To low carb or not to low carb

Where are those little reply buttons always hiding?

I understand, Maurie, that the whole idea of SD (or glucose variability as Walsh call it) is that the very bouncing up and down is injurious in and of itself. But I still think that the # has more meaning depending on what the numbers are varying between! For example if someone had a range of 65 to 140 their approximate SD (using Jrtpup's shortcut) is 37. If they had blood sugars between 200 and 275 their SD would also be 37! I'd be perfectly happy with the former and miserable with the latter! Maybe I'm belaboring the point. I guess the idea is that SandA1C together give you more information than just A1C alone!

Hi Zoe - My numbers tend to range from 65 to 140 and my pump calculates an SD of around 25 so that I wouldn't put that much weight on the short cut.

I was trying to point out that although many of us like standard deviations in the low twenties showing pretty modest volatility, John Walsh who cannot be lumped with those providers who set low goals for us because we can't do anything doesn't consider 27 or even 40 as indicating by itself that some changes need to be made.

Maurie

Oh well, so much for shortcuts! That's okay I have enough numbers already! And I would give anything to stay between 65 and 140! Good work!

Totally agree Zoe. I've said it so many times you must be nauseous LOL I don't think either is really as worthwhile without the other.

Ok, an answer based on my life as a T1 for 37 years.
Low carb diet, probably not, but as long as you test yourself then you should be OK . . . and if that ratio doesn't work for you then figue out what the proper ratio should be ~ 1:15 is commmon, mine is around 1:12. You simply do it by testing yourselk around 1:30 minutes after you eat, and see how far you are from your target.
When my BS is high I need to use 1 unit of novolog for every 40 points too high to bring it down. So if 1 am 200 and i want to be at 120 then I take 2 units, and it brings me to right when I want to be. What I have observed is that it is 1 unit for every 40-50 points too high ~ but, as you can imagine, that varies with each diabetic.
I know a T1 who have gone low-carb when she probably should nopt have, and it caused nothing but problems for her. Including (a hot topic where I live) drivng with diabetes.
I have always been right around 7.0 and after 37 years I have no complications whatsoever from my diabetes. In my opinion (only MY opinion) doing that low carb thing for a T1 can really cause problems.
After I wrote this, I skimmed some of your replies, and yes, activity is a big factor here.

You can't really begin to say if 18 or 27, or any other standard deviation is good or bad just by looking at that one number. The calculation may be horrendous, but it's meaning really isn't all that complicated and is pretty straightforward.

If my diabetes caregiver told me that my SD was important but couldn't tell me what it means, I'd back away slowly and find a new caregiver.

Basically, assuming all your BGs fall under a bell shaped curve, you expect around 68% of your BGs to be within one standard deviation of your average and aound 95% of your BGs to fall within 2 standard deviations of your average.

So, if my average BG is 100, then a standard deviation of 27 means that a I would expect to find 68% of my BGs to fall between 127 and 73, and 95% to fall between 154 and 48. If my average is 100 and my standard deviation is 18, I'd expect 68% of my BGs to fall between 118 and 82, and 95% of my BGs to fall within 136 and 64.

In this case, is 18 better than 27? Sure. But is 27 bad? If so, based on what?

Wanna be proactive in bringing down your standard deviation? You don't have to make any changes at all. Just take more samples and, assuming nothing else changes, your standard deviation will go down simply because of the way standard deviation is calculated.

If you look at the formula, the "variation" is in the numerator and the number of samples (how many times you take your BG) is in the denominator. Mathematically, all you have to do is take more samples without ever changing how much your BG varies at all, and, voila, lower standard deviation.

True,

But when you calculate your sd, all it is doing is estimating exactly that, what percentage of your BGs fell within a certain range. For SD, the range is 1 and 2 standard deviations away from the mean, with 68% of your readings expected to fall within one standard deviation of the average, and 95% of your data falling within 2 standard deviations from the average.

You could just decide what is a useful range for you, and determine what the percentages actually are just like Zoe has done.

Here I go again. =P

From your example, it means you've been between 70 and 130 for 68% of your readings, and 40 and 160 for 95% of your readings. Your SD can't actually tell you what the upper and lower limit of your range actually is. You'd have to look at your actual BGs to see what that is.

So, it's possible that you've actually never been as low as 40 at all.

I agree. T1 Diabetic or not, if you follow what you just said, you should be fine.

Right now I shoot for 60 carbs/meal ~ but we all know how that can go.
Many years ago, as a diabetic, and before carb counting. I was a very active swimmer, and I think I was on either 3200 or 3500 calories per day.

If there is not a CHO deficiency why does the brain then convert to working off ketones? Although not as readily the rest of the body will convert to ketone use as well. Unless there is a CHO deficiency the body would have no need for ketones unless of course there is an insulin deficiency.

Ketones are a consequence of burning fat. The more fat you burn, the more ketones you produce.

You're right, there is a minimum amount of CHO that your body requires. However, if done correctly, low-carbing balances minimal carb intake with gluconeogenesis from protein intake to meet your body's minimum requirement, as Gerri says. Gluconeogenesis from protein is the reason why people lose muscle mass if they just cut calories accross the board when they diet. With no extra source of dietary protein to turn to, your liver will call on your muscle to be broken down for gluconeogenesis. Gerri quotes a 58% conversion from protein to glucose, but that number varies a lot from study to study. 58% is near the upper limit, but given that carbs are restricted, I'd imagine that number is attainable.

