Decreased active GLP-1 response following large test meal in patients with type 1 diabetes using bolus insulin analogues.
Postprandial plasma immunoreactive active glucagon-like peptide-1 (p-active GLP-1) levels in type 1 diabetic patients who did not use bolus insulin responded normally following ingestion of test meal, while a small response of p-active GLP-1 levels was seen in type 2 diabetic patients. To determine whether p-active GLP-1 levels are affected by ingestion of test meal in type 1 diabetic Japanese patients who used bolus rapid-acting insulin analogues, plasma glucose (PG), serum immunoreactive insulin (s-IRI), serum immunoreactive C-peptide (s-CPR), and p-active GLP-1 levels were measured 0, 30, and 60 min after ingestion of test meal in Japanese patients without diabetic complications (n=10, group 1) and control subjects with normal glucose tolerance (n=15, group 2). HbA1c levels were also measured in these groups. The patients in group 1 were treated with multiple daily injections or CSII using injections of bolus rapid-acting insulin analogues before ingestion of test meal. There was no significant difference in mean of sex, age, or BMI between groups. Means of HbA1c, basal and postprandial PG, and postprandial s-IRI levels with integrated areas under curves (0-60 min) (AUC) in group 1 were significantly higher than those in group 2. Means of basal and postprandial s-CPR, and postprandial p-active GLP-1 levels with AUCs were significantly lower in group 1 than in group 2. These results indicated that postprandial p-active GLP-1 levels following ingestion of test meal in type 1 diabetic Japanese patients using bolus rapid-acting insulin analogues were decreased relative to those in controls. (+info)
Clinical performance of a device that applies local heat to the insulin infusion site: a crossover study.
BACKGROUND: Fast-acting insulin analogs have been available since 1996. The absorption rate of these insulins is still too slow to mimic the physiological insulin action in healthy subjects. This study investigates the clinical performance of InsuPatch, a local skin-heating device, on postprandial glucose excursion. METHODS: Twenty-four type 1 diabetes mellitus subjects on continuous subcutaneous insulin infusion were included in this crossover study [10 male, 14 female, age: 43.5 +/- 11.3 years, diabetes duration: 18.3 +/- 10.5 years, glycosylated hemoglobin: 7.4 +/- 0.8%, body mass index: 25.0 +/- 3.0 kg/m(2) (mean +/- standard deviation)]. The impact of local skin heating was measured by dividing the two-hour area under the curve by integration time (AUC/t(120)) for blood glucose (BG) above baseline after two standardized breakfast and dinner meal pairs (with and without heating) per subject. For the first breakfast pair, venous insulin concentration was also measured. RESULTS: A significant reduction was found for the AUC/t(120) after breakfast and after dinner meals (42 breakfast meal pairs, AUC/t(120) not heated 66.4 +/- 32.8 mg/dl vs heated 56.8 +/- 34.0 mg/dl, p = .017; 38 dinner meal pairs, AUC/t(120) not heated 30.8 +/- 31.0 mg/dl vs heated 18.4 +/- 23.9 mg/dl, p = .0028). The maximum venous insulin concentration with heating was 27% higher than without heating (n = 23). The number of hypoglycemic events on days with heating (n = 9) was similar to the number of days without heating (n = 13). CONCLUSIONS: Local heating of the skin around the infusion site significantly reduced postprandial BG by enhancing insulin absorption. The heating device was well tolerated, and it could facilitate development of closed-loop systems. (+info)
Performance of a glucose meter with a built-in automated bolus calculator versus manual bolus calculation in insulin-using subjects.
BACKGROUND: Patients consider multiple parameters in adjusting prandial insulin doses for optimal glycemic control. Difficulties in calculations can lead to incorrect doses or induce patients to administer fixed doses, rely on empirical estimates, or skip boluses. METHOD: A multicenter study was conducted with 205 diabetes subjects who were on multiple daily injections of rapid/ short-acting insulin. Using the formula provided, the subjects manually calculated two prandial insulin doses based on one high and one normal glucose test result, respectively. They also determined the two doses using the FreeStyle InsuLinx Blood Glucose Monitoring System, which has a built-in, automated bolus calculator. After dose determinations, the subjects completed opinion surveys. RESULTS: Of the 409 insulin doses manually calculated by the subjects, 256 (63%) were incorrect. Only 23 (6%) of the same 409 dose determinations were incorrect using the meter, and these errors were due to either confirmed or potential deviations from the study instructions by the subjects when determining dose with meter. In the survey, 83% of the subjects expressed more confidence in the meter-calculated doses than the manually calculated doses. Furthermore, 87% of the subjects preferred to use the meter than manual calculation to determine prandial insulin doses. CONCLUSIONS: Insulin-using patients made errors in more than half of the manually calculated insulin doses. Use of the automated bolus calculator in the FreeStyle InsuLinx meter minimized errors in dose determination. The patients also expressed confidence and preference for using the meter. This may increase adherence and help optimize the use of mealtime insulin. (+info)
Commentary on "Performance of a glucose meter with a built-in automated bolus calculator versus manual bolus calculation in insulin-using subjects".
