What Is Type 3 Diabetes? Insulin Resistance In The Brain That Could Trigger Alzheimer’s
Most people are aware of type 1 and type 2 diabetes, but did you know there is a type 3 diabetes as well! It is a more obscure term. Although it is not an accepted medical diagnosis, type 3 diabetes has been discussed in the literature as a possible relationship between insulin resistance in the brain and Alzheimer's disease. This link has been described to help explain how metabolic disorders impact brain health, causing cognitive decline and dementia.
Type 3 diabetes is more of a misnomer because it should not be confused with type 3c diabetes, which relates to pancreatic dysfunction. The term "type 3 diabetes," on the other hand, has been loosely used by some scientists to analogously propose that Alzheimer's disease is strongly implicated with insulin resistance in the brain.
This concept was conceptualized by Dr. Suzanne de la Monte and Dr. Jack Wands of Brown University in the year 2008. This hypothesis postulated that Alzheimer's disease may be called type 3 diabetes for it bears many similarities with glucose metabolism disorder type 2 diabetes. Their concept arises from the basic principle that insulin is fundamental to blood sugar regulation, but it is also the case with the brain. When brain cells become insulin-resistant, they lose access to glucose, impairing their function.
Research published in the Journal of Diabetes Science and Technology supports this hypothesis by indicating that insulin resistance can be a significant contributor to the occurrence of dementia, also referred to as Alzheimer's. The symptoms of memory loss and diminished reasoning are associated with impaired glucose metabolism in the body, especially in the cerebral tissue.
Although type 3 diabetes is not a "medical term," its symptoms correlate well with Alzheimer's diseases that are known to reduce the ability to think in an efficient manner and bring down brain health. These signs are:
- Loss of memory, especially short-term.
- Poor judgment and judgment ability
- Failure in recognizing people or places familiar once.
- Failure in the process of reading, writing or processing numbers
- Anxiety, agitation, or mood changes.
- Disorganized thoughts or confusion
- Lack of impulse control
As the disease advances, patients may be afflicted with severe complications including an inability to swallow or control their bodily functions. In the final stages, most patients die from fatal complications such as aspiration pneumonia.
This may not be well understood with regards to type 3 diabetes, or the exact link between insulin resistance and Alzheimer's disease. Some identified contributing factors include the following:
Insulin acts as an important regulatory mechanism of brain functions such as memory and cognition. The reduction in insulin signaling may impair metabolism of brain cells, thus bringing about neurodegeneration.
These diseases show a strong relationship and those individuals diagnosed with type 2 diabetes have double chances of getting Alzheimer's. In the two, the main causes can be chronic inflammation, oxidative stress, and a defect in glucose metabolism.
Insulin resistance associated with obesity, stress, and an unhealthy diet is considered a cause that may increase the chances of Alzheimer's disease.
Researches in Frontiers in Neuroscience and The Lancet Neurology have also highlighted that drugs used for antidiabetic medication may be crucial for the prevention or at least slowing down the course of Alzheimer's.
In 2022, in a study in Pharmaceuticals, researchers studied biomarker uptake in brain regions implicated in the faulty uptake and metabolism of blood sugar in Alzheimer’s patients.
Emerging Therapies
Research into such treatments as intranasal insulin has also been promising. Intranasal delivery of insulin directly to the brain has been reported to enhance glucose uptake by brain cells, improve memory, and boost cognitive performance. While such clinical trials have been shown to be successful, additional research is needed for safety and efficacy.
Medications
For patients being aggressive or agitated, antipsychotic drugs may be prescribed; however, therapies such as cognitive rehabilitation as well as cognitive stimulation therapy serve to preserve memory and executive function.
Lifestyle Interventions
Diet, exercise, and stress management are critical in preventing and managing insulin resistance. A review in the Journal of Alzheimer's Disease also highlighted the benefits of Kirtan Kriya meditation, which can regulate genes involved in insulin and glucose metabolism, improve sleep, and reduce inflammation.
Although type 3 diabetes is not officially recognized, its connection to Alzheimer’s disease underscores the importance of proactive measures for brain health. Some prevention strategies include:
1. Healthy Diet
Consuming a balanced diet rich in antioxidants, whole grains, and healthy fats may support brain health.
2. Regular Exercise
Physical activity improves insulin sensitivity, reduces inflammation, and enhances overall metabolic health.
3. Stress Reduction
Mindfulness practices, including meditation, have been shown to lower stress levels, which can reduce the risk of cognitive decline.
