Blunted insulinemia using high dialysate glucose concentration during hemodialysis

The benefit of high glucose concentrations in the dialysate remains under debate. The aim of this study was to analyze and to compare the acute insulin response using a common but high glucose concentration in the dialysate representing a parenteral mode of glucose administration to oral glucose administration in stable and fasting nondiabetic hemodialysis patients during their routine hemodialysis session. Glucose was either given by a standardized oral load (75 g) or using a glucose concentration of 11.1 mmol/L (200 mg/dL) in the dialysate for the duration of an hour. The insulin response per unit glucose stimulus was determined from the slope of paired insulin and glucose concentrations measured in 15-minute intervals using standard techniques. This slope is mathematically equivalent to the insulinogenic index (IG) and has been shown to be independent of extracorporeal clearance by ongoing hemodialysis. In 10 subjects, the IG was 9.3 ± 2.6 U/mol with oral glucose delivery but only one-third of that value (3.0 ± 1.1 U/mol, p < 0.001) when glucose was delivered through the dialysate. Administration of glucose using dialysate thus leads to a blunted insulin response per unit glucose stimulus. This may cause prolonged hyperglycemia which should be avoided in patients treated with hemodialysis.