A regional blood flow model for glucose and insulin kinetics during hemodialysis

The distribution and elimination of a bolus of glucose injected during hemodialysis (HD) was examined using a distributed double-pool regional blood flow model. Intracorporeal glucose disposal was assumed as insulin-independent (λ) in the central high-flow compartment comprising blood, brain, and internal organs, including pancreatic insulin secretion (a, C1) and hepatic insulin clearance (α). Insulin-dependent (γ) glucose utilization was allocated to the low-flow system comprising muscle, skin, and bone. This model was compared with a compact single-pool model using the same model parameters except for the distribution volume (V). Six parameters (C1, a, α, λ, γ, and V) were identified from data obtained in seven nondiabetic patients (59-115 kg). The fraction Fd of glucose removed by HD significantly (p < 0.05) correlated with baseline glucose concentration Cg,0 (5.561 ± 0.646 mmol/L; r = 0.535), extracorporeal clearance Kg (0.137 ± 0.024 L/min; r = 0.537), a (0.278 ± 0.095 L/mmol, r = -0.586), and λ (0.099 ± 0.078 L/min, r = -0.587). V was much larger in the double-compartment (17.8 ± 5.1 L) than in the single-compartment model (10.0 ± 3.0 L). The modeled glucose compartment volumes could be of interest for fluid management in HD patients. The use of extracorporeal glucose disposal to detect impaired glucose utilization (a, λ) remains to be validated in diabetic HD patients.