#63 February 2019 Update on My T1D Management

This is a monthly update on my glycemic management of type 1 diabetes (T1DM) using Humalog and Lantus insulin injections with resistance exercise and a ketogenic whole-food diet as described in my book, The Ketogenic Diet for Type 1 Diabetes also available on Amazon in print. My other book, Conquer Type 2 Diabetes with a Ketogenic Diet, is also available on Amazon in print. I would appreciate anyone who has read and benefited from either of these books to leave a review on Amazon. The number and ratings of the reviews are used by Amazon to order the search results when people are looking for books on diabetes.

I now also offer online coaching for those who need some individual attention in optimizing their glycemic control for either type 1 or type 2 diabetes. See the Coaching page for more info.

I have made several changes over the past seven months in my attempt to further improve the glycemic control of my T1DM. Many of the changes have not been successful. However, I don’t think it is possible to predict their success in advance and at least I now know what doesn’t work at this time in my life. For example during these past seven months, I have tried multiple different basal insulin schedules and doses trying to exactly match my changes insulin sensitivity throughout the day (due to exercise). I still have not solved this puzzle unfortunately. All of the different basal insulin combinations seem to result in the same problem. When my fasting blood glucose (BG) is normal, I will get hypoglycemia after exercise 25-33% of the days. In the past I had problems with hyperglycemia as well. This, I believe, was corrected by adding a 2-mile walk before and after weightlifting. Below are the changes that I feel have been helpful (I am leaving out the unhelpful ones):

  1. Two meals per day. This prevents overlapping meal-time insulin doses and frees up time for other activities.
  2. Achieved a leaner body composition which in turn dramatically reduced my insulin requirement per kg of body weight which reflects an improved insulin sensitivity.
  3. Standardized my exercise regimen to hopefully improve the predictability of the blood glucose (BG) response to insulin. By standardize, I mean the same exercises with the same duration and only minor occasional increases in intensity over time.
  4. Emphasized avoiding hypoglycemia as a more important goal compared to achieving any particular mean BG level. Hypoglycemia (BG < 71 mg/dl) is both unpleasant to experience and is life-threatening, whereas, mild transient hyperglycemia (BG > 120 mg/dl) is very unlikely to cause problems.
  5. Using cronometer.com to design different meal plans that I enjoy and can eat over and over again, each composed of the same amounts of macronutrients (protein, fat, and carbs) and each containing > 100% of the RDA for all vitamins and minerals. Since I do feel I get the best results from a low carb ketogenic diet and I feel a higher protein intake will best preserve my muscle mass as I age (currently 58 years old), I chose to design each meal so that I get a daily total intake of about 2.2 grams protein/kg BW/day and less than 40 grams of total carbohydrate and less than 30 grams of net carbs.
  6. Weighing my food on a kitchen scale helps to precisely follow my own meal plan.
  7. The combination of 6. and 7. above also makes achieving a lean body composition a lot easier.
  8. Taking metformin at 2,500 mg/day, 1,500 mg with breakfast and 1,000 mg with dinner really reduces my meal-time insulin requirements.
  9. In December 2018, I obtained Humalog diluent from Eli Lilly (they kindly sent it to me for free) and I made a 5-fold diluted Humalog solution to use as my meal-time insulin. This way I can accurately deliver Humalog in 0.1 IU increments or decrements which translates to 0.5 IU on my insulin syringe.
  10. The past few months I have developed a spreadsheet to estimate my Humalog doses. For the past 20 years, I have been using the “experienced guessing” approach. I have always been uncomfortable with this approach, but did not have an alternative until now. The approach is simple in principle, using least squares linear regression of insulin versus change in BG. The spreadsheet is customized to a fixed number of BG measurements and insulin (basal and rapid-acting) dosing opportunities per day. I would say it is still in the testing phase and would not call it a true success until I have reached my BG control goals.

I have greatly simplified my data presentation down to the bare essentials. At this point in time, I think the four most important metrics are: mean BG, standard deviation (SD) of BG, % of BG meter reading in the normal range (71 – 120 mg/dl), and % of BG meter reading < 71 mg/dl (a rough measure of the frequency of hypoglycemia). 