Since the early 2000s, there has been an exponentially increasing development of new diabetes-applied technology, such as continuous glucose monitoring, bolus calculators, and "smart" pumps, with the expectation of partially overcoming clinical inertia and low patient compliance. However, its long-term efficacy in glucose control has not been unequivocally proven. In this issue of Journal of Diabetes Science and Technology, Sussman and colleagues evaluated a tool for the calculation of the prandial insulin dose. A total of 205 insulin-treated patients were asked to compute a bolus dose in two simulated conditions either manually or with the bolus calculator built into the FreeStyle InsuLinx meter, revealing the high frequency of wrong calculations when performed manually. Although the clinical impact of this study is limited, it highlights the potential implications of low diabetesrelated numeracy in poor glycemic control. Educational programs aiming to increase patients' empowerment and caregivers' knowledge are needed in order to get full benefit of the technology. (+info)
Effect of metformin on hepatic glucose production in Japanese patients with type 2 diabetes mellitus.
We investigated the effect of metformin on hepatic glucose production and peripheral glucose uptake in Asian patients with type 2 diabetes mellitus. We recruited ten Japanese patients whose fasting glucose levels remained poorly controlled under meal-time injection of short-acting insulin. Metformin was added to their insulin therapy, and both hepatic glucose production and peripheral glucose uptake were assessed before and one week after metformin treatment, with the use of stable isotope [6,6-(2)H(2)] glucose. Metformin was titrated to a maximum dose of 500 mg. As a result, fasting glucose levels and hepatic glucose production were significantly improved after the metformin treatment (p < 0.01 and 0.02), whereas their peripheral glucose uptake was not significantly changed (p = 0.63). Furthermore, the change of fasting glucose levels was significantly correlated with that of hepatic glucose production, whose coefficient rho was 0.76 (p = 0.01). On the other hand, there was no significant correlation between the change of fasting glucose levels and that of peripheral glucose uptake (p = 0.43). In conclusion, low dose of metformin significantly reduced hepatic glucose production in Japanese patients with type 2 diabetes mellitus. The efficacy of metformin on correcting fasting hyperglycemia was strongly associated with reduced hepatic glucose production, rather than ameliorated peripheral glucose uptake. (+info)
Ultrafast-acting insulins: state of the art.
Optimal coverage of prandial insulin requirements remains an elusive goal. The invention of rapid-acting insulin analogs (RAIAs) was a big step forward in reducing postprandial glycemic excursions in patients with diabetes in comparison with using regular human insulin; however, even with these, the physiological situation cannot be adequately mimicked. Developing ultrafast-acting insulins (UFIs)-showing an even more rapid onset of action and a shorter duration of action after subcutaneous (SC) administration-is another step forward in achieving this goal. The need for UFIs has been gradually recognized over the years, and subsequently, a number of different approaches to cover this need are in clinical development. A rapid increase in circulating insulin levels can be achieved by different measures: modification of the primary structure of insulin molecule (as we know from RAIAs), addition of excipients that enhance the appearance in the monomeric state post-injection, or addition of enzymes that enable more free spreading of the insulin molecules in the SC tissue. Other measures to increase the insulin absorption rate increase the local blood flow nearby the insulin depot in the SC tissue, injecting the insulin intradermally or applying via another route, e.g., the lung. The development of these approaches is in different stages, from quite early stages to nearing market authorization. In time, daily practice will show if the introduction of UFIs will fulfill their clinical promise. In this review, the basic idea for UFIs will be presented and the different approaches will be briefly characterized. (+info)
Ultra-rapid absorption of recombinant human insulin induced by zinc chelation and surface charge masking.
BACKGROUND: In order to enhance the absorption of insulin following subcutaneous injection, excipients were selected to hasten the dissociation rate of insulin hexamers and reduce their tendency to reassociate postinjection. A novel formulation of recombinant human insulin containing citrate and disodium ethylenediaminetetraacetic acid (EDTA) has been tested in clinic and has a very rapid onset of action in patients with diabetes. In order to understand the basis for the rapid insulin absorption, in vitro experiments using analytical ultracentrifugation, protein charge assessment, and light scattering have been performed with this novel human insulin formulation and compared with a commercially available insulin formulation [regular human insulin (RHI)]. METHOD: Analytical ultracentrifugation and dynamic light scattering were used to infer the relative distributions of insulin monomers, dimers, and hexamers in the formulations. Electrical resistance of the insulin solutions characterized the overall net surface charge on the insulin complexes in solution. RESULTS: The results of these experiments demonstrate that the zinc chelating (disodium EDTA) and charge-masking (citrate) excipients used in the formulation changed the properties of RHI in solution, making it dissociate more rapidly into smaller, charge-masked monomer/dimer units, which are twice as rapidly absorbed following subcutaneous injection than RHI (Tmax 60 +/- 43 versus 120 +/- 70 min). CONCLUSIONS: The combination of rapid dissociation of insulin hexamers upon dilution due to the zinc chelating effects of disodium EDTA followed by the inhibition of insulin monomer/dimer reassociation due to the charge-masking effects of citrate provides the basis for the ultra-rapid absorption of this novel insulin formulation. (+info)