Dialysis and Diabetes

The number of diabetic dialysis patients is increasing and approximately 25-33% of dialysis patients have diabetes mellitus. This rate is expected to increase over time, therefore special approaches are required for diabetic patients in dialysis practices.

Kidney disease in diabetes usually begins with hyperfiltration and microalbuminuria (30-300 mg per day). Over time, proteinuria increases, glomerular filtration rate decreases and azotemia develops. This process may vary depending on the type of diabetes.

The transition period to end-stage renal failure in insulin-dependent (Type I) diabetic patients is usually 15-30 years. In non-insulin-dependent (Type II) diabetic patients, this period varies between 1-20 years.

Dialysis should be started when the creatinine clearance is 10-20 ml/min, this is valid even if the serum creatinine is as low as 3-5 mg/dl. Dialysis should be performed if symptoms of uremia (anemia, pruritus, nausea, vomiting, loss of appetite, weakness, ammonia-smelling breath) and fluid overload (feet edema, ascites, pulmonary edema) are observed. Serum creatinine of 5-8 mg/dl may also be another indication.

Note: It has been shown that life expectancy is extended and eye, heart and foot complications are prevented in diabetic patients who are diabetic. Studies have shown that diabetic retinopathy accelerates 1-2 years before dialysis is started.

The treatment method is determined by factors such as the patient's age, education, place of residence, family and social structure, patient comfort and accompanying diseases. Transplantation, especially living relative transplantation, is considered a better treatment option. Hemodialysis and peritoneal dialysis are other treatment options.

• Age > 65 years

• Extremity gangrene

• Severe coronary artery disease

• Immobility due to peripheral neuropathy or peripheral vascular disease

• Before starting hemodialysis, a vascular access site should be created by a cardiovascular surgeon. Since the risk of atherosclerosis is high in diabetic patients, it is difficult to select suitable vessels. This procedure should be performed when creatinine clearance drops to 20-30 ml/min. The status of the vessels should be evaluated with Doppler ultrasound and large-diameter, healthy arteries and veins should be preferred. Arterio-venous fistulas (AVF) are healthier, especially elbow region fistulas such as brachiocephalic AVF or transposition of the basilic vein are long-lasting. After the fistula operation, 4-6 weeks should be waited for the vessels to develop. If native AVF cannot be performed, an arteriovenous graft (artificial vessel) can be considered as a second option. Hemodialysis can be performed with permanent catheters placed in large vessels (such as the subclavian vein or jugular vein) in patients with advanced vascular problems. However, peritoneal dialysis should be preferred if there is no contraindication.

• When using dialysate, diabetic patients should use dialysate containing bicarbonate. Dialysates containing 5.5 mmol/l glucose reduce the risk of sudden hypoglycemia during dialysis.

• Dry weight is a condition that is definitely targeted at the end of dialysis in diabetic patients. In other words, the patient should not be left with too much fluid. However, diabetic patients may not tolerate excessive fluid withdrawal due to atherosclerosis and autonomic neuropathy and may develop hypotension or cramps. Therefore, fluid intake should not exceed 2 kg between two dialysis sessions and long-term, slow dialysis should be applied. Methods such as 8-hour hemodialysis 3 times a week or frequent dialysis 5 times a week can also be applied.

• Diabetic hemodialysis patients experience hypotension, nausea and vomiting more frequently during dialysis than other patients. This may be due to cardiac causes, impaired peripheral vascular resistance, hypoalbuminemia, malnutrition, anemia or antihypertensives used before dialysis. The following can be done to prevent:

• High sodium dialysate and linear sodium model

• Low-speed ultrafiltration

• Interrupted ultrafiltration

• Use of hypertonic albumin

• Hematocrit should be kept above 30%

• Antihypertensives should not be taken in the morning

• Eating should not be done during dialysis

• Foot exercises should be done

• Dialysate temperature should be reduced (especially near the end of dialysis)

• Some drugs such as Midodrine and Fludrocortisone can be used (not available in Turkey)

• Online hemofiltration

• Acetate-free biofiltration

• Fifty percent of diabetic patients on dialysis use antihypertensive drugs. Hypertension during dialysis may result from activation of the renin-angiotensin system due to excessive fluid withdrawal. Angiotensin-converting enzyme inhibitors may be used in dialysis. Beta blockers are generally not recommended in diabetic patients because they may impair glucose control and mask symptoms of hypoglycemia, but they have been shown to have beneficial cardiac effects. Calcium antagonists and alpha blockers may be considered as second-line options.

