Difference Between Diabetes Insipidus and Diabetes Mellitus

糖尿病急症vs Diabetes Mellitus

Both diabetes mellitus and insipidus are characterized by increased frequency of urination and increased thirst.

Diabetes Mellitus

Diabetes mellitus is a disease associated with elevated blood sugar levels. There are three types of diabetes mellitus. Type 1 diabetes starts in childhood. Beta cells in islets of Langerhan in pancreas fail to synthesize insulin or defective insulin with minimal biological activity is synthesized. It can be due to genetic impairment of insulin receptors, as well. Type 2 diabetes is due to impairment of insulin sensitivity at target cells. Insulin is synthesized at increasingly higher levels till pancreatic cells fail and then, exogenous insulin is required. Pregnancy induced diabetes mellitus is due to the action of hormones of pregnancy. They tend to increase blood sugar levels opposing the action of insulin.

Classical triad of symptoms is increased thirst (polydipsia), increased hunger (polyphagia) and increased frequency of urination (polyuria). In Diabetes mellitus, fasting blood sugar level is above 120mg/dl. Oral glucose tolerance test is the gold standard in diagnosing diabetes mellitus. Blood sugar level 2 hours after ingesting 75g of glucose is above 140mg/dl in diabetes mellitus.

Type 1 diabetics need exogenous insulin injections to control blood sugar. Type 2 diabetics can be managed with oral hypoglycemic drugs such as metformin and tolbutamide. Complications of diabetes are classified into two broad categories. Complications associated with small blood vessels (retinopathy, nephropathy and neuropathy) are known as micro-vascular complications, and those associated with large blood vessels (peripheral vascular disease, stroke and myocardial infarction) are known as macro-vascular complications.

糖尿病急症

糖尿病是一种水和电解质保留的疾病。有两种类型的糖尿病脂肪。中枢性糖尿病是由于加压素的合成受损。在下丘脑，下丘脑 - 高噬症和垂体后疾病中，血管加压素的形成受损。下丘脑疾病的30％是肿瘤（恶性或良性）；30％是创伤后，30％是未知来源。其余的可能是由于感染，梗塞和遗传误差的遗传性误差。肾原性糖尿病是由于加压素的作用受损而引起的。如果加压素受体（V - 2）或水通道（Aquaporin - 2）在收集肾脏的管道中，加压素的作用会降低。

In both central and nephrogenic diabetes insipidus, there is excessive water loss leading to the passage of diluted urine and dehydration. Thirst is what keeps them alive. It ensures adequate water intake to counteract the fluid loss from both intracellular and extracellular compartments.

Diabetes Mellitus vs. Diabetes Insipidus

• Diabetes insipidus (DI) is a disease of reduced vasopressin action and diabetes mellitus (DM) is a disease of reduced insulin action.

•DM是胰腺和靶细胞的疾病，而DI是大脑和肾脏的疾病。

• DM causes high blood sugar levels while DI doesn’t.

• DM causes polyphagia while DI doesn’t.

• DM causes polyuria by osmotic diuresis (increased glucose holds and takes water out in urine with it), and DI causes polyuria by reduced water reabsorption at collecting ducts of kidneys.

•DM用口服降血糖药物和胰岛素治疗，而DI接受合成加压素治疗。