Testing for Diabetes: How and Why
November 5th, 2019
In my first article on diabetes, I discussed the different types of diabetes (including a few that may be new to you), the symptoms accompanying each type, and the negative effects on your health. This information is so important for all of us! Diabetes could easily be called an epidemic; it is rampant around the globe. The World Health Organization recently reported that the number of people with diabetes has risen from 108 million in 1980 to 422 million in 2014.1 To sound the alarm even louder, the Center for Disease Control reports that one in four people who have diabetes don’t even know it.2
Now that I have your attention, let me outline a number of tests you can take to measure your blood sugar to find out where you may be on the diabetes spectrum. This will arm you with the knowledge necessary to move forward in your health journey.
What is Diabetes?
Just to recap (if you missed it in my first article), diabetes is a chronic disease that occurs either when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces, resulting in high blood sugar.3 The problem is compounded because high blood sugar causes inflammation and can lead to a host of health concerns for those who have any of the forms of diabetes. Blindness, kidney failure, and cardiovascular disease are a few of the more serious health risks for those with diabetes. Let me explain how diabetes sets you on the path for heart complications.
Can Elevated Blood Sugar Cause Heart Problems?
Well, diabetes contributes to a process called “glycation.” Glycation is the result of insulin not properly metabolizing sugars, which are high if you are diabetic. This excess sugar, which should be metabolized and used for energy,4 remains in your bloodstream and attaches to proteins and lipids (fats). Glycation then forms harmful advanced glycation end products (literally AGE!) These AGE molecules do just that: age your body.
These damaging little molecules are destructive to the collagen in your body, including the arteries and blood vessels in your heart. They become brittle as a result and plaque forms in your arteries and blood vessels. This vascular damage can lead to heart attacks and strokes.5 Advanced glycation end products are considered the major cause of most diabetic complications due to the increased sugar levels in the blood. AGEs have been linked to Alzheimer’s (type 3 diabetes), neuropathy (nerve damage causing numbness), retinal (eye) disease, and kidney failure.6
The good news is that diabetes, for the most part, can be controlled and even reversed through diet and lifestyle. The first step is assessing your risk factors, so I recommend everyone take a blood test. If you have type 1 diabetes, it is a good idea to test for Hashimoto’s and Celiac disease. Likewise, if you have type 2 diabetes and are over age 60, it is a good idea to have your healthcare professional evaluate you for if you have early signs of dementia, which can progress into Alzheimer’s.
I’ll walk you through some tests you can take, and explain what levels show.
What Are the Diabetes Tests and Levels?
Most of the tests for diabetes measure blood glucose or insulin levels, but do so in a variety of different ways. The top range listed is “ideal – normal” rather than just “normal,” because optimal health is the goal — not just “normal” health. The most common tests include:
Glycated Hemoglobin or A1C Test:
This is the most common blood sugar test. It measures how many of your red blood cells are glycated, or coated with sugar. It provides your average blood glucose for 2 to 3 months without fasting or using a sweet substance.
Random Blood Sugar Test:
With this test, a blood sample will be taken at a random time. Regardless of when you last ate, a random blood sugar level test is taken.
- Ideal – Normal: below 125 mg/dL (6.9 mmol/L)
- Prediabetes: 126 mg/dl or higher
- Diabetes: 200 milligrams per deciliter (mg/dL) — 11.1 millimoles per liter (mmol/L)mg/dl or higher
Fasting Insulin Test:
For this test, you can’t eat or drink anything for 8 hours before the test is administered.
- Ideal – Normal: below 8uIU/ml (ideally, below 3)
- Mild Insulin Resistance: 5 mg/dL (5.3 mmol/L) mg/dl
- Moderate Insulin Resistance: 10 uIU/mL (>60 pmol/L) mg/dl or higher
- Severe Insulin Resistance: greater than 12 uIU/mL (>72 pmol/L)
Insulin Tolerance Test:
In an insulin tolerance test, insulin is injected into a patient’s vein, after which blood glucose is measured at regular intervals.
Ideal – Normal:
- Fasting glucose is between 75–95 mg/dL (4.2–5.3 mmol/L).
- Fasting insulin is between 3–8 uIU/mL (18–48 pmol/L).
Mild Insulin Resistance:
- Fasting glucose is greater than 95 mg/dL (5.3 mmol/L).
- Fasting insulin is greater than 8 uIU/mL (>48 pmol/L).
Moderate Insulin Resistance:
- Fasting glucose is greater than 100 mg/dL (>5.6 mmol/L).