Really, the point is just to provide enough protein to fuel gluconeogenesis.

Higher fat is required because gluconeogenesis actually requires energy to run, so with lower carb, your body turns to fat to produce the energy needed for running both gluconeogenesis and daily activity. That's where the ketones come in.

Burning ketones is really just a stop-gap measure once liver glycogen is significantly reduced enough to affect bloodglucose balance. Once gluconeogenesis kicks in, there's plenty of glucose being produced to maintain BG levels and run your brain and heart.

So, technically, even though you are cutting dietart carbs significantly, there really isn't a CHO deficeiency.

Driving doesn’t have anything to do w/ the number of carbs, it’s having the carbs and insulin balanced correctly. Which is certainly easier said than done.

yep I am your soul sister here Pup...feel exactly as you do about "low carb". It's just about feeling good...that's it!

Scott, post-prandial highs were what made me decide to go on insulin. My BG would go up after a meal and just hang out there for hours. If I ate while my BG was high, it just went higher and then stayed up there, instead. Waiting around for my BG to come back down was really interfering in the rest of my life and I felt powerless in general because the spikes were happening despite eating less than 6g of carb for breakfast and 12g for lunch and dinner. My endo put me on bolus insulin only, reasoning that my overall BG level would come down on its own if I could avoid spiking it. I've been on Humalog for three months now and I'm doing really, really well. My fasting BG is around 4.6 mmol/L (83 mg/ml) every morning. I only use Humalog for meals and corrections and I'm finding that I don't need to correct very often at all these days. This may change in time, but right now it's working very well for me and I feel good! Of course, YMMV, but you might talk to your doctor about it if you're interested.

What a great discussion this is! I've just read the whole thing, from the beginning, and I am deeply, deeply impressed not only by the breadth of knowledge, but also by the compassion and modesty.

I have only a few things to contribute. Jenny Rhul has a calculator at Blood Sugar 101 that converts A1cs to BG in mg/dl or mmol/L. Fill in any one value and it will give the other two--very useful!

I calculate my Standard Deviation for my BG on my Excel spreadsheet--which is where I keep my records of my BG, carb intake and insulin use. Excel will figure out the SD for a range of numbers, so I don't have to. My control is pretty good these days. I can see that from the list of numbers and don't really need the SD to tell me. But if I have a low or a high, then the SD will increase. It's useful to me to see how much difference that makes overall, but I suspect this is most meaningful because I tend to have the same pattern for testing my BG from day to day. It's not as good as a pump, of course, because I have to do every test myself. The numbers that interest me most these days are my BG before bedtime and when I get up in the morning. If those two numbers are the same or very close, I feel good because I know that my BG was very stable all night long.

A1cs can be in the normal range for many reasons, as we've noted already. That's why the number can't be relied upon all by itself. For me, the A1c is a general measure of my progress over the last couple of months. I was only dx'd in October so a steadily lowering A1c is proof that what I've been seeing on my meter is pretty accurate and that means that I'm doing a lot of things right. I'm happy with that.

Low carbing nearly always works for people who are trying to bring their BG down. Bernstein's way of eating will do it if someone is willing to give it a try. A lot of people can eat more carb than he advises and still maintain excellent BG control without gaining weight. I think that's absolutely fantastic and I am happy to cheer for them. I don't follow Dr. B to the letter, but the general direction he describes does work for me and I'm grateful to him for it. For me, 30g of carbs is plenty every day. But I'm 53 years old and have a fairly sedentary life. I walk a couple of miles every day, sometimes more, but I'm not and don't have any plan to be an athlete. If I were a lot more active, I might need to increase the amount of carb I eat, but I'm not sure. I might only need to increase the amounts of protein or fat. I don't plan to make this experiment, though things could change in the future.

In the end, the thing we all need to do is whatever works for us. Clearly there's no single, magic answer and no high, golden road to perfect control and complication-free life.

But to carry this discussion a bit farther, the fewer carbs you eat the less insulin you take and therefore fewer peaks and valleys. So low carb is probably safer for driving. But you need to know how to adjust your insulin to reflect a change in your diet. As acidrock said, it has to be balanced.

I agree with that as I think that w/ the lower bolus amunt for lower carber options your risk goes down and is likely easier to control, all of which are really helpful benefits from consciously reducing ones carb intake. I am driving my mother-in-law crazy this week but am pretty much ignoring her demands to “eat more”.

You are right, driving has nothing to do with carbs . . . I guess I drifted there a bit.
What I do feel strongly about is people who try to keep their blood sugar too low, which can obviously cause drving problems. Part of that is eating less carbs and/or taking too much insulin. Yes, a balance is needed there.

The real question I have not been able to answer is why did the ADA pick 140 as their threshold for IGT?

It's a World Health Organisation definition with, they admit very little evidence to support it.
http://www.who.int/diabetes/publications/Definition%20and%20diagnosis%20of%20diabetes_new.pdf
page 18ff.