Insulin Resistance
The key feature of type 2 diabetes mellitus is insulin resistance. What this means is that the response to insulin is deficient. This is neatly illustrated by the test depicted in the graph. Two subjects are given a dose of insulin, and then the concentration of glucose in the blood (plasma glucose) is measured at different times following the insulin injection. The various actions of insulin promote a decrease in blood glucose. In a subject who is insulin resistant (red line), this decrease is less. In practice, such a test is not used to evaluate patients suspected of having type 2 diabetes mellitus. Instead, diabetes mellitus is diagnosed by tests that reveal evidence of hyperglycemia. One such test is the HbA1c test. Traditionally, this test has been used to monitor the effectiveness of diabetes treatments in controlling hyperglycemia (glycemic control). It has only recently been adopted for diagnosis following an effort to nationally standardize the test. This test measures the percentage of glycated hemoglobin in the blood, which will be higher if there have been more periods of hyperglycemia in the recent past. An HbA1c of 6.5% or greater is diagnostic for diabetes mellitus. The advantage of this test is that it doesn't require fasting, and can be done at any time of the day. Another way to reveal hyperglycemia is to look at the fasting plasma glucose. This test needs to be performed in the morning when the subject hasn't eaten for the previous 8 hours. A more sensitive test is the oral glucose tolerance test, as shown in the figure below. This test measures how the body responds to a glucose challenge, usually a drink containing 75 grams of glucose. At various times following consumption of the glucose drink, the blood glucose is measured. Blood glucose increase Continue reading >>
Insulin Resistance: What You Need To Know
Chances are, somewhere alone the lines, you’ve read about or heard the phrase “insulin resistance.” It’s one of those terms that some folks in the medical profession — and in the media — often use, but it’s not always explained very well. As a result, it can seem rather vague and even be a little confusing. Insulin: “do your job” To understand the meaning and implications of insulin resistance, it helps to first take a look at the hormone insulin. The pancreas makes insulin in special clusters of cells called islets. Within these islets are beta cells that faithfully churn out insulin and release it into the blood where it’s set free to do its job (Coach Bill Belichick would approve!). Like all hormones, insulin has a very specific role: it helps the body use glucose from the carbs that you eat for energy. Specifically, it signals muscle, fat, and liver cells to take up glucose from the blood to be used for fuel. If the body says, “No thanks, I’m good,” that energy (glucose) gets stored as glycogen (and, if glycogen stores are full, fat) for use later on. Insulin is a blood glucose regulator, meaning that it helps keep blood sugar levels at a safe level, preventing it from going too high (hyperglycemia) or too low (hypoglycemia). In addition, insulin puts a halt on glucose release from the liver, which also prevents blood sugar levels from climbing. When things go haywire You have to admit — when the body is working as it should, it’s pretty amazing. The pancreas and insulin are no exception. However, things do go awry, unfortunately. Not so much with insulin, but more with how the body’s cells respond to insulin. Basically, muscle, fat, and liver cells start giving insulin the cold shoulder and they ignore or “resist” what insulin is Continue reading >>
How Does Fat Affect Insulin Resistance And Diabetes?
According to the Centers for Disease Control, 29 million people in America have diabetes and 86 million have prediabetes. Insulin resistance is recognized as a predictor of type 2 diabetes, heart disease, and obesity. But what causes insulin resistance? In this NutritionFacts.org video, Dr. Michael Greger talks about how fat affects insulin resistance, and about how the most effective way to reduce insulin sensitivity is to reduce fat intake. We’ve also provided a summary of Dr. Greger’s main points below. Insulin Resistance of People on High-Fat Diets vs. High-Carb Diets In studies performed as early as the 1930s, scientists have noted a connection between diet and insulin intolerance. In one study, healthy young men were split into two groups. Half of the participants were put on a fat-rich diet, and the other half were put on a carb-rich diet. The high-fat group ate olive oil, butter, mayonnaise, and cream. The high-carb group ate pastries, sugar, candy, bread, baked potatoes, syrup, rice, and oatmeal. Within two days, tests showed that the glucose intolerance had skyrocketed in the group eating the high-fat diet. This group had twice the blood sugar levels than the high-carb group. The test results showed that the higher the fat content of the diet, the higher the blood sugar levels would be. What Is Insulin Resistance? It turns out that as the amount of fat in the diet goes up, so does one’s blood sugar spikes. Athletes frequently carb-load before a race because they’re trying to build up fuel in their muscles. We break down starch into glucose in our digestive tract; it circulates as blood glucose (blood sugar); and it is then used by our muscle cells as fuel. Blood sugar, though, is like a vampire. It needs an invitation to enter our cells. And that invit Continue reading >>
Why Does Insulin Resistance Make You Gain Weight, Especially In The Belly And Upper Part Of The Body?
