Type 3 diabetes

Type 3 diabetes is a proposed pathological linkage between Alzheimer's disease and certain features of type 1 and type 2 diabetes.^[1] Specifically, the term refers to a set of common biochemical and metabolic features seen in the brain in Alzheimer's disease, and in other tissues in diabetes;^[1][2] it may thus be considered a "brain-specific type of diabetes."^[3] It was recognized at least as early as 2005 that some features of brain function in Alzheimer's disease mimic those that underlie diabetes.^[4] However, the concept of type 3 diabetes is controversial, and as of 2021 it was not an officially recognized diagnosis.^[5]

The techniques used to prevent the disease in patients with diabetes are similar to individuals who do not show signs and symptoms of the disease.^[8] The four pillars of Alzheimer's disease prevention^[9] are currently used as a guide for individuals of who are at risk of developing Alzheimer's disease. As with Alzheimer's disease more broadly, there is no cure for type 3 diabetes, but disease progression may be slowed with certain drugs.^[5]

Signs and symptoms

Alzheimer's disease is associated with a progressive decline in mental faculties. At early stages, forgetfulness, poor judgment, lack of awareness of date or location, and mood disturbances may be evident. This progresses to major difficulties in performing everyday tasks and recognizing familiar people. At later stages, the ability to speak is lost, and control of basic body functions is lost or greatly diminished.^[10]

These symptoms may be exacerbated in individuals with pre-existing type 1 or type 2 diabetes. Individuals with type 1 diabetes are often diagnosed at a young age, usually between childhood and adolescence.^[6] In some cases, brain development in these patients is negatively impacted, resulting in cognitive impairment earlier in life.^[6] In type 2 diabetes, which is usually diagnosed later in life, patients often exhibit cognitive impairment that correlates with the length of time since initial type 2 diabetes onset, and with poor glycemic control.^[6][11] The observation that both types 1 and 2 diabetes can contribute to the development of Alzheimer's disease led to the hypothesis that Alzheimer's disease reflects a brain-specific "type 3" of diabetes.^[11]

Cause

There are a number of mechanisms that attempt to explain the cause, progression and the link between type 1 diabetes, type 2 diabetes and Alzheimer's disease.^{[12][6][1][13]}

Insulin resistance

A minor to medium decline in

Mediterranean diet, a diet based around fruit, vegetables, olive oil, nuts and seafood has been shown to lower the risks of Alzheimer's disease in patients.^[9] Specifically, patients who followed this diet which is modeled on particular Mediterranean nations presented decreasing amounts of amyloid-beta plaques between their nerve cells in the brain,^[22] signifying the cell connections within the brain were firing correctly. This diet also presented increases in the thickness in the memory division of the brain cortex in the formal and parietal lobes and areas of cognition such as language and memory.^[22] Updated versions of the Mediterranean diet such as the DASH diet have been recommended for patients, adding juicing and supplements to the recommendation for patients.^[22]

Physical and mental exercise

Mediation and yoga have been found to reduce stress, which is a major element in the cause of Alzheimer's disease.^[9] Stress has a negative impact on a patient's genes such as producing inflammation in the brain, a key component of Alzheimer's disease.^[25] Simple twelve minute meditation each day reduces levels of stress in patients and extends the flow of blood to key areas of the brain responsible for memory performance.^[9][25] Yoga also stimulates the Anterior Cingulate Gyrus, a key area in the brain which manages memory recall, stress, emotive and cognitive stability.^{[citation needed]}

Psychological well-being

Melatonin administration

Melatonin is discharged by the pineal gland as a neurohormone.^[3] Melatonin is a central hormone in the treatment of patients with Alzheimer's disease as it adjusts sleep patterns that are abnormal, which occurs in over forty five percent of patients.^[3][27]

Glucagon-like Peptide 1 administration

The administration of the hormone Glucagon-like Peptide 1 has shown to control the deregulation of glucose metabolism in patients with Alzheimer's disease.^[28] This hormone can recover cerebral dysfunction in diabetes induced Alzheimer's disease. The hormone Glucagon-like Peptide 1 can lessen the brain's inflamed reaction caused by amyloid beta oxidative stress.^[13][28] Glucagon-like Peptide 1 can also increase the rate of neurogenesis within the brains of Alzheimer's patients.^[13] Glucagon-like Peptide 1 has the possibility to increase the production of neurons to substitute impaired neurons within the brain.^[13] This hormone can also decrease the brain's insulin resistance in Alzheimer's patients.^[28]

References