Insulin Requirements in Dialysis Patients

Pathophysiology of Insulin Requirements in Dialysis

• Patients with early CKD stages experience increased insulin resistance, requiring higher insulin doses, but as they progress to end-stage kidney disease (ESKD) and dialysis, they need substantially less insulin 1, 2
• The kidney normally clears 30-80% of insulin, so decreased kidney function in dialysis patients leads to reduced insulin clearance and prolonged insulin action 2
• Several mechanisms contribute to hypoglycemia risk in dialysis patients, including decreased gluconeogenesis by the kidneys, impaired insulin clearance and reduced insulin degradation, increased erythrocyte glucose uptake during hemodialysis, impaired counterregulatory hormone responses, and nutritional deprivation common in dialysis patients 1

Specific Insulin Dose Adjustments for Dialysis Patients

• For patients with type 1 diabetes on dialysis, the American College of Endocrinology recommends reducing total daily insulin dose by 35-40% 3, 4
• For patients with type 2 diabetes on dialysis, the American Diabetes Association recommends reducing total daily insulin dose by approximately 50% 3, 4
• For pre-hemodialysis days, the Endocrine Society suggests reducing basal insulin dose by 25% 3, 5
• Some patients (15-30%) with ESKD may experience "burn-out diabetes," requiring minimal or no insulin therapy, according to the American Association of Clinical Endocrinologists 1, 5

Clinical Considerations and Monitoring

• Continuous glucose monitoring is recommended for dialysis patients to detect asymptomatic and nocturnal hypoglycemia, as suggested by the American Diabetes Association 4
• HbA1c is less reliable in dialysis patients due to decreased red blood cell lifespan and anemia, according to the National Kidney Foundation 5

Practical Approach to Insulin Management

• For insulin-naive dialysis patients or those on low doses, the European Association for the Study of Diabetes recommends starting with 0.3-0.5 units/kg/day 6
• For patients already on higher insulin doses (≥0.6 units/kg/day), the American College of Endocrinology suggests reducing the total daily dose by 20% when hospitalized 6

Hypoglycemia Prevention

• The American Diabetes Association recommends monitoring blood glucose more frequently on dialysis days and the day after 5
• The Endocrine Society suggests considering using a basal-plus approach rather than basal-bolus insulin regimens to minimize hypoglycemia risk 6
• The American Association of Clinical Endocrinologists recommends targeting more moderate fasting blood glucose levels (110-130 mg/dL) rather than aggressive targets 5
• The National Kidney Foundation advises being vigilant for signs and symptoms of hypoglycemia, which may be more common and more dangerous in dialysis patients 5

Insulin Management for Type 1 Diabetes Patients with Severe Renal Impairment

Insulin Adjustment and Monitoring Recommendations

• The Endocrine Society recommends considering further reducing basal insulin dose by 25% on pre-dialysis days to prevent hypoglycemia, as decreased kidney function leads to reduced insulin clearance and prolonged insulin action 7
• The International Society of Nephrology suggests adjusting carbohydrate ratio from current levels to approximately 1:25-30 (less insulin per carb) to account for changes in insulin sensitivity in patients with end-stage renal disease (ESRD) 8
• The Endocrine Society advises against relying solely on HbA1c for glycemic monitoring in dialysis patients, as HbA1c is less reliable in this population due to decreased red blood cell lifespan and anemia 7

Preventing Hypoglycemia During Dialysis

Understanding the Problem

• Hypoglycemia during dialysis is extremely common and dangerous, occurring in 46-52% of ambulatory diabetic patients on maintenance hemodialysis and is associated with increased mortality, according to the Endocrine Society 9, 10
• Glucose levels drop progressively during hemodialysis, reaching their lowest point at the end of the dialysis session, followed by a glycemic peak after dialysis, as reported in Diabetologia and Endocrine Reviews 11, 12

Glucose Monitoring Strategy

• The American Diabetes Association recommends implementing continuous glucose monitoring (CGM) as the preferred monitoring method to detect asymptomatic hypoglycemia during and after dialysis sessions, as traditional monitoring misses most episodes, according to Diabetologia 13, 14, 15
• CGM metrics, such as mean glucose, GMI, and time-in-range, are more reliable than HbA1c in dialysis patients, as HbA1c is falsely low due to anemia, erythropoietin use, and reduced red blood cell lifespan, as stated in Diabetologia 11, 13, 15

