The topic of insulin action (resistance and sensitivity) has come up multiple times over the years in my articles and posts, but it is admittedly much more complex than I often make it out to be. In a DiabetesInControl article I posted last summer, you can find a short list of all the factors that can potentially improve insulin action (basically insulin sensitivity). In reality, though, sometimes it is impossible to know exactly what is affecting it.
Recently, I spent the majority of two days traveling in a car and not exercising, and I reached the point where I could barely eat anything without my blood glucose rising over 200 mg/dL, even when giving twice or three times my usual insulin dose for the same food. Just sitting in a car and not exercising resulted in full muscle glycogen stores, with no room to store more carbohydrate—hence the resulting muscular insulin resistance. Even I was frustrated by dealing with my lack of immediate control, even though I knew that physical inactivity was the cause.
Based on my personal experience, I want to take some of the burden of always being on top of blood glucose levels off of anyone with diabetes. Sometimes you can do everything right and your insulin action can still less (or more) than expected. It’s not necessarily your fault, nor can you always anticipate how to best combat it.
Here is my short list of factors from my personal experience that can make people insulin resistant one day and insulin sensitive the next—and not always as you would expect. I call those the “head scratching days,” but sometimes it’s more like hair pulling!
If you’ve had a prior hypoglycemic event
Going too low and staying there for a while (such as during sleep) may increase insulin resistance more than just having a simple hypo event and treating it quickly. Morning insulin resistance is the most variable anyway (higher levels of cortisol then). It is admittedly my most frustrating time of day since often the same exact breakfast and starting blood glucose level will result in a different rise in blood glucose levels. Sometimes an overnight low explains it, but sometimes it doesn’t.
If your blood glucose has been running high
Hyperglycemia begets more hyperglycemia because it causes insulin resistance. That is why sometimes it takes way more insulin than you would expect just to get back to a normal level, and it may take hours. Try not to overdose on insulin in the meantime (especially you’re your bedtime) or you’ll end up low and back on the blood glucose rollercoaster.
If you’ve drastically changed your normal exercise patterns
Heightened insulin action due to your last workout is fleeting, and sitting in a car for two days is a dramatic change for me, particularly since my basal and other insulin doses are set for being active, not for being inactive. Even a week of detraining (due to injury, vacation, sickness, or other life event) can cause insulin resistance to rise rapidly in everyone, not just in people with diabetes. If you start working out more overall or just more regularly, your overall insulin needs (including basal) may also decrease. Just try to be as consistent as possible to make it easier for yourself to manage.
If you ate more calories, fat, or protein than you realized
Eating out at restaurants is really hard for me because no matter what I order, it seems like it takes two to three times my usual insulin doses to cover it. It is likely because protein and fat kick in and affect blood glucose levels later on (3-6 hours after a meal) and restaurant meals have more calories in them than most home-cooked meals. Fat, sugar, and salt keep people coming back to the restaurant for more! You can strategically use protein and fat intake overnight or after exercise to help prevent later-onset lows, though.
If you’re stressed, mentally or physically
It is truly amazing how much of an impact that stress has on blood glucose levels. Just try going to court (if you’re not an attorney) and keep your blood glucose in check while your adrenaline is pumping. Your cortisol levels also go up and raise blood glucose. So, just being stressed out during the day, or being exhausted or sick (physical stress), can cause insulin resistance. Try to take deep breaths and get some exercise during the day to combat both the stress and the resulting insulin resistance. Getting sick and running a fever or having an infection can also drive your blood glucose and insulin needs up.
If you’re lacking on sleep
Not getting enough sleep is physically (and often mentally) stressful. I knew an oceanography professor who had to harvest samples at sea, sometimes for days at a time, on no sleep. The longer he went without sleeping, the higher his insulin resistance became. Lack of sleep may be causing some of your unexplained highs since more cortisol (a stress hormone) is released when you are sleep-deprived.
If you’ve had some alcohol to drink
Alcohol interferes with the normal function of the liver in making and releasing glucose. While it can lead to hypos, it can also be used strategically to relieve insulin resistance or to keep it in check—and luckily it does not take much alcohol to have an effect. An older guy called me on a diabetes hotline I was manning for a TV station once and explained that he usually had two shots of whiskey at night and woke up with good blood glucose levels, but that if he ever had to skip the whiskey, he would wake up too high. He wanted to know what he should do. I said, “Keep drinking the whiskey!” No more than one drink daily for women or two for men is recommended, though, so do not overdo it or you raise your risk of other health problems.
If it’s a certain time of the month (women only)
You may have everything else accounted for and your blood glucose levels are still skyrocketing for apparently no reason—except that you’re either ovulating (and releasing extra hormones that promote insulin resistance) or in the few days or week leading up to your period when insulin resistance is highest. This has been a bigger issue for me later in life since my cycles seem to be more extreme, although I do not know if this is the case for all women. I helped a diabetes educator recently figure out that she was pregnant when she simply could not figure out why her blood glucose levels were so whacked out; it can be as simple an explanation as that (and hopefully a desired one, if pregnant).
Regardless of what is causing your (unexplained) insulin resistance, just try to manage your blood glucose levels the best you can and lose the guilt over not knowing exactly why it is high and not being totally in control 24/7. Even the most knowledgeable of us have our head scratching and/or hair pulling days trying to figure it out!