scholarly journals Noninvasive In Vivo Estimation of Blood-Glucose Concentration by Monte Carlo Simulation

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4918
Author(s):  
Chowdhury Azimul Haque ◽  
Shifat Hossain ◽  
Tae-Ho Kwon ◽  
Ki-Doo Kim
Keyword(s):  
Monte Carlo ◽  
Blood Glucose ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Synthetic Data ◽  
Real Data ◽  
Pearson's R ◽  
Blood Glucose Concentrations ◽  
Finger Model

Continuous monitoring of blood-glucose concentrations is essential for both diabetic and nondiabetic patients to plan a healthy lifestyle. Noninvasive in vivo blood-glucose measurements help reduce the pain of piercing human fingertips to collect blood. To facilitate noninvasive measurements, this work proposes a Monte Carlo photon simulation-based model to estimate blood-glucose concentration via photoplethysmography (PPG) on the fingertip. A heterogeneous finger model was exposed to light at 660 nm and 940 nm in the reflectance mode of PPG via Monte Carlo photon propagation. The bio-optical properties of the finger model were also deduced to design the photon simulation model for the finger layers. The intensities of the detected photons after simulation with the model were used to estimate the blood-glucose concentrations using a supervised machine-learning model, XGBoost. The XGBoost model was trained with synthetic data obtained from the Monte Carlo simulations and tested with both synthetic and real data (n = 35). For testing with synthetic data, the Pearson correlation coefficient (Pearson’s r) of the model was found to be 0.91, and the coefficient of determination (R2) was found to be 0.83. On the other hand, for tests with real data, the Pearson’s r of the model was 0.85, and R2 was 0.68. Error grid analysis and Bland–Altman analysis were also performed to confirm the accuracy. The results presented herein provide the necessary steps for noninvasive in vivo blood-glucose concentration estimation.

Effect of low blood glucose on plasma CRF, ACTH, and cortisol during prolonged physical exercise

1991 ◽  
Vol 71 (5) ◽  
pp. 1807-1812 ◽  
Author(s):  
I. Tabata ◽  
F. Ogita ◽  
M. Miyachi ◽  
H. Shibayama
Keyword(s):  
Blood Glucose ◽  
Physical Exercise ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Plasma Concentrations ◽  
Bicycle Exercise ◽  
Low Intensity ◽  
Prolonged Physical Exercise ◽  
Blood Glucose Concentrations ◽  
Exercise In Humans

The effects of low blood glucose concentration during low-intensity prolonged physical exercise on the hypothalamus-pituitary-adrenocortical axis were investigated in healthy young men. In experiment 1, six subjects who had fasted for 14 h performed bicycle exercise at 50% of their maximal O2 uptake until exhaustion. At the end of the exercise, adrenocorticotropic hormone (ACTH) and cortisol increased significantly. However, this hormonal response was totally abolished when the same subjects exercised at the same intensity while blood glucose concentrations were maintained at the preexercise level. In experiment 2, in addition to ACTH and cortisol, the possible changes in plasma concentration of corticotropin-releasing factor (CRF) were investigated during exercise of the same intensity performed by six subjects. As suggested by a previous study (Tabata et al. Clin. Physiol. Oxf. 4: 299–307, 1984), when the blood glucose concentrations decreased to less than 3.3 mM, plasma concentrations of CRF, ACTH, and cortisol showed a significant increase. At exhaustion, further increases were observed in plasma CRF, ACTH, and cortisol concentrations. These results demonstrate that decreases in blood glucose concentration trigger the pituitary-adrenocortical axis to enhance secretion of ACTH and cortisol during low-intensity prolonged exercise in humans. The data also might suggest that this activation is due to increased concentration of CRF, which was shown to increase when blood glucose concentration decreased to a critical level of 3.3 mM.

scholarly journals Effects of cholecystokinin on appetite and pyloric motility during physiological hyperglycemia

2000 ◽  
Vol 278 (1) ◽  
pp. G98-G104 ◽  
Author(s):  
C. K. Rayner ◽  
H. S. Park ◽  
S. M. Doran ◽  
I. M. Chapman ◽  
M. Horowitz
Keyword(s):  
Blood Glucose ◽  
Glucose Concentration ◽  
Guar Gum ◽  
Blood Glucose Concentration ◽  
Acute Effect ◽  
Saline Control ◽  
Significant Difference ◽  
Blood Glucose Concentrations ◽  
Pyloric Motility ◽  
Food Consumed