Insulin resistance is a condition that impairs the ability to efficiently remove and process glucose from the bloodstream. Glucose, or blood sugar, is a vital energy source required by all cells, organs and systems of the body for normal function. The inability to utilize glucose in the blood results in excess levels in the blood, effects metabolism, and significantly increasing the chances of developing type 2 diabetes. How Does Insulin Resistance Happen Much like leptin resistance, insulin resistance occurs when a needed substance is present in the body, but unable to be utilized by the cells of the body. Specifically, the muscles and cells of the body do not respond or recognize the presence of insulin, resulting in decreased amounts of glucose being delivered to the cells. Insulin is a hormone produced in the pancreas and important for glucose regulation and energy production. The body reacts to this decrease in glucose in the cells by sending signals demanding more glucose for energy, As long as the pancreas can produce enough insulin, meeting the demand for increased amounts of glucose, the body appears to functions normally and glucose levels remain at healthy levels. Should the demand for glucose exceed the ability to produce insulin, blood glucose levels increase which increases the health risks associated with this condition. Causes of Insulin Resistance While researchers have yet to determine an exact cause of insulin resistance, they believe it is closely related to being overweight, having excess fat around the waist and physical inactivity. Genetics and heredity also appear to influence who develops insulin resistance. Insulin resistance risk increases with age; affecting 10% of people between the ages of 20 and 40, but nearly 40% of people over the age of Continue reading >>
Too Little Sleep May Fuel Insulin Resistance
People who consistently get too little sleep face bigger concerns than daytime fatigue and crankiness. Over the long term, sleep deprivation also increases the risk of serious health problems including obesity and type II diabetes. Scientists have come up with a number of plausible explanations for this increased risk. Various studies have shown, for instance, that how much we sleep can affect blood sugar levels, hormones that control appetite, and even the brain's perception of high-calorie foods. A small new study, published Monday in the Annals of Internal Medicine, adds a key piece to the puzzle by drilling down to the cellular level: Sleep deprivation, the study found, impairs the ability of fat cells to respond to insulin, a hormone that regulates metabolism and is involved in diabetes. In the study, seven healthy young men and women spent a total of eight days and nights in a sleep lab. They were allowed to sleep normally on four of the nights, and on the other nights they were limited to just 4.5 hours. In order to neutralize the effects of appetite or overeating, the researchers strictly controlled the participants' meals and calorie intake. After the four nights of sleep deprivation, blood tests revealed that the participants' overall insulin sensitivity was 16% lower, on average, than after the nights of normal sleep. Moreover, their fat cells' sensitivity to insulin dropped by 30%, to levels typically seen in people who are obese or who have diabetes. "This is the equivalent of metabolically aging someone 10 to 20 years just from four nights of partial sleep restriction," says Matthew Brady, the senior author of the study and an associate professor of medicine at the University of Chicago. "Fat cells need sleep, and when they don't get enough sleep, they bec Continue reading >>
Does Fat Cause Insulin Resistance?
For decades now, we have been told that fatness (or “obesity”) is a major cause of diabetes. Health “experts” have warned about this, but they could never say how being overweight could cause insulin resistance (IR). Without IR, you can’t have Type 2 diabetes, so the whole “blame fat” theory has been suspect. Well, now they have a plausible explanation. Obesity may cause inflammation, causing IR, leading to diabetes. But is this theory true? Does adipose (fat) tissue really create inflammation? Or do both obesity and inflammation come from some other cause? Get ready for some science as I try to explore these questions. In a new report in the Journal of Leukocyte Biology, two Japanese scientists report that “obesity is associated with a state of chronic, low-grade inflammation.” They explain that as fat cells get larger, they seem to attract immune cells called macrophages. These cells produce inflammatory chemicals called cytokines that help cause insulin resistance. Chief among these chemicals are interleukin-6 and tumor necrosis factor-alpha. In animal models, insulin resistance doesn’t occur until after macrophages invade the fat cells. So the question remains, which comes first, the inflammation or the fatness? What draws the immune cells into adipose tissue? Remember that most overweight people never develop diabetes. And some overweight people have much more inflammation than others. (The same is true of thin people, of course.) Why do some develop this fat-related inflammation and some don’t? Some think that weight itself provokes inflammation. According to French scientists writing in the journal European Cytokine Network, weight loss is associated with reduced “macrophage infiltration” and reduced inflammation. Also, another chemical, Continue reading >>
Insulin Resistance: The Real Reason Why You Aren’t Losing Weight
