Effect of subcutaneous insulin detemir on glucose flux, lipolysis and electroencephalography in type 1 diabetes

Insulin analogues in type 1 diabetes mellitus: getting better all the time

The treatment of type 1 diabetes mellitus consists of external replacement of the functions of β cells in an attempt to achieve blood levels of glucose as close to the normal range as possible. This approach means that glucose sensing needs to be replaced and levels of insulin need to mimic physiological insulin-action profiles, including basal coverage and changes around meals. Training and educating patients are crucial for the achievement of good glycaemic control, but having insulin preparations with action profiles that provide stable basal insulin coverage and appropriate mealtime insulin peaks helps people with type 1 diabetes mellitus to live active lives without sacrificing tight glycaemic control. Insulin analogues enable patients to achieve this goal, as some have fast action profiles, and some have very slow action profiles, which gives people with type 1 diabetes mellitus the tools to achieve dynamic insulin-action profiles that enable tight glycaemic control with a risk of hypoglycaemia that is lower than that with human short-acting and long-acting insulins. This Review discusses the established and novel insulin analogues that are used to treat patients with type 1 diabetes mellitus and provides insights into the future development of insulin analogues.

Basal insulin peglispro: Overview of a novel long-acting insulin with reduced peripheral effect resulting in a hepato-preferential action

Basal insulin peglispro (BIL) is a novel basal insulin with a flat, prolonged activity profile. BIL has been demonstrated in a dog model, in healthy men and in patients with type 1 diabetes (T1D) to have significant hepato-preferential action resulting from reduced peripheral activity. In the IMAGINE-Phase 3 clinical trial program, more than 6000 patients were included, of whom ~3900 received BIL. Of the 7 pivotal IMAGINE trials, 3 studies were double-blinded and 3 were in T1D patients. BIL consistently demonstrated a greater HbA1c reduction, less glycaemic variability and a clinically relevant reduction in the rates of nocturnal hypoglycaemia across comparator [glargine and isophane insulin (NPH)] studies. Trials using basal/bolus regimens had higher rates of total hypoglycaemia with BIL due to higher rates of daytime hypoglycaemia. Severe hypoglycaemia rates were similar to comparator among both patients with T1D or type 2 diabetes (T2D). T1D patients lost weight compared with glargine (GL). Patients with T2D tended to gain less weight with BIL than with glargine. Compared to glargine, BIL was associated with higher liver fat, triglycerides and alanine aminotransferase (ALT) levels, including a higher frequency of elevation of ALT ≥3 times the upper limit of normal, but without severe, acute drug-induced liver injury. Injection site reactions, primarily lipohypertrophy, were more frequent with BIL. In conclusion, BIL demonstrated better glycaemic control with reduced glucose variability and nocturnal hypoglycaemia but higher triglycerides, ALT and liver fat relative to conventional comparator insulin. The hepato-preferential action of BIL with reduced peripheral activity may account for these findings.

Sustained Treatment with Insulin Detemir in Mice Alters Brain Activity and Locomotion

Aims

Recent studies have identified unique brain effects of insulin detemir (Levemir^®). Due to its pharmacologic properties, insulin detemir may reach higher concentrations in the brain than regular insulin. This might explain the observed increased brain stimulation after acute insulin detemir application but it remained unclear whether chronic insulin detemir treatment causes alterations in brain activity as a consequence of overstimulation.

Methods

In mice, we examined insulin detemir’s prolonged brain exposure by continuous subcutaneous (s.c.) application using either micro-osmotic pumps or daily s.c. injections and performed continuous radiotelemetric electrocorticography and locomotion recordings.

Results

Acute intracerebroventricular injection of insulin detemir activated cortical and locomotor activity significantly more than regular insulin in equimolar doses (0.94 and 5.63 mU in total), suggesting an enhanced acute impact on brain networks. However, given continuously s.c., insulin detemir significantly reduced cortical activity (theta: 21.3±6.1% vs. 73.0±8.1%, P<0.001) and failed to maintain locomotion, while regular insulin resulted in an increase of both parameters.

Conclusions

The data suggest that permanently-increased insulin detemir levels in the brain convert its hyperstimulatory effects and finally mediate impairments in brain activity and locomotion. This observation might be considered when human studies with insulin detemir are designed to target the brain in order to optimize treatment regimens.