With 12.2% of American adults and a growing number of children with diabetes, you might call it an epidemic. Each year over a million new cases of diabetes are diagnosed in adults alone. (1)
Diabetes is a very dangerous, destructive, and often painful disease. The older you get, the more likely you are to develop it. That’s why it’s important to know the symptoms of insulin resistance.
In addition to those already with the full-blown disease is the number of people with impaired glucose tolerance (“pre-diabetes”), a condition in which blood glucose levels are higher than normal but not consistently high enough to qualify as diabetes. This means that, if left unaddressed, the risk of pre-diabetes developing into diabetes is very high. (2) It’s estimated that 33.9% of American adults (84.1 million people) have pre-diabetes. (3)
Food is broken down into glucose (sugar) in the body, then insulin (a hormone secreted by the pancreas) transports and facilitates its use as energy in cells. With several potential contributing factors, sometimes not enough insulin is produced or cells don’t respond to it. Diabetes is the condition in which sugar builds up in the blood rather than being burned as fuel.
Impaired glucose tolerance doesn’t announce itself. No one wants diabetes. Symptoms of diabetes include:
- increased thirst and urination
- increased hunger
- blurred vision
- numbness, tingling, or pain in the feet or hands
- sores that do not heal
- unexplained weight loss
- dry skin
- increased risk of infections, including yeast infection.
Further, people with diabetes are at higher risk for other serious health conditions, including:
- heart disease
- high cholesterol
- kidney disease
- metabolic syndrome
- neuropathy (nerve damage)
Diabetes doesn’t develop overnight; it’s often a long process during which the body’s ability to regulate blood sugar fails. Most people with pre-diabetes don’t know they have it, as it’s often asymptomatic.
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.
Hormones trigger your body to eat when it’s hungry and to stop eating when you’ve had enough; it’s a complex process. Leptin is a hormone created in adipose tissue that is closely linked with insulin in sensing how much sugar is in the blood. When it reaches a certain level, leptin production increases to tell your brain to stop eating.
Leptin and insulin work on opposite sides of the same process and regulate each other. When insulin increases, leptin decreases and vice versa. If there’s an imbalance with insulin or cells become resistant to it, leptin production can decrease and you constantly feel hungry. (11)
Furthermore, it’s possible for cells to become resistant to leptin; you feel hungry even if your stomach is full and your blood sugar is at the appropriate level. This can lead to over-eating and weight gain. The more weight you gain, the less sensitive to leptin your body becomes.
Insulin resistance has been repeatedly established as a contributor to high blood pressure. When uptake of insulin is reduced, absorption of salt by the kidneys is affected, resulting in sodium overload and consequential hypertension. (12) This can occur in people that don’t have diabetes: blood sugar levels might be okay but one of the things that insulin does is open blood vessels. Constricted blood vessels make the pressure rise. (13)
When cells are resistant to insulin and insulin production remains at a normal rate, insulin can accumulate in the blood in excess relative to the amount of glucose. This condition is called hyperinsulinemia. Many studies have associated hyperinsulinemia with hypertension, although the causes may vary.
Some suggest that hypertension due to other causes lead to insulin resistance; others have found the reverse to be true. It all depends on the individual and many risk factors. (14) All studies agree on one thing: high blood pressure is an indicator of insulin resistance. When insulin sensitivity increases, the incidence and risk of hypertension decrease. (15)
5. Lethargy and fatigue
Chronic fatigue is one of the by-products of diabetes because the body isn’t burning energy properly. With pre-diabetes, reactive hypoglycemia (too little blood sugar) can occur after a carbohydrate-rich meal. You get a surge of energy immediately after eating, insulin responds by spiking to manage the food intake, then energy crashes. This can leave you feeling sluggish and sleepy. Eating in this pattern over time, with insulin spikes and crashes, can lead to insulin resistance. (16)
Most people with diabetes are overweight or obese. Excessive weight reflects diet and lifestyle factors that naturally feed into fatigue: lack of exercise and nutrient-poor foods. (17) Excess omega-6 fats can induce depression, which exacerbates feelings of fatigue, decreased physical activity, and consequential insulin resistance.