Many people have weight loss as one of their key resolutions. Sadly, 35 percent of people also give up on that goal before the month even ends. It’s not necessarily lack of time or willpower that causes you to struggle with weight loss year after year. The real reason that you may have struggled to lose weight is insulin resistance, or a condition I call metabolism dysfunction. So you may be thinking, “Why is it so hard for me to lose weight?” I’m doing “everything right,” and yet still weight loss is difficult. Perhaps (like many of my patients) you’re already following a strict diet and working out several times a week, but to no avail. The weight still won’t come off — or, worse, you are gaining weight for seemingly no reason at all! You have become resigned to being overweight. Weight problems aren’t a permanent and immovable fixture for the rest of your life. If you’re finding that weight is easy to gain and hard to lose, it’s not your fault! Weight problems aren’t just about overeating or under exercising — they’re about metabolic changes (The MD Factor Diet, 2015) that are collectively known as insulin resistance. Lab tests conducted in my practice have confirmed that over 89 percent of my patients have this real and often undiagnosed issue. So the good news is that the right combination of diet, exercise, and will to succeed you can reverse your MD factor and finally find success in losing weight and keeping it off for good. In a nutshell, insulin resistance is the inability of your body to properly convert the food that you eat into energy to fuel your cells. People with the MD Factor have difficulty regulating their blood sugar, which is often due to insulin resistance or even diabetes. In both instances, their bodies are unable t Continue reading >>
The Ketogenic Diet And Insulin Resistance
We recently touched on how you can use the ketogenic diet to control symptoms of diabetes such as elevated glucose and triglycerides. In this article, we examine research showing the impact that the ketogenic diet has on levels of the hormone insulin, a key regulator of blood sugar in the body. What is Insulin’s Role in the Body? Before we look at the research, we need to know our main players. Insulin is a protein-based hormone produced by beta-cells located in the pancreas. The pancreas, which is located under the stomach, also produces enzymes that aid with digestion. Insulin’s primary purpose is to regulate the metabolism of fats and carbohydrates. The digestive system breaks down carbohydrates, such as sugars and starches, into a molecule called glucose. This compound can be used by cells to produce energy through a process called cellular respiration. Insulin allows cells in the body absorb glucose, ultimately lowering levels of glucose in the blood stream. After a meal is consumed, blood glucose levels increase and the pancreas responds by releasing insulin into the blood. Insulin assists fat, liver, and muscle cells absorb glucose from the blood, resulting in lower levels of blood glucose. Insulin stimulates liver and muscle tissues to store excess glucose as a molecule called glycogen and also reduces glucose production by the liver. When blood sugar is low, the hormone glucagon (produced by alpha-cells in the pancreas) stimulate cells to break down glycogen into glucose that is subsequently released into the blood stream. In healthy people who do not have type II diabetes, these functions allow levels of blood glucose and insulin to stay in a normal range. What Is Insulin Resistance and Why Is It a Problem? Unfortunately, for many Americans and other peopl Continue reading >>
Insulin Resistance: Causes, Symptoms And Prevention
Insulin, a hormone made by the pancreas, allows cells to absorb glucose so that it can be used as energy. The cells of individuals with insulin resistance are unable to use insulin effectively. When cells cannot absorb glucose, it builds up in the blood. If glucose levels are higher than normal, but not high enough to be diagnostic for diabetes, it is referred to as prediabetes. This page will look at the current understanding of insulin resistance and explain how it is a risk factor for both diabetes and other conditions. The article will also explain the signs and how it can be avoided. Contents of this article: Here are some key points about insulin resistance. More detail and supporting information is in the main article. Insulin resistance itself does not present any symptoms if it occurs without prediabetes or diabetes Blood sugar levels with insulin resistance are normal Insulin resistance alone is not treated, but preventing prediabetes or diabetes from developing can be achieved through lifestyle measures What is insulin resistance? Insulin resistance increases the risk of developing prediabetes, and, eventually, type 2 diabetes. Around 15-30 percent of people with prediabetes go on to be diagnosed with type 2 diabetes within 5 years, according to figures from the Centers for Disease Control and Prevention (CDC). Similarly, the American Heart Association (AHA) say that about half of people with high blood sugar go on to develop type 2 diabetes within a decade. The AHA also point out that this means half of these people do not develop diabetes - "your choices make a difference." In other words, individuals can reduce their chances of progressing to type 2 diabetes in the future by making some preventive lifestyle changes. Not only that, but these steps can also Continue reading >>
Insulin Resistance And The Polycystic Ovary Syndrome: Mechanism And Implications For Pathogenesis
