Pushing the envelope

I had my quarter meeting with my diabetologist (specialized endo) yesterday. My A1c came back with 5.5% and this is the lowest A1c I ever had. There are several reasons for this A1c but the most important one is the use of analog insulins. I have used Actrapid and Protaphane (NPH) from 1987 to 2005 with success for my A1c (around 6%) but many negative side effects. In the year 2004 to 2005 it was nearly unbearable because I had far too many lows at night (have I slept in these two years?). Still the Actrapid was too slow to catch the meal and I had huge spikes into the 200 mg/dl range at the 1 hour mark. This all changed after switching to Levemir and NovoLog (or NovoRapid as it is called in Germany). The two shots of Levemir per day reduced the rate of lows tremendously. One week later I switched to NovoLog. Due to the shorter lifespan or activity phase it is much easier to have physical activity while having this Insulin on Board. The lows are mild and easier to catch in comparison to lows caused by Actrapid. I can achieve to neutralize the spike at the 1 hour mark without an additional waiting time before eating. These are in general the benefits of the new analog insulins and I am just happy that they have worked for me.

Since this switch to analog I have improved my control step by step. The next chart shows the proportion of lows (blue) to healthy blood glucose (green, 65-140 mg/dl) to elevated glucose (red, 140-200 mg/dl) to very negative blood glucose (black, greater than 200 mg/dl). The process to count for every category is complicated. We connect every glucose number with a linear function and then we calculate the blood glucose for every minute of the day. The resulting numbers are then used for this chart. The effect is that the longer your blood glucose is elevated the more the amount of red will increase in this chart. So it is hard to cheat here - what you see is what I have achieved in the year 2009 to 2010:

As you can see I managed to reduce the number of glucose in red (140-200 mg/dl) over a period 12 months. In some periods with the price of a higher rate of lows (blue). But this was a learning process and at the end the rate of lows is comparable to the beginning.

Now fast forward to the year 2011. The last three months lead to an A1c of 5.5%. The difference to 2009 is more subtle. Obviously the quality of control was not as even or reliable as it has been in 2009. Overal it seems that I have catched several phases of degradation in control early. This is one of the goals of the chart: detect negative developments early and work on the causes. This kind of worked for me but still I need to be more constant in my effords - which is easier said than done. For the last three months one would not assume that the A1c was that good. There are other phases in this chart with much better control. Again this shows that meter glucose numbers do not always give you the full picture. With a CGMS it would have been possible to identify the cause. For example it might be possible that the numbers at night where lower than usual. The spikes I had over the last months show their influence in an increased red. Still these spikes were just too short to influence the A1c. Still these spikes are not good for long term complications.

My doc asked me to focus more on constance than A1c. He said that I am pushing the envelope too hard at the cost of too many swings and lows. It would be a great achievement to work more on the variability and this will indirectly improve the rate of lows too. I think the lows are much more harmless now than they have been on the old insulin. But I had some nasty lows in the last month and so I think my doc is right. I have managed to be free of complications after having T1 for more than 23 years. All my effords to control this thing have paid out. But good control does not end with a good or healthy A1c. Variability in blood glucose and the impact of lows on my quality of life should be considered too. It is a balancing act.

Here is another chart for the variability. The mean glucose for the day is the red line. The black lines show the minima and maxima in one day. The yellow area is the standard deviation. The green area is the targeted blood glucose (70-140 mg/dl). The chart shows good control. But still on some days the maxima and minima should be more closely together than they are.

So this is my new challenge: reduce the variability and the number of lows without loosing my current quality of control. If this is not possible I am willing to exchange that for increasing the A1c to 5.8%. Strangely enough I am exited about this new challenge.

Good work! My A1C went up by .6% when I started on the pump, but my measured variability decreased substantially.

In quality control, early methods tested when you were going out of range and then corrected, just like your current strategy. Modern quality control is based on statistical process control, reducing variation. Have you thought about how to reduce variability? We all know about low carb, the law of small numbers. But what more we do to reduce variability?

@SuFu: good to read that the sacrifice of some A1c percentages has payed out for you. I am not sure if I will manage to achieve the same without a pump. We will see.

@bsc: a CGMS is a tool to achieve tight process control. This is something I have in mind as well. For that I will wait for the next generation sensors from Dexcom (they should come out soon). To reduce the number of stupid mistakes is another way to reduce variability :wink: That is more a question of having the right mindset and following it with persistence. An approach likely to fail but what are challenges for if they are easy to achieve? I think the point is to work on the causes of variability. If the cause is clear we can evaluate if it was possible to prevent it or not. On some points we can make improvements and on some we will have to accept our human nature or the complexity involved. For me it it not so much about single glucose readings. As you have pointed out: it is the process to control and this process is happening whether we are measuring or not. We need to be more aware of the typical recurring situations were we fail to make correct decisions. In these situations we need to stop in our tracks to evaluate and consider in depth. Maybe this can make the difference.