Before I get started, just a reminder about the upcoming Metabolic Therapeutics Conference, February 1-4 in Tampa, Florida. I’ll be speaking about The Management of Type 1 Diabetes with a Ketogenic Diet. This is the second annual conference featuring researchers and clinicians with expertise in ketogenic diet therapies, including Dr. Dominic D’Agostino, Dr. Colin Champ, Dr. Thomas Seyfried and many others. Click here to learn more and sign up.
In November 2016 I had more low and high blood glucose (BG) values than I would have liked, but we know that perfectly normal BG values are not necessarily achievable with the current technology of subcutaneously injected or pumped insulin analogs and home BG meters even with a ketogenic diet. A continuous glucose monitor (CGM) could improve glycemic control further.
Speaking of CGMs, I have decided to get one as soon as it becomes available in the United States. Americans are eagerly waiting for FDA approval of the Freestyle Libre CGM system (manufactured by Abbott). It is different than any currently CGM on the market, but I think it will serve my needs and active lifestyle well. Thanks to Dr. Troy Stapleton for posting his new CGM on Twitter and direct messaging me about it. The Freestyle Libre CGM system measures interstitial (the fluid below the skin) glucose every minute. Interstitial glucose readings can lag behind BG readings by 5-10 mins which is meaningful if BG is changing rapidly. As a physician, I could get the currently available Freestyle Libre Pro CGM system in the United States. However, my reason for getting the patient, rather than the professional, version is to use the readings to make changes in glycemic management on the fly so to speak. I am particularly interested in being able to treat (with glucose) low interstitial glucose readings that may occur anytime, but especially during exercise, and to treat elevated interstitial glucose readings (due to intense exercise from weightlifting) after exercise with rapid-acting insulin (Humalog). One of the major advantages of this system in my mind is accuracy. The CGMs currently on the market require at least two BG readings/day to be entered into the CGM to keep it calibrated. The Freestyle Libre CGM system does not require any BG readings to be entered into the device. BG may still need to be measured with a home BG meter particularly if symptoms do not correlate with the interstitial glucose readings after the user has determined that the device provides comparable readings to an accurate home BG glucose meter (I use the FreeStyle Freedom Lite meter also manufactured by Abbott).
Glycemic Management Results for November 2016
My BG results in November were comparable to October with some measures slightly worse and some slightly improved. Overall, satisfactory.
Rather than repeat the results in the tables again in the text, I’ll just comment on them. There are two changes in how I present the data this month. See below.
Below are my mean BG values, insulin doses, and BG frequency distribution for current and previous time periods using the new target ranges mentioned in previous two posts. I was aiming for less hypoglycemia which I accomplished, 19% vs 21% of BG values were < 61 mg/dl, but I would really prefer this to be less than 10%. For unknown reasons, I experienced a rather sudden increase in BG (30% of BG values were elevated to between 111 and 200 mg/dl) requiring additional insulin beginning on Nov. 21 that came under control by the end of the month. Note: I immediately address elevated BG with extra doses of rapid-acting (Humalog) insulin and increase my basal insulin (Lantus) if the morning fasting BG is elevated, both of which I had to do this month.
As presented in blog post #15 exogenous insulin cannot mimic normal insulin secretion, so persons with type 1 diabetes (T1DM) should not expect to have truly normal BG values. They just need to be low enough to prevent long-term complications and not so low as to cause unpleasant hypoglycemic symptoms, brain damage, seizure, injury, coma, or death. I have set my target BG range at 61-110 mg/dl because values in this range are not likely to lead to harm or complications of T1DM. Your target BG range should be determined with your physician because one size does not fit all. As mentioned last month, normal mean BG is in the range 90-95 ± 7-12 mg/dl (mean ± standard deviation (SD)) and coefficient of variation is 8-13% as a frame of reference. The standard deviation and coefficient of variation are measures of BG variability which I believe are important in T1DM. Achieving a normal standard deviation or coefficient of variation in T1DM would be difficult, if not impossible, with current exogenous insulin therapy. Monitoring the standard deviation and/or coefficient of variation and finding ways to improve it to the best of one’s ability is desirable. Following a low carbohydrate ketogenic diet is one such method of reducing BG variability, mean BG, insulin doses, and hypoglycemia. The ketogenic diet may also provide an alternate/additional brain fuel in the form of ketones to protect the brain when BG does go low. The alternative energy that ketones supply to the brain may prevent or blunt the sympathoadrenal response to hypoglycemia which in turn reduces or eliminates the symptoms of and harm from hypoglycemia. This hypothesis needs to be tested before it can be stated as fact. And as I mentioned last month, having BG close to normal most of the time also minimizes symptoms of mild hypoglycemia and potentially the harm from hypoglycemia as well due to lack of activation of the sympathetic nervous system and adrenal gland responses to hypoglycemia i.e. sympathoadrenal-induced fatal cardiac arrhythmia, see here.
Below are my BG readings along with exercise type and time. I managed to increase the number of days of weightlifting which I now enjoy more than aerobic exercise. This is why the mean number of hours of exercise per week increased compared to last month.
