Understanding Insulin Resistance
Insulin Resistance is a syndrome (not a disease) in which certain cells in the body have a sluggish reaction to blood sugar (also known as blood glucose.) Specifically, in insulin resistance fat and skeletal muscle do not efficiently remove glucose from the blood stream. The resulting increase in blood glucose causes the pancreas to secrete even more insulin in order to clear glucose from the blood stream. This leads to hyperinsulinemia (too much insulin circulating in the blood stream), which causes a wide range of problems.
Insulin resistance is the underlying mechanism of Type II (so-called “Adult Onset”) diabetes – every Type II diabetic is by definition insulin resistant. Type II Diabetes is simply severe insulin resistance – usually of long standing. Insulin resistance is receiving increased recognition as the precursor to diabetes, so that some doctors are making the diagnosis of “pre-diabetes,” which usually means marked insulin resistance in an individual that does not meet the technical definition of deabetes. It takes years for most people to progress from insulin resistance to diabetes: however, the latest medical research shows that the damage that we associate with diabetes – primarily heart disease and eye and kidney problems – begins relatively early in the development of insulin resistance, long before a person has diabetes.. A great deal of published medical research is beginning to show that insulin resistance is one cause of a range of common and troubling illnesses: certain types of cancer; sleep apnea; high blood pressure; cognitive deficits of aging, including Alzheimer’s; and many others.
The cause of insulin resistance is most likely a combination of genetics, excess caloric intake (too much food!), and a sedentary lifestyle (too little exercise and physical activity.) In any one person, any one of those three factors may be the primary cause. For instance, an individual with a strong genetic tendency to insulin resistance may develop signs of it even when they are at a normal weight, eating what they’ve always eaten. Another person may have only a slight tendency to insulin resistance, but as a result of eating too much (which also causes weight gain) and exercising too little, they develop insulin resistance manifestations despite a lack of family history of diabetes. There are a couple of extremely important caveats here: One, it has never been proven that an excess of carbohydrate or simple sugars causes insulin resistance. It is likely that too much simple sugars from sweets and high-fructose corn syrup (the sweetener in sodas and other manufactured food items) does overburden the insulin-secreting cells of the pancreas (know as beta cells, in the Islets of Langerhans.) However, at this point it would be speculative to state that this causes insulin resistance. We do know, however, that excessive calories from most any source have to be stored as fat in the body. There is probably some type of feedback mechanism involving fat cells, muscle cells, the pancreas and the liver that contributes to the development of insulin resistance in susceptible individuals when a certain threshold of body fat, caloric intake, plasma free fatty acids, and stored cellular energy is reached (especially in the absence of adequate skeletal muscle activity – exercise.) . Thus, it is highly unlikely that any person who exercises adequately – adequately for their genetic makeup – will develop insulin resistance. Fitness is the most important, and the only absolutely proven, factor that influences insulin resistance. In other words, Lance Armstrong can consume 10,000 calories an hour during the Tour De France, and it doesn’t really matter whether those calories are from mayonnaise or white sugar – he’s burning so much energy, and there is such a demand for blood sugar by his muscle cells, that it is nearly impossible for him to develop insulin resistance at that level of fitness and caloric expenditure.
Diagnosing Insulin Resistance
Insulin resistance, metabolic syndrome, syndrome X, pre-diabetes are all different names for the same condition, and reflect what a “hot topic” this has become. As such, there is a plethora of information circulating about this subject. And like all information, some is good, some is bad. You may have heard of various ways of determining if you are insulin resistant, such as whether you are “apple-shaped” or “pear-shaped”, which is a visual way of asking whether you store excess weight (fat) in your abdomen and belly, or in your hips. However, the only reliable way to determine whether or not you are insulin resistant is through standard blood work (some labs offer insulin resistance panels – these are usually unnecessary, and overly expensive.)
The following two lab indices are clear indicators of insulin resistance:
- First, anyone with Type II Diabetes, which technically means anyone with a fasting glucose of over 120 on two separate occasions, or a Hemoglobin A1C over 6.0, is by definition insulin resistant.
- Second, a Triglyceride to HDL Cholesterol ratio of 3:1 (per Gerald Reavens, MD, Stanford University)
Elevations in the following lab indices are suggestive of insulin resistance, but are not diagnostic. There are many possible causes why these might be elevated: insulin resistance is only one of them.
Elevated Uric Acid
Elevated Liver Enzymes
Elevated Fasting Serum Insulin
Elevated Fasting serum glucose (over 99)
In addition, the following can increase suspicion of insulin resistance, but need to be considered in the context of the rest of a person’s health history:
Body Mass Index (BMI) of over 30
Waist circumference greater than 40 inches in men, 35 inches in women
Family History of Type II Diabetes
African American, American Indian, Hispanic American/Latino, or Asian American / Pacific Islander Ancestry
Keep in mind that if you are on a medication that effects blood sugar or lipids, such as Actos or a statin medication, your lab numbers have been altered by the medication and are no longer useful to tell you if you are insulin resistant.
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In practice, I work with patients with insulin resistance, pre-Diabetes, and Diabetes. I use dietary coaching and modification, exercise and lifestyle counseling, and nutritional supplementation in order to reverse the manifestations of insulin resistance and gain control over Diabetes. I also work with patients concerned about diabetes due to family history or for other reasons, to evaluate their risk and take a preventive approach. Please explore the rest of this website, to learn more about the general philosophy and practice of naturopathic medicine. Of course, I am happy to meet with you to discuss your particular situation, and to explore with you how I can help you feel your best.