Changes in blood glucose and lactate concentrations with hemodialysis

Blood glucose concentrations are recognized to vary during hemodialysis (HD), with hypoglycemia reported with glucose-free dialysates. As glucose can be converted to lactate, and conversely lactate to glucose, we wished to study factors associated with peri-dialytic changes in blood glucose.

We prospectively collected data including patient profile, dialysis prescription, hemodynamic parameters, medications, dialysis adequacy and monthly blood tests for three consecutive months. All patients used a 100 mg/dl glucose dialysate. Linear mixed model, general estimated equation and binary logistic regression were used for analysis.

We studied 157 sessions in 55 patients, median age 67.1 (58.5-72.6) years, 67% male, 71% diabetic, 40% prescribed insulin, dialysis vintage 20.4 (10.7-57.7) months. Mean single pool Kt/Vurea and normalized protein nitrogen appearance rate (nPNA) were 1.70 ± 0.34 and 1.01 ± 0.30 g/kg/day respectively. Hypoglycemia (<70 mg/dl) occurred during 10 sessions (6.4%). 25% of non-diabetes experienced hypoglycemia. The % change in peri-dialytic blood glucose was associated with the % change in lactate (estimate of fixed effect = 0.23 p < 0.001) and pre-HD glucose (estimate of fixed effect = 0.09, p < 0.001). The fall in glucose was not associated with urea clearance, consumption of food, administration of insulin or antidiabetic medications, nPNA, body mass index, or pyridoxine concentrations.

Peri-dialytic hypoglycemia cannot simply be explained by dialyzer clearance, as the corresponding fall in lactate would potentially suggest increased gluconeogenesis. Despite using a glucose containing dialysate, asymptomatic hypoglycemia occurred in 6.4% of sessions, suggesting a role for peri-dialytic blood glucose monitoring and avoiding fasting during dialysis.