Tight control and risk of complications


First of all, I'm new here. I've been reading these forums since I was first diagnosed as Type I diabetic three months ago. They are really helpful to me. Im from Spain, so sorry if my English is not the best.

Since I was first diagnosed I decided to have a tight control of my blood glucose (under 6). Now I usually have low level of glucose without hypoglycaemias (the lowest glucose was 60) and usually i don't go over 140 (maybe it helps that I was recently diagnosed)

My question is related to the complications and tight control.

The DCCT states that a tight control reduce the risk of the following complications:
- Retinopathy
- Albuminuria
- Neuropathy

It seems pretty clear based on this conclusion that a tight control is a target.

BUT reading the Complication of diabetes article in the wikipedia we can find contradictory information, is not that the tight control is bad, it is that some studies suggest that the complications are not completely related to how good you manage your blood glucose, instead with the autoimmune condition (http://en.wikipedia.org/wiki/Complications_of_diabetes_mellitus#Chronic),

Could it be that retinopathy or other complications may be treated with drugs instead of the BG control?

In an hypothetical case, if a DM1 has a perfect control, as good as a PWOD, for example with a perfect artificial pancreas, they still has risk of complications?

Why the DCCT find that some complications are reduced with tight control?

I am really interested to know what are your thoughts about this. There are more studies that support the conclusions of the DCCT?

- http://en.wikipedia.org/wiki/Complications_of_diabetes_mellitus#Chronic
- http://en.wikipedia.org/wiki/Diabetes_control_and_complications_trial
- http://care.diabetesjournals.org/content/26/suppl_1/s25.full
- http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-glucose-control/tight-diabetes-control.html
- http://jasn.asnjournals.org/content/17/2/353
- http://care.diabetesjournals.org/content/28/8/1959


A few very important ones you left out:

Heart disease

...and some others, but these are the biggies.

Any of these conditions can be caused by other factors that have nothing to do with diabetes. People with perfectly healthy BG metabolism get these things too.

What is consistently found in study after study after study is that diabetes is a significant factor for increased risk with these ailments, and poor BG control among diabetics strongly correlates with the degree of increased risk a diabetic faces for these problems.

There is no way to drive one's risk of these other problems to zero -- diabetic or not. However, the results of the DCCT and other studies is pretty convincing that better control results in lower risk, and getting close to "normal" reduces the risk close to that of a non-diabetic. Not the same, but much, much closer than a1c's above 6-7%.

DCCT (and other studies) shows that the best way to reduce complications is to control BG. Congratulations on doing a good job of controlling your BG. It is hard but well worth the effort. But there are no guarantees in life, and that includes diabetes. Some will get complications even with very tightly controlled BG, others will not get complications even when BG is not so well controlled.

Other studies show that there is more to complications than simply controlling BG. Genetics is apparently important in this regard. Unfortunately there is no way to control the genes you have, which is why this is not of much help for any patient to help minimize their own risk. Here is a paper that describes this research and includes numerous references. Genetics of Diabetes Complications

The DCCT was painfully clear, tighter control guarantees and is causal for dangerous lows in which OTHERS intervention was required c. 30% of the time because of that excessively tight control.

The lower we force ourselves, the more certain dangerous lows will happen.

The debate is when are lows too many? When is forcing ourselves pretending to be "normal" (ie non-diabetic) dangerous. -shrug-.

I would argue strongly that the DCCT did not show that tight control is a cause of or guarantees dangerous lows. Tight control and lows where correlated events. The cause of lows is a mismatch between insulin dosing and carb intake resulting in more insulin dosed than required.

Clearly, given the prevalence of people on this board who are able to exert tight control over their diabetes without experiencing dangerous lows, tight control cannot be the cause.

Man, can I relate to this, just last night!

I've been achieving pretty tight control as defined by the medical community (not tight by my standards and many people here, but heck -- a 6.0 a1c is pretty tight!), and I have had virtually no serious hypos since I got all settled and adjusted to pumping.

Then, last night, I had a very heavy carb meal, and what's worse, it was an "estimate" situation. For which I estimated wrong.

By the time I started to feel low I was already at 59. Corrected, and dipped all the way to 45 (and feeling all the typical symptoms full-on) before it turned the corner.

