Monitoring of blood glucose

Battery-driven insulin pumps of the size of a pocket calculator with a subcutaneous injection needle have yet been developed. Though microprocessor-controlled, they are unable to exclude hypoglycemic states when extreme deviations occur. Knowledge of the current glucose level is indispensable for optimal insulin dosing. Up to now, alternative physiological parameters are unknown. 

The in vivo application of glucose sensors is restricted by immunological reactions of the organism against the implanted material. The 

Another problem with the development of implantable sensors is the need to calibrate the sensor ex vivo. This requires a high enzyme stability since the sensor has to be calibrated before implantation. The longest lifetime reported for enzymes immobilized in an implanted sensor was between 6 and 10 days (Shichiri et al., 1987). Neither physical entrapment nor chemical binding and crosslinking of GOD have provided a higher stability for continuously operated glucose sensors. 

The physiological oxygen concentrations in arterial blood, 0.15 mmol/1, and venous blood, 0.01 mmol/1, are much lower than that of glucose (5-15 mmol/1). Continuous flow-through blood glucose sensors based on oxygen probes therefore exhibit a nonlinear current-concentration dependence (Layne et al., 1976). 

Kessler et al. (1984) developed a glucose sensor with an extremely low oxygen demand and a stability of 3 months, which appears to be suitable for implantation. Another sensor that might be implantable is based on the use of ferrocene as an electron acceptor for GOD (Cass et al., 1984 David et al., 1985), which eliminates the need for oxygen. The sensor exhibits an advantageous linear range of 1-30 mmol/l. However, experiments with the sensor implanted subcutaneously in animals revealed a rapid sensitivity decrease (Pickup, 1987). 

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Discuss the major sources of errors in amperometric monitoring of blood glucose. 

Frequent monitoring of blood glucose levels and adjustments of insulin are required to avoid hypoglycemia... 

Periodic monitoring of blood glucose, lipids, and blood pressure ... 

Patients and clinicians can evaluate blood glucose control through a combination of self-monitoring of blood glucose data and hemoglobin HbAlc testing. 

SMBG Self-monitoring of blood glucose UPT Urine pregnancy test... 

World-wide, about 130 million people are believed to suffer from diabetes, a disease which occurs when the body does not adequately produce the insulin needed to maintain a normal circulating blood glucose (80-120 mg/dl). It is estimated that the disease is in rapid expansion (300 million in 2025). Frequent monitoring of blood glucose is crucial for effective treatment and to reduce the morbidity and mortality of diabetes. Blindness, kidney and heart failure, peripheral neuropathy, pure circulation, gangrene are the severe complications which, over time, are related to diabetes. 

Major commercial electrochemical systems for self-monitoring of blood glucose... 

Peripheral tissues (such as liver, skeletal muscle, and adipose) retain normal responsiveness to insulin, and management of the disease involves subcutaneous insulin injection with monitoring of blood glucose several times per day. 

The closed-loop type artificial pancreas (specifically 8-cell), which consists of an automatic continuous monitor of blood glucose level (BGL) and an automatic injector of insulin which are coupled with feed-back system, has great potential for prevention of diabetic complication such as micro-angiopathies(l). A large-scale closed-loop type artificial pancreas for bedside use has already been developed and is clinically used at some laboratories and hospitals (2-4). However, this device is limited to only bedside use. On the other hand, the open-loop type artificial pancreas which consists of only a insulin injecting pump without an automatic continuous monitor of BGL, has been developed and is going to be clinically used(5-7). This system, however, can not completely control BGL as well as the bare pancreas in a normal body and often causes lower BGL(8-9). 

Clarke WL, Cox D, Gonder-Frederick LA, Carter W, Pohl SL. Evaluating clinical accuracy of systems for self-monitoring of blood glucose. Diabetes Care 1987, 10, 622-628. 

Type 1 diabetes is treated with insulin replacement therapy, usually by insulin injection or insulin pump, along with attention to dietary management and careful monitoring of blood glucose levels. Today most insulin is produced using genetic recombination techniques insulin analogues are a form of modified insulin with different onset-of-action times or duration-of-action times. 

The dose is adjusted according to the usual monitoring of blood glucose (or urine, if glucose meters are imavailable). Daily (total) dose increments should be 4 units at 3-4-day intervals. 

Doctor, nurse and patient are faced with a lifetime of collaboration. Compliance is not a one-sided process, and the patients need all the consideration and support they can get. They should learn about their disease and its management, including home monitoring of blood glucose, and about the need for appropriate diet, exercise and avoidance of smoking. 

Cordray JP, Merceron RE, Guillerd X, Nys P. Baisse du fer serique due a 1 auto-surveillance glycemique chez le dia-betique. [Low serum iron level caused by self-monitoring of blood glucose in the diabetic patient.] Presse Med 1991 20(7) 310. 

Portable meters for measurement of blood glucose concentrations are used in three major settings (a) in acute and chronic care facilities (at the patient s bedside and in clinics or hospitals) (b) in physicians offices and (c) by patients at home, work, and school. The last, self-monitoring of blood glucose (SMBG), used by approximately 1 miUion diabetic patients, is performed in the United States at least once a day by 40% and 26% of individuals with type 1 and 2 diabetes, respectively. The worldwide market for SMBG is 2.7 billion per year, with annual growth estimated at 10% to 12%. ... 

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