Tomorrow’s Medicine

New Test for Diagnosing Insulin Resistance Could Turn the Tide Against Diabetes

Diabetes is the scourge of our times, but we have been chasing the wrong culprits. A simple, $40 test of insulin resistance could put us on the right track.

Thomas Morrow, MD
Insulin resistance at a glance. This excerpt from a LabCorp report gives results for its lipoprotein insulin resistance test and some blood cholesterol measurements. The report is a model posted on the company’s website.

This article marks a milestone. My first Tomorrow’s Medicine column ran in the April 2003 issue of Managed Care. As I thought about what to write about for this column, I reflected back on the past 15 years.

Since the beginning, Tomorrow’s Medicine has focused on cutting-edge, highly technical, innovative developments coming out of the pharma, device, and diagnostic industries. I have focused on biotech drugs capable of targeting the most esoteric receptors, small-molecule therapies that potentially can cure cancer, artificial limbs controlled by the brain, fish skin that heals diabetic wounds, diagnostic tests that can detect the tiniest of abnormalities, and, most recently, our newfound ability to actually change the genetic structure of humans.

Thomas Morrow, MD

Shiny objects of medicine, all of them. New and glittery, they catch the eye and capture the imagination. But I have paid little, if any, attention to primary care, which is my specialty. Some FOMO? Perhaps. But after 15 years, it is time to make amends.

Body and soul snatcher

In the summer of 1883, Elliott Joslin, a medical student at Harvard, documented his first consultation with a patient with diabetes. He dedicated a lifetime to diabetes and became the first doctor to specialize in the disease. The Joslin Diabetes Center in Boston is named after him. Joslin documented what he considered a rapid increase in the number of Americans with diabetes and calculated the prevalence of diabetes at about 0.3%. Now roughly 12% of American adults have diabetes, or about 30.2 million Americans.

One way to think about diabetes is that it is a reflection of lifestyle changes that are unprecedented in human history. This results not only in diabetes but a plethora of chronic conditions that are now among the most devastating diseases in human history: obesity, metabolic syndrome, hypertension, stroke, heart disease. And there’s developing evidence of a connection between diabetes and Alzheimer’s disease, so much so that some people are calling Alzheimer’s disease type 3 diabetes.

These are the killers of body and soul in the developed world today. A host of causal factors are responsible for the scourges: bad science, bad policy, profit-driven food companies, and some preconceived ideas that kept scientists, policymakers—and, yes, physicians—focused on the wrong culprits for half of a century.

For example, in nutrition, we mobilized a war on fat (especially animal fat) and picked the wrong replacement fats (high omega-6 oils and trans fat) along with carbs—lots and lots of carbs. We ignored more than 150 years of data on our increasing sugar intake and watched as diabetes and other diseases increased logarithmically.

How did we respond? We launched an expensive armada of new drugs, diagnostic tests, devices, and surgical techniques. Yet the prevalence of diabetes increased, as did the prevalence of its metabolic precursor, insulin resistance, which affects half of all Americans.

It is pretty simple, actually. Continually high blood glucose levels from sugar and carb intakes result in high levels of insulin to process that blood glucose. But those high levels result in cells “ignoring” the insulin and, in a feedback loop, that leads to higher levels of insulin and the vicious cycle of insulin resistance. Insulin resistance is also associated with the build-up of fat in the liver and other tissue.

Insulin resistance can be measured, but it is expensive and time consuming. Now, a simple, inexpensive but highly innovative test, the lipo­protein insulin resistance score, or LP-IR, is available. It is marketed by LabCorp under the name of NMR LipoProfile.

The price? About $40, a far cry from almost any new pharmaceutical.

I would be more than willing to bet a mortgage payment that 95% of readers have never heard of this test, but the technology to conduct it was available when I was an undergrad way, way back in the ’70s. The nuclear magnetic resonance machine is a forerunner of today’s sophisticated MRI scanners, and these machines can quantify a wide range of compounds based on their resonance “signatures.”

Researchers have been working with nuclear magnetic resonance machines for years in hopes of developing a way to simplify the diagnosis of insulin resistance. Once you can quantify insulin resistance, you can start to manage it. Insulin resistance can be diagnosed years, even decades, before prediabetes and diabetes, giving you much more time to reverse it and prevent the complications that result. As seen in multiple landmark studies, including the Women’s Health Study, Multi-Ethnic Study of Atherosclerosis, and JUPITER, the LP-IR score indicates not only the magnitude of insulin resistance but also an individual’s future risk for developing type 2 diabetes regardless of blood glucose values, waist circumference, or BMI.

By combining the specific magnetic signatures of molecules in the blood in an algorithmic fashion (it actually “sees” thousands of them all at once), the LP-IR test can also accurately calculate the LDL, HDL, and total cholesterol concentration. What’s more, it measures the size and number of lipid particles, information that is related to their atherogenic potential.

Recent advancements have led LabCorp to seek FDA approval for another score also derived from the same signature analysis, the GlycA, a novel biomarker of systemic inflammation and cardiovascular risk. It is based on the same nuclear magnetic resonance technology and uses different data from the signals of a host of other “bad guys” in the blood, including but not limited to C-reactive protein, interleukin 6, and haptoglobin.

Back to the future

But a diagnostic test is only as good as the treatments it begets—and the simpler, less expensive the treatments, the better. We have them for insulin resistance.

Two recent studies done on either side of the Atlantic have demonstrated two different methods that actually reverse not only insulin resistance but also diabetes!

A study conducted in England and Scotland showed that weight loss could lead to remission of diabetes. True, it was a major amount of weight loss—30 pounds. But diabetes remitted in 86% of those who lost that amount of weight and the results were promising in those who lost less. And compare weight loss with all the medications and procedures that ensue from diabetes.

A recent U.S. study added to the evidence that reducing intake of sugar and other highly refined carbohydrates and increasing dietary fat can result in a favorable state of nutritional ketosis: insulin levels drop precipitously and the damage done by insulin resistance and high blood glucose levels starts to heal.

New technology is hard to ignore. But perhaps we need to take a break and go back to the psychology of behavior change and basics. Perhaps we should try to focus on behavior change instead of depending on $10,000 drugs and $40,000 procedures. Perhaps primary care can start to reverse these troubling trends. And perhaps a simple, inexpensive test can take us back to the time of Elliot Joslin. I just hope it doesn’t take another 135 years.

Thomas Morrow, MD, is a retired physician executive and part-time consultant. He has been the founding medical director of five HMOs and a disease management company, a medical director at Genentech, and president of the National Association of Managed Care Physicians. You can contact him at thomasmorrowmd@hotmail.com.