438-P: Very-Low-Dose Metformin Can Safely Improve Glycemic Control in Type 2 Diabetic Patients Receiving Maintenance Hemodialysis (HD)

Objective: Use of metformin in patients with impaired renal function is controversial as it may increase the risk of lactic acidosis. To evaluate metformin with appropriate dose reduction can safely improve glycemic control in patients with type 2 diabetes (T2D) on HD.

Methods: In six relatively poor-controlled HD patients with T2D (av. BMI=29.7±5.9, glycoalbumin: GA>27%) treated with insulin degludec (8-35 units/day) + dulaglutide (0.75mg/week), low-dose metformin (250-500mg/day) was added on. From starting of metformin administration serum lactate level and pH were monitored biweekly in all patients. Glycemic control was assessed by CGM and the mean amplitude of glycemic excursions (MAGE) was calculated before and 4 weeks after.

Results As shown in figure (each color represents the average glycemic profile of one patient), glycemic control was improved by low-dose metformin as average MAGE was significantly decreased from 128.4+69.1 mg/dL to 83.4+43.3 mg/dL (p<0.05) without episode of hypoglycemia. Average GA was significantly reduced from 32.0% to 22.62% (p<0.01), whereas serum pH and lactate stayed stable up to 3 months.

Conclusion More than 90% of metformin or lactate is cleared, and acid-base balance is adjusted by a single hemodialysis session. Unlike pre-HD patients with impaired renal function, in patients on maintenance HD metformin is potentially safe and useful in controlling plasma glucose level when the dose is appropriately reduced.