• Excessive fluid withdrawal and hypotension may lead to cardiac arrhythmias, coronary ischemia, angina pectoris, etc. in patients. O2 inhalation, nitroglycerin (oral, subcutaneous or IV) and antiarrhythmic drugs can be used according to the type of arrhythmia. Since diabetic patients are more prone to hypokalemia, attention should be paid to potassium levels in arrhythmias.

• Patients with good blood sugar control and HbA1c levels below 7.5% live longer. In addition, cholesterol and triglyceride levels must be under control to protect against cardiovascular disease. Among dialysis patients, Type 2 (non-insulin dependent) diabetics are twice as likely as Type 1 (insulin dependent) diabetics, and this rate triples after the age of 64. The risk of Type 2 patients increases with age, obesity, and decreased physical activity. These patients should first receive diet, weight loss, and exercise recommendations. While more than half use oral sugar-lowering drugs, insulin use increases in later periods. Uremic Type 2 patients are usually recommended insulin, but oral drugs are used more widely. Insulin resistance and inappropriate insulin secretion response are seen in Type 2 diabetes. Uremia suppresses insulin secretion; therefore, these patients may need less sugar-lowering treatment.

• Lower extremity amputation may occur in 5-25% of diabetic dialysis patients. To prevent this, daily washing and drying, nail and toe care, wearing tight shoes and socks, and regular podiatrist examinations are required. In ischemia-related lesions, a vascular surgeon should be consulted immediately and amputation can be prevented with vascular bypass surgery. Diabetic foot wounds require urgent treatment; if necessary, wound debridement and growth factor treatments should be used. The amputation rate does not differ in CAPD, transplantation, and hemodialysis treatments.

• Sensorimotor and/or autonomic neuropathy may be seen in diabetic hemodialysis patients. Paraplegia and quadriplegia may be seen in uremic diabetics. Gastroparesis (nausea, vomiting, diarrhea) may also occur. Neuropathic findings may decrease with renal transplantation and CAPD. Good glucose control (HbA1c below 7.5%) may improve these findings. Drugs such as Neurontin (Gabapentin) and Tegretol (Carbamazepine) may be used for severe pain and burning complaints, dose adjustment is necessary.

• Adynamic bone disease is more common in diabetic hemodialysis patients. Aluminum deposition from aluminum phosphate binders may cause bone fractures. Bone fractures may be observed within two years of starting hemodialysis. Aluminum-containing phosphate binders should be avoided. Aluminum levels should be checked before and after desferrioxamine infusion in patients with bone pain or fractures.

• It is common in diabetic hemodialysis patients. A daily diet of 25-30 kcal/kg should be recommended, 50% of which should be carbohydrate and protein amount should be 1.3-1.5 g/kg/day. Dialysate fluid should contain 200 mg/dl glucose. Metoclopramide can be used for gastroparesis, antibiotics and Loperamide can be used for diabetic diarrhea. Parenteral amino acid solutions can also be used in patients with nutritional problems. The albumin level in the blood should be above 3.5 gr/dl.

• The prevalence of coronary heart disease in diabetic dialysis patients is 46.4%, which is higher than in non-diabetic patients (32.2%). Atrial and ventricular arrhythmia, heart block, asystole, pulmonary congestion and cardiogenic shock are more common in these patients. While some physicians are wary of beta blockers, their beneficial effects in terms of coronary ischemia and arrhythmia have also been observed. Troponin T test can be used to prevent cardiac risk.

• Early dialysis

• ACE inhibitors or angiotensin receptor blockers

• Keeping blood pressure low

• Use of aspirin or Plavix

• Preventing fluid overload (low salt intake, diuretics)

• Statins (keep LDL-cholesterol at 100 mg/dl)

• Treatment of anemia

• Use of trimetazidine (Vastarel) (personal experience)

• If necessary, PTCA (Percutaneous Transuminal Coronary Angioplasty) or bypass surgery can be performed. Both methods give similar results in 2-year survival, but the hospital stay and mortality may be slightly longer with bypass surgery. This situation is also being reduced with new techniques.