This blog is a collection of short updates, mostly from the ADA conference.
Diet (Macronutrients) Does not Impact T1D Risk
Macronutrients are carbohydrates, protein, fat, sugar, and fiber (things that you eat large amounts of). This study also looked at glycemic index and glycemic load. It did not look at micronutrients, such as vitamins and minerals (things that you eat small amounts of). This study enrolled people who already tested positive for autoantibodies to see how long it took them to show symptoms of type-1 diabetes.
This study covered 881 people divided into four groups by age: 1-4 years old, 5-12 y/o, 13-22 y/o, and 23 and over. Here is the summary of their findings:
Given multiple comparisons, there was no significant association between rate of progression from IA to T1D and daily dietary intake of any macronutrients analyzed, after adjusting for [confounders]. ... Baseline dietary macronutrient intake does not appear to influence rate of T1D diagnosis in children, adolescents, or adults with IA.
This study is strong evidence that feeding low carb, low sugar, low fat, or any other type of macronutrient based diet cannot prevent (or even delay) the onset of type-1 diabetes, at least among people who have autoantibodies.
Abstract: https://diabetes.diabetesjournals.org/content/70/Supplement_1/1116-P
Maternal C-Peptide Generation
It has been known that women with T1D often have increased levels of C-peptide when pregnant, and especially later in pregnancy. In the past this has been considered a hopeful sign that pregnancy caused beta cells to regrow (generating the C-peptide) and that perhaps research into this phenomena could lead to a way to regrow beta cells in others with T1D.
Unfortunately, a study at ADA2021 implies that beta cells are not regrowing. Rather, the fetuses C-peptides are moving across the placenta so they are found in the mother. To quote the abstract:
... This suggests transfer of C-peptide from fetal to maternal serum and is inconsistent with pregnancy-related β-cell regeneration.
Tweet: https://twitter.com/ClaireMeek5/status/1409028250450509824
Full Paper: https://care.diabetesjournals.org/content/early/2021/06/05/dc21-0028
Leptin
Leptin is a hormone generated by fat cells which helps the body regulate hunger and energy use, and may regulate other body processes as well. Back in 2011 there was hope that it might become a cure for T1D, but clinical trials were unsuccessful. However, there is still hope that Leptin (in addition to standard insulin use) might end up helping to treat T1D by lowering insulin spikes after meals, resulting in better control.
A poster at ADA reported on a phase-I study (7 treated people, 3 in a control group). Basically, they gave a small dose of Leptin to people with T1D who were fasting, and then cut their pump basal insulin by 50%. The control group's blood sugar and glucagon levels went up (as expected), but the treated group's levels went down, even though they were getting less insulin. The effect lasted less than 3 hours. This is a good result, if you are positioning Leptin as a "take with meals" drug to lower blood sugar spikes caused by eating. However, this is not a cure, and I don't expect to cover it in the future.
ADA 2021 had results for a 10 person study: https://www.hcplive.com/view/oral-leptin-formulation-offers-short-term-benefit-type-1-diabetes-patients
Abstract of poster: https://diabetes.diabetesjournals.org/content/70/Supplement_1/121-LB
Viacyte Update
Viacyte was in the news this summer because they released some data at ADA (American Diabetes Association) 2021 Scientific Sessions. Unfortunately, the data they released was from one person who was part of their "PEC-Direct" study. The PEC-Direct study still requires people to take immune suppressive drugs for the rest of their lives. Therefore, I don't consider this to be a cure, because it swaps one drug regimen (insulin replacement) for another drug (immune suppression). Immune suppression has serious long term side effects, possibly worse than T1D itself. Furthermore, I don't put much stock in single person results, so their press release had two reasons for me not to get excited.
The data showed that one person's transplanted beta cells were working well 9 months after the transplant. Her A1c was 6.6% (compared to 7.4% before the operation) and her time within range was 84% (up from 54%). She was still injecting insulin, however.
Viacyte is also running another study called PEC-Encap. This study will use encapsulated stem cells and so these people will not need to take immune suppressive drugs for the rest of their lives. I do consider that a cure. Last I heard (from the JDCA) they were hoping to have interim results from this study in the second half of 2021 (soon!) Those are the results I care about.
JDCA update on Viacyte from early 2021: http://thejdca.org/viacyte-2021
Viacyte press release on PEC-Direct: https://viacyte.com/press-releases/viacyte-reports-compelling-preliminary-clinical-data-from-islet-cell-replacement-therapy-for-patients-with-type-1-diabetes/
Viacyte press release on PEC-Encap: https://viacyte.com/press-releases/viacyte-announces-initiation-of-phase-2-study-of-encapsulated-cell-ther-apy-for-type-1-diabetes-patients/
News coverage: https://endpts.com/after-years-of-failure-viacyte-shows-off-first-proof-of-concept-for-diabetes-stem-cell-transplants/
Viacyte is part of a long line of attempts to cure T1D by encapsulating beta cells. This sounds easy: just wrap the implanted cells in a membrane that lets sugar and oxygen in, insulin and carbon dioxide out, and does not allow T-cells to enter). Seems straightforward. For all of the last 25+ years there have been companies working on this, and none has succeeded yet. So it is clear to me that there is something more complex and difficult about this path than we currently know. At the moment, I think there are 3 companies working on this approach that are in human trials, or close to it.
BCG News
Dr. Faustman's lab released their most recent BCG result as a poster at the ADA 2021 conference. They reported on demethylation of signature Treg genes. BCG (Bacillus Calmette–Guérin) is a biologic which has been given to over a billion people (in low dose) as a tuberculosis vaccine, and is also approved (in much higher doses) as a bladder cancer treatment. It is a generic drug with a very long record of safety.
BCG was tested as a T1D cure or preventative several times in the early 2000s (including once by this same lab), and all those clinical trials were unsuccessful. However, Dr. Faustman's continues to run clinical trials with BCG.
In my view, these results are another step in the collapse of BCG as a possible cure.
When this research started 20 years ago, it was based on curing mice.
Then, the first results in people (in a tiny phase-I trial) showed very
small progress to a cure in people. Later, a follow on trial showed no
progress to a cure in people, but maybe small progress to treatment.
Now we have these results which don't show any progress to treatment,
but instead are looking at demethylation, a type of gene expression change. The particular change they report certainly does not cure T1D, and may have
nothing to do with T1D at all. By itself, it does not
show progress to either a cure or treatment.
Poster: https://diabetes.diabetesjournals.org/content/70/Supplement_1/1142-P
