Thursday, January 2, 2020

Insulin Clearance

I recently came across this paper on insulin clearance. It's a little technical but discusses the insulin-degrading enzye (IDE) and how it affects type 2 diabetes.

As we all know, insulin makes blood glucose (BG) go down, and glucagon makes it go up. In most cases, the absolute amount of these hormones is not as important as their ratio. But other hormones can affect BG levels as well. For example, the hormone somatostatin inhibits the secretion of both insulin and glucagon as well as other hormones.

And IDE can also affect BG levels by degrading insulin in the liver.

So if, for some reason, you were producing too much insulin and not enough glucagon, IDE could help to control the excessive insulin levels. This is called insulin clearance, and it seems to decline with the progression of type 2 diabetes. Lower levels of IDE are found in obesity and type 2 diabetes. Less insulin clearance would result in higher insulin levels, and these could cause insulin resistance.

However, there's no agreement on whether lower levels of IDE are because insulin levels are declining or insulin resitance is increasing (essentially reducing the levels of effective insulin) or whether they are the result of dysfunction in the liver.

From a practical point of view, it doesn't matter that much what causes the decline in IDE levels. What matters to us is how this decline affects our BG levels. The authors found that exercise can increase IDE levels.

One interesting thing about all this is as an illustration of how complex the control of BG levels is. Many hormones and enzymes are involved, and we may have differences in the effectiveness of the various hormones and enzymes. Is it any wonder that we don't always see the same results from some drug or diet? Results of big clinical studies are reported as averages. But there are usually outliers.


We have to constantly experiment, keep records, and work out what is best for us. It's a lot of work, but it's worth that effort. Good control now will mean fewer problems in the future.


Wednesday, January 1, 2020

Helping Obese Mice (humor)

OK, I admit it. I'm a worrier. I worry about big issues, like climate change. But I also worry about smaller issues, like what I would do if we had five straight days of snow so I couldn't get out and I was almost out of toilet paper and coffee.

[Correction: Being out of coffee is a big issue.]

But one thing I don't worry about a lot is obese mice. As long as they don't eat all my food, I don't care how svelte my resident mice are. So when I saw an article titled "Watermelon supplements bring health benefits to obese mice," I didn't exactly race to the supermarket to buy watermelon for my live-in mice.

I did wonder why the researchers even thought about giving mice watermelon in the first place. Were they sitting around in the shade some hot day eating watermelon when one of them said, "Say, I wonder if watermelon would solve the urgent national problem of obese mice? Might they have a better self-image if they were healthier after eating this fruit?"

Then I read on. "The study was funded by the National Watermelon Promotion Board."  Ah, that explains it.

Food industry groups support research that takes some product they're pushing, extracting something from it, and giving a lot of the extract to mice or people, hoping it will show some benefit. If it doesn't, you'll never hear about it: "Kale extract doesn't help diabetics" is a headline you'll never see in your newspaper, ever. If it does help, the story will be trumpeted everywhere: "Kale extract may cure diabetes in platypuses." Even if the effect is miniscule and the test organism rare, the PR experts hope you won't remember the details, just "cure diabetes," so you'll buy a lot of it.

Thus unless you're losing sleep over the problems of fat mice, when you see news stories lauding some common food as an obesity or diabetes treatment, see who sponsored the study. If it's a food industry group, take the findings with a grain of salt.

Unless, of course, you're on a low-salt diet.