Except for that, my control is most very precise -- I know with enough precision what I'm eating the vast majority of the time, and the IC calcs work very well. My typical meal is start 80-100 mg/dl, pre-bolus for the carbs, set up a square-wave to cover protein if there's a significant amount.

Then, rarely peak over 140 after eating (usually touch up against 135 most times), 3 hours postprandial I'm back down near where I started in the 80-100 range.

It's very predicatable and reliable -- when I have good data to work from (i.e. carb & protein content).

So, what would you have me do, Stuart, stop all this work at tight control, that's very successful, because now and then I might estimate wrong?

For me personally the problem isn't tight control, it's huge carb loads and estimation errors. For a small carb meal, say 15-20g, you can be off by 25% and still not be at too much risk.

OTOH, a 90 carb experience (about what I estimated the total was after it all went so bad) off by 25% will result in lots of "too much insulin" if over estimating, which is what I did.

im also pretty well controlled and dont have any serious hypos. i eat low carb and try to avoid fast acting as much possible, covering parts of my meals with physical activity and some with basal (i guess, could i still have significant pancreatic function after 3 years?). ive only had one low in the 40s in three years of t1 and a handful of 50s. no one has ever had to help me. yet. eating low carb and testing 7 or 8 times a day helps.

when i read things like its our genes and doesnt matter how tight we keep our control, i wanna run out and get some ice-cream. jeez!

Tight control also means avoiding major lows - not just avoiding highs. And to the original poster, I would take what I read on Wikipedia with a grain of salt. most of the info there is, in my opinion, anecdotal. Anecdotal experiences have value, but are also rather subjective.

As others have posted, there are also things like genetics, one's autoimmune system situation, and environmental etc. These are things we can't have control over, so tight bg control is the best we can do to have a longer and healthier life. The way I look at my type 1 (30+ years with it) is that at least it isn't like MS where the individual doesn't have has much say in the progression of things. I am one of those here who have tight control, without a lot of lows. But I did have some complications related to living with the wrong Dx for a while (diagnosed with type 2 because I was "old" - 30 years old). Once I got the correct Dx, and took control, my various "systems" have stabilized.

I have had pretty OK control and don't recall too many "awful" results (peak A1C was 7.7, long story, you can find it on my page, LOL...) but have had pretty tight control since 2008 (dx 1984@ 16 and am 47 now, 30th anniversary tour!) but still am losing hair on my legs and have one "tiny" bleeder way off on the side in one eye. No other complications. I had done some long bike rides lately (70 and 100 miles, in a Tour de Cure!) and had burning pain in a toe and was sure it was D related but read some cycling books and apparently it's a recognized condition associated with long bike rides.

I have had pretty OK control and don't recall too many "awful" results (peak A1C was 7.7, long story, you can find it on my page, LOL...) but have had pretty tight control since 2008 (dx 1984@ 16 and am 47 now, 30th anniversary tour!) but still am losing hair on my legs and have one "tiny" bleeder way off on the side in one eye. No other complications but complications nonetheless.

I had done some long bike rides lately (70 and 100 miles, in a Tour de Cure!) and had burning pain in a toe and was sure it was D related but read some cycling books and apparently it's a recognized condition associated with long bike rides.

Artwoman has it right!

Tight control is about preventing BOTH highs and lows.Its not something to be afraid of and in fact will usually contribute to better quality of life in the long run. Do you jump to an aggressively narrow range right off the bat? Not hardly - you need to learn all about how YOUR D works and then how to work with it. There is no reason that you can not aspire to gluco normal numbers - getting there take time and study of how your body responds to the food you eat, the amount and timing of the insulins you use and how you work in the exercise for health part of the puzzle.
It does not happen overnight and is done in small steps as you figure out what works for you. When you have the knowledge and the tools then you can find a way to safely stay as close to gluco normal as is possible for you personally. How you get there will be different from how I get there but it is doable.

I think that the relationship between average bg (or A1C) and the microvascular complications like retinopathy, kidney disease, etc., is very compelling.

But note that even the lowest A1C bins in the DCCT study (or other studies including diabetics) do not show reduction to zero for risk of complication. Partly this is just because so few T1's are able to get truly normalized bg's.

