分泌醛固酮的肾素-血管紧张素系统的功能下降，醛固酮生成减少，因此存在低醛固酮血症促进低钾血症的发生。第三种情况是某种类型的肾性酸中毒，这是由于肾小管的作用，促进了酸中毒的发生，进而引起高钾血症，因为钾离子将氢离子交换到细胞内以避免血清酸中毒，从而导致血清钾升高。

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