How does Insulin Resistance Develop?
Insulin resistance is a primary factor in impaired glucose tolerance. Insulin production and its various mechanisms of action are complex and not fully understood. What is known about insulin resistance:
- The cells of the body develop a resistance to the effects of insulin.
- Insulin is essential for the regulation of the glucose circulating in the blood; it induces glucose to be taken up by the cells.
- Insulin is also the chemical messenger that signals to the liver (which stores glucose), to hold on to its glucose and store it rather than release it into the blood. Glucose is packaged up for storage in the liver in the form of glycogen.
- Insulin normally maintains a fine energy balance, never allowing the blood glucose level to rise too much for too long.
- Resistance initially results in the pancreas simply secreting more insulin to maintain safe blood glucose levels and keep high blood sugars at bay.
- Insulin resistance can eventually be accompanied by persistently higher glucose levels (pre-diabetes), and then the persistent hyperglycemia of type 2 diabetes; the release of extra insulin cannot be maintained to compensate for the increasing insulin resistance.
8 Symptoms of Insulin Resistance
Insulin resistance is the term used to describe when cells have trouble absorbing sugar from the blood. Although sometimes subtle, your body may tell you when it’s having a hard time. Here are signs to look for.
1. Brain fog
There’s a link between brain insulin resistance and neurological disease, such as Alzheimer’s (AD). (4)
“AD is fundamentally a metabolic disease with substantial and progressive derangements in brain glucose utilization and responsiveness to insulin and insulin-like growth factor [IGF] stimulation…Metabolic abnormalities have been linked to brain insulin and insulin-like growth factor (IGF) resistance with disruption of signaling pathways that regulate neuronal survival, energy production, gene expression, and plasticity.” (5)
Insulin plays very critical roles in learning and memory. (6) When brain cells are unable to absorb nourishment, their function is reduced, resulting in brain fog and potentially loss of memory and cognition.
2. High cholesterol
There is a link between chronically high LDL (low-density lipoprotein) cholesterol and diabetes. Insulin resistance is associated with increased LDL (and lowered HDL, high-density lipoprotein) cholesterol levels: cholesterol is synthesized faster but not correspondingly absorbed by cells when blood sugar is high. (7) Research has found that low HDL increases the risk of a cardiovascular event (heart attack, stroke). (8) There must be a balance between LDL and HDL to maintain proper metabolism.
In addition, insulin resistance increases the process of energy burning in adipose (fat) tissue but the free fatty acids that occur as a result affect how the liver processes triglycerides (the type of fat that is stored for energy). (9)
Blood cholesterol concentration depends on triglyceride levels, so if your liver isn’t metabolizing fat properly, cholesterol (just another type of fat) can increase. (10) When triglycerides accumulate in non-adipose tissues, lipotoxicity can result. Lipotoxicity contributes to insulin resistance.