Some of these complications, there are other important risk factors too. e.g. for most microvascular diseases, high blood pressure is also a huge risk factor. Obviously controlling bg and blood pressure together, is just hugely important.

And other complications are less tightly coupled to average bg. e.g. macrovascular heart disease, frozen shoulder, hypothyroidism. It seems that for some of these the risk may be entirely unrelated to average A1C, i.e. they are associated autoimmune inflammations and not the result of high bg's.

Tight blood glucose control does not reduce diabetes related complications! Studies have shown that it reduces the risk of complications. The only guarantees we have in life are death and taxes.

Yeah, but I find it helps to at least think that there is a reduced risk of stuff - otherwise, I wouldn't bother with all the work.

I just feel better when my BG is near normal. And since I got improved control there is no more sign of retinopathy.

I have been type 1 for 68 years, and I do not have any serious diabetes related complications. While participating in the Joslin medalist type 1 study in Boston, I was told that several participants freely admitted that they do not take good care of themselves, and they eat a lot of food containing sugar and other fast acting carbs. Despite their bad eating habits, they do not have any complications after many years of type 1. All of the 900+ participants have been type 1 for at least 50 years, and are US citizens. Dave has already mentioned some of this in his post. I was also told by the lady in charge during my participation that several participants had used tight control, but have still experienced some serious complications. These are that exceptions to the rule. The majority of the participants in this study have done at least reasonably well with their control, and they do not have any serious complications.

After almost 60 years of type 1, I was diagnosed with spots of retinopathy, and neuropathy. My A1c had been in the range 5.4-6.0 for many years, but I still had these complications. My control involved too many highs and lows, a roller coaster type of control. Those highs and lows can produce an average which is quite good, so the A1c will also be good. That can give us a sense of false security. The roller coaster control is traumatic to our bodies, and complications can result, even though the A1c is good. I started pumping insulin in 2007, and my control was much more stable, with not so many highs and lows. The retinopathy disappeared, and has been gone for seven years. The neuropathy is still present, but it rarely bothers me now. Avoiding complications seems to required a good A1c and stability with not so many highs and lows. If I had started pumping in the 1990's I may not have had any complications at all.

I read an article a few years ago that said the life expectancy of young type 1 diabetics in the US is almost as good as for non diabetics. That is very encouraging news!!

The DCCT was completed in the early 1990s, when technology just wasn't as good as it is now. With our insulin pumps and CGMs, we can aim for tight control without too many highs or hypos (avoiding the rollercoaster, as Richard says). It also isn't just genetics that allow people to avoid complications--more than 67% of Joslin medalists (50+ years with T1D) in a recent study still had some measurable insulin production. I think that having some remnant endogenous insulin production helps to prevent complications. For me, bottom line, I am definitely going with tight control--there is great benefit (reduced risk of complications) without much downside (for me).

Thank you for making the distinction. Not sure I agree, but appreciate your points.

Lows are cause by excess insulin, somewhere in the equation. Whether absorbed too rapidly, too little food to make energy required, excess exertion, somewhere its excess is the reason for any low, yes?

Given we are the sole cause of that insulin we get into our bodies via whatever means, I propose the tighter we strive for "perfect" the more we push, will guarantee that more lows occur causally.

The DCCT was very clear, we gotta be much more careful if out "cruising altitude" is too near "normal". THe harder we push for control, we gotta be real, real, real careful we dont push too hard.

You're welcome!

You are conflating the cause of lows (too much insulin) with a correlation (striving for tighter control).

Yes, by striving for tighter control (a closer match of insulin dosing to TAG), statistically and reasonably, we are at a greater risk of mismatching insulin to TAG. However, understanding the very clear difference between the cause and correlated events is what allows us to have tight control by striving to minimize the risk of mismatching by utiilzing targetted intervention strategies in our managemnet plan. Correlations can be broken as shown by any number of people on this forum.

We are striving to decrease our risk of complication. The DCCT clearly shows that tighter control is correlated with decreased risk of complication.

We are balancing risk with risk, no doubt, but we absolutely must be crystal clear about the difference between cause and corralation.

Very well put, Super_Sally. Words of wisdom! Thanks.