Chronic Kidney Disease（慢性肾脏病）

Chronic kidney disease

Chronic kidney disease is a broad term that includes subtle decreases in kidney function that develop over a minimum of three months.In contrast, acute kidney injury refers to any deterioration in kidney function that happens in less than three months.Now the kidney’s job is to regulate what’s in the blood, so they might remove waste,or make sure electrolyte levels are steady, or regulate the overall amount of water, and even make hormones - the kidneys do a lot of stuff!Blood gets into the kidney through the renal artery, and once inside it goes gets into tiny clumps of arterioles called glomeruli where it’s initially filtered, and the filtrate which is the stuff that gets filtered out, moves into the renal tubule.The rate at which this filtration takes place is known as glomerular filtration rate or GFR.In a normal healthy person, this is somewhere around 100-120 milliliter of fluid filtered per minute per 1.73 m2 of body surface area.The value is slightly less in women than men and it decreases slowly in all of us as we grow older.

慢性肾脏病是一个广泛的术语，它包括在至少三个月的时间内发展的肾功能的细微下降。相比之下，急性肾损伤是指在不到三个月的时间内发生的肾功能恶化。肾脏的工作是调节血液中的物质，这样他们就可以清除废物，或者确保电解质水平稳定，或者调节水的总量，甚至生成激素——肾脏可以做很多事情!血液通过肾动脉进入肾脏，一旦进入肾脏，就会进入微小的小动脉团，称为肾小球是最初被过滤的地方，滤液就是被过滤掉的东西，进入肾小管。这种过滤发生的速率称为肾小球滤过率或GFR。在正常健康的人体内，这大约是100-120毫升的液体以每分钟过滤1.73平方米的体表面积。女性的量略低于男性，随着年龄的增长，所有人都会慢慢下降。

One of the most common causes of chronic kidney disease is hypertension.In hypertension, the walls of arteries supplying the kidney begin to thicken in order to with stand the pressure, and that results in a narrow lumen.A narrow lumen means less blood and oxygen gets delivered to the kidney, resulting in is chemic injury to the nephrons glomerulus.Immune cells like macrophages and fat-laden macrophages called foam cells slip into the damage glomerulus and start secreting growth factors like Transforming Growth Factor ß1or TGF-ß1.These growth factors cause the mesangial cells to regress back to their more immature stemcell state known as mesangioblasts and secrete extracellular structural matrix.This excessive extracellular matrix leads to glomerulosclerosis, hardening and scarr,and diminishes the nephron’s ability to filter the blood - over time leading to chronic kidney disease.

高血压是慢性肾病最常见的原因之一。在高血压中，为肾脏供血的动脉壁开始变厚以承受压力，从而导致内腔狭窄。狭窄的内腔意味着较少的血液和氧气被输送到肾脏，从而导致肾小球的化学损伤。巨噬细胞和富含脂肪的巨噬细胞，被称为泡沫细胞，它们会滑入受损的肾小球，并开始分泌生长因子，如转化生长因子1或TGF- 1。这些生长因子使系膜细胞回归到其较不成熟的干细胞状态，即成系膜细胞和分泌细胞外结构基质。这种过度的细胞外基质导致肾小球硬化症、硬化和瘢痕，并减少肾单位对血液的过滤能力，从而导致慢性肾病。

The second most common cause of CKD is diabetes, excess glucose in the blood starts sticking to proteins in the blood — a process called non-enzymatic glycation because no enzymesare involved.This process of glycation particularly affects the efferent arteriole and causes it to get stiff and more narrow - a process called hyaline arteriosclerosis.This creates an obstruction that makes it difficult for blood to leave the glomerulus,and increases pressure within the glomerulus leading to hyperfiltration.In response to this high-pressure state, the supportive mesangial cells secrete more and more structural matrix expanding the size of the glomerulus.Over many years, this process of glomerulosclerosis, once again, diminishes the nephron’s ability to filter the blood and leads to chronic kidney disease.Although diabetes and hypertension are responsible for the vast majority of CKD cases, there are other systemic diseases like lupus and rheumatoid arthritis, can also cause glomerulosclerosis.Other causes of chronic kidney disease include infections like HIV, as well as long-term use of medications like NSAIDs, and toxins like the ones in tobacco.

CKD的第二个最常见的原因是糖尿病，血液中的过量葡萄糖开始附着在血液中的蛋白质——一种被称为非酶的糖化过程，因为没有酶参与。这种糖化过程尤其会影响出球小动脉，使其变得僵硬和狭窄——一种叫做玻璃样动脉硬化的过程。这会造成阻塞，使血液难以离开肾小球，并增加肾小球内压力导致超滤过。在这种高压状态下，支持系膜细胞分泌越来越多的结构基质，扩大肾小球的大小。随着时间进行，肾小球动脉硬化的这一过程再次削弱了肾单位过滤血液的能力,导致慢性肾病。尽管糖尿病和高血压是CKD病例的主要原因，但也有其他系统性疾病，如狼疮和类风湿性关节炎，也会引起肾小球硬化。慢性肾脏疾病的其他原因包括HIV感染，以及长期使用非甾体抗炎药，以及烟草中的毒素。

Now, normally urea in the body gets excreted in the urine, but when there’s a decreased glomerular filtration fate, less urea get filtered out, and therefore it accumulates in the blood, a condition called azotemia, which can cause general symptoms like It nausea and a loss of appetite.As the toxin levels really build up, they can affect the functioning of the central nervous system - causing encephalopathy.This results in asterixis, a tremor of the hand that kind of resembles a bird flapping its wings and is best seen when the person attempts to extend their wrists.Further accumulation of these toxins in the brain can even progress to coma and death.The build up of toxins can also cause pericarditis which is inflammation of the lining of the heart.In addition, there can be increased tendency for bleeding, since excess urea in the blood makes platelets less likely to stick to each other, and so there’s less clot formation.

