Brain intertwined with thyroid hormone molecules

Hypothyroidism and Diabetes: Unlocking the Brain Connection

Lena Kashyap in Health & Wellness December 2025 • 3 min read.

"Can managing thyroid hormones improve brain health in type 2 diabetes? New research explores the surprising link between hypothyroidism and cognitive function."

Thyroid hormones are essential for brain development and function. They influence everything from nerve cell growth to the formation of connections between brain cells. When thyroid hormone levels are off, it can have significant effects on cognitive processes.

Type 2 diabetes, a condition affecting millions worldwide, is known to impact brain health. Memory problems and difficulties with thinking clearly are common complications. Researchers are working to understand exactly how diabetes affects the brain and what can be done to protect it.

A recent study investigated the connection between hypothyroidism (low thyroid hormone levels) and brain health in a rat model of type 2 diabetes. The results suggest that managing thyroid hormone levels could play a role in protecting the brain from the harmful effects of diabetes.

The Study: Investigating Hypothyroidism in a Diabetic Rat Model

Brain intertwined with thyroid hormone molecules

Researchers used a specific strain of rats, called Zucker diabetic fatty (ZDF) rats, that are prone to developing type 2 diabetes. They induced hypothyroidism in some of these rats by administering methimazole, a medication that reduces thyroid hormone production. The goal was to observe how hypothyroidism affected cell growth and the development of new nerve cells (neuroblasts) in a specific brain region called the hippocampus, which is crucial for learning and memory.

The study focused on two key markers in the hippocampus:

Ki67: A protein indicating cell proliferation, showing how actively cells are dividing and growing.
Doublecortin (DCX): A protein found in young, developing nerve cells, indicating the formation of new neurons.

The researchers compared the levels of these markers in three groups of rats: healthy control rats, diabetic rats, and diabetic rats with induced hypothyroidism. They also measured hormone levels (thyroid hormones and corticosterone, a stress hormone) to understand the hormonal changes occurring in each group.

The Implications: A Promising Avenue for Brain Health

This research offers a promising avenue for protecting brain health in individuals with type 2 diabetes. While more research is needed, the findings suggest that carefully managing thyroid hormone levels could help to counteract the negative effects of diabetes on the brain. Future studies in humans are essential to confirm these findings and to determine the optimal strategies for thyroid hormone management in diabetic patients. However, these initial results highlight the complex interplay between metabolic health and brain function, offering hope for new interventions to support cognitive well-being.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.5115/acb.2010.43.3.185, Alternate LINK

Title: Effects Of Hypothyroidism On Cell Proliferation And Neuroblasts In The Hippocampal Dentate Gyrus In A Rat Model Of Type 2 Diabetes

Subject: Cell Biology

Journal: Anatomy & Cell Biology

Publisher: Korean Association of Anatomists

Authors: Sun Shin Yi, In Koo Hwang, Ji Won Choi, Moo-Ho Won, Je Kyung Seong, Yeo Sung Yoon

Published: 2010-01-01

Everything You Need To Know

How does hypothyroidism potentially complicate brain health in individuals with type 2 diabetes?

Hypothyroidism, characterized by low thyroid hormone levels, can exacerbate the impact of type 2 diabetes on brain health. Thyroid hormones are critical for nerve cell growth and the formation of connections between brain cells. When these hormone levels are insufficient, cognitive processes can be significantly affected, potentially worsening the memory problems and cognitive difficulties already associated with type 2 diabetes. The study using Zucker diabetic fatty rats showed that induced hypothyroidism affected cell growth and the development of new nerve cells in the hippocampus, a key region for learning and memory.

What specific markers did the study focus on to evaluate the impact of hypothyroidism on the brains of diabetic rats, and why were these markers chosen?

The study focused on two key markers in the hippocampus of Zucker diabetic fatty rats: Ki67 and Doublecortin (DCX). Ki67 is a protein that indicates cell proliferation, showing how actively cells are dividing and growing, thus reflecting the brain's capacity for repair and maintenance. Doublecortin (DCX) is a protein found in young, developing nerve cells, indicating the formation of new neurons. These markers were chosen because they provide insights into the effects of hypothyroidism on cell growth and neurogenesis (the creation of new nerve cells) within the hippocampus, a brain region crucial for learning and memory, which is often affected in type 2 diabetes.

What implications does managing thyroid hormone levels have for individuals with both type 2 diabetes and hypothyroidism?

Managing thyroid hormone levels could potentially counteract the negative effects of type 2 diabetes on the brain. By maintaining optimal thyroid hormone levels, it may be possible to support nerve cell growth and the formation of connections between brain cells, which are essential for cognitive functions like memory and learning. The research suggests that carefully managing thyroid hormone levels could help protect the brain from the harmful effects of diabetes. Future studies in humans are essential to confirm these findings and to determine the optimal strategies for thyroid hormone management in diabetic patients.

What is the significance of using Zucker diabetic fatty (ZDF) rats in research examining the link between hypothyroidism and brain health in type 2 diabetes?

Zucker diabetic fatty (ZDF) rats are a specific strain of rats that are prone to developing type 2 diabetes. Their genetic predisposition makes them a suitable model for studying the disease's progression and its effects on various organs, including the brain. By using ZDF rats, researchers can better mimic the conditions and complications seen in human type 2 diabetes, allowing for more relevant insights into how hypothyroidism interacts with diabetes to affect brain health. This model facilitates the investigation of potential therapeutic interventions, such as managing thyroid hormone levels, to mitigate cognitive decline associated with diabetes.

Beyond thyroid hormones, what other hormonal factors might influence the brain health of individuals with both type 2 diabetes and hypothyroidism, and how?

Corticosterone, a stress hormone, is another hormonal factor that can influence brain health in individuals with both type 2 diabetes and hypothyroidism. Elevated levels of corticosterone, often seen in chronic stress and metabolic disorders like diabetes, can negatively impact the hippocampus, a brain region crucial for learning and memory. The interplay between thyroid hormones and corticosterone can further complicate brain health, as stress hormones can interfere with thyroid hormone signaling and exacerbate cognitive dysfunction. Managing both thyroid hormone levels and stress responses may be essential for protecting brain health in this population. Further research is needed to fully understand these complex hormonal interactions and their effects on cognitive well-being.