Basal bolus dosing: a clinical experience.

Curr Diabetes Rev. 2005 May;1(2):215-20

Authors: King AB, Armstrong DU

Basal bolus insulin dosing (BBD) may be defined as the physiological replacement of basal and bolus insulin to achieve near normal glycemia without hypoglycemia and loss of life quality. Normally, continuous and variable basal insulin release provides partial suppression of hepatic glucose production to maintain euglycemia during the fasting period. With meals, additional insulin is released in a biphasic pattern to further suppress hepatic glucose production and to increase glucose transport into muscle, fat and liver. Newer subcutaneous insulins for bolus and basal mimic near normal secretion. In addition, improvements in continuous subcutaneous insulin infusion pump features such as dual wave insulin delivery allow improved postprandial glycemia. Insulin dosing is done in a three step process. Firstly, the dosage is estimated based on formulas derived from body weight or previous insulin requirements. Secondly, pre-dosing adjustments modify these formulas by considering estimations of insulin sensitivity based on clinical judgment and laboratory evaluations. Lastly, post-dosage adjustments are based on timed, self-monitored, blood glucose determinations assisted by overall average glucose determinations such as hemoglobin A1c. Continuous glucose monitoring systems have provided a more insightful tool for dosage adjustments. Daily consecutive intensive glucose evaluations using a continuous glucose monitoring system and corresponding dosage adjustments may offer an even better tool for insulin dosing selection.

PMID: 18220597 [PubMed - indexed for MEDLINE]

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The future of continuous glucose monitoring: closed loop.

Curr Diabetes Rev. 2008 Aug;4(3):269-79

Authors: Hovorka R

Improvements in accuracy of real-time continuous glucose monitoring facilitate the development of closed-loop systems consisting of a continuous glucose monitor, a control algorithm, and an insulin pump. Closed-loop systems can be divided according to the way meal delivery is handled as “fully closed-loop” or “closed-loop” with meal announcement systems. Depending on the subcutaneous (sc) or intravenous (iv) body interface, three major types of closed-loop systems are recognised, (i) sc sensing and sc delivery system, (ii) the iv sensing and intraperitoneal delivery system, and (iii) the iv glucose sensing and iv insulin delivery system. Given the current research focus, this review centres on the sc-sc closed-loop approach, which has the greatest potential for a near-future commercial exploitation as recognised by the JDRF Artificial Pancreas Project. Other approaches utilising intraperitoneal or intravenous sensing/delivery are also discussed. Closed-loop systems may revolutionise diabetes management but their introduction is likely to be gradual starting from simpler applications such as hypoglycaemia prevention or overnight glucose control progressing to more complex approaches such as 24/7 glucose control. The most important question is what is achievable with existing technologies and when the first generation of closed-loop systems will find its way into clinical practice.

PMID: 18690909 [PubMed - indexed for MEDLINE]

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