人體的奧秘 - 廢老殺手糖尿病

Diabetes mellitus (or simply diabetes) refers to the abnormally high glucose level in the blood.
糖尿病 (diabetes mellitus) 是指血液裡的葡萄糖 (glucose) 濃度過高。 {參閱：「升糖素＆降糖素」}

The normal range of blood glucose level should be 4.0 - 5.4 millimole per liter (or 72 to 99 milligram per deciliter). Up to 7.8 millimoles per liter (144 milligrams per deciliter).
正常人的血糖濃度大概在每升 4.0 到 5.4 毫摩爾 (millimole) 的範圍，也就是每厘升 (centiliter) 7.2 到 9.9 毫克，飯後最高可以到每升 7.8 毫摩爾，也就是每厘升 14.4 毫克。

There are mainly 2 types of diabetes, type 1 and 2.
(i)Type 1 diabetes refers to diabetes with genetic-related autoimmunity.
(ii)Type 2 diabetes refers to the malfunction of the insulin receptor on cells.
糖尿病可以分成2個型。
(一) 1型糖尿病 - 源於遺傳問題。
(二) 2型糖尿病 - 源於降糖素 (或者胰島素) 的受體出現問題，無法正常運作。
____________________________
Patients with type 1 diabetes (T1D) are usually born with a damaged DNA which is responsible for major histocampatibility complex (MHC) formation.
1型的病人通常是天生就有遺傳物 (DNA) 上的缺陷，導致病人白血球的受體 (MHC)，尤其是淋巴球出現問題。

As the MHC is important in the communication of T-cells, the damaged MHC means an error in the T-cells communication. In T1D, the MHC class II on the antigen-presenting cell (APC) in thymus prefers to present less 'beta-cell related antigens'.
最明顯就是病人的胸腺淋巴球 (T-cell) 在胸腺被過濾時，部份針對降糖細胞 (beta cell) 的胸腺淋巴球會因為受體的缺陷而通過過濾。{參閱：「基本的胸腺介紹」}

Autoimmune T-cells passes the clonal selection. Those autoimmune T-cells then kill the beta cells in the pancreas, which leads to the insufficient insulin secretion and the sign of diabetes.
這些胸腺淋巴球攻擊病人自己的降糖細胞。因為沒了降糖細胞就沒有降糖素，結果就出現血糖濃度大幅上升。

Therefore, T1D predominantly occurs around 5-7 in the young age.
所以，1型的病人通常的發病年齡是 5 到 7 歲。
____________________________
Patients with type 2 diabetes (T2D) are usually having cells with insulin resistance, i.e. the insulin receptors are not responding quite well to the insulin.
2型病人的細胞通常都不太管降糖素，也就是細胞上降糖素的受體很難啟動。

Risk factors include aging, obesity, hypertension, lack of exercise and depression, as they may deteriorate the insulin resistance.
肥胖、高齡、高血壓、缺乏運動、憂鬱等等的因素會增加受體的啟動難度。

When cells have insulin resistance, beta cells need to secrete more insulin in order to lower the blood glucose level. Therefore, those beta cells undergo hyperplasia and hypertrophy.
當受體難以啟動，降糖細胞就要分泌更多的降糖素來達到同樣的結果。為了分泌更多的降糖素，降糖細胞的數量變多了，大小也變更大。

However, this model is unsustainable. Beta cells will eventually die off due to some cellular factors like endoplasmic reticulum stress and substance accumulation.
這看似沒什麼關係，其實不然。這種變化如果持續下去往往會導致降糖細胞壓力過大和物質不平衡，最後大規模凋亡。

The death of the beta cell leads to a significant drop in insulin secretion and the sign of diabetes.
降糖細胞的凋亡使得身體無法分泌降糖素，而出現糖尿病的病徵。

Therefore, T2D predominantly occurs in the elderly and the fatty.
所以，2型病人通常是長者和胖子。
____________________________
Patients with diabetes may develop 5 major symptoms, the polyphagia, the polydipsia, the glycosuria, the polyuria and the weight loss.
糖尿病病人通常會出現5個症狀：多食、多飲、糖尿、多尿、體重減輕。

(i) Polyphagia - Although patients with diabetes have a high glucose level in the blood, they are not absorbed by the cells because of lacking insulin. Therefore, patients always feel hungry as the cells don't get enough energy, i.e. glucose.
(一) 多食症 (polyphagia) - 雖然病人血糖濃度很高，但是因為沒有降糖素，細胞就無法從血液吸收葡萄糖，導致病人的細胞長期營養不足，造成飢餓感。

(ii) Glycosuria - As the blood has a high concentration of the glucose, they leak out from the blood during the filtration of the kidney. It causes the urine to have glucose inside.
(二) 糖尿症 (glycosuria) - 因為病人的血糖濃度很高，血液被腎球過濾時會有葡萄糖的泄漏，造成糖尿。

(iii) Polyuria - Because of the glycosuria, the filtrate in the nephron contains more glucose. This causes a higher concentration gradient in water which leads to more water being filtered out from the blood to the kidney. Then, it causes the patient to go to the toilet frequently.
(三) 多尿症 (polyuria) - 因為糖尿症使許多的葡萄糖進入腎元，造成濾液整體濃度變高。這會導致更多的水被過濾到腎元，造成病人常常去廁所。

依家有冇咩最新既醫療科技對付到二型 ？

(iv) Polydipsia - As the blood has a high concentration of the glucose, in the other words, the blood has a lower concentration in water, which causes the patients to feel thirsty.
(四) 多飲症 (polydipsia) - 高血糖濃度，代表低血水濃度，加上多尿症，造成病人常常口渴。