- Fasting insulin is greater than 10 uIU/mL (>60 pmol/L).
Severe Insulin Resistance:
- Fasting glucose is greater than 110 mg/dL (>6.1 mmol/L). Greater than 125 mg/dL (>7.0 mmol/L) is diabetes.
- Fasting insulin is greater than 12 uIU/mL (>72 pmol/L).9
Fasting Blood Sugar Test:
In this test, a blood sample will be taken after an overnight fast.
- Ideal – Normal: less than 95mg/dl or less per deciliter
- Prediabetes: 100 to 125 mg/dL (5.6 to 6.9 mmol/L)
- Diabetes: 126 mg/dL (7 mmol/L) mg/dl or higher on two separate tests
Oral Glucose Tolerance Test:
For this test, you will fast overnight, and the fasting blood sugar level is measured. Then you drink a sugary liquid, and blood sugar levels are tested periodically for the next two hours.
- Normal: 140 mg/dL (7.8 mmol/L) less
- Prediabetes: 140 and 199 mg/dL (7.8 mmol/L and 11.0 mmol/L)
- Diabetes: more than 200 mg/dL (11.1 mmol/L) after two hours
Fasting Plasma Glucose (FBC):
This test is usually done in the morning to check your fasting blood glucose levels. Fasting means not having anything to eat or drink (except water) for at least 8 hours before the test.
- Normal: <100 mg/dl
- Prediabetes: 100–125 mg/dl
- Diabetes: <125 mg/dl or higher
Oral Glucose Tolerance Test (OGTT):
The OGTT is a test that checks your blood glucose levels before and 2 hours after you drink a sweet drink designed for the test.
- Normal: <140 mg/dl
- Prediabetes: 140–190 mg/dl
- Diabetes: 200 mg/dl or higher
A modification of this test is commonly used to check for gestational diabetes between weeks 24 and 28 weeks of pregnancy. After eating normally in the days prior to the test, you will fast for 8 hours, then drink a glucose solution. After one hour, your blood will be tested.
- Normal: <140 mg/dl
- Diabetes: >190 mg/dL
If your range falls between 140 mg/dl and >190 mg/d after the one-hour test, your healthcare provider will likely perform a three-hour test. For the three-hour test your blood will be checked several times after fasting for eight hours and then drinking the solution to see how your body manages glucose over time.
- Normal fasting: <95 mg/dL
- One hour after drinking the glucose solution, normal: <180 mg/dL
- Two hours after drinking the glucose solution, normal: <155 mg/dL
- Three hours after drinking the glucose solution, normal: <140 mg/dL
If one of the results is higher than normal, your healthcare professional may schedule another test in four weeks. If a second test has higher-than-normal results, you will be diagnosed with gestational diabetes.10
Type 1 Diabetes Test:
For type 1 diabetes, urine will be tested to look for the presence of ketones, a byproduct produced when muscle and fat tissue are used for energy because the body doesn’t have enough insulin to use the available glucose.
A healthcare professional may also test for destructive immune system cells called autoantibodies, which are a marker for autoimmunity. Four particular autoantibodies are markers of autoimmunity in type 1 diabetes:
- Islet Cell Antibodies (ICA) – Present in 69%-90% and 54%-75% of type 1 patients.
- Glutamic Acid Decarboxylase Antibodies (GAD-65) – Present in 80% of type1 patients.
- Insulin Autoantibodies (IAA) – Present in about 70% of children at time of type 1 diagnosis.
- Tyrosine Phosphatase Antibodies(IA-2A)11
Alzheimer’s or Type 3 Diabetes Test:
While there is not one particular all-inclusive test for dementia, Alzheimer’s and other types of dementia are carefully diagnosed by a healthcare professional based on many factors including:
- Medical history
- A physical exam
- Lab tests
- Characteristic changes in thinking (MMSE Exam, see below)
- Day-to-day function and behavior12
To screen if you have early stages of dementia or late stage dementia (Alzheimer’s), your doctor can administer a few different exams to gauge mental acuity. One such test is called the Mini Mental State Examination or MMSE. The MMSE measures concentration, memory, and language. The results determine the extent of dementia that is present and the speed of its progression.
- Normal: Score of 27 or higher
- Moderate Dementia: Score between 10 – 20
- Severe Dementia: Score less than 10
Note: A lower score on the MMSE does not always mean the patient has dementia, as other conditions may be present, which a doctor can diagnose upon further testing.13
What are the Autoimmune Tests and Levels?
