Your Mileage May Vary

YMMV.

That particular acronym, standing for Your Mileage May Vary, is all too common on the insulin-pumpers’ website.

It applies to those of us with any chronic disease, and one of the main problems with “evidence-based” medicine is that it tends to rely on how the “average patient” reacts. There is no such animal as an “average patient.”

I had first-hand experience of this when a doctor, pre-pump, tried to put me on what he called a sliding scale of insulin, and gave it also to nurses in the local hospital. They insisted on using his scale when I was in the hospital for something else. I looked at the dose of insulin they insisted was necessary when my blood sugar was a little high at bedtime, and said “that’s going to put me into insulin shock.” They insisted on giving me the dose anyway. Luckily insulin shock still woke me up back then, and at 3 am I woke up shocky, hit the call button, and demanded a snack for insulin shock. They insisted on checking my blood sugar first, which only confirmed what I had tried to tell them earlier. I know now that that particular sliding scale, which was probably worked out for the average diabetic of my weight, simply did not work for me. I am very insulin sensitive, and while I absolutely need insulin and will see a very fast and uncontrolled rise of blood sugar without it, I need a very small amount, given my weight.

It isn’t just person-to-person differences, either. It can be time of day, time of month, stress, air bubbles, absorption rate of injected or infused insulin, or just the natural cussedness of the universe. Sometimes it can be how what you eat gets into your bloodstream.

Your blood sugar does not rise the instant you put carbohydrates into your mouth. The food has to be chewed and swallowed, as almost nothing is absorbed directly from the mouth or esophagus. It has to reach the stomach. One of the side affects of diabetes in many people is gastroparesis, which is delayed passage of food through the digestive system. To further confuse the person trying to keep diabetes under control, this delay is highly variable.

As a general rule, food I eat at breakfast time gets into my bloodstream, as glucose, fairly quickly. I’ve taken to eating yogurt for breakfast because most of the carbohydrates are lactose, which absorbs fairly slowly, and because the relatively high protein content also slows absorption. At noon my food absorption is a little slower, and by dinner time it’s slower yet – slow enough I normally spread my insulin out over 4 hours or so.

Changing my eating habits, as I did two days ago for Thanksgiving dinner, can cause an unexpected change in how fast the dinner actually gets into my bloodstream as glucose.

I didn’t have a huge dinner, or an unbalanced one, but I had more than normal, and upped my pre-meal insulin to compensate. I kept to a four-hour dual bolus, but by the time we went to another house for dessert, my blood sugar was running low. We had pie for dessert. I had a small piece, and I was still low, but I did take more insulin to balance the pie.

By the time I got home I was well into insulin shock, with a blood sugar below 50, and over the next two hours I ate enough to bring it up to normal by bedtime.

Four hours later my blood sugar was over 300.

I’m pretty sure that what happened was that the relatively large dinner caused more than the usual delay between swallowing food and the actual rise in blood sugar. As a result the amount of insulin I took, which was reasonable for the amount of food I ate, was enough to put me into insulin shock. Later that night the food caught up with the insulin, but by that time I had eaten enough extra to treat the shock earlier that my blood sugar went high.

The only way a doctor can prevent this is by insisting that you eat exactly the same meals at the same times every day. But we’re people. Most of us can’t keep up that kind of regime. And if we don’t accept that rigid a regime, we have to be intelligent enough to treat ourselves, to a certain extent.

I’ll probably do the same thing for Christmas dinner. But I’ll know to spread the insulin out over more than 4 hours.

Measuring Blood Sugar

Back in the middle of the 20^th century, long before I had diabetes or even thought much about it, I saw a magazine ad that talked about diabetes. It might have been an insulin ad. What I do remember was that it featured a Russian troika – a three-horse hitch – and likened controlling diabetes to driving a troika. Three things have to be balanced: insulin, food and exercise, and misjudging any of the three can throw you to the wolves.

That balancing act is hard enough today, with all the tools we have to help. It was a lot harder 42 years ago, when I was diagnosed. And I hate to think of what it must have been like at the time of the ad.

The key is being able to keep track of your blood sugar. Really high, and you need insulin – exercise may actually push you higher. A little high, and aerobic exercise may bring you down. Too low, and you need food, preferably fast-acting carbohydrates. But at the time of the ad, measuring blood sugar meant several hours of lab work, and you might hear back from the doctor the next day. In order to utilize food, insulin and exercise optimally, you have to have some idea of what your blood sugar is right now, and whether it is rising or falling.

There are some symptoms. Sweating, shaking, blurred vision, and tingling lips can all be symptoms of low blood sugar. They can also be due to other things. (I was put on hormones at menopause primarily because I could not tell the difference between a hot flash and low blood sugar.) But those symptoms tend to decrease with years of living with diabetes.

Symptoms of high blood sugar are even subtler. I may start feeling a little odd when my blood sugar is three or four times normal, but my feelings were certainly not enough to tell me when I was high. Anyway, in those days doctors normally prescribed a fixed amount of insulin and a fairly rigid diet, and pretty much ignored exercise.

My current glucose monitor

What was desperately needed was a way for diabetics to find out what their blood sugar was, preferably without slashing their fingers with a modified razor blade. (That’s how they used to get blood samples.) Eventually, and over the initial objections of some physicians and regulatory agencies who were afraid that patients would self-treat, glucose monitors were developed. From the point of view of most diabetics, the objections were just plain silly. We have to treat ourselves. We give ourselves shots of insulin (which cannot be taken by mouth because it would simply be digested.) We exercise. We eat. Doesn’t it make sense that the more we know about which of the three we need, the better?

The first monitors were reportedly large, clunky and slow. They improved rapidly, and by the time I got my first one, in the late ’80s, they were pocket sized (if you had large pockets.) My testing kit today fits easily into the belt pouch I use as a purse. I still have to poke my fingers many times a day, but I get results in five seconds. One important thing is not covered, though – I can’t tell whether I’m going up or down from an instantaneous reading.

There is also a problem of expense. Tight control means testing before each meal, at bedtime, before you drive, regularly during driving, and every 20 to 30 minutes when exercising. Test strips are not cheap, and there is a real problem getting insurance companies to cover enough strips.

I’m not the only person with diabetes to feel this way, and there’s been a good deal of research on continuous glucose monitors. The first one I tried was the glucowatch. This used a patch sensor on the arm or wrist, and gave the blood sugar on the “face’ of the watch. It could also be read by a computer. Drawbacks? Many. First, it would only operate for 12 hours, and took a while without readings to initialize. Second, the patch was very irritating to my skin. I invariably had a major welt that lasted a week or more when I removed the watch and patch. Third, any sweat made the readings unreliable – and sweating is a symptom of low blood sugar. The watch did confirm that I was having low blood sugars at night and that I responded by “bouncing” high – a fairly common reaction, and much better than staying low with possibly fatal results. But the combination of problems led me to stop using it.

Modern continuous glucose monitors are much better, though by no means perfect, and I’ll talk about them, and the problems with getting insurance companies to cover them, in the future.