Heart Disease Sufferers Should Not Trust Fasting Blood Sugar Results

HeartHawk Health Guide
  • Like many other heart disease sufferers, especially those taking niacin as this supplement can raise blood sugar, I routinely (perhaps once per year) have my fasting blood sugar tested to remain on guard for diabetes and pre-diabetes.  As most of us are already aware, diabetes as well as any form of elevated blood sugar, is a significant risk factor for cardiovascular disease.  Given the ubiquity of the fasting blood sugar test as a measure of both endocrine and heart health one would think that a "normal result" (about 70-100 mg/dl) would signal an end to any worries and doubts.  You also couldn't be more wrong.  Let my story serve as a warning.

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    Because I take a great deal of niacin (2-3 grams daily) for my lipoprotein(a) problem, I have always taken the precaution of having my fasting blood sugar testing periodically.  It has always been normal or modestly elevated as one might expect and I have never given it another moment of thought.  However, I also am a member of a fascinating community of everyday people (some are doctors and medical professionals) that continually contribute personal research and test data as part of a community-based heart disease prevention and reversal program.  Several of the members provided information on how to get a free blood glucose meter and urged me to test my post-prandial blood sugar, not just my fasting blood sugar.  I did and the findings were astounding.


    Post-prandial is simply a fancy medical term for "after eating."  What I did was to fast each night, test my fasting blood sugar in the morning, eat a measured amount of carbohydrates from a single food, and then test it again at hourly intervals.  Here are some results.


    JUN27-7:30AM, 106mg/dL (all night fast)


    My fasting blood sugar is a little high but consistent with levels for those on high doses of niacin.  Next, I fasted the rest of the day except for water and other meds to get my blood sugar down.

    JUN27-8:21PM, 81mg/dL


    As you might guess it is getting lower from not eating.

    Eat one 330g (with peel) navel orange (no, I didn't eat the peel)

    JUN27-9:21PM 166mg/dL


    This value is way too high.  It should be at least below 140mg/dL.

    JUN27-10:46PM 126mg/dL


    Over two hours later and still not normal (below 126).

    JUN28-6:30AM 96mg/dL


    Test results after all-night fast.  Not a bad number.


    Eat 15g of Oat Bran

    JUN28-8:15AM, 178mg/dL


    Wow! One hour later and look at the number.  And I thought oat bran was healthy!

    JUN28-10:15, 133mg/dL


    Two hours later and still too high.  Now, let's fast for another two hours.


    JUN28-12:30PM 88mg/dL


    Now that's more like it but it took way to long to get my blood sugar back down to normal - another indication of impaired glucose tolerance (IGT).  Next, let's test what alcohol will do to me.  Drank one Bloody Mary (8 oz tomato juice, 1 oz vodka - cheap stuff - never waste good stuff in tomato juice!)

    JUN28-1:30PM 100mg/dL

    Hey, only 100!  At least I can still have a cocktail from time to time!  That's a bonus!

  • Now, I'm tossing in 15g of pretzel sticks to provoke a higher response - see you in an hour.

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    JUN28-2:30PM 133mg/dL

    Holy cow!  Only 44 pretzel sticks and look at the spike!  Yeah, I know on an empty stomach with no other food but STILL!  Here's the kicker.  The tomato juice was 10g of carbs plus the alcohol.  The pretzels were only 11g.  Tomato juice + vodka pops me 12mg/dL while the pretzels do 33mg/dL.  Hmmm!


    Time to fast again.


    JUN29-1:30PM 96mg/dL


    Funny how my morning blood sugars after fasting are higher than my daytime levels several hours after eating.  Theories suggest morning cortisol levels might be a factor.

    Eat 100g of blueberries

    I'll post again in about an hour

    JUN29-3:00PM 110mg/dL

    At 3:45 I ate a chicken breast (190g cooked weight)

    JUN29-4:50PM 93mg/dL

    OK, this is goofy the more I eat the more my BG drops.  I know its not carbs but geez, there should be SOMETHING!

    I wonder if there is some kind of circadian rhythm thing going on here.

    Finally, I had some lab work done to get a precise measurement form a venous blood draw.  The standard test is called an Oral Glucose Tolerance Test (OGTT) where you rapidly drink 75mg of glucose (orange flavored but - wow - talk about sweet.  Here are the results

    Fasting Glucose: 84mg/dL (great)

    1/2 Hour Glucose: 162  (uh oh)

    One Hour Glucose: 194 (just below diabetic)

    2 Hour Glucose: 166 (still way too way)


    So, here is the takeaway message.  Never trust a fasting blood sugar alone to tell you about your metabolic condition.  Had I not randomly tested my post-prandial blood sugar I never would have known that I was glucose intolerant.  Given that I am also very thin (BMI of 20) no doctor was ever concerned enough to test me.


    Diabetes is a significant risk factor for heart disease and it is more of a sliding scale in terms of risk.  Technically, I am not yet diabetic but I need to start paying attention to what I eat, getting more frequent exercise, and get tested more frequently (thankfully my Hba1c is still below 6.0% (but barely at 5.9%).  I hate to sound like a broken record but, here is yet one more reason to adopt "informed, self-directed healthcare" as opposed to "just trust your doctor healthcare".  Remember, you may have great doctors, but they have to be concerned with and treat thousands of patients and cannot focus on only one.  You can!


    Looking out for your heart health,




Published On: July 11, 2009