Overview
Metabolic complications of peritoneal dialysis refer to protein-energy malnutrition and other abnormalities in nutrient metabolism that can occur during peritoneal dialysis. Patients with varying degrees of nutrient deficiencies and factors contributing to nutrient deficiencies have different nutrient requirements and require attention and appropriate intervention.
Classification
1. Glucose and insulin metabolism
Patients with uremia may develop abnormalities of glucose and insulin metabolism such as decreased glucose tolerance, insulin resistance and hyperinsulinemia due to retention of uremic toxins. The inhibitory effect of parathyroid hormone on insulin secretion by pancreatic B-cells can reduce glucose tolerance in uremic patients. As continuous ambulatory peritoneal dialysis (CAPD) patients use glucose dialysis solution, the continuous absorption of glucose can be up to 100-200 g per day. caloric intake is insufficient can be borrowed glucose dialysis solution to supplement, and can prevent hypoglycemia, but prolonged use of high-glucose dialysis solution can appear dyslipidemia, as well as damage to the patient’s peritoneal function. In order to reduce the absorption of glucose, patients are advised to adjust sodium and water intake appropriately, thus reducing the need for hypertonic solutions.
2. Lipid metabolism
In uremia, the activity of certain lipid-soluble enzymes is reduced, and abnormalities in lipid metabolism can occur. at the beginning of CAPD, many patients show hypertriacylglycerolemia, and most of them have normal serum cholesterol levels. in the first year of CAPD, the blood levels of triacylglycerol and cholesterol are elevated, and this is particularly evident in the first month. The prevalence of lipid metabolism abnormalities varies between dialysis modalities and between individuals on dialysis, and may be related to the use of high-glucose dialysate and differences in dietary energy intake. In patients with severe hypertriglyceridemia, it is recommended that sodium and water intake be adjusted to minimize the use of hyperosmolar dialysis solutions, and that medications that can cause hypertriglyceridemia be avoided.
3. Erythropoietin and anemia
In chronic renal insufficiency, anemia may develop due to retention of uremic toxins, inadequate intake of hematopoietic substances, reduction of renal erythropoietin, and chronic loss of blood. Although adequate dialysis can improve anemia, the best way to correct anemia is to use erythropoietin. It can also improve malnutrition in dialysis patients, and has a certain effect on the endocrine regulation and improvement of patients.
4.Mineral metabolism in CAPD
In uremia patients, glomerular filtration rate decreases, and phosphorus excretion is impeded, while vitamin D deficiency reduces intestinal calcium absorption, leading to high phosphorus and low calcium, secondary hyperparathyroidism, and increased secretion of parathyroid hormone. with elevated parathyroid hormone in CAPD patients, patients develop insulin resistance, which affects the lipid metabolism of patients. Blood parathyroid hormone level is positively correlated with serum albumin and creatinine level, which can reflect the nutritional status of dialysis patients, so it is advocated that the blood parathyroid hormone level should be maintained at 150~200ng/L. 5.
5. Vitamin and trace element deficiency
Insufficient dietary intake or loss of dialysis fluid during peritoneal dialysis can lead to vitamin deficiencies, of which water-soluble vitamin deficiencies are the most obvious. Vitamin C, vitamin B6, vitamin B1 and folic acid are reduced in peritoneal dialysis patients. Patients should pay attention to the dosage of vitamin C. Hyperoxalemia can occur with large amounts. In conclusion, deficient vitamins and trace elements should be actively supplemented.