Control of Hypoglycemia in Patients with Type 1 Diabetes May Be Helped with New Smartphone App

Since the onset of insulin delivery and glucose monitoring in patients with type 1 diabetes in the early 1900s, there has been a convergence of insulin pumps and continuous glucose monitoring devices into a feedback loop to improve insulin therapy and blood glucose control. Speaking on Friday at the Cardiometabolic Health Congress, Howard A. Wolpert, MD, of the Joslin Diabetes Center, noted that many of the advances in insulin therapy have been driven by the developments in glucose monitoring. For instance, urine testing can reduce the instances of severe hyperglycemia, and continuous interstitial glucose monitoring can provide intensive diabetes management without hypoglycemia.

Generally speaking, different types of insulin can be categorized into short-acting, regular, long-acting. Wolpert emphasized that health care providers should consider the difference between the pharmacokinetics of insulin, which reflects the insulin levels in a patient’s blood, and the pharmacodynamics, which reflects the bioactivity of insulin in a patient. By looking only at the pharmacokinetics of insulin, the physician can be deceived as to how quickly and over what length of time the insulin has an effect. There is also marked inter- and intra-individual variability in the pharmacodynamics of insulin therapy.

Results from a recent study show that insulin detemir exhibited less dose-to-dose pharmacodynamic variability in each patient than insulin glargine, which exhibited less pharmacodynamic variability than NPH insulin. Combination insulin therapy, consisting of a basal insulin and a prandial bolus, results in predictable pharmacodynamics and more closely mimics patterns seen in individuals without diabetes. The downside is a more complex therapy that includes more injections.

Monitoring therapy primarily focuses on avoiding hypo- and hyperglycemic events in patients with diabetes. The main benefit of continuous glucose monitoring is identifying trends after eating meals that have a high glycemic index. Data from continuous glucose monitors shows that insulin delivery should be matched with carbohydrate absorption not rather than carbohydrate intake.

Contrary to previous assumptions, recent data show that patients with type 1 diabetes exhibit an increase in glucose concentration and insulin requirements, after eating a meal high in dietary fat. Therefore, Wolpert concluded, focusing on the carbohydrate content of a meal is not sufficient to accurately calculate mealtime insulin doses when striving for tight glycemic control. In this study, there was marked inter-individual variability in the insulin dose needed to compensate for the intake of dietary fat, which would not allow for a fixed increase in insulin dose. At a minimum, patients needed to receive 75% more insulin than their regular dose after consuming a meal high in dietary fat.

Dietary protein has also been shown to affect post-prandial blood glucose in patients with type 1 diabetes. In a study presented at the most recent American Diabetes Association meeting, researchers revealed that patients had an increase in blood glucose measurements 100 minutes after meals containing 75-100 g of protein.

Building on the near-universal use of smartphones in the US, Wolpert and collaborators are designing an app that will help patients with diabetes log their hypoglycemic events and, eventually, better control these events by becoming more aware of preceding signs and symptoms.