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Diabetes Management Blood Glucose Monitoring Use of Automated Bolus Calculators for Diabetes Management Frank L Schwartz 1 and Cynthia R Marling 2 1. Professor of Endocrinology, The Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, Ohio, US; 2. Associate Professor, School of Electrical Engineering and Computer Science, Russ College of Engineering and Technology, Ohio University, Athens, Ohio, US Abstract Fewer than 30 % of patients with diabetes who are on insulin therapy achieve target glycated haemoglobin (HbA 1C ) levels. Automated bolus calculators (ABCs) are now almost universally used for patients on insulin pump therapy to calculate pre-meal insulin doses. Use of ABCs in glucose monitors and smart phone applications have the potential to improve glucose control in a larger population of individuals with diabetes on insulin therapy by overcoming the fear of hypoglycaemia and assisting those with low numeracy skills. Keywords Automated bolus calculators, glucose algorithms, blood glucose measurement, continuous glucose monitoring, glycaemic control Disclosure: The software and methodology implemented in the 4 Diabetes Support System have been submitted to the US patent office, application number US60/901,703, and rights are co-owned by the Ohio University Technology Transfer Office, Cynthia R Marling and Frank L Schwartz. Acknowledgements: The authors gratefully acknowledge the following sources of funding: National Science Foundation, Medtronic, Ohio University Russ College Biomedical Engineering Fund, JO Watson, DO Endowed Diabetes Research Chair of the Osteopathic Heritage Foundation, Ohio University Heritage College of Osteopathic Medicine Research and Scholarly Affairs Committee, and the Ohio University Diabetes Research Initiative. Received: 11 July 2013 Accepted: 25 July 2013 Citation: European Endocrinology, 2013;9(2):92–5 Correspondence: Frank L Schwartz, Professor of Endocrinology, JO Watson Chair for Diabetes Research, The Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, 331 Academic Research Center, Athens, OH 45701, US. E: schwartf@ohio.edu Automated Bolus Calculators Barriers to Intensive Glucose Control Insulin dosing algorithms have been used for years by healthcare providers to improve glucose control in patients with diabetes. With the development of insulin pumps and their increased use in the early 1980s, and with the publication of the results from the Diabetes Control and Complications Trial (DCCT) in the early 1990s demonstrating the benefits of intensive glucose control in preventing the long-term complications of diabetes, both the capacity and need to achieve intensive glucose control occurred. 1–4 The first technology to assist patients in calculating meal insulin boluses, which was developed to improve post-prandial glucose control, was in a personal digital assistant (PDA), reported by Gross et al. 5 in 2003. This became the prototype for the meal ‘bolus wizard’ developed by Medtronic MiniMed (Northridge, CA) for use in their insulin pumps. Currently, all commercially available insulin pumps have some form of automated bolus calculator (ABC) algorithm software built into them, although the parameters for each ABC vary. 6 Over the last few years, glucose meters have begun incorporating ABCs (e.g. ACCU-CHEK® Aviva Expert® and FreeStyle InsuLinx® Blood Glucose Monitoring System) to assist with pre-meal insulin dosing for patients using basal/bolus insulin regimens other than pumps (insulin syringes, pens or spring-loaded insulin delivery devices such as the V-Go®). With the increasing use of smart phone technology to support diabetes self-management it is only a matter of time before applications with ABCs are incorporated into them. 7 This paper reviews the current use of ABCs to calculate insulin dosages and discusses the potential future software innovations which could hopefully help healthcare providers and their patients more safely achieve intensive glucose control and improve disease outcomes. There are multiple barriers facing patients with diabetes and their healthcare providers as they attempt to achieve optimal glucose control. First, hypoglycaemia and/or fear of hypoglycaemia are the major limiting factors to intensive glucose control 8,9 for patients, their families and healthcare providers. In reality, less than 50 % of patients with diabetes achieve target glucose or glycated haemoglobin (HbA 1C ) levels and less than 30  % of patients who take diabetes medications reach recommended target levels. 10 From a patient’s perspective, additional barriers range from the cost of medications, durable medical products and medical care, to the complexity and time requirements of intensive self-management, social time demands, and, in some cases, the lack of family support or personal motivation. 11,12 From a provider’s perspective, the time requirements (and lack of reimbursement) to analyse voluminous glucose records (data overload) and make frequent insulin or medication adjustments during and also between office visits are significant barriers to intensive management. 13,14 This has been called the clinical inertia of diabetes care. 15 92 Basics of Meal Bolus Calculators Insulin meal bolus calculators have been shown to improve post-prandial glucose control, reduce dosing errors, allay fears of hypoglycaemia and improve confidence in self-management in individuals with diabetes of all ages that use them. 16–20 Meal bolus insulin dose calculations are based on [1] the target blood glucose level, [2] the current glucose level, [3] the carbohydrate-to-insulin ratio (CIR), [4] total grammes of carbohydrate (CHO) to be consumed in the meal, and [5] an insulin sensitivity factor (ISF) (see Table 1). Each of these factors is different for each patient and each must be determined and individualised by the provider for each patient based on frequent glucose testing and © Touch ME d ica l ME d ia 2013