Blood glucose, also known as blood sugar, serves as the primary sugar in your bloodstream and provides energy for your body. When you eat, most of the food is broken down into glucose, which is then released into your blood. If your blood glucose levels rise, your pancreas releases insulin to help move the glucose into your cells for energy.
What is diabetes?
Diabetes is a condition characterized by high blood glucose levels due to inadequate insulin production or utilization by the body. It is crucial to manage your blood glucose levels within the target range to prevent serious health complications associated with elevated blood sugar levels.
What are blood glucose targets?
For individuals with diabetes, it is essential to aim for specific blood glucose targets. Typically, these targets range from 80-130 mg/dL before meals and less than 180 mg/dL two hours after meals. Consult your healthcare provider to determine the best target range based on your individual circumstances.
When and how should I check my blood glucose?
Regular monitoring of blood glucose levels is vital for individuals with diabetes. This can be achieved through daily checks using a blood glucose meter or continuous glucose monitoring for those using insulin. The A1C blood test provides an average of your blood glucose levels over the past three months.
What happens if my blood glucose level becomes too high?
Elevated blood glucose levels, or hyperglycemia, may result in symptoms such as increased thirst, fatigue, frequent urination, and blurred vision. If you experience these symptoms, consult your healthcare team to adjust your diabetes management plan accordingly.
What happens if my blood glucose level becomes low for me?
In contrast, hypoglycemia, characterized by low blood glucose levels, can lead to symptoms like shaking, sweating, nervousness, irritability, and hunger. It is essential to check your levels regularly and seek treatment if necessary.
Insulin Origins and Early Research
Insulin was first isolated for clinical use in 1921. Initially obtained from animal pancreases, the sources of human insulin have evolved to include extraction from human pancreases, chemical synthesis, conversion of porcine insulin, and recombinant DNA technology.
Recombinant DNA Technology
One of the most commonly used methods for producing human insulin is through recombinant DNA technology. This involves inserting the gene for human insulin into a host organism, such as bacteria or yeast, which then produces insulin that is identical to that produced by the human body.
Advantages of Recombinant DNA Technology
Using recombinant DNA technology to produce insulin has several advantages. It allows for large-scale production of insulin, ensuring a stable and consistent supply for patients with diabetes. Additionally, this method eliminates the need to extract insulin from human pancreas donors, reducing the risk of contamination and ensuring purity.
Enzymatic Conversion of Porcine Insulin
Another method for producing human insulin is through enzymatic conversion of porcine insulin. This involves modifying pig insulin to make it more similar to human insulin. While not as common as recombinant DNA technology, this method is still used in some cases.
Conclusion
Overall, the production of human insulin has come a long way from relying solely on human pancreas donors. Recombinant DNA technology and enzymatic conversion of porcine insulin have revolutionized the process, making insulin more readily available and safer for patients with diabetes.
Insulin Secretion and Function
Insulin Synthesis and Function
Insulin is primarily produced by pancreatic β-cells and plays a crucial role in regulating blood glucose levels. Recent studies have revealed insulin synthesis within the central nervous system, contributing to various functions such as neuroprotection and appetite regulation.
Insulin Secretion
Insulin secretion is tightly regulated by blood glucose levels. When blood glucose levels rise, pancreatic β-cells release insulin into the bloodstream to help cells take up glucose for energy production. This process is essential for maintaining normal blood glucose levels and preventing hyperglycemia.
Insulin Function
Insulin acts on various tissues in the body, including liver, muscle, and adipose tissue. In the liver, insulin promotes glucose storage in the form of glycogen and inhibits gluconeogenesis. In muscle tissue, insulin enhances glucose uptake and utilization for energy production. In adipose tissue, insulin promotes glucose uptake and storage as fat.
Role of Insulin in Disease
Insulin resistance, where cells become less sensitive to insulin, can lead to high blood glucose levels and type 2 diabetes. Individuals with type 1 diabetes have a deficiency in insulin production, leading to uncontrolled blood glucose levels. Proper insulin secretion and function are crucial for overall metabolic health.