Recent studies suggest that the interaction between small intestinal nutrient stimulation and the blood glucose concentration is important in the regulation of gastric motility and appetite. The purpose of this study was to determine whether the effects of cholecystokinin octapeptide (CCK-8) on antropyloric motility and appetite are influenced by changes in the blood glucose concentration within the normal postprandial range. Seven healthy volunteers were studied on 4 separate days. A catheter incorporating a sleeve sensor was positioned across the pylorus, and the blood glucose was stabilized at either 4 mmol/l (2 days) or 8 mmol/l (2 days). After the desired blood glucose had been maintained for 90 min, an intravenous infusion of either CCK-8 (2 ng ⋅ kg− 1 ⋅ min− 1) or saline (control) was given for 60 min. Thirty minutes after the infusion began, the catheter was removed and subjects drank 400 ml of water with guar gum before being offered a buffet meal. The amount of food consumed (kcal) was quantified. The order of the studies was randomized and single-blinded. There were fewer antral waves at a blood glucose of 8 than at 4 mmol/l during the 90-min period before the infusions ( P < 0.05) and during the first 30 min of CCK-8 or saline infusion ( P = 0.07). CCK-8 suppressed antral waves ( P < 0.05), stimulated isolated pyloric pressure waves (IPPWs) ( P < 0.01), and increased basal pyloric pressure ( P < 0.005) compared with control. During administration of CCK-8, basal pyloric pressure ( P < 0.01), but not the number of IPPWs, was greater at a blood glucose of 8 mmol/l than at 4 mmol/l. CCK-8 suppressed the energy intake at the buffet meal ( P < 0.01), with no significant difference between the two blood glucose concentrations. We conclude that the acute effect of exogenous CCK-8 on basal pyloric pressure, but not appetite, is modulated by physiological changes in the blood glucose concentration.

PAF increases hepatic vascular resistance and glycogenolysis in vivo

1991 ◽  
Vol 260 (3) ◽  
pp. G471-G480 ◽  
Author(s):  
K. L. Hines ◽  
A. Braillon ◽  
R. A. Fisher
Keyword(s):  
Blood Flow ◽  
Blood Glucose ◽  
Glucose Concentration ◽  
Glycogen Phosphorylase ◽  
Blood Glucose Concentration ◽  
Portal Pressure ◽  
Hepatic Glycogen ◽  
Hepatic Portal ◽  
Adrenalectomized Rats

Administration of platelet-activating factor (PAF) to portal venous circulation of anesthetized fed rats produced decreases in mean arterial pressure and increases in hepatic portal pressure and blood glucose concentration. These responses to PAF were dose dependent with ED50 values of 0.02-0.05 micrograms/kg and specific as lyso- and enantio-PAF did not reproduce effects of PAF. Specific PAF receptor antagonist SRI 63-675 (75 micrograms/kg) inhibited significantly these PAF (0.1 micrograms/kg)-induced responses in rats. Administration of prazosin (500 micrograms/kg) and propranolol (400 micrograms/kg) to rats abolished phenylephrine (50 micrograms/kg)-induced increases in mean arterial pressure, hepatic portal pressure, and blood glucose concentration but did not prevent PAF (1 microgram/kg)-induced alterations in these parameters. Glycogen phosphorylase alpha levels were increased significantly in livers of rats after administration of PAF (1 microgram/kg) or phenylephrine (50 micrograms/kg). Administration of prazosin and propranolol to rats inhibited phenylephrine- but not PAF-induced activation of hepatic glycogen phosphorylase. Hepatic adenosine 3',5'-cyclic monophosphate (cAMP) concentration was increased slightly by PAF, but these increases were eliminated by adrenergic blockade, suggesting that activation of hepatic glycogen phosphorylase by PAF is not dependent on increases in cAMP. Increases in hepatic portal pressure and blood glucose concentration in response to PAF (0.1 micrograms/kg) were not attenuated in adrenalectomized rats. Moreover, PAF (0.1 micrograms/kg) stimulated increases in hepatic portal pressure after administration of the ganglionic blocking agent chlorisondamine (2.5 mg/kg) to adrenalectomized rats. Administration of PAF (0.05 micrograms/kg) to rats instrumented with pulse Doppler flow probes produced decreases in hepatic arterial and portal vein blood flow and increases in hepatic arterial and portal vascular resistance. These observations provide direct evidence that PAF regulates hepatic hemodynamics and glycogenolysis in vivo. It is suggested that PAF plays an important role in regulating hepatic blood flow and supplying extrahepatic tissues with energy substrates by sympathetic-independent mechanism(s) after its release in acute pathophysiological situations.