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Glycemic Management Results for February 2019

My February 2019 insulin doses and BG results were a bit worse compared to last month due to multiple changes in calorie intake and experiments with different basal insulin schedules and doses. Oh well.

The graphs below show the total daily doses of Humalog (blue) and Lantus (green) individually and the total of both insulin doses (red) and my actual BG readings (purple) below. The increase in insulin doses started on Jan. 27, 2019.

The table below shows the mean BG, standard deviation (SD) of BG, coefficient of variation of BG (which is simply SD divided by mean BG expressed as a percentage) as well as my current body weight and mean insulin dose totals. My height is 5’8″.

This image has an empty alt attribute; its file name is post-63-variability-table.png

I should mention that I believe the increase in insulin dose for February was related to an increase in calorie intake that was needed due to a two-week period of feeling hungry, cold, and tired. My calorie intake was increased from 1900 kcal/day to 2600 kcal/day in 100 kcal/day increments during the month of February.

The table below shows the % of BG meter reading in three BG ranges. 

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Lessons Learned From Different Basal Insulin Schedules and Dosing

I have been experimenting with numerous different basal insulin (Lantus) schedules and doses (one to three doses per day, given at four different times of the day, with a wide range of doses at each time: that is a lot of different combinations). Because basal insulin is by design, long-acting, the main lesson I have learned after all these experiments is that the amount of basal insulin released from the injection site can not be varied enough to adjust for changes in insulin sensitivity due to exercise. I think if I did not exercise at all, my BG would be much better regulated (although my total daily insulin dose would be significantly higher). This is why I have returned to once daily Lantus dosing. I am choosing bedtime to administer it because my basal insulin requirements appear to be the most while sleeping. During the day, there are two 5 hour periods that are covered by Humalog from meals, and there is one 6-hour period influenced by exercise (lower basal insulin requirement). In other words, this 16-hour period does not require as much basal insulin as the overnight sleeping period. I should also mention that I think the marked increases in BG during olympic weightlifting (OWL) that occurred in the past are currently being compensated for by doing a 2-mile walk before and another 2-mile walk after the OWL. For March 2019, I will find a dose of Lantus at bedtime that results in a fasting BG between 71-120 mg/dl say 80% of the time. I no longer feel that perfection is a realistic goal, at least for me. So I will be OK with occasional mild lows (60s mg/dl) and highs (<200 mg/dl). Any fasting BG < 60 mg/dl has and will prompt a Lantus dose reduction. As stated above, I anticipate whatever bedtime Lantus dose I come up with will cause hypoglycemia 25-33% of the days during or after exercise if my post-breakfast i.e. pre-exercise BG is 95 mg/dl (which has generally been what I aim for). This month, my approach will be to reduce the breakfast Humalog dose (by setting the post-target BG higher) to try to compensate for the exercise-related improved insulin sensitivity and thus avoid the exercise-related hypoglycemia.

I should mention there are many different ways to approach this problem of changing insulin sensitivity with exercise. I have heard Dr. Richard Bernstein say that he lifts weights one or two days a week. He takes multiple doses of liquid glucose during his workout to compensate for the improved insulin sensitivity rather than making any adjustments in basal insulin. This is certainly a valid approach, but I was hoping to find a method that did not require much or any glucose supplementation (my personal preference) particularly since I am exercising daily rather than 1-2 days/week. After all, I am trying to remain in nutritional ketosis.

More on Blood Glucose Standard Deviation

In doing simulations with random numbers between 71 and 120, the mean is about 95 with a standard deviation of about 15. And, of course, any numbers lower than 71 or higher than 120 will result in even higher standard deviations. Therefore, my goal of achieving a standard deviation of 12 mg/dl is quite unlikely. Oh well.

My Goals For 2019

I will continue to strive for normal BG values and my goals are to:

  1. Minimize or eliminate hypoglycemia i.e. BG < 71 mg/dl. 
  2. Aim for a mean BG value of 96 mg/dl with a standard deviation as close to 12 mg/dl as possible.
  3. Aim for % of BG meter reading in the range of 71-120 mg/dl of > 80%.
  4. I realize these are lofty goals, but having a challenging target is motivating to me and I am not discouraged by the fact that I have not yet achieved all of them.