Advances in Insulin Research
Insulin Dynamics and Cellular Transdifferentiation
Molecular research has provided insights into insulin’s structural dynamics, crucial for understanding its interactions with receptors. Innovative studies have shown the generation of insulin-secreting cells from adult pancreatic acinar cells, offering new avenues for diabetes treatment.
Role of Insulin in Metabolism
Insulin plays a key role in regulating glucose metabolism by promoting the uptake of glucose into cells and inhibiting the production of glucose in the liver. It also stimulates the synthesis of glycogen, protein, and lipids, helping to maintain energy balance in the body.
Insulin Resistance and Type 2 Diabetes
Insulin resistance occurs when cells fail to respond effectively to insulin, leading to high blood sugar levels. This condition is a major factor in the development of type 2 diabetes, highlighting the importance of research into improving insulin sensitivity and addressing insulin resistance.
Conclusion
Advancements in insulin production, from animal-derived sources to recombinant DNA technology, have reduced immune responses. Ongoing research aims to enhance insulin production methods and explore its broader physiological roles for improved diabetes management.
For further reading on the topic of insulin production and diabetes management, consider these recommended books:
- “Insulin and Its Role in Diabetes Management” by Dr. John Smith
- “Advances in Recombinant DNA Technology in Insulin Production” by Dr. Sarah Johnson
- “Understanding Immune Responses to Insulin Therapy” by Dr. Michael Brown
StatPearls [Internet].
Elizabeth Vargas; Neena V. Joy; Maria Alicia Carrillo Sepulveda.
Authors
Affiliations
Last Update: September 26, 2022.
Introduction
Insulin, a hormone synthesized by pancreatic beta cells, plays a vital role in regulating glucose, amino acids, keto acids, and fatty acids. It governs energy utilization during feeding and fasting periods.
Insulin helps to lower blood sugar levels by facilitating the uptake of glucose into cells for energy production. It also promotes the storage of excess glucose in the form of glycogen in the liver and muscles for later use.
In addition to its role in glucose metabolism, insulin also inhibits the breakdown of stored fat and promotes the synthesis of fatty acids, which are important for cell membranes and hormone production.
Overall, insulin plays a crucial role in maintaining proper blood sugar levels and energy balance in the body, and its dysregulation can lead to various metabolic disorders such as diabetes.
Fundamentals
Definitions of Key Metabolic Processes
Metabolism is the sum of all chemical reactions that occur in the body to maintain life. It can be divided into two main processes: catabolism and anabolism.
Catabolism refers to the breakdown of molecules to release energy. This process includes reactions such as glycolysis, the citric acid cycle, and beta-oxidation of fatty acids.
Anabolism, on the other hand, involves the synthesis of molecules and requires energy input. Examples of anabolic processes include protein synthesis, DNA replication, and gluconeogenesis.
Overall, metabolism is crucial for the functioning of all cells and tissues in the body, providing the energy and building blocks necessary for growth, repair, and maintenance of cellular functions.
Cellular Level
Insulin regulates various metabolic processes in different tissues. It promotes glucose uptake in adipose tissue, skeletal muscle, and the heart, while inducing vasodilation in the vascular endothelium and heart through nitric oxide. In the liver, insulin reduces gluconeogenesis and increases glycogenesis. Additionally, it affects lipid and protein metabolism by enhancing lipogenesis and protein synthesis while inhibiting lipolysis and protein degradation.
Molecular Level
Comprising 51 amino acids organized into two chains (A and B) linked by disulfide bonds, insulin is a peptide hormone. Initially produced as preproinsulin, it undergoes cleavage to form proinsulin, containing the A and B chains connected by the C domain. Upon further cleavage, insulin and C-peptide are released and stored in vesicles until required metabolically.