POLYCYSTIC ovary syndrome (PCOS) is an exceptionally common disorder of premenopausal women characterized by hyperandrogenism and chronic anovulation ( 1 , 2 ). Its etiology remains unknown. Although there have been no specific population-based studies, a 510% prevalence of this disorder in women of reproductive age is probably a reasonable conservative estimate. This is based as an upper limit on studies of the prevalence of polycystic ovaries, which found that 20% of self-selected normal women had polycystic ovary morphology on ovarian ultrasound ( 3 ). Many of these women had subtle endocrine abnormalities ( 3 ). The lower estimate is based on the reported 3% prevalence rate of secondary amenorrhea for 3 or more months ( 4 ) and the fact that up to 75% of women with secondary amenorrhea will fulfill diagnostic criteria for PCOS ( 5 ). PCOS women can also have less profound disturbances in menstrual function ( 1 , 3 , 6 ). Since the report by Burghen et al. ( 7 ) in 1980 that PCOS was associated with hyperinsulinemia, it has become clear that the syndrome has major metabolic as well as reproductive morbidities. The recognition of this association has also instigated extensive investigation of the relationship between insulin and gonadal function ( 1 , 8 11 ). This review will summarize our current understanding of insulin action in PCOS, address areas of controversy, and propose several hypotheses for this association. Abnormalities of steroidogenesis and gonadotropin release will not be discussed in detail; these changes have been reviewed recently by Erhmann and colleagues ( 12 ) and by Crowley ( 13 ), respectively. The association between a disorder of carbohydrate metabolism and hyperandrogenism was first described in 1921 by Achard and Thiers ( 14 ) and was call Continue reading >>
Insulin Resistance
Insulin resistance (IR) is a pathological condition in which cells fail to respond normally to the hormone insulin. The body produces insulin when glucose starts to be released into the bloodstream from the digestion of carbohydrates in the diet. Normally this insulin response triggers glucose being taken into body cells, to be used for energy, and inhibits the body from using fat for energy. The concentration of glucose in the blood decreases as a result, staying within the normal range even when a large amount of carbohydrates is consumed. When the body produces insulin under conditions of insulin resistance, the cells are resistant to the insulin and are unable to use it as effectively, leading to high blood sugar. Beta cells in the pancreas subsequently increase their production of insulin, further contributing to a high blood insulin level. This often remains undetected and can contribute to the development of type 2 diabetes or latent autoimmune diabetes of adults.[1] Although this type of chronic insulin resistance is harmful, during acute illness it is actually a well-evolved protective mechanism. Recent investigations have revealed that insulin resistance helps to conserve the brain's glucose supply by preventing muscles from taking up excessive glucose.[2] In theory, insulin resistance should even be strengthened under harsh metabolic conditions such as pregnancy, during which the expanding fetal brain demands more glucose. People who develop type 2 diabetes usually pass through earlier stages of insulin resistance and prediabetes, although those often go undiagnosed. Insulin resistance is a syndrome (a set of signs and symptoms) resulting from reduced insulin activity; it is also part of a larger constellation of symptoms called the metabolic syndrome. Insuli Continue reading >>
Too Much Insulin? How To Reset Your Metabolism
By: Mark Hyman, M.D. Are your hormones out of balance? Does your life feel like a song played badly out of tune? If so, the problem may have to do with imbalances in your hormones, which are wreaking havoc on your body and mind. Today I want to focus on the most common — and therefore the most problematic — of hormonal problems in Americans today: too much insulin. When you eat too much sugar, flour and white rice, your insulin levels spike. When this happens, your cells become resistant to its effects. So you pump out more and more insulin, become even more resistant to its effects, and end up in the vicious cycle of insulin resistance. Insulin resistance can cause energy and mood swings — and it can take you down the slippery road toward high blood pressure, heart disease, obesity, cancer, brain aging, dementia, and more. Between 80 and 100 million Americans suffer from insulin resistance. It is not exactly the same in everyone, but the ultimate consequences can be similar. How do you know if you suffer from insulin resistance? Most people with insulin resistance have extra fat around the middle. (Quick Tip: Check your waist-to-hip ratio — the measurement around your belly button divided by the measurement around your hips. If it is greater than 0.8, you likely have insulin resistance.) You may be tall, thin, short, fat, or any combination of these and still have insulin resistance. The only way to know for sure is to take an insulin response test, which measures blood sugar and insulin while you are fasting and one and two hours after you consume a 75-gram sugar drink. Just measuring blood sugar alone isn’t enough. You have to measure insulin — this is something that many doctors miss. Fortunately, balancing blood sugar and correcting insulin resistance a Continue reading >>
What Is The Biochemistry Of Insulin Resistance?
