How many beta cells does a person normally have?

How many beta cells can a person lose and still have normal pancreatic function?

Do we lose all beta cells before the pancreas shuts down?

Is there a test we can take to see how many beta cells we have?

It's very hard to study beta cell mass in living people. You can't do a biopsy because of the danger of damaging the pancreas. Most of what we know about beta cell mass comes from autopsies and even they are hard to do because as soon as you die the digestive enzymes in the pancreas start to digest it!

The best study of human pancreases where they knew the medical histories of the people whose pancreases they were showed that fat people with diabetes had more beta mass than thin people with diabetes, and that many fat people who were not diabetic actually grew huge amounts of new beta cells to keep up with their growing bulk. In fact, it looked like one difference between fat people with and without diabetes was that the ones without--2/3 of all fat people--could grow new cells, while those with diabetes the cells died shortly after reproducing.

But as long as you are alive there isn't anything you can do to check out your beta cells. And many of the claims that drugs increase beta cell mass are drawn from test tube studies or from animal studies. NOT examinations of humans who took the drugs. Often they deduce that a drug, like say Byetta, improves beta cell mass simply by measuring the insulin output.

I've written this up in some detail on my How Blood Sugar Control Deteriorates page. The pancreas autopsy study is linked at the bottom of the page. It is fairly technical but probably one of the most interesting studies ever published about diabetes for those of you who enjoy reading journal studies.

So, how do we know if anyone ever has a beta cell that has died?

If the pancreas is removed from a body immediately after death and slices are immediately stained with the necessary insulin-related antibody reagents, microscopy can be used to find beta cells that were active ("living") at the time of death. I suspect that studies have compared pancreatic slices of people with diabetes to similar slices from non-diabetic people and have found the diabetic people to have fewer active beta cells. I know this has been done with mice and rats and it very likely as been performed with human bodies that were donated for medical research.

CarolynC:

Good answer, uh! It sounds very logical...

Carolyn and Jenny, I'm enjoying seeing you two post here

Thank you, Daryl. You're very kind. I've enjoyed reading what you and everyone else have to say, too.

Carolyn C,

The data about beta cell loss comes from a fascinating pancreas autopsy study done with patients from the Mayo clinic where they had medical records that told them what the people's blood sugar and weight had been in the 2 years before they died.

Here's the refence:
Butler AE, Janson J, Bonner-Weir S, Ritzel R, Rizza RA, Butler PC. Beta-cell deficit and increased beta-cell apoptosis in humans with type 2 diabetes. Diabetes. 2003;52:102-110.

http://diabetes.diabetesjournals.or...t/full/52/1/102

It's a really fascinating study if you enjoy reading studies.

Thanks for the link, Jenny. It was very interesting. I was surprised to see that subjects with impaired fasting glucose (IFG, basically pre-diabetics) had already lost 40% of their beta cells, as opposed to about 60% "dead" beta cells for Type 2 diabetics. I hadn't realized it was already that bad for people with "only" IR. Also, the average age at death of 80 years for lean (BMI < 25) type 2 diabetics in the study versus 60 years old at death for overweight or obese (BMI > 25) type 2 diabetics is striking. I'm already 50 years old, so this makes me even more convinced that I need to lose weight and keep it off.

Reading the study was timely for me personally because I'm teaching chemistry graduate students how to use ANOVA in tomorrow's lecture. This gives me another example I can show the class about the use of ANOVA in interpreting data.

Carolyn,

The studies you can find cited and linked on my page about how diabetes develops at

http://www.phlaunt.com/diabetes/14046669.php

show that for most people who become diabetic fasting glucose doesn't deteriorate until AFTER they are diabetic by post-meal blood sugars or very shortly before.

The use of the fasting glucose test to diagnose diabetes instead of the OGTT is the main reason why most people in the U.S. at diagnosis already have neuropathy,though it takes years to develop.

So whenever you read about people with IFG, assume that they really are in the early stage of full fledged diabetes.

The exception is a small group, more male than female, who appear to have a defect in the production of basal insulin alone. They can lose fasting control but still have normal post-prandials.

Occasionally I have run into such people online and they are the ones who cannot understand why "diabetics" can't eat huge amounts of carbs since they can do so and get normal numbers.

Not understanding the different kinds of diabetes is a real problem. Mine, for example, for many years had normal fasting blood sugar with no post-prandial control at all, but with doctors only testing fasting glucose I could not get diagnosed. I also have an extremely high urinary threshhold for glucose so they didn't catch the problem on urine dips until I got up to well over 250 mg/dl and happened to be at the doctor 3 hours after eating. Even then, after testing the fasting glucose they told me I was fine.

This is why I am so interested in the different forms of diabetes.