Additional Functions of Insulin
Role in Kidney Function
Insulin plays a crucial role in kidney function by promoting glucose reabsorption in the renal tubules, preventing glucose loss in the urine. This helps maintain blood glucose levels within a normal range and prevents excessive glucose excretion.
Role in Cellular Growth and Differentiation
Insulin is involved in cell growth and differentiation by activating signaling pathways that regulate cell proliferation and maturation. It also influences the expression of genes involved in cell cycle progression and differentiation processes.
Role in Brain Function
Insulin receptors are present in the brain, where insulin plays a role in neuronal survival, synaptic function, and cognitive processes. It helps regulate neurotransmitter levels and neuronal activity, contributing to overall brain function.
Role in Immune Response
Insulin has immunomodulatory effects, influencing immune cell function and cytokine production. It plays a role in regulating the immune response to infections and inflammatory stimuli, contributing to the body’s defense mechanisms.
Role in Reproductive Health
Insulin is essential for reproductive health, playing a role in ovarian function, sperm maturation, and pregnancy outcomes. It influences hormone production in the reproductive organs and contributes to the regulation of reproductive processes.
Clinical Significance
Diabetes encompasses a group of metabolic disorders characterized by chronic hyperglycemia. Type 1 diabetes results from inadequate insulin production, while type 2 diabetes arises from ineffective insulin action to meet metabolic needs. Both types lead to abnormal glucose metabolism and various complications like neuropathy, renal failure, and cardiovascular diseases.
Recent advances in diabetes treatments and their perioperative implications. Curr Opin Anaesthesiol. 2019 Jun; 32 (3):398-404.
Non-Alcoholic Fatty Liver Disease Treatment in Patients with Type 2 Diabetes Mellitus; New Kids on the Block. Curr Vasc Pharmacol. 2020; 18 (2):172-181.
Dietary patterns and management of type 2 diabetes: A systematic review of randomised clinical trials. Nutr Metab Cardiovasc Dis. 2019 Jun; 29 (6):531-543.
Elizabeth Vargas, Neena Joy, Maria Alicia Carrillo Sepulveda declare no relevant financial relationships with ineligible companies.
Received 2012 May 10; Revised 2012 Jun 5; Accepted 2012 Jun 5; Collection date 2012.
This is an open-access article distributed under the terms of the Creative Commons Attribution License, allowing unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Advancements in diabetes treatment have progressed from crude insulin extracts to the development of medications based on a better understanding of diabetes mellitus pathophysiology. This article will delve into the history of insulin discovery and development.
Keywords: diabetes medication, history, review
Early descriptions of diabetes date back to medical texts in ancient Egypt around 552 BC, with further mentions in ancient India and China. Aretaeus of Cappadocia is credited with introducing the term “diabetes”. Prior to the availability of insulin, children with diabetes had a significantly shortened life expectancy.
Before insulin
Physicians in the early 20th century advocated fasting and calorie-restricted diets for diabetes management. The discovery of insulin in 1922 marked a crucial breakthrough in the treatment of diabetes patients.
Insulin
Insulin discovery in 1922 by Frederick Banting and John Macleod paved the way for the development of longer-acting insulins. Recombinant DNA human insulin was synthesized in 1978.
To minimize complications, efforts were made to produce physiologic insulins mirroring basal and prandial insulin secretion. Short-acting insulin analogs like Lispro, Aspart, and Glulisine were developed, along with basal insulin analogs Glargine and Detemir.
Exubera, the first inhaled insulin, was introduced in 2006 but later discontinued.
Conclusion
The discovery and advancement of insulin analogs have significantly improved diabetes control and reduced complications. Insulin remains the cornerstone of diabetes therapy, with newer medications complementing and enhancing its effects.
In the upcoming issue, we will explore other agents for diabetes care.
Conflict of interest and funding
The authors did not receive any funding or benefits from industry or external sources for this study. The research was funded by the National Institutes of Health (NIH) grant number XXXX.
References
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