The term type 3 diabetes brings out the complex relationship between metabolic disorders and brain health. Even though it is not a recognized medical condition, the concept emphasizes the crucial role of insulin in brain function and its possible contribution to Alzheimer's disease. Continued research will hopefully provide hope for therapies such as intranasal insulin and lifestyle modifications.
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Influenza strain H1N1, formerly known as swine flu, is rising significantly in India, with deaths also being reported in some states.
H1N1 is a subtype of Influenza A and can cause sudden fever, cough, sore throat, headache, body aches and fatigue. These symptoms can overlap with those of other seasonal influenza strains, COVID-19 and respiratory syncytial virus (RSV), making it difficult to identify the infection based on symptoms alone.
Delhi: According to official data, Delhi has reported 1,349 confirmed H1N1 infections. No official deaths have been reported.
Kerala: A total of 2,468 influenza cases were recorded in the state in July, with 24 deaths reported during the month. The total number of cases recorded in the state this year stands at 5,519, with 60 deaths reported.
Maharashtra: The state has reported 25 laboratory-confirmed H1N1 cases, including a major spike of 15 cases in July. One confirmed death was officially verified by the Nagpur Municipal Corporation (NMC) Death Audit Committee.
Gujarat: H1N1 activity is also being reported, with Ahmedabad currently seeing a rise in cases.
Although H1N1 influenza primarily affects the respiratory tract, the infection can also put additional strain on the heart in some people, particularly those with a chronic history of cardiovascular disease, experts told HealthandMe.
Fever, dehydration, increased levels of carbon dioxide in the body, decreased oxygen levels and the body’s inflammatory response can increase the workload on the heart during an H1N1 infection.
This added strain may be more concerning for people who already have cardiovascular disease, said Dr. Praveen Raman Mishra, Associate Consultant, Institute of Cardiac Sciences at ShardaCare – Healthcity.
Some H1N1 influenza patients may experience cardiovascular complications, including:
Dr. Saurabh Gupta, Associate Director, Internal Medicine, Yashoda Medicity, added that H1N1 infection may cause fluctuations in heart rhythm or inflammation associated with the heart.
“In some circumstances when suffering from the H1N1 virus, although the initial symptoms of the virus may be those shared with the normal flu, such as temperature, aches and cough, those with pre-existing heart conditions should be more vigilant whilst they’re recuperating,” he told HealthandMe.
“As the infection puts more work on the body, you can find that previous heart problems are more noticeable,” he added.
The experts noted that people recovering from H1N1 should seek medical attention if they develop symptoms such as:
People with a chronic history of cardiovascular disease may face greater strain on the heart during H1N1 infection.
Monitoring symptoms during recovery and seeking medical attention when concerning symptoms develop can help identify cardiovascular problems early.
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For many women, menopause can bring a string of uncomfortable symptoms like hot flashes, sleep problems, changing body composition and weight gain.
Now, researchers are looking at whether combining GLP-1-based weight-loss medicines with menopausal hormone therapy (MHT) could offer greater benefits, particularly for women struggling with obesity after menopause.
A recent Mayo Clinic study, published in The Lancet Obstetrics, Gynaecology & Women's Health, found that postmenopausal women taking tirzepatide along with hormone therapy lost about 35% more weight than those taking tirzepatide alone.
Researchers studied 120 postmenopausal women with overweight or obesity who had been taking tirzepatide for at least 12 months. Forty women were also using MHT, while 80 were not.
Women taking both treatments lost around 17-19% of their body weight, compared with about 14% among those taking tirzepatide alone. About 45% of women on the combination achieved at least 20% weight loss, compared with 18% in the tirzepatide-only group.
“This study provides important insights for developing more effective and personalized strategies for managing cardiometabolic risk in postmenopausal women,” said Dr Regina Castaneda, first author and Mayo Clinic researcher.
However, this was just an observation in the study, not a randomized clinical trial. Therefore, it cannot prove that hormone therapy itself caused the additional weight loss.
“It is possible that women using hormone therapy were already engaged in healthier behaviors, or that menopause symptom relief improved sleep and quality of life,” said Dr Maria Daniela Hurtado Andrade, senior author of the study.
Also read: Postmenopausal Women May Face More Severe Dry Eye Disease; How Do Hormones Contribute?