All of the tests I have outlined are for diabetes, and will equip you with the knowledge of where you are on the diabetic spectrum. However, I also recommend anyone with diabetes have other tests conducted for autoimmune conditions which commonly accompany diabetes. These tests will give you a picture of where you fall on the autoimmune spectrum, so you can address all your health conditions, and take back your health completely!
Celiac Disease Test:
Celiac disease commonly accompanies type 1 diabetes, so it is a good idea to have a celiac test administered by your healthcare professional if you have type 1 diabetes, because often people with this condition don’t even realize they have it. There are two blood tests used to diagnose it:
- Serology testing: This test detects the presence of antibodies in your blood. Elevated levels of certain antibody proteins indicate an immune reaction to gluten.
- Genetic testing: This test measures human leukocyte antigens (HLA-DQ2 and HLA-DQ8), which can be used to rule out celiac disease.
If you are going to have your blood tested for celiac, do not eliminate gluten from your diet, as it might make the results of blood tests appear normal. Gluten must be present in your blood to test if antibodies to it are present. If the results of the tests indicate celiac disease, your doctor will probably order an endoscopy as well. This is the use of a tiny camera to measure damage to the villi in the small intestine.14
Hashimoto’s Thyroiditis Test:
It is also a good idea to have a test conducted for Hashimoto’s thyroiditis, or hypothyroidism, which can be diagnosed when a doctor determines the presence of particular symptoms including:
- A goiter, an enlarged thyroid gland, upon physical exam.
- Laboratory tests showing hypothyroidism- elevated thyroid stimulating hormone (TSH). A normal range for TSH is 0.4 mU/L. If TSH is higher than 4.0 mU/L on repeated tests, it indicates hypothyroidism.15
- Low thyroid hormone (Free thyroxine or Free T4) levels.
- TPO antibody is elevated.
C-reactive Protein (CRP) test for inflammation:
A common risk factor for cardiovascular disease is diabetes, so I recommend a CRP test if you have any form of diabetes. The American Heart Association (AHA) recommends the following guidelines for assessment of cardiovascular disease risk:
- Normal or Low Risk: CRP levels of 1 mg per liter or lower
- Moderate Risk: CRP levels of 1-3 mg per liter
- High Risk: CRP levels greater than 3 mg per liter
- Heart Attack: CRP levels greater than 10 mg per liter16
Antinuclear Antibody (ANA):
This test is used to detect certain autoimmune diseases including Sjogren’s syndrome and lupus, among others. Antinuclear antibodies (ANA) are produced by your immune system when it doesn’t distinguish between your own cells and invaders. When this happens, you produce something called autoantibodies, which can be detected in your blood. They’re termed “antinuclear” because they target substances within the nucleus of a cell. ANA cause inflammation, fatigue, and pain, particularly in joints and muscles.
There are two types of ANA test: the indirect fluorescent antibody, in which blood cells are mixed with a reagent and examined under a slide, and the immunoassay, an automated test that looks for certain proteins produced in an immune response and compares them against a standard determined by the particular lab.
- Indirect fluorescent antibody (IFA) — the results are reported as a titer, or ratio. The lower the dilution ratio at which ANA is detected, the greater the amount of autoantibody present. Low levels of ANA are in the range of 1:40 to 1:60. A titer in the range of 1:160 will likely mean your healthcare provider will order additional tests for autoantibodies that are specific to a certain illness.17
- Immunoassay — the results are usually reported as a number with an arbitrary unit of measure (abbreviated as a “U” on the report, for example). A positive result from this method will be a number of units that is above that particular lab’s reference number for the lowest value that is considered positive.18
Increased levels of homocysteine, an amino acid in your blood that you make from methionine, another amino acid found in meat and fish, is often associated with heart disease. However, it has also been linked to autoimmune disease, particularly rheumatoid arthritis, and IBD.19 Homocysteine levels in the blood are measured as micromoles/liter (µmol/L); a micromole is a scientific measurement used to quantify extremely small quantities.
- Optimal: Between 10 to 12
- High: >15
- Low: <1020
Whatever your diabetes and autoimmune test results show, there is a way you can take back your health and reverse diabetes and autoimmunity. If you need information on the types of diabetes please see my first article in this 3-part series. In my next article on diabetes, I explain 6 ways you can naturally balance your blood sugars, whatever level they are, and return them to optimal levels.
- David Perlmutter, Grain Brain, (New York, New York, 2013), 221