Insulin resistance is a condition that impairs the ability to efficiently remove and process glucose from the bloodstream. Glucose, or blood sugar, is a vital energy source required by all cells, organs and systems of the body for normal function. The inability to utilize glucose in the blood results in excess levels in the blood, effects metabolism, and significantly increasing the chances of developing type 2 diabetes. How Does Insulin Resistance Happen Much like leptin resistance, insulin resistance occurs when a needed substance is present in the body, but unable to be utilized by the cells of the body. Specifically, the muscles and cells of the body do not respond or recognize the presence of insulin, resulting in decreased amounts of glucose being delivered to the cells. Insulin is a hormone produced in the pancreas and important for glucose regulation and energy production. The body reacts to this decrease in glucose in the cells by sending signals demanding more glucose for energy, As long as the pancreas can produce enough insulin, meeting the demand for increased amounts of glucose, the body appears to functions normally and glucose levels remain at healthy levels. Should the demand for glucose exceed the ability to produce insulin, blood glucose levels increase which increases the health risks associated with this condition. Causes of Insulin Resistance While researchers have yet to determine an exact cause of insulin resistance, they believe it is closely related to being overweight, having excess fat around the waist and physical inactivity. Genetics and heredity also appear to influence who develops insulin resistance. Insulin resistance risk increases with age; affecting 10% of people between the ages of 20 and 40, but nearly 40% of people over the age of Continue reading >>
What Is Insulin Resistance?
Insulin is a hormone produced by the pancreas that helps unlock the body's cells so that sugar (glucose) from the food we eat can be used by the cells for energy. In people with type 2 diabetes, a combination of problems occurs, and scientists aren't really sure which is the chicken and which is the egg. The person's body may not be producing enough insulin to meet their needs, so some glucose can't get into the cells. Glucose remains in the bloodstream, causing high blood glucose levels. In many cases, the person may actually be producing more insulin than one might reasonably expect that person to need to convert the amount of food they've eaten at a meal into energy. Their pancreas is actually working overtime to produce more insulin because the body's cells are resistant to the effects of insulin. Basically the cells, despite the presence of insulin in the bloodstream, don't become unlocked and don't let enough of the glucose in the blood into the cells. Scientists don't know exactly what causes this insulin resistance, and many expect that there are several different defects in the process of unlocking cells that cause insulin resistance. Medications for type 2 diabetes focus on different parts of this insulin-cell interaction to help improve blood glucose control. Some medications stimulate the pancreas to produce more insulin. Others improve how the body uses insulin by working on this insulin resistance. Physical activity also seems to improve the body's ability to use insulin by decreasing insulin resistance, which is why activity is so important in diabetes management. Find more information about diabetes in The Joslin Guide to Diabetes available from the Joslin Online Store. Continue reading >>
6 Signs You May Have Insulin Resistance
Insulin resistance and PCOS. You may have been diagnosed with the latter, but are not sure whether you also have the former. An insulin resistance test should be one of the first that your doctor does after diagnosing PCOS. Unfortunately, that’s not always the case… In this article I’ll outline some classic signs and symptoms to help inform you of whether you should be pushing for further testing. Of course, you’re smart women, you know this is not a diagnosis. I’m not a doctor, I’m a degree-qualified nutritionist. Even if I was a doctor, I could not diagnose you via a blog. You need to get a blood test done to know for sure. So, book one as soon as you can. What Is Insulin Resistance? Insulin is our storage hormone. When we eat, our body detects a rise in blood sugar (glucose). Our body doesn’t like blood sugar to be high. This is because cells can be damaged if it’s high for prolonged periods of time. These cells include those in the brain, liver, pancreas, heart, and eyes. Therefore, in response to high blood sugar, the body stores excess glucose in muscle and liver cells for later use. Insulin is the hormone that allows this to happen. It tells the cells to open up and let the glucose in. Insulin is excreted by the pancreas. It binds to a receptor on the cell and tells it to open up. This process is similar to the way a key opens a door. Insulin resistance occurs when insulin no longer works effectively due to chronic low grade inflammation. The key has been used too much, the lock gets worn and the key no longer fits. As a result, the blood glucose level stays high. The brain believes that more insulin is required. It sends a message to the pancreas to get it to make even more. However, the ‘lock’ is still worn so the extra insulin doesn’t hel Continue reading >>