Glycemic Targets

• The American College of Cardiology recommends targeting more moderate fasting glucose levels of 110-130 mg/dL rather than aggressive targets, as very low HbA1c levels are associated with increased mortality in hemodialysis patients, creating a U-shaped mortality curve, according to Diabetologia and Endocrine Reviews 9, 14, 15
• The Endocrine Society suggests aiming for HbA1c of 7-8% in dialysis patients with high comorbidity burden or hypoglycemia risk, rather than the standard <7% target, as reported in Endocrine Reviews 9, 10, 16

Timing and Meal Considerations

• Total daily insulin requirements may decrease by 15% post-dialysis, with a 25% reduction in basal insulin needs the day after dialysis compared to the day before, according to Endocrine Reviews 12
• Monitor for post-dialysis hyperglycemia, which typically peaks 2.5 hours after dialysis ends, as reported in Endocrine Reviews 12

Critical Pitfalls to Avoid

• Never rely solely on HbA1c for glycemic management in dialysis patients, as it underestimates mean glucose levels and correlates poorly with actual glycemic control, according to Diabetologia 11, 13, 15
• Avoid aggressive glycemic targets that increase hypoglycemia risk without mortality benefit in this population, as recommended by the Endocrine Society 9, 10
• Hypoglycemia-related hospitalizations before dialysis initiation strongly predict higher mortality after starting dialysis, according to Endocrine Reviews 9, 10

Managing Hypoglycemia During Hemodialysis

Insulin Dose Adjustments and Glucose Monitoring

• The Endocrine Society recommends reducing basal insulin by 25% on pre-hemodialysis days for type 1 diabetes patients, and reducing total daily insulin dose by approximately 50% when on dialysis for type 2 diabetes patients 17
• The American Journal of Kidney Diseases suggests avoiding excessive ultrafiltration, which can exacerbate hypotension and compromise glucose homeostasis, and considers slowing the ultrafiltration rate or performing isolated ultrafiltration 18
• The Endocrine Society recommends using glucose meters with HK, GDH-NAD, or GDH-FAD methodology instead of GDH-PQQ or glucose oxidase (GO) methodology in dialysis patients, as they produce falsely elevated readings with peritoneal dialysis solutions containing icodextrin and other interfering substances 17
• Low hematocrit (<35%) may result in falsely high glucose readings with GO-based meters, and high triglycerides, uric acid (>20 mg/dL), or bilirubin may cause pseudohypoglycemia, according to the Endocrine Society 17

Dialysis Prescription Modifications

• The American Journal of Kidney Diseases recommends increasing dialysate sodium concentration if needed, switching from acetate to bicarbonate-buffered dialysate, and reducing dialysate temperature to prevent hypoglycemia 18

Acute Management of Hypoglycemia in Dialysis Patients

Immediate Treatment Protocol

• Administer glucose immediately when blood glucose falls below 3.3 mmol/L (60 mg/dL), even if the patient is asymptomatic, because dialysis patients often experience silent but potentially life‑threatening hypoglycemia. 19
• Give oral glucose (15–20 g) as the first‑line therapy in conscious patients who can safely swallow. 19
• Provide intravenous dextrose promptly to unconscious patients or those unable to swallow, then switch to oral glucose once consciousness is regained. 19

Post‑Treatment Management

• After the acute episode, reduce insulin doses by 35–50 % to lower the risk of recurrent hypoglycemia. 19
• Once the patient can swallow, offer oral carbohydrate snacks to replenish liver glycogen and help prevent recurrence, acknowledging the impaired gluconeogenesis in end‑stage renal disease. 19

Glucose Monitoring Strategy

• Implement continuous glucose monitoring (CGM) as the primary method of glucose surveillance, because intermittent finger‑stick checks miss most hypoglycemic events during and after dialysis exchanges. 20
• Base therapeutic decisions on CGM‑derived metrics such as mean glucose, glucose management indicator, and time‑in‑range rather than on HbA1c, which underestimates true glycemic control in dialysis patients due to anemia, erythropoietin therapy, and shortened red‑cell lifespan. 20