Mayo Clinic Minute: Is Alzheimer’s Type 3 Diabetes?

Mayo Clinic Minute: Is Alzheimer’s Type 3 diabetes?

Are some cases of Alzheimer's disease triggered by a form of diabetes in the brain? Perhaps they are, according to researchers. Mayo Clinic's campuses in Rochester, Minnesota, and Jacksonville, Florida, recently participated in a multi-institution clinical study, testing whether a new insulin nasal spray can improve Alzheimer’s symptoms.
“This study has furthered our understanding of the gene that is the strongest genetic risk factor known for Alzheimer’s disease,” says Dr. Guojun Bu, a Mayo Clinic neuroscientist. "About 20 percent of the human population carries this riskier form of [the gene] APOE, called the E4," says Dr. Bu. It's believed that more than 50 percent of Alzheimer’s cases can be linked to APOE4, according to the study, which was published in Neuron.
Watch: The Mayo Clinic Minute
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It's an accepted fact that people with Type 2 diabetes have a higher risk of Alzheimer's disease. One reason may be reduced blood flow to the brain because of damaged blood vessels, Dr. Bu explains. "And, therefore, the supply of essential nutrients to the brain is also impaired."
Dr. Bu has found genetics may also be to blame. A variant of the so-called Alzheimer’s gene, APOE4, seems to interfere with brain cells' ability to use insulin, which may eventually cause the cells to starve and die. Unofficially, it's called Type 3 diabetes. "What it refers [to] is that their brain's insulin utilization or signaling is not functioning. Their risk of developing Alzheimer’s disease is about Continue reading

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Relative contribution of type 1 and type 2 diabetes loci to the genetic etiology of adult-onset, non-insulin-requiring autoimmune diabetes

Abstract
In adulthood, autoimmune diabetes can present as non-insulin-requiring diabetes, termed as ‘latent autoimmune diabetes in adults’ (LADA). In this study, we investigated established type 1 diabetes (T1D) and type 2 diabetes (T2D) genetic loci in a large cohort of LADA cases to assess where LADA is situated relative to these two well-characterized, classic forms of diabetes.
We tested the association of T1D and T2D GWAS-implicated loci in 978 LADA cases and 1057 non-diabetic controls of European ancestry using a linear mixed model. We then compared the associations of T1D and T2D loci between LADA and T1D and T2D cases, respectively. We quantified the difference in genetic risk between each given disease at each locus, and also calculated genetic risk scores to quantify how genetic liability to T1D and T2D distinguished LADA cases from controls.
Overall, our results showed that LADA is genetically more similar to T1D, with the exception of an association at the T2D HNF1A locus. Several T1D loci were associated with LADA, including the major histocompatibility complex region, as well as at PTPN22, SH2B3, and INS. Contrary to previous studies, the key T2D risk allele at TCF7L2 (rs7903146-T) had a significantly lower frequency in LADA cases, suggesting that this locus does not play a role in LADA etiology. When constrained on antibody status, the similarity between LADA and T1D became more apparent; however, the HNF1A and TCF7L2 observations persisted.
LADA is genetically closer to T1D than T2D, although the genetic load of T1D risk alleles is less than childhood-on Continue reading

Is Alzheimer’s Type 3 Diabetes?

Is someone you love suffering from Alzheimer’s disease? If so, you know how devastating this tragic disease is—not only for the people who suffer from it, but for their friends and families as well. That’s why we fear it even more than cancer, heart disease, Type 2 diabetes, or stroke. But here’s something you might not know. Increasingly, scientists are calling Alzheimer’s disease by another name: Type 3 diabetes.
The scientist who coined this term—Suzanne de la Monte, a neuropathologist at Brown University—discovered that rats with insulin resistance (the forerunner of diabetes) “developed an Alzheimer-like disease pattern, including neurodegeneration.” Dr. de la Monte says that Alzheimer’s has “virtually all of the features of diabetes, but is largely confined to the brain.”
Dr. de la Monte’s findings are consistent with the fact that diabetics have a much higher rate of Alzheimer’s disease than non-diabetics. They’re also in line with research showing that people with high blood glucose levels are at elevated risk for dementia even if they don’t have diabetes.
Recent studies are shedding still more light on the connection between Alzheimer’s and insulin resistance or diabetes. For example:
A 2017 study found that the fluctuations in fasting plasma glucose and HbA1c (a long-term blood glucose measurement) that are common in diabetics are independently associated with a higher risk for Alzheimer’s disease.
A 2016 study of patients with mild cognitive impairment (MCI) concluded that Type 2 diabetes “may accelerate cognition deteriorati Continue reading

Alzheimer’s :: Is It Really Type 3 Diabetes?

Alzheimer’s and diabetes: What’s the link? Is there even a link?
You may have heard that Alzheimer’s Disease is recently being touted as “type 3 diabetes.” In fact, this link was first suggested way back in 1989, but is just starting to get traction and buzz now. So, I wanted to find out, is it just sensational headlines? Or is there some actual science behind it?
Specifically, I wanted to dig into the research to give you the goods on whether Alzheimer’s represents the evolution of diabetes to that of a brain disease: “type 3 diabetes.”
But, before we dive into the concept of “type 3” diabetes, let’s get a super-quick primer on blood sugar regulation, and types 1 and 2 diabetes.
BLOOD SUGAR REGULATION 101
Your body needs to regulate so many aspects of your blood for optimal health. Blood sugar level is just one of them. When blood sugar levels get too low or too high for too long, you can end up with diabetes.
When you eat or drink your blood sugar goes up. This is your digestive system doing its job to absorb nutrients from your food. And this is normal and healthy.
FUN FACTOID: Blood sugar increases are mostly from eating carbs, and fats/proteins can reduce blood sugar increases caused by carbs. So eat some healthy fat or protein with carbs!
When your blood sugar level increases, your body takes that sugar from your blood to use it as energy in your cells or store it for later use. It does this with the hormone “insulin.”
When your blood sugar level increases, your body takes that sugar from your blood to use it as energy in your cells or store Continue reading

Got the night munchies? Beware diabetes and heart disease

How many of us can honestly say that we've never raided the fridge at 3 a.m., egged on by an uncontrollable hunger for ice-cream? Doing this once or twice is fine, but new research says that if you make this a habit, you could be in trouble.
Late-night snacking is a strange habit, and there are various theories as to why so many of us are inclined to raid our cupboards and fridges past our bedtime. One study has suggested that our craving for certain types of food — those rich in starch, salt, and sugars — late in the evening may be explained by our ancestors' needs.
The study authors explained that early humans did not know when and where their next meal would come from, so binge eating late in the day where possible allowed their bodies to store the energy needed for survival.
But now, our snacks are driven more by pleasure than by necessity, so their effects are much less wholesome. Researchers agree that caving in to your munchies and eating late in the evening leads to negative health outcomes, such as a heightened risk of obesity.
This may not only be tied to the snacks' nutritional value, though; it might also be linked to how our bodies are programmed to work, and how our circadian — or internal — clocks function. Our bodies are adjusted to the natural day-night cycle, and so they tell us when we should eat, sleep, and be active.
If the circadian clock is ignored, health and well-being are also impacted. For instance, it was found that eating outside the normal waking and activity hours may cause excess weight gain.
And now, emerging research from the Nation Continue reading