Eating corn oil has been specifically shown to lead to lethargy and the development of insulin resistance. (18) Use grass-fed butter, olive, sesame, coconut, and avocado oils instead.
6. Obesity and belly fat
THE strongest predictor of insulin resistance is obesity. (19)
“Some experts believe obesity, especially excess fat around the waist, is a primary cause of insulin resistance. Scientists used to think that fat tissue functioned solely as energy storage. However, studies have shown that belly fat produces hormones and other substances that can cause serious health problems such as insulin resistance, high blood pressure, imbalanced cholesterol, and cardiovascular disease (CVD).
“Belly fat plays a part in developing chronic, or long-lasting, inflammation in the body. Chronic inflammation can damage the body over time, without any signs or symptoms. Scientists have found that complex interactions in fat tissue draw immune cells to the area and trigger low-level chronic inflammation. This inflammation can contribute to the development of insulin resistance, type 2 diabetes, and CVD. Studies show that losing the weight can reduce insulin resistance and prevent or delay type 2 diabetes.” (20)
7. Polycystic ovarian disease (PCOS)
PCOS is an endocrine disorder in which there’s an imbalance of sex hormones estrogen and progesterone, resulting in small cysts on the ovaries. Studies have linked PCOS to insulin resistance in almost every case; hyperinsulinemia has been implicated as well. (21) The mechanism by which PCOS occurs is the existence of abnormalities in certain insulin receptors. (22)
The interaction of hormones in the body is astoundingly complex; it therefore makes sense that imbalance in one will result in a ripple effect.
8. Skin conditions
Acanthosis nigricans (AN) is a condition in which skin darkens and changes texture to a velvety feel. It most often occurs in the armpits, groin, back of the neck, between fingers and toes, and on elbows and knees. (23) AN is associated with insulin resistance and can be either benign or malignant. (24)
It occurs when hyperinsulinemia interacts with insulin-like growth factor receptors (IGF-1) that stimulate skin proteins and connective tissue growth. (25) AN is also often found in obese children and adults without notable insulin resistance. (26)
Skin tags (clinically called acrochordons) are also a symptom of insulin resistance and can occur concurrently with AN or on their own. (27)
High blood glucose can make your skin dry and itchy due to excessive fluid loss and hormone irregularities.
How To Overcome These Symptoms of Insulin Resistance
Insulin resistance is reversible (and preventable).
The first and foremost consideration is body mass index (BMI). If you are overweight for your height and build, you are at risk for a host of illnesses and disease. The very strong correlation between overweight and obesity with insulin resistance and diabetes makes weight loss the most important step in reversing impaired glucose tolerance. We know it’s not easy but it is necessary for good health.
Change your diet. Cut out added sugars, processed foods, soft drinks, and artificial sweeteners. Add vegetables, herbs, fruits, and chlorella. Reduce the carbohydrates you eat, including starches like bread, pasta, rice, and legumes. Replace with lean animal and/or plant proteins.
Exercise regularly. Exercise-even in the form of a brisk walk-is good for every part of your body and mind.
“…a large body of evidence supports the role of exercise in improving insulin sensitivity and its beneficial outcomes in insulin resistant states. Epidemiological studies…have reported substantial decreases in the relative risk of type 2 diabetes with lifelong regular physical activity. Large scale randomised controlled clinical trials…demonstrate a 58% reduction in progression of impaired glucose tolerance to type 2 diabetes by intensive lifestyle modification which included a minimum of 20-30 minutes of exercise per day.” (28)
Minimize stress. Find constructive ways to manage stress. Chronic stress is detrimental to every bodily system. Specifically, high cortisol levels (a stress hormone) are known to contribute to insulin resistance.
Get adequate quality sleep. Not getting enough sleep wreaks havoc on hormones and is known to cause impaired glucose tolerance, often leading to diabetes.
If you suspect your body may be developing impaired glucose tolerance, your healthcare provider can test your blood sugar levels to find out for sure. Insulin resistance is a better predictor of diabetes and cardiovascular disease than cholesterol. (29) If caught early, the trend is readily reversible without sustaining long-term damage.
There are plenty of things in life that are outside the realm of your control-blood sugar isn’t one of them.