Modeling of insulin secretion and insulin mass balance during hemodialysis in patients with and without type 2 diabetes

Comparable Hemodilution with Hypertonic Glucose in Patients with and without Type-2 Diabetes Mellitus during Hemodialysis

(1) Background: It was examined whether glucose-induced changes in the relative blood volume are suitable to identify subjects with and without type-2 diabetes mellitus (T2D) during hemodialysis. (2) Methods: The relative blood volume was continuously recorded during hemodialysis and perturbed by the infusion of glucose comparable to the dose used for intravenous glucose tolerance tests. Indices of glucose metabolism were determined by the homeostatic model assessment (HOMA). Body composition was measured by a bioimpedance analysis. The magnitude and the time course of hemodilution were described by a modified gamma variate model and five model parameters. (3) Results: A total of 34 subjects were studied, 14 with and 20 without T2D. The magnitude of the hemodilution and the selected model parameters correlated with measures of anthropometry, body mass index, absolute and relative fat mass, volume excess, baseline insulin concentration, and HOMA indices such as insulin resistance and glucose disposition in a continuous analysis, but were not different in a dichotomous analysis of patients with and without T2D. (4) Conclusions: Even though the parameters of the hemodilution curve were correlated with measures of impaired glucose metabolism and body composition, the distinction between subjects with and without T2D was not possible using glucose-induced changes in the relative blood volume during hemodialysis.

Changes of Hemodynamic Parameters after Intradialytic Glucose Injection

BACKGROUND

Intradialytic hypotension (IDH) is a frequent complication of hemodialysis (HD). Current methods of IDH prevention are insufficient.

METHODS

We analyzed the intradialytic time course of systolic (SBP), diastolic (DBP), mean arterial (MAP), pulse pressure (PP), and heart rate (HR) in a group of chronic kidney disease (CKD) patients. First, 30 min into HD, a 40% glucose solution was injected into the venous line of the extracorporeal circulation at a dose of 0.5 g/kg of dry weight. Pressures and HR were measured in frequent intervals. Relative volume overload was determined by bioimpedance spectroscopy.

RESULTS

Thirty-five participants were studied. SBP increased after 5, 10, and 20 min of glucose infusion. DBP increased after 2 and 3 h and also at the end of HD. PP increased after 5, 10, and 20 min of glucose infusion and fell after the 2nd and 3rd hour and also at the end of HD. MAP increased after 2 and 3 h of glucose injection and at the end of HD. Significant interactions of the time course of SBP, DBP, MAP, with HR at baseline and of the time course of PP with fluid overload were observed. Symptomatic hypotensive episodes were absent.

CONCLUSIONS

Glucose infusions during HD prevent symptomatic IDH and do not cause severe hypertensive episodes.

Cardiovascular Response to Intravenous Glucose Injection during Hemodialysis with Assessment of Entropy Alterations

BACKGROUND

The quality of autonomic blood pressure (BP) control can be assessed by the entropy of serial BP data. The aim of this study was to evaluate the effect of hemodialysis (HD) and glucose infusion (GI) on amplitude aware permutation entropy (AAPE) of hemodynamic variables during HD in chronic kidney disease patients with and without type-2 diabetes mellitus (DM).

METHODS

Twenty-one patients without DM (NDO) and ten with DM were studied. Thirty minutes after the start of HD, a 40% glucose solution was administered. Hemodynamic data were extracted from continuous recordings using the Portapres® system.

RESULTS

AAPE decreased during HD in all patients and all hemodynamic signals with the exception of AAPE of mean and diastolic BP in DM patients. GI led to an increase in AAPE for cardiac output in all patients, while AAPE for heart rate and ejection time increased only in DM studies, and AAPE for systolic, diastolic, and mean arterial pressure, as well as total peripheral resistance, increased only in NDO patients.

CONCLUSIONS

The reduction in entropy during HD indicates impaired autonomic control in response to external perturbations. This state is partially reversed by the infusion of glucose with differences in central and peripheral responsiveness in DM and NDO patients.

Recent Advances and Future Perspectives in the Use of Machine Learning and Mathematical Models in Nephrology

We reviewed some of the latest advancements in the use of mathematical models in nephrology. We looked over 2 distinct categories of mathematical models that are widely used in biological research and pointed out some of their strengths and weaknesses when applied to health care, especially in the context of nephrology. A mechanistic dynamical system allows the representation of causal relations among the system variables but with a more complex and longer development/implementation phase. Artificial intelligence/machine learning provides predictive tools that allow identifying correlative patterns in large data sets, but they are usually harder-to-interpret black boxes. Chronic kidney disease (CKD), a major worldwide health problem, generates copious quantities of data that can be leveraged by choice of the appropriate model; also, there is a large number of dialysis parameters that need to be determined at every treatment session that can benefit from predictive mechanistic models. Following important steps in the use of mathematical methods in medical science might be in the intersection of seemingly antagonistic frameworks, by leveraging the strength of each to provide better care.

Glucose tolerance in patients with and without type 2 diabetes mellitus during hemodialysis

AIMS

The disposal of a glucose bolus was studied to identify glucose metabolism in patients with and without type 2 diabetes mellitus (T2DM) during their regular hemodialysis (HD) treatment.

METHODS

Plasma glucose, insulin, and c-peptide concentrations were measured during a 60 min observation phase following a rapid glucose infusion (0.5 g/kg dry weight). Glucose disposition and elimination rates were determined from kinetic analysis, and insulinogenic index was calculated. Insulin resistance (R_HOMA) was determined by homeostatic model assessment (HOMA).

RESULTS

35 HD patients (14 with T2DM) distinguished by a higher age (median: 70 vs. 55 y, p < 0.01) in T2DM patients were studied. Glucose kinetic data showed only small differences between patients with or without T2DM, but as R_HOMA measured in all patients increased, a larger fraction of glucose was removed by the extracorporeal system (r = 0.430, p = 0.01). One hour after glucose bolus injection the glucose level was not different from that before HD also in patients with T2DM (p = 0.115).

CONCLUSIONS

The larger glucose amount recovered in dialysate in patients with increasing R_HOMA indicates that impaired glucose disposal could be measured during HD using a non-invasive dialysis quantification approach without blood sampling. Glucose infusion during HD is safe also in patients with T2DM.