| @@@Testing For Early Insulin Resistance ---Dr. Michael Cutler | Jul 09, 2012 | Comments 1
Knowing if you are becoming insulin resistant is crucial to your health future. When cells start to become resistant to insulin’s influence in taking sugar out of the blood, your risk for diabetes and heart disease grows. So it’s important to recognize some of the early signs of this difficulty.
Testing For Early Insulin Resistance And Metabolic Syndrome
There really aren’t any accepted standards or national guidelines for insulin measurement. Because insulin resistance occurs on a continuum, it takes more than just measuring insulin levels in order to catch it early. Here are the tests that I discuss in this article that can assist you in determining if you are trending toward insulin resistance:
Adiponectin
Proinsulin
HgbA1c
Fasting Insulin, then 30 minute and 2-hour insulin after 75g glucose load
Fasting glucose test followed by a 2-hour glucose test (with a 75g glucose load)
Comprehensive metabolic panel (a common medical test)
GGTP (an additional liver function test)
Uric acid
Also, a newer test, called a nutrient analysis, is very valuable in determining what nutrients you are lacking in your diet or not absorbing well. This is not a standard test your doctor can order along with the others. Rather, it is done at a specialty lab such as Spectracell Laboratories (www.spectracell.com).
@@@Learning The Lab Test Numbers
You’ll want to know how to interpret these tests. If your doctor does not know, you’ll have to be the expert.
The first test you should understand is for adiponectin, a helpful, fat-derived protein that plays an important role in regulating blood sugar and lipid metabolism. It moderates fat tissue, promotes insulin sensitivity and suppresses heart blood vessel inflammation (i.e., it is anti-inflammatory). It is a unique marker that is a common factor in obesity, inflammation, dyslipidemia, glucose intolerance, and the risk of heart disease and diabetes. Therefore, a declining adiponectin level is an early marker of insulin resistance and metabolic syndrome.
Next is the test for proinsulin. Proinsulin is simply the precursor molecule to insulin. Proinsulin gets split apart to form insulin and “C-peptide.”
Why is it important to measure proinsulin A number of studies suggest that proinsulin concentrations correlate strongly with insulin resistance.1 It is the ratio of proinsulin-to-insulin that gives the clue. Proinsulin has also been shown to be a strong predictor of type 2 diabetes2 as well as a tool for management of diabetics.3
I@@@nsulin Measurements
Insulin measurements are important, too. A fasting insulin level followed by another measurement of insulin level two hours after consuming 75 grams of glucose is the standard. To indicate normal health, these tests should show less than 10 μIU/ml in the fasting state; less than 57.5 μIU/ml 30 minutes after the glucose ingestion; and less than 25 μIU/ml 2 hours after. Values higher than these indicate your insulin is too high and, therefore, in the resistant stage.
Hemoglobin A1C is a measurement of blood sugar over a three-month average. Even when it is barely elevated (at 5.4 percent to 6.4 percent), it is an early indicator of rising blood sugar and reflective of inadequate insulin function. The HbA1c level is also a way to determine your risk of dying early from these inflammatory illnesses, including heart disease. In a British study4 reported in 2001, researchers concluded: “The predictive value of HbA1c for total mortality was stronger than that documented for cholesterol concentration, body mass index and blood pressure.”
@Blood Sugar
Blood sugar is also important to measure, of course. According to the American Diabetic Association, when your fasting blood sugar is between 100-125 mg/dl, you are considered to have impaired glucose tolerance; and if it is more than 125 mg/dl, you are frankly diabetic. They also say that if your two-hour postprandial blood sugar is between 140-199 mg/dl you have impaired glucose tolerance and if more than 199 mg/dl, you have frank diabetes.
However, in the anti-aging medicine circles, we think your numbers don’t even have to be elevated that much to indicate impending disease.