正常情况下，尿素会在尿液中排泄，但当肾小球滤过性降低时，尿素过滤减少，因此它会在血液中积累，这是一种叫做氮血症的疾病，它会引起一般的症状，比如恶心和食欲不振。随着毒素水平的增加，它们会影响中枢神经系统的功能——引起尿素症性脑病。这会形成扑翼样震颤，一种类似鸟类拍打翅膀的手的震颤，当人们试图伸展他们的手腕时最明显。在大脑中进一步积累这些毒素甚至会导致昏迷和死亡。毒素的积累也会导致心包炎，这是心脏内膜的炎症。此外，出血的趋势也会增加，因为血液中过量的尿素使得血小板不太可能粘附在一起，所以血栓形成的可能性也更小。

Finally, in some cases, someone can develop uremic frost, where urea crystals can deposit in the skin and they look like powdery snowflakes.In addition to getting rid of waste, the kidneys play an important role in electrolyte balance.Potassium levels are particularly important, and normally the kidney helps with potassium excretion.In chronic kidney disease, just like with urea, less potassium is excreted and more builds up in the blood, and it leads to hyperkalemia, which is worrisome because it can cause cardiacarrhythmias.Another key role of the kidneys relates to balancing calcium levels.Normally, the kidney helps to activate vitamin D which helps to increase absorption of calcium from the diet.In chronic kidney disease, there’s less activated vitamin D, so less calcium is absorbed into the blood, resulting in hypocalcemia - low calcium levels.As calcium levels in the blood falls, parathyroid hormone is released, causing the bones tolose calcium.Over time, this resorption of calcium from the bones leaves them weak and brittle, a condition known as renal osteodystrophy.

The kidneys also release key hormones.For example, normally when the kidneys start sensing a lower than normal amount of fluid getting filtered, they respond by releasing the hormone renin to increase the blood pressure.In chronic kidney disease, the falling glomerular filtration rate leads to more and more renin secretion which leads to hypertension.Now, remember that hypertension is a cause of chronic kidney disease itself, so this creates quite the vicious cycle.

最后，在某些情况下，有些人可以形成尿素霜，尿素晶体可以沉积在皮肤上，看起来就像粉状的雪花。除废物外，肾脏在电解质平衡中起着重要的作用。钾的水平尤其重要，通常肾脏可以帮助钾的排泄。在慢性肾病中，就像尿素一样，钾排泄减少，在血液中积聚更多，导致高钾血症，这是令人担忧的，因为它会引起心律失常。肾脏的另一个关键作用是平衡钙的水平。正常情况下，肾脏有助于激活维生素D，这有助于从饮食中增加钙的吸收。在慢性肾脏疾病中，缺乏活性维生素D，钙不能被吸收到血液中，导致低钙血症-低钙水平。当血液中的钙含量下降时，甲状旁腺激素就会释放出来，从而导致骨骼中钙的流失。随着时间的推移，骨骼中钙的回吸收入血会使骨质变得疏松脆弱，这是一种叫做肾性骨营养不良的疾病。肾脏也释放关键的激素。例如，正常情况下，当肾脏开始感觉到低于正常量的液体被过滤时，它们会释放肾素以增加血压。在慢性肾病中，肾小球滤过率下降导致肾素分泌增多，导致高血压。现在，请记住高血压是慢性肾脏疾病本身的原因，因此这就形成了一个恶性循环。

The kidney also secretes the hormone erythropoietin which stimulates the production of red blood cells from the bone marrow.In chronic kidney disease, erythropoietin levels fall and this leads to lowered production of red blood cells, and ultimately anemia.Ultimately the diagnosis of chronic kidney disease comes down to looking at changes in the glomerular filtration rate over time.Chronic kidney disease might be suspected with a GFR of less than 90 ml/min/1.73 m2, and irreversible kidney damage might happen with a GFR below 60 ml/min/1.73 m2.To confirm the diagnosis a kidney biopsy can be done to look for changes like glomerulosclerosis.Treatment for chronic kidney disease often involves managing the underlying cause.In severe situations, dialysis or a kidney transplant might be needed.

肾脏还分泌促红细胞生成素，刺激从骨髓产生的红细胞。在慢性肾脏疾病中，红细胞生成素水平下降，导致血红细胞数量降低，最终导致贫血。最终诊断慢性肾病是观察肾小球滤过率随时间的变化。慢性肾病可能被怀疑为GFR小于90 ml/min/1.73 m2，而不可逆的肾损害可能发生在GFR低于60ml /min/1.73 m2。为了确认诊断，可以做肾活检，以寻找肾小球硬化的变化。治疗慢性肾脏疾病通常需要管理潜在的病因。在严重的情况下，可能需要透析或肾脏移植。

Alright, as a quick recap，chronic kidney disease is when the glomerular filtration rate falls below 90 ml/min/1.73 m2 over at least three months.Chronic kidney disease is mainly caused by diabetes and hypertension, and complications include electrolyte abnormalities, accumulation of toxins in the body, hypertension, and bone abnormalities.Thanks for watching, you can help support us by donating on patreon, or subscribing to our channel, or telling your friends about us on social media.

好吧,作为一个快速回顾,慢性肾脏疾病是,肾小球滤过率低于90毫升/分钟/ 1.73平方米/至少三个月。慢性肾脏疾病主要由糖尿病和高血压引起，并发症包括电解质异常、体内毒素积累、高血压和骨异常。感谢收看，你可以通过众筹，或者订阅我们的频道，或者在社交媒体上告诉你的朋友来支持我们。