Physiological changes in blood glucose affect appetite and pyloric motility during intraduodenal lipid infusion

1998 ◽  
Vol 275 (4) ◽  
pp. G797-G804 ◽  
Author(s):  
J. M. Andrews ◽  
C. K. Rayner ◽  
S. Doran ◽  
G. S. Hebbard ◽  
M. Horowitz
Keyword(s):  
Blood Glucose ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Sensory Function ◽  
Fasting State ◽  
Lipid Infusion ◽  
Visual Analog Scales ◽  
Small Intestinal ◽  
Blood Glucose Concentrations ◽  
Pyloric Motility

We evaluated the effects of varying blood glucose concentration within the normal postprandial range and its interaction with small intestinal nutrients on antropyloric motility and appetite. Eight healthy males (19–40 yr) underwent paired studies, with a blood glucose level of 5 or 8 mmol/l. Manometry and visual analog scales were used to assess motility and appetite, during fasting and intraduodenal lipid infusion (1.5 kcal/min). In the fasting state, antral waves were suppressed at 8 mmol/l compared with 5 mmol/l ( P = 0.018). However, pyloric motility was no different between the two blood glucose concentrations. Hunger was no different at 5 mmol/l compared with 8 mmol/l, but fullness was greater at 8 mmol/l ( P = 0.01). During intraduodenal lipid infusion, antral waves were suppressed ( P < 0.035) and isolated pyloric pressure waves (IPPWs) were stimulated ( P < 0.02) compared with during the fasting state, with no difference between blood glucose concentrations, although the temporal patterning of IPPWs varied between blood glucose concentrations. The amplitude of IPPWs was greater at 5 mmol/l compared with 8 mmol/l ( P < 0.001), and hunger decreased at 8 mmol/l compared with 5 mmol/l ( P = 0.02). We conclude that “physiological” hyperglycemia modifies gastric motor and sensory function and that synergy exists between blood glucose concentration and small intestinal nutrients in modulating gastric motility and appetite.

scholarly journals Noodles Made from High Amylose Wheat Flour Attenuate Postprandial Glycaemia in Healthy Adults

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2171
Author(s):  
Kim Ang ◽  
Carla Bourgy ◽  
Haelee Fenton ◽  
Ahmed Regina ◽  
Marcus Newberry ◽  
...  
Keyword(s):  
Young Adults ◽  
Blood Glucose ◽  
Wheat Flour ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Lower Blood Glucose ◽  
Postprandial Glycaemia ◽  
Lower Blood ◽  
High Amylose ◽  
Blood Glucose Concentrations

Previous research has not considered the effect of high amylose wheat noodles on postprandial glycaemia. The aim of the study is to investigate the effect of consumption of high amylose noodles on postprandial glycaemia over 2-h periods by monitoring changes in blood glucose concentration and calculating the total area under the blood glucose concentration curve. Twelve healthy young adults were recruited to a repeated measure randomised, single-blinded crossover trial to compare the effect of consuming noodles (180 g) containing 15%, 20% and 45% amylose on postprandial glycaemia. Fasting blood glucose concentrations were taken via finger-prick blood samples. Postprandial blood glucose concentrations were taken at 15, 30, 45, 60, 90 and 120 min. Subjects consuming high amylose noodles made with flour containing 45% amylose had significantly lower blood glucose concentration at 15, 30 and 45 min (5.5 ± 0.11, 6.1 ± 0.11 and 5.6 ± 0.11 mmol/L; p = 0.01) compared to subjects consuming low amylose noodles with 15% amylose (5.8 ± 0.12, 6.6 ± 0.12 and 5.9 ± 0.12 mmol/L). The total area under the blood glucose concentration curve after consumption of high amylose noodles with 45% amylose was 640.4 ± 9.49 mmol/L/min, 3.4% lower than consumption of low amylose noodles with 15% amylose (662.9 ± 9.49 mmol/L/min), p = 0.021. Noodles made from high amylose wheat flour attenuate postprandial glycaemia in healthy young adults, as characterised by the significantly lower blood glucose concentration and a 3.4% reduction in glycaemic response.