A meta-regression analysis of published data from 20 studies of 95,783 individuals followed for 12.4 years was reported in a 1999 issue of Diabetes Care. The researchers concluded that there is a risk of heart attack even from minimally elevated blood sugar, and well below the threshold for diabetes.5 Furthermore, even though a “normal” fasting blood sugar is below 100 mg/dl, a study in a 2005 New England Journal of Medicine showed that fasting blood sugars above 87 mg/dl correlates with increased risk and impending type 2 diabetes.6
@A Strategy For Determining Early Disease Development
The earliest detection of insulin resistance and metabolic syndrome takes place when adiponectin drops below normal values. At that point, you still expect to see the other tests in the normal range (glucose, HbA1C, insulin and proinsulin). At this early stage, you’ll definitely want to look seriously at eating nutrient-rich whole foods and aiming for 50 percent or more of your diet as raw foods. Exercise and stress management are also important.
By the time proinsulin levels also rise (along with low adiponectin, high insulin and rising post prandial blood sugar levels), you’re in the third stage of insulin resistance. However, your fasting blood sugar may still be in the normal range; and, therefore, it is a late finding.
When you know all these facts, you’re practically an expert in insulin resistance, and you understand the ways to detect it before you become a full-on diabetic. Also, since insulin resistance is the main finding in metabolic syndrome, the precursor to diabetes and heart disease, you’ll want to learn important strategies to treating it — which I’ll cover in my next column.
To you best health and to feeling good,
Michael Cutler, M.D. Easy Health Options
1 Mykkänen L, Haffner SM, Hales CN, et al. The relation of proinsulin, insulin and proinsulin-to-insulin sensitivity and acute insulin response in normoglycemic subjects. Diabetes. 1997; 46: 1990—1995.
2 Hanley AJG, D’Agostino R Jr, Wagenknecht LE, et al. Increased proinsulin levels and decreased acute insulin response independently predict the incidence of type 2 diabetes in the Insulin Resistance Atherosclerosis Study. Diabetes 2002 Apr;51(4):1263-70.
3 Pfutzner, A, Kunt T, et al. Fasting Intact Proinsulin Is a Highly Specific Predictor of Insulin Resistance in Type 2 Diabetes. Diabetes CareMarch 2004; 27(3):682-687.
4 Khaw KT, et al. Glycated haemoglobin, diabetes, and mortality in men in Norfolk cohort of European prospective investigation of cancer and nutrition (EPIC-Norfolk). BMJ, 2001;322(7277):15-18.
5 Coutinho M, et al.The relationship between glucose and incident cardiovascular events. Diabetes Care, 1999. 22(2): 233-40.
6 NEJM 2005;353:1454-62.
@@@Co-Association Between Insulin Sensitivity and Measures of Liver Function
This interesting recent study1 reports on the relationship in apparently healthy men (472 men free of coronary heart disease and diabetes and taking no blood pressure-, lipid-, or uric acid-lowering medication) of various measures of liver function and insulin sensitivity. This could be a useful way to help evaluate one’s insulin sensitivity with simple blood tests.
Insulin sensitivity S1 was determined using “the minimal model of glucose disappearance.” The insulin sensitivity was found to correlate independently with serum gamma-glutamyl transferase (GGT), aspartate transaminase, and alkaline phosphatase activities; blood pressure; leukocyte count; and erythrocyte sedimentation rate.
The authors explain that there is a difference between correlation and clustering of risk factors. “For example, dyslipidemia and hypertension may both be associated with insulin resistance, but processes underlying their associations could be shared or separate. Evaluation of simple correlation will not discriminate which alternative predominates, whereas this can be achieved by an assessment of co-association. Co-association will be present when high or low levels of a particular combination of risk factors show a strong tendency to be present together [clustering] in individuals.” “In apparently healthy men, blood pressure and indices of subclinical inflammation do not cluster with other insulin resistance-related risk factors, despite correlating with insulin sensitivity. In contrast, both GGT activity and uric acid concentrations correlated with insulin sensitivity and co-associated with insulin resistance-related risk factors and are therefore components of a true risk factor cluster.”
“Among inflammation-related variables, S1 was a significant independent negative determinant of serum globulin concentration, ESR, and WBC.” “Among liver function-related variables, S1 was a significant independent negative determinant of GGT, AST, and ALP activities and of uric acid concentrations and was an independent positive determinant of serum bilirubin concentration.”
1.Godsland and Johnston. Co-association between insulin sensitivity and measures of liver function, subclinical inflammation, and hematology. Metab Clin Exp 57:1190-7 (2008).
http://care.diabetesjournals.org/content/32/4/695.full |
제 목 : predictor of IR
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