Glucose metabolism and self-regulation — Is insulin resistance a valid proxy of self-control?

The Effects of Self-Control on Glucose Utilization in a Hyperinsulinemic Euglycemic Glucose Clamp

Abstract. Background. The glucose hypothesis of self-control posits that acts of self-control may draw upon glucose as a source of energy, leading to a decrease in blood glucose levels after exerting self-control, mirroring the temporary depletion of self-control, but supporting evidence is mixed and inconclusive. This might partly be due to using methods that are not suitable to reliably quantify glucose utilization. Aims. We aimed at examining whether self-control exertion leads to an increase in glucose utilization. Method. In a sample of N = 30 healthy participants (50% women, age 26.5 ± 3.5 years) we combined a hyperinsulinemic euglycemic glucose clamp (a well-established and validated procedure in experimental endocrinology to reliably quantify systemic glucose utilization) with a standard self-control dual-task paradigm. In the first task, the experimental group completed a variation of a paper-and-pencil crossing out letter task (COLT) that demanded self-control; the control group completed a variation of the COLT that did not demand self-control. The second task for both groups was a computerized two-color word Stroop which demanded self-control. Results. We did not find a significant main effect for time, nor a time × group interaction with respect to glucose utilization, which indicates that glucose utilization did not differ significantly over time or between groups. Limitations. Due to the time-consuming and complicated clamp method, our sample was rather small. Conclusion. Our results revealed little evidence for the notion that self-control efforts are associated with a relevant increase in peripheral glucose utilization.

Self-regulation resources and physical activity participation among adults with type 2 diabetes

Physical activity plays a crucial role in the prevention and treatment of type 2 diabetes. Therefore, it is important to understand why so few adults with type 2 diabetes regularly engage in physical activity. The role of self-regulation in the context of health-related behavior adherence, especially in terms of physical activity engagement and adherence, has largely been reviewed based on the strength energy model. Building on this line of research, the aim of this theoretical work was to highlight how self-regulation and ego depletion can influence the lower rate of physical activity participation among adults with type 2 diabetes, compared to adults from the general population.

Ginsenoside Re Ameliorates Brain Insulin Resistance and Cognitive Dysfunction in High Fat Diet-Induced C57BL/6 Mice

The ameliorating effects of ginsenoside Re (G Re) on high fat diet (HFD)-induced insulin resistance in C57BL/6 mice were investigated to assess its physiological function. In the results of behavioral tests, G Re improved cognitive dysfunction in diabetic mice using Y-maze, passive avoidance, and Morris water maze tests. G Re also significantly recovered hyperglycemia and fasting blood glucose level. In the results of serum analysis, G Re decreased triglyceride (TG), total cholesterol (TCHO), low-density lipoprotein cholesterol (LDLC), glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT) and increased the ratio of high-density lipoprotein cholesterol (HDLC). G Re regulated acetylcholine (ACh), acetylcholinesterase (AChE), malondialdehyde (MDA), superoxide dismutase (SOD), and oxidized glutathione (GSH)/total GSH by regulating the c-Jun N-terminal protein kinase (JNK) pathway. These findings suggest that G Re could be used to improve HFD-induced insulin resistance condition by ameliorating hyperglycemia via protecting the cholinergic and antioxidant systems in the mouse brains.