Diabetes Demystified: An Introductory Guide

Authors: Ganghee Lefkowitz (1), Hadia Syed (2), and Indu Devakonda (3)

Editor: Monsurat Lawal, Ph.D.

Author Affiliations:  (1) Westlake High School, Westlake Village, CA, (2) Urbana High School, Ijamsville, MD, (3) Monta Vista High School, Cupertino, CA.

Introduction

Diabetes mellitus is a prevalent and serious metabolic disorder characterized by the body's inability to produce or utilize insulin effectively. Insulin is a hormone vital in regulating blood sugar levels. When insulin production is insufficient or its action is impaired, blood glucose levels can become dangerously elevated [1]. This introductory guide highlights diabetes mellitus, offering a clear and concise overview of the disease, its types, and its impact on health. By presenting essential facts and insights, this guide provides a foundational understanding of diabetes and its implications in managing and preventing this metabolic disorder.

Keywords

Insulin Resistance, Blood Sugar Regulation, Type 1 Diabetes, Type 2 Diabetes, Metabolic Disorder

Origin and Etymology

The term "diabetes mellitus" originates from a combination of Greek and Latin words. The Greek word "diabetes" means "to pass through," which reflects the frequent urination associated with the condition [2]. The Latin word "mellitus" means "honey-sweet," describing the sweet taste of the urine observed in affected individuals due to high sugar content. Thus, "diabetes mellitus" translates to "sweet urine diabetes." Historically, diabetes has been recognized for millennia. The earliest records of the disease date back to ancient Egypt around 3,500 years ago, when physicians were aware of its symptoms and sought various remedies. Ancient Egyptian treatments included consuming brews made from wheat, honey, and herbs. In India during the 5th-6th centuries, physicians recommended dietary changes, including freshly made meals, to manage the condition [3]. These early practices laid the groundwork for modern understanding and diabetes management.

Types and Prevalence by Race, Region, or Country

Diabetes is influenced by a combination of environmental factors and genetics, with varying prevalence across different populations and regions [4]. The disease affects approximately 11% of the global population and is classified into several types: Type 1 diabetes, Type 2 diabetes, gestational diabetes, and other less common forms (Figure 1). Geographic and demographic studies reveal that diabetes is most prevalent in regions such as the United States, China, and India, with India showing the highest rates of increase in diabetes cases. The condition is notably more common in developing countries across various age groups. Ethnic and racial groups also exhibit differing susceptibility to diabetes. Research indicates that Arabs, Asian Indians, Chinese, and Hispanics have higher rates of diabetes, with prevalence ranging from 14% to 20% [2]. Certain populations experience even higher rates; for example, Nauruans have a prevalence of around 40%, while Pima and Papago Indians have an alarming prevalence of approximately 50%. These variations highlight the significant impact of both genetic predispositions and environmental factors on the prevalence of diabetes worldwide.

Figure 1: Diabetes in one frame

The Health Effects of Diabetes

Diabetes mellitus, characterized by elevated blood glucose levels, can have profound and far-reaching effects on overall health. The chronic elevation of blood sugar, whether due to inadequate insulin production (Type 1 diabetes) or insulin resistance (Type 2 diabetes), leads to various short-term and long-term health complications [5].

Cardiovascular Complications: Diabetes significantly increases the risk of cardiovascular diseases, including heart attacks, strokes, and hypertension. Elevated blood glucose levels contribute to the buildup of plaque in the arteries (atherosclerosis), which can lead to reduced blood flow and increased risk of heart disease and stroke. Diabetes also often coexists with other risk factors such as high blood pressure and high cholesterol, exacerbating cardiovascular issues.

Neuropathy: Chronic high blood sugar levels can damage nerves throughout the body, a condition known as diabetic neuropathy. This damage can lead to symptoms, such as numbness, tingling, pain, or weakness, typically starting in the extremities (hands and feet). Neuropathy can affect various bodily functions with complications like foot ulcers, infections, and impaired mobility.

Retinopathy: Diabetes can cause damage to the blood vessels in the retina, leading to diabetic retinopathy. This condition can result in vision impairment and, if untreated, may progress to blindness. Regular eye examinations are crucial for early detection and management to prevent severe vision loss.

Nephropathy: Diabetic nephropathy refers to kidney damage caused by diabetes, leading to impaired kidney function or even kidney failure. High blood sugar levels can damage the small blood vessels in the kidneys, affecting their ability to filter waste from the blood. Monitoring kidney function and managing blood glucose levels are essential to prevent progression to end-stage renal disease.

Increased Risk of Infections: People with diabetes are at a higher risk of infections due to impaired immune response and poor blood circulation. High blood glucose levels can also hinder the body’s ability to heal wounds effectively, increasing susceptibility to infections, particularly in the skin and urinary tract.

Foot Complications: Diabetes can lead to poor blood flow and neuropathy in the feet, leading to an increased risk of foot injuries, infections, and ulcers. These complications can be severe and lead to amputations if not properly managed. Regular foot care and monitoring are crucial for people with diabetes to prevent serious issues.

Insulin and Blood Sugar Regulation

Insulin is a pivotal hormone in regulating blood glucose levels, critical in maintaining metabolic balance and overall health. Produced by the beta cells of the pancreas, insulin facilitates glucose uptake into cells and helps regulate blood sugar levels.