The table below shows the BG variability results for current and previous time periods. This month I have converted time spent (hours) with BG < 61 mg/dl and time spent (hours) with BG > 110 mg/dl to % time by simply dividing each by 24 (hours in a day). I also added a column for % time in target range (BG 61-100 mg/dl). I also added two additional columns showing the 10th and 90th percentiles of my BG readings. I changed the labeling of Quintile 1 and Quintile 3 to 25th %tile and 75th %tile (my abbreviation for percentile) to correct the error of using the word Quintile instead of Quartile (my mistake). Also note that Quartile 1 is mathematically identical to 25th percentile as is Quartile 3 and 75th percentile. The BG median shown in the previous table is identical to the 50th percentile. Thus, these percentiles show the spread of the BG readings about the median and are measures of BG variability. The other measures of BG variability were defined and explained in blog post #10. Compared to last month, some of the results were improved while others were not. Overall, satisfactory.
The actual daily insulin doses and daily insulin dose totals are shown in the graphs below. Note I had to increase my total daily insulin dose from 25.5 IU/day to 37.5 IU/day over a twelve day period, an increase of 12 IU (a 47% increase) for reasons that are unclear to me. Similarly, I had to decrease the total daily insulin dose back down to 29 IU/day over the next four days. I have been contacted by several individuals with T1DM who experienced a similar increase in insulin dose at different points in time after starting a ketogenic diet and thought this represented an insulin resistant state caused by the ketogenic diet. I told them that I do not think this is the case and that these increases (and decreases) just represent the usual variability that type 1’s experience. After all, a ketogenic diet is used to treat and reverse insulin resistance. I am aware of “physiologic insulin resistance” in non-diabetics used to describe slightly elevated fasting BG and an attenuated insulin response to a glucose tolerance test in those on a very low carbohydrate ketogenic diet. However, I do not think this would apply to those with T1DM on a ketogenic diet.
My Ketonix breath acetone results since June 1, 2015 are shown below. There has been a gradual reduction in breath ketones. I suspect, but cannot prove, that this is related to an increased carbohydrate content of my meals. I have gradually increased the amount of berries, nuts, and seeds that I eat to help increase diet variety and add nutrients while at the same time decreasing added fats including coconut oil, olive oil, and butter. I recently started to supplement with MCT oil, one tablespoon twice daily with my meals to help increase ketones and keep total calories about the same: 2,500 kcal/day due to the reduction in coconut oil, olive oil, and butter. I estimate I am now eating about 70 grams of carbohydrate per day of which 30 grams is fiber i.e. 40 grams of net carbs per day.
In November, I finally achieved a new personal record (PR) in weightlifting in the snatch: increasing it from 140 to 150 lb. My clean & jerk PR is still stuck at 185 lb. since the end of March 2016. Fortunately, I don’t need to make a living from weightlifting, so any PRs are just plain fun.
In December, I will continue weightlifting and aerobic exercise daily with as many days of weightlifting as I can tolerate i.e. not experiencing fatigue or joint soreness/stiffness. The aerobic exercise consists of swimming, rowing, or cycling at low intensity for ≈ 0.5 – 2 hours. I am using a heart rate (HR) monitor during cycling and rowing with the goal of not exceeding a HR of 124 bpm. This is derived from Phil Maffetone’s formula: 180 – age. See here. The purpose is to exercise aerobically so as to burn mainly fat and to minimize utilizing glucose for muscle energy which can result in hypoglycemia in those with T1DM. It also gives me a day to recover from weightlifting i.e. intense aerobic exercise is fatiguing. I will see if this reduces BG reductions during cycling and the need for glucose supplementation during exercise (typically 6-12 grams of glucose). The three times I cycled at this lower HR in October, I was able to omit glucose supplementation without a large change in BG: a reduction of 24 mg/dl and an increase of 3 mg/dl and 32 mg/dl, respectively. It is too early to say that this is causally related.
My Thoughts about Management of Type 1 Diabetes with a Ketogenic Diet
The goal of glycemic management in T1DM with a ketogenic diet is to keep BG as close to normal (≈ 90-95 ± 7-12 mg/dl (mean ± SD)) as is safely possible (i.e. avoiding hypoglycemia) to avoid diabetic complications, a reduction in lifespan, and unpleasant symptoms of as well as injury and death from hypoglycemia. For me, a well-formulated whole-food nutrient-dense ketogenic diet (see blog post #9 for more details), daily exercise, frequent BG measurements, and lower insulin-analog doses (Humalog/Lantus) have improved my glycemic control, hypoglycemic reactions, and quality of life. I also feel, but cannot prove, that this eating plan and the resulting nutritional ketosis reduces the symptoms of hypoglycemia and protects the brain from the consequences of moderate degrees of hypoglycemia (see blog post #12 for more details). I also think that hypoglycemia unawareness (due to my frequent asymptomatic hypoglycemic episodes) contributes to my lack of symptoms of hypoglycemia. As pointed out in blog post #29, this may not necessarily be a bad thing. Exercise with its resulting varying insulin sensitivity and hormonal changes actually makes glycemic management more difficult i.e. challenging, but I enjoy exercise and feel it has other health and lifespan-extending benefits. Hopefully, my BG values and variability as well as lower insulin doses are close enough to normal to avoid any reduction in lifespan, diabetic complications, and harm from hypoglycemia. Only time will tell.
Till next time ….