How Will I Achieve These Goals

  1. This month, I will will go back to once daily Lantus at bedtime, but use my spreadsheet to calculate the breakfast Humalog dose using a higher post-breakfast BG target to thus avoid exercise-related hypoglycemia.
  2. I will continue using the 5-fold diluted Humalog to more precisely adjust my meal-time insulin dose.
  3. I will continue refining my mathematical method to predict my insulin doses based on prior BG responses. I think this will be a useful tool for me. I think it could be expanded to include a multiple linear regression model that uses meal protein, carbohydrate, and fat grams as independent variables along with changes in BG to predict insulin doses. That said, I think keeping meal macronutrients constant is a better approach so I will continue that for now.

I hope these measures will result in additional improvements next month.

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8 comments

  1. Alexandra

    Thank-you very much for sharing your experimental life as a T1 and exerciser. I gather that Dr Bernstein strongly prefers Tresiba to Lantus as a basal insulin. I’d be very interested to know your thoughts on this.

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    • Keith Runyan, MD

      Yes, he likes Tresiba due to both its longer duration of action and his perception that Lantus is associated with an increased risk of cancer. I wrote about this a long time ago, 2016, I think, but I could not find it quickly using the search tool. I had linked to the more recent studies that did not confirm an increased risk of cancer in diabetic patients taking Lantus. A Google search will find them for you. If there were an established increased risk, it would be noted in the prescribing information. The original studies were epidemiological and not clinical trials, so it was not possible to draw a cause and effect conclusion about Lantus and cancer. Despite the longer half-life of Tresiba, Dr. Bernstein still uses it twice daily, so I’m not sure there would be a great difference between the two insulins other than that Tresiba is more expensive.

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      • Alexandra

        Googling as you suggest, I came across this article:
        https://www.diabettech.com/diabetes/lantus-lethal-or-lifesaver-doc-gbdoc/
        I am not yet on insulin. I was hoping soon to persuade my GP to prescribe a very small dose of basal insulin as despite my very low carb diet (<15g carbs daily) my morning fasting bg levels are worsening. However, I am definitely underweight, so I find the writer's claim, that not having a lot of fat for the injection of Lantus to go in to can lead to fast instead of slow absorption, scary. The unclear research conclusions about Lantus and cancer bother me much less.

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      • Keith Runyan, MD

        Ok, Alexandra. We can change over to a different question. You found one lay person who had hypoglycemia after injecting Lantus, but didn’t after injecting Levemir. He thinks he does not have subcutaneous fat to inject into. Not true. I suspect he was using an improper injection technique. I also have little subcutaneous fat as many do, so the simple solution is to “pinch” up the skin so that when the needle passes through the skin, it will not be deep enough to hit the underlying muscle. It will have no other place to go than the subcutaneous fat with one exception. It is also possible to hit a vein. If a dose of Lantus or any other long-acting insulin is injected in a vein, that can result in a rapid-effect. Thus, one should look closely to avoid veins before deciding where to direct the needle. I really can’t explain why Levemir did not have the same result, but I can say the most likely cause of his hypoglycemia is user error, not Lantus. This article that he referenced http://diabetes.diabetesjournals.org/content/diabetes/53/6/1614.full.pdf states that different insulins do have differences in their effects and that these differences are very individual and thus not predictable or necessarily applicable to you. I probably should have not told you to Google, because I forget that lay persons have a difficult time distinguishing between science and less meaningful information. Understand this is not intended to be insulting in any way. It just that some of these issues do require significant medical knowledge to sort out. That said, if you did not Google, you would not have found my blog. Thus, Google is a double-edged sword. LOL. I hope you have a successful discussion with your physician about starting insulin.

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  2. Brad

    You’re right, when you dont work out basal is much easier. I’ve had periods where I don’t work out for a couple weeks here and there and my basal is always much better. For now I try to do a workout of similar intensity each day. cardio is almost always just a two mile run at a similar speed. I didn’t used to use a CGM until recently. I go low way more often at the gym than I thought I was before using one. Good point, I enjoy reading them.

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