Noninvasive Blood Glucose Assay by Near-Infrared Diffuse Reflectance Spectroscopy of the Human Inner Lip

1993 ◽  
Vol 47 (7) ◽  
pp. 875-881 ◽  
Author(s):  
R. Marbach ◽  
Th. Koschinsky ◽  
F. A. Gries ◽  
H. M. Heise
Keyword(s):  
Blood Glucose ◽  
Glucose Concentration ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Multivariate Calibration ◽  
Diffuse Reflectance Spectroscopy ◽  
Blood Glucose Concentration ◽  
Venous Blood ◽  
Time Lag ◽  
Blood Glucose Concentrations

Near-infrared (NIR) spectra of the human inner lip were obtained by using a special optimized accessory for diffuse reflectance measurements. The partial-least squares (PLS) multivariate calibration algorithm was applied for linear regression of the spectral data between 9000 and 5500 cm−1 (Λ = 1.1–1.8 μm) against blood glucose concentrations determined by a standard clinical enzymatic method. Calibration experiments with a single person were carried out under varying conditions, as well as with a population of 133 different patients, with capillary and venous blood glucose concentration values provided. A genuine correlation between the blood glucose concentrations and the NIR-spectra can be proven. A time lag of about 10 min for the glucose concentration in the spectroscopically probed tissue volume vs. the capillary concentration can be estimated. Mean-square prediction errors obtained by cross-validation were in the range of 45 to 55 mg/dL. An analysis of different variance factors showed that the major contribution to the average prediction uncertainty was due to the reduced measurement reproducibility, i.e., variations in lip position and contact pressure. The results demonstrate the feasibility of using diffuse reflectance NIR-spectroscopy for the noninvasive measurement of blood glucose.

The effect of premixed insulin to blood glucose concentration in patients with type 2 diabetes mellitus

2020 ◽  
Vol 30 (6) ◽  
Author(s):  
Arina D. Puspitasari ◽  
Hayu Kusuma ◽  
Dinda M.N. Ratri ◽  
Cahyo Wibisono ◽  
Budi Suprapti
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Blood Glucose ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Postprandial Blood Glucose ◽  
Premixed Insulin ◽  
Acting Insulin ◽  
Blood Glucose Concentrations

AbstractBackgroundOne of the therapies used to treat type 2 diabetes mellitus (T2DM) disease is combination insulin which consists of rapid-acting insulin and intermediate-acting insulin (premixed). This study aimed to examine the profile of premixed insulin related to blood glucose concentration and to identify the drug interactions due to the combination of premixed insulin with other drugs taken by T2DM patients.MethodsThis study was a prospective observational study with cross-sectional data that were analyzed descriptively. The respondents invited were T2DM patients with or without complication or comorbid disease who received premixed insulin with or without a combination of oral antidiabetic therapy in the Outpatient Unit of Universitas Airlangga Hospital, Surabaya. The research instruments used are data sheet, patient medical record, and fasting and postprandial blood glucose concentration.ResultsA total of 118 patients received premixed insulin therapy, but only 80 patients were included in the inclusion criteria. Based on types of insulin, the combination of 30% aspart and 70% protamine aspart was used by 91.25% T2DM patients, and a combination of 25% insulin lispro and 75% protamine lispro was used by 8.75% T2DM patients. There were 30.3% of patients who could achieve the target of 80–130 mg/dL in fasting blood glucose concentrations, and 35.1% of patients achieved the target of ≤180 mg/dL in postprandial blood glucose concentration. Drug interactions may occur in patients who use premixed insulin with glimepiride, lisinopril, fenofibrate, candesartan, irbesartan, and gemfibrozil.ConclusionsIn this study, premixed insulin have not reached the target of fasting and postprandial blood glucose concentrations in most patients.

scholarly journals Glycogen metabolism in the liver of the neonatal gsd/gsd and control (GSD/GSD) rat

1982 ◽  
Vol 202 (3) ◽  
pp. 623-629 ◽  
Author(s):  
D G Clark ◽  
S D Neville ◽  
M Brinkman ◽  
O H Filsell
Keyword(s):  
Blood Glucose ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Glycogen Metabolism ◽  
Hepatic Glycogen ◽  
Living Tissue ◽  
Neonatal Rats ◽  
And Control ◽  
Blood Glucose Concentrations