Role of Insulin in Blood Sugar Regulation: Insulin’s primary function is to lower blood glucose levels by promoting glucose uptake into cells, particularly muscle and fat cells, used for energy or stored as glycogen. When you eat, carbohydrates are broken down into glucose, which enters the bloodstream. In response to rising blood glucose levels, the pancreas secretes insulin. Insulin binds to receptors on cell membranes, triggering several reactions that allow glucose to enter the cells, thereby reducing blood sugar levels. Additionally, insulin helps regulate glucose storage in the liver by promoting glycogen synthesis and inhibiting glycogenolysis (the breakdown of glycogen into glucose).

Insulin Resistance: In conditions such as Type 2 diabetes, insulin resistance occurs when cells become less responsive to insulin. Despite normal or elevated insulin levels, glucose uptake into cells is impaired, leading to higher blood glucose levels. To compensate, the pancreas produces more insulin. Over time, this can lead to pancreatic beta-cell dysfunction and exacerbate hyperglycemia (elevated blood sugar). Insulin resistance is often associated with obesity, physical inactivity, and genetic factors.

Insulin Deficiency: Type 1 diabetes, an autoimmune condition, results in the destruction of pancreatic beta cells, leading to little or no insulin production. Without adequate insulin, the body's ability to regulate blood glucose levels is severely compromised, leading to persistent hyperglycemia. Individuals with Type 1 diabetes must administer insulin through injections or an insulin pump to manage their blood sugar levels effectively.

Insulin Regulation and Metabolic Homeostasis: Insulin works with other hormones, such as glucagon and epinephrine, to maintain metabolic homeostasis. Glucagon, produced by the alpha cells of the pancreas, raises blood glucose levels by promoting glycogen breakdown and glucose release from the liver. This counter-regulatory mechanism ensures that blood sugar levels remain stable between meals and during fasting or physical activity.

Impact of Insulin Therapy: For individuals with diabetes, insulin therapy is crucial for managing blood glucose levels. Therapy can be tailored to individual needs, involving various types of insulin with different action profiles (rapid-acting, short-acting, intermediate-acting, and long-acting). Proper management of insulin therapy, combined with lifestyle modifications such as diet and exercise, helps control blood sugar levels and prevent complications associated with diabetes.

Future Mandatory Directions in Diabetes Management

Due to the several negative effects associated with diabetes mellitus, those suffering from the disease must take certain precautions to have stable internal and external conditions. The future direction to manage diabetes with improved outcomes could focus on promising research areas. This approach might include exploring the potential of gene therapy to modify genes for improved insulin production, developing artificial pancreas technology for automated blood sugar regulation, or using stem cells to regenerate insulin-producing cells in the pancreas, offering a potential cure for diabetes.

Glossary

1. Hyperglycemia: An ill-health condition characterized by abnormally high blood sugar (glucose) levels.

2. Glucose: The main energy source for body cells. It comes from the carbohydrates you consume in your diet.

3. Insulin: A hormone produced by the pancreas that helps regulate blood sugar levels by allowing cells to absorb glucose from the bloodstream.

4. Diabetes: A chronic condition characterized by impaired insulin production or function, leading to high blood sugar levels. There are two main types: Type 1 and Type 2 diabetes.

5. Pre-diabetes: A stage where blood sugar levels are higher than normal but not high enough for a diabetes diagnosis. People with pre-diabetes are at increased risk of developing type 2 diabetes.

6. Chronic: Persisting for a long time or constantly recurring. In the context of hyperglycemia, it refers to consistently elevated blood sugar levels.

7. Complications: Health problems triggered by a primary disease or condition. In hyperglycemia, uncontrolled high blood sugar can lead to various health problems.

8. Diabetic Ketoacidosis (DKA): A life-threatening condition that can occur in people with type 1 diabetes when the body breaks down fat for energy due to a lack of insulin.

9. Neuropathy: Damage or dysfunction of nerves, which can cause pain, numbness, tingling, weakness, and other symptoms. Hyperglycemia can lead to diabetic neuropathy, particularly affecting the feet and legs.

10. Blood Sugar Monitoring: Regularly checking blood sugar levels using a glucometer and test strips. Blood sugar monitoring is an essential part of managing hyperglycemia, especially in diabetic individuals.

References 

1.         Nathan, D.M., DCCT/Edic Research Group: The diabetes control and complications trial/epidemiology of diabetes interventions and complications study at 30 years: overview. Diabetes Care. 37, 9–16 (2014)

2.         Ahmed, A.M.: History of diabetes mellitus. Saudi Med. J. 23, 373–378 (2002)

3.         Lakhtakia, R.: The history of diabetes mellitus. Sultan Qaboos Univ. Med. J. 13, 368 (2013)

4.         Shojima, N., Yamauchi, T.: Progress in genetics of type 2 diabetes and diabetic complications. J. Diabetes Investig. 14, 503–515 (2023)

5.         Holt, R.I., Cockram, C.S., Ma, R.C., Luk, A.O.: Diabetes and infection: review of the epidemiology, mechanisms and principles of treatment. Diabetologia. 1–13 (2024)