Effects of insulin detemir and NPH insulin on body weight and appetite-regulating brain regions in human type 1 diabetes: a randomized controlled trial

Comparison of Insulin Glargine and Detemir Effects on Hormones of Appetite and Metabolic Control in Patients with Type 1 Diabetes: A Randomized Clinical Trial

The aim of this study was to compare the insulin glargine and detemir effects on hormons affecting appetite and metabolic control of patients with type 1 diabetes. This single-blind randomized clinical trial was conducted on patients aged 2 to 18 years with type 1 diabetes who were referred to the endocrinology department of Ali-Asghar Children Hospital in Tehran, from April to September 2019. Patients were randomly allocated to receive insulin Glargine or insulin Detemir. Before starting treatment, blood samples were obtained for routine biochemical tests and factors affecting appetite, including Leptin, Ghrelin, Aguti-Related Peptide (AGRP), and Peptide-YY3-36 (PYY 3-36). Patients were evaluated monthly and insulin dose was adjusted based on target glucose and carbohydrate counting. At the end of three months, the anthropometric values , HbA1C and factors that influence appetite were measured again in both groups, and the results were compared. A total of 40 children with a new onset of type 1 diabetes under 18 years who were hospitalized in Ali Asghar Children Hospital were randomly assigned into two groups as Glargine (n = 20) and Detemir (n = 20). The mean age of patients in the Glargine group was 11.07 ±4.18 years and in the Detemir group was 8.06 ± 3.56. In Glargine group HbA1C, Cholesterol, LDL, AGRP significantly decreased and leptin increased after treatment., while the change of BMI Z-score was not significant. There was a significant decrease of HbA1C in the Detemir group after treatment but there was no significant change of other variables. There was no significant difference for all the variables between two groups after treatment. There was no significant difference for BMI, metabolic control and appetite hormones between Glargine and Detemir groups. BMI-z score did not change in Glargine group while leptin increased and AGRP decreased after treatment. HbA1C decreased significantly after treatment in both groups.

A review of the NG17 recommendations for the use of basal insulin in type 1 diabetes

AIMS

To revisit the data analysis used to inform National Institute of Health and Care Excellence (NICE) NG17 guidance for initiating basal insulin in adults with type 1 diabetes mellitus (diabetes).

METHODS

We replicated the data, methodology and analysis used by NICE diabetes in the NG17 network meta-analysis (NMA). We expanded this data cohort to a more contemporary data set (extended 2017 NMA) and restricted the studies included to improve the robustness of the data set (restricted 2017 NMA) and in a post hoc analysis, changed the index comparator from neutral protamine Hagedorn (NPH) insulin twice daily to insulin detemir twice daily.

RESULTS

The absolute changes in HbA_1c were similar to those reported in the NG17. However, all 95% credible intervals for change in HbA_1c point estimates crossed the line of null effect, except for detemir twice daily (in the NICE and extended 2017 NMAs) and NPH four times daily. In the detemir twice-daily centred post hoc analysis, the 95% credible intervals for change in HbA_1c crossed the line of null effect for all basal therapies, except NPH.

CONCLUSIONS

In NG17, comparisons of basal insulins were based solely on efficacy of glycaemic control. Many of the trials used in this analysis were treat-to-target, which minimize differences in HbA_1c . In the NMAs, statistical significance was severely undermined by the wide credible intervals. Despite these limitations, point estimates of HbA_1c were used to rank the insulins and formed the basis of NG17 guidance. This study queries whether such analyses should be used to make specific clinical recommendations.

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.

Brain Insulin Resistance at the Crossroads of Metabolic and Cognitive Disorders in Humans

Ever since the brain was identified as an insulin-sensitive organ, evidence has rapidly accumulated that insulin action in the brain produces multiple behavioral and metabolic effects, influencing eating behavior, peripheral metabolism, and cognition. Disturbances in brain insulin action can be observed in obesity and type 2 diabetes (T2D), as well as in aging and dementia. Decreases in insulin sensitivity of central nervous pathways, i.e., brain insulin resistance, may therefore constitute a joint pathological feature of metabolic and cognitive dysfunctions. Modern neuroimaging methods have provided new means of probing brain insulin action, revealing the influence of insulin on both global and regional brain function. In this review, we highlight recent findings on brain insulin action in humans and its impact on metabolism and cognition. Furthermore, we elaborate on the most prominent factors associated with brain insulin resistance, i.e., obesity, T2D, genes, maternal metabolism, normal aging, inflammation, and dementia, and on their roles regarding causes and consequences of brain insulin resistance. We also describe the beneficial effects of enhanced brain insulin signaling on human eating behavior and cognition and discuss potential applications in the treatment of metabolic and cognitive disorders.

Weight-sparing effect of insulin detemir: a consequence of central nervous system-mediated reduced energy intake?

Insulin therapy is often associated with adverse weight gain. This is attributable, at least in part, to changes in energy balance and insulin's anabolic effects. Adverse weight gain increases the risk of poor macrovascular outcomes in people with diabetes and should therefore be mitigated if possible. Clinical studies have shown that insulin detemir, a basal insulin analogue, exerts a unique weight-sparing effect compared with other basal insulins. To understand this property, several hypotheses have been proposed. These explore the interplay of efferent and afferent signals between the muscles, brain, liver, renal and adipose tissues in response to insulin detemir and comparator basal insulins. The following models have been proposed: insulin detemir may reduce food intake through direct or indirect effects on the central nervous system (CNS); it may have favourable actions on hepatic glucose metabolism through a selective effect on the liver, or it may influence fluid homeostasis through renal effects. Studies have consistently shown that insulin detemir reduces energy intake, and moreover, it is clear that this shift in energy balance is not a consequence of reduced hypoglycaemia. CNS effects may be mediated by direct action, by indirect stimulation by peripheral mediators and/or via a more physiological counter-regulatory response to insulin through restoration of the hepatic-peripheral insulin gradient. Although the precise mechanism remains unclear, it is likely that the weight-sparing effect of insulin detemir can be explained by a combination of mechanisms. The evidence for each hypothesis is considered in this review.

Emotional eating is associated with increased brain responses to food-cues and reduced sensitivity to GLP-1 receptor activation

OBJECTIVE

The neural correlates and pathophysiology of emotional eating are insufficiently known. Glucagon-like peptide-1 (GLP-1), a postprandial hormone, plays a role in feeding behavior by signaling satiety to the brain. GLP-1 receptor agonists, used for treatment of type 2 diabetes (T2DM), promote weight loss. This study investigated the association between emotional eating and responses to food-cues in brain areas involved in satiety and reward processing, as well as GLP-1 receptor agonist-induced effects on these brain responses.

METHODS

T2DM patients with obesity, normoglycemic individuals with obesity, and lean individuals (n = 48) were studied in a randomized placebo-controlled crossover study. Using functional MRI, we determined the relation between emotional eating and regional brain responses to visual food stimuli and acute effects of intravenous administration of the GLP-1 receptor agonist exenatide on these responses.

RESULTS

Emotional eating scores positively correlated with responses to food-cues in lean subjects in the insula, in normoglycemic subjects with obesity in the insula, and in T2DM patients in the amygdala, orbitofrontal cortex, and insula. Emotional eating scores negatively correlated with exenatide-induced reductions in responses to food-cues in normoglycemic subjects with obesity in the amygdala and in T2DM patients in the insula.

CONCLUSIONS

Our findings indicate that emotional eaters have altered brain responses to food-cues and are less sensitive to the central effects of GLP-1 receptor activation.