1. The metabolism of hepatic glycogen, labelled with [6-3H]glucose at day 19.5 of gestation and with 14C from [U-14C]galactose at delivery, was followed for 10 h in food-deprived gsd/gsd and control (GSD/GSD) neonatal rats. 2. In the affected pups glycogen was maintained at 12% (w/w) and there was no loss of incorporated radioactivity. 3. The 3H and 14C in glycogen from the controls were both decreased by 80%, but 14C was removed at 0-5 h and [6-3H]glucose at 5-10 h. 4. Blood glucose concentrations in the unaffected neonatal rats fell from 5.3 mM at 20 min to 1.7 mM after 10 h. In the gsd/gsd pups blood glucose concentration was decreased from 2 mM at birth to 0.3 mM at 2.5 h: it was maintained at 0.8 mM between 5 and 10 h. 5. In neonatal rats that had been dead for 10 h, hepatic glycogen was decreased by 34% in the controls and by 22% in the gsd/gsd pups. These results demonstrate that liver from the affected rats contains glycogenolytic activity, but that it is not expressed in living tissue.

Early hyperglycemia following alloxan administration in vivo is not associated with altered hepatic mitochondrial function: acceptable model for type 1 diabetes?

2011 ◽  
Vol 89 (7) ◽  
pp. 477-484 ◽  
Author(s):  
Dairo A. Rendon ◽  
Jose A. Alvarez-Bustamante
Keyword(s):  
Type 1 Diabetes ◽  
Blood Glucose ◽  
Mitochondrial Dysfunction ◽  
Glucose Concentration ◽  
Alloxan Diabetes ◽  
Blood Glucose Concentration ◽  
Diabetic State ◽  
Acceptable Model

Alloxan and oxidative stress, which have been detected in livers of laboratory animals shortly after in vivo alloxan administration, cause in vitro mitochondrial dysfunction, thus questioning alloxan diabetes as an acceptable model for type 1 diabetes, a model that cannot legitimately be used to investigate mitochondrial metabolism in a diabetic state. In the current study, the blood glucose concentration increased in the drug-treated group of Sprague–Dawley rats (compared with the placebo group) 45 or 60 min after alloxan treatment, whereas at 30 min the blood glucose concentration was unchanged. State 4, state 3, respiratory control, efficiency of oxidative phosphorylation, and mitochondrial ATP synthase activity, assayed using glutamate plus malate, pyruvate plus malate, or succinate as a substrate, were not negatively altered during the entire study. These results indicated that early increases of blood glucose concentration, after in vivo alloxan administration, did not lead to liver mitochondrial dysfunction, suggesting that alloxan diabetes can be used for the study of liver mitochondrial respiration in a diabetic state.

scholarly journals Blood Glucose Concentration after Cardiopulmonary Resuscitation Influences Functional Neurological Recovery in Human Cardiac Arrest Survivors

1997 ◽  
Vol 17 (4) ◽  
pp. 430-436 ◽  
Author(s):  
Marcus Müllner ◽  
Fritz Sterz ◽  
Michael Binder ◽  
Wolfgang Schreiber ◽  
Alexander Deimel ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Blood Glucose ◽  
Glucose Concentration ◽  
Neurological Outcome ◽  
Blood Glucose Concentration ◽  
Neurological Recovery ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Poor Neurological Outcome ◽  
Blood Glucose Concentrations

Experimental data suggest that postischemic blood glucose concentration plays an important role in modulating both ischemic cerebral infarction and selective neuronal necrosis. This study investigated the association between functional neurological recovery and blood glucose concentrations in human cardiac arrest survivors. A group of 145 nondiabetic patients were evaluated after witnessed ventricular fibrillation cardiac arrest. Data regarding cardiac arrest were collected according to an internationally accepted protocol immediately after arrival. Blood glucose was measured on admission and 6, 12, and 24 h thereafter. To control for duration of cardiac arrest and cardiogenic shock, both known to influence outcome as well as blood glucose, levels, Spearman rank partial correlation was used. In this multivariate analysis, a high admission blood glucose level tended to be associated with poor neurological outcome ( rs = −0.16, n = 142, p = 0.06). The association between high median blood glucose levels over 24 h and poor neurological outcome was strong and statistically significant ( rs = −0.2, n = 145, p = 0.015). High blood glucose concentrations occurring over the first 24 h after cardiac arrest have deleterious effects on functional neurological recovery. Whether cardiac arrest survivors might benefit from reduction of blood glucose levels needs further investigation.

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