(v) Weight loss - As the cells have insufficient energy, they break down fatty acids and proteins instead, which may causes weight loss.
(五) 體重減輕 - 因為細胞沒有足夠的葡萄糖供應，繼而分解脂類和蛋白質，造成體重減輕。
____________________________
When diabetes goes serious, complications may develop. There are a lot of diabetic complications, but most of them are derived from the arteriosclerosis.
嚴重的糖尿病會發展出併發症 (complication)。糖尿病會引起超多的併發症，但其實很多都是源於動脈硬化 (arteriosclerosis)。

(1) Arteriosclerosis - A high glucose level in the blood leads to changes in the chemical environment of blood vessels. It causes the decrease in secretion of vasodilators like nitric oxide. A decrease in the number of vasodilators means blood vessels
cannot enlarge lumens when needed, and it is called the endothelial dysfunction. The blood vessels lose the elasticity or even being damaged and form plaques. All these deteriorate the blood flow of patients and cause the hypoxia of tissues.
(一) 動脈硬化 (arteriosclerosis) - 血液長期在一個高血糖的環境下，血管會因為少了刺激而減少擴張。血管不擴張就是失去彈性的表現，更有機會發展成內壁的隆腫 (atherosclerosis)。這惡化了糖尿病人的血液循環效率，很可能會造成組織缺氧 (hypoxia)。

Here are some complications that associated with the arteriosclerosis.
(i) Stroke - Serious arteriosclerosis in the brain.
(ii) Hypertension - as blood vessels are narrow, the blood flow with higher pressure.
(iii) Lost of sensation in limbs - The nerves are damaged due to the insufficient blood supply.
(iv) Amputation - Ulcers may occur when blood supply is poor.
(v) Blindness - The retinal nerves are damaged due to the insufficient blood supply.
(vi) Kidney failure - Arteriosclerosis occurs in the glomerulus and causes the malfunction of the nephron.
(vii) Gastroparesis - The food stays in the stomach due to the damage of the vagus nerve.
這邊列出一些動脈硬化所發展出的併發症。
(一) 中風 (stroke) - 腦部中有嚴重的動脈硬化。
(二) 高血壓 (hypertension) - 因為動脈硬化，內腔無法擴張，造成高血壓。
(三) 肢體 (limb) 失去感覺 - 肢體神經因為血液供應不足而壞死。
(四) 截肢 (amputation) - 肢體因為血液供應不足而出現潰瘍 (ulcer)，甚至壞死。
(五) 失明 - 視網膜細胞因為血液供應不足而壞死。
(六) 腎衰竭 (kidney failure) - 腎球出現動脈硬化。
(七) 胃癱 (gastroparesis) - 迷走神經 (vagus nerve) 因為血液供應不足而壞死。

(2) Diabetic ketoacidosis (DKA) - If patients constantly have not enough insulin, cells have not enough energy as glucose can't enter the cell. The body breaks down lipids into ketone bodies in order to supply energy for the brain. When there are too much ketone bodies being produced, they will acidify the blood and causes acidosis. The cells would try to increase the pH by giving out the potassium, which may leads to hyperkalemia. DKA may causes coma and death if it remains untreated.
(二) 酮酸中毒 (diabetic ketoacidosis) - 當病人長期沒有足夠的降糖素，細胞就無法獲得血液中的葡萄糖。身體為了維持腦部運作，只能把脂類分解成酮體 (ketone bodies)，作為葡萄糖的緊急代替品。但太多的酮體會酸化血液 (acidosis)，身體為了中和血液又會出現高血鉀 (hyperkalemia)，最終會導致病人昏迷甚至死亡。

(3) Hyperosmolar & Hyperglycemia state (HHS) - When there is a high glucose level, the glucose acts as a solute of the blood which means that the concentration of water in the blood is low. When the concentration of water in blood is higher than that of cells, the water flows out from the cells. This leads to the deterioration of polydipsia and polyuria. The severe dehydration may leads to coma.
(三) 高滲壓狀態 (Hyperosmolar & Hyperglycemia state) - 極高血糖濃度，代表極低血水濃度。當血液中水份的濃度比細胞高，水就會從細胞中流出，當中包括腦細胞，所以會造成昏迷和神智不清。這個狀態也會惡化多尿症和多飲症。
____________________________
以前既文章，有興趣既可以參考下
「基本的器官介紹」系列
目錄：lihkg.com/t/785268/
唔想睇文既可以睇片：rebrand.ly/basic_anatomy_and_physiology

「解剖與生理」系列
「升糖素＆降糖素」: lihkg.com/t/790368
_______________

暫時冇咩聽過有新野

可能係我唔知啦..

睇落好似好嚴重咁

我冇殺人 唔好屈我

切腳指同整盲人姐

認左佢啦 連登仔會多謝你

正經post 無人理
推

都仲係打胰島素 就算打刺激返胰臟分泌既抗體都唔夠胰島素控制得好

食少d升糖高既野係咪可以防二型

咁當然啦

好老土
但其實講到尾都係做多D運動同食少D高糖高鹽高脂既野

唔係老土 有更好既方法邊知唔想提出

係我地可以做到既野唔多

做運動好煩

一型好陰功 有時響電視見到小朋友細細個就要定期打針，過同friend唔同既生活

我有一型
但18歲先發病

辛苦了巴打

巴打個時點發現..

銅酸中毐，睇急症發現

一黎就咁大劑

世事無常啊 對生活影響應該都幾大..