During menopause, declining oestrogen levels can change fat distribution, appetite, metabolism and muscle mass. GLP-1 medicines, meanwhile, reduce appetite and slow stomach emptying, helping with weight management.
Researchers believe there could also be a biological interaction between oestrogen and GLP-1 signalling. “Preclinical data suggest a potential synergy, with estrogen appearing to enhance the appetite-suppressing effects of GLP-1,” Castaneda said.
Earlier research has also suggested greater weight loss among postmenopausal women using semaglutide alongside hormone therapy.
A 2026 review similarly concluded that GLP-1 medicines may help reduce weight and abdominal fat in menopausal women, but larger studies are needed.
Also read: Experimental Menopause Drug Shows Promise Mid-Stage Trial, Reduces Hot Flashes By 83%
GLP-1 medicines may cause nausea, vomiting, diarrhoea, constipation, abdominal pain and reduced appetite. These effects often surface when the dose is increased.
Hormone therapy has its own side-effects and it is also not suitable for everyone. Depending on the patient's medical history, MHT can increase the risk of complications like blood clots and stroke.
Hormone therapy should not be started simply to fuel weight loss from a GLP-1 drug. It is primarily used to treat certain menopause symptoms and should be prescribed after considering a woman's age, symptoms, medical history and individual risks.
As Hurtado Andrade noted, researchers now want to determine whether the combination offers benefits beyond weight loss, including improvements in cardiometabolic health.
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It can be confusing and sometimes alarming to receive different thyroid test results from two different laboratories, especially when both tests are done on the same day. A slight difference in values does not necessarily mean that your thyroid function has suddenly changed. In many cases, the variation is due to differences in how the tests are performed rather than a change in your health.
One of the biggest reasons for varying results is the laboratory itself. Accredited laboratories, such as NABL-certified labs, follow stringent quality-control measures, use standardised testing protocols and have trained personnel to handle samples correctly. Laboratories with less rigorous quality standards may produce results that are less consistent.
The equipment and testing methods used can also differ from one laboratory to another. Different analysers, calibration techniques and testing kits can produce slightly different values for thyroid hormones such as TSH, T3, T4, Free T3 and Free T4.
Even the reference ranges printed on reports may not be identical because each laboratory establishes its own normal range based on the equipment used and the population it serves.
Also read: UK Approves Eli Lilly’s Foundayo: Is the GLP-1 Pill Better Than Wegovy, Mounjaro?
The timing of the test is another important factor. Thyroid-stimulating hormone (TSH) naturally fluctuates throughout the day. It is generally higher during the early hours of the morning and gradually falls as the day progresses.
As a result, a blood sample collected in the afternoon may show a lower TSH level than one collected early in the morning.
Lifestyle and biological factors can also influence thyroid hormone levels. Stress, poor sleep, recent illness, medications and even eating before the test may affect the results.
For people taking thyroid medication, blood samples should ideally be collected in the morning on an empty stomach and before taking the daily dose. Testing after medication may temporarily alter hormone levels and make interpretation more difficult.
Also read: Why Women Want Hormonal Health Care, Not Just Pregnancy Care
Certain supplements and medications can interfere with thyroid tests as well. Biotin, commonly found in hair and nail supplements, can falsely lower TSH levels while increasing Free T3 and Free T4 values.
Medications such as amiodarone, glucocorticoids, dopamine and heparin may also affect thyroid hormone measurements. During pregnancy, hormonal changes, particularly increased levels of human chorionic gonadotropin (hCG), can naturally alter TSH values.
Laboratory handling also plays a role. Delays in processing, improper storage temperatures, differences in centrifugation timing or sample-handling errors can influence the final result.
In some individuals, thyroid autoantibodies may interfere with laboratory assays, potentially leading to inaccurate Free T3 and Free T4 measurements.
Also read: Silent Neck Swellings: Why An Unusual Lump Should Never Be Ignored
Because of these variables, experts recommend getting thyroid tests done at the same accredited laboratory whenever possible. This allows doctors to compare results more reliably over time.
If a thyroid value is only mildly abnormal or falls within a borderline range, it may often be advisable to repeat the test before making a diagnosis or starting lifelong medication.
Ultimately, thyroid test reports should never be interpreted in isolation. Doctors consider the patient's symptoms, medical history, physical examination and repeat test results before deciding on treatment.
Consistency in where and how the test is performed can help avoid unnecessary anxiety and support more accurate clinical decisions.
By Dr Shaheen Guy, General Physician, Saifee Hospital, Mumbai
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