Not sensitive to changes in exogenous insulin . The mechanism may cause impaired glucose tolerance, as follows: ① to reduce insulin secretion ; ② when uremia level as the basis of increased growth hormone secretion , so antagonistic to strengthen the role of insulin ; ③ insulin receptor with target cells obstacles to the role of insulin has Weakened ; ④ the glycogen synthase activity decreased Erzhi obstacles glycogen synthesis . Currently considered the main cause of these changes may be urea , creatinine , and the molecular weight of poison and other toxic effects . 2 . Negative nitrogen balance negative nitrogen balance can result in patients suffering from weight loss , cachexia and hypoalbuminemia. Hypoalbuminemia is an important cause of renal edema one of the reasons . Negative nitrogen balance caused by factors : ① patients restricted protein intake or anorexia , nausea and vomiting, decreased protein intake Erzhi ; ② certain substances such as methyl guanidine enable organizations to enhance protein catabolism ; ③ infection may Lead to enhanced protein degradation ; ④ Erzhi protein loss due to bleeding ; ⑤ with the loss of a certain amount of urine proteins . When a large number of blood urea uremia infiltrated by the intestine . Luminal bacteria can decompose and release ammonia urea , ammonia transport by the blood to the liver , may re- synthesis of urea , but also non- essential amino acid synthesis , which is beneficial to the body . Therefore suggested that uremic patients may be lower than normal protein intake , even less than 20g per day can maintain nitrogen balance , but must be given a higher nutritional value of protein, essential amino acids that is rich with nutrients . In recent years, some people think . In order to maintain nitrogen balance in uremic patients , protein intake should be no significant difference between normal subjects ;而且that only to the pursuit of the decrease of blood urea nitrogen and limit excessive protein intake , Keshizishen excessive consumption of protein , and therefore Harmful to the patient . 3 . Hyperlipidemia in uremic patients was mainly due to liver triglyceride synthesis required for lipoprotein ( pre- β- lipoprotein ) increased , so increased production of triglycerides ; may also lipoprotein lipase (lipoprotein lipase) activity decreased Caused by decreased clearance of triglycerides , it is easy to form hypertriglyceridemia . Such changes may be related to the accumulation of the methyl guanidine .