Diabetes Overview Quiz

Diabetes Mellitus

• Diabetes Mellitus is a chronic disease.
• Several types exist, the most common being Type 1 and Type 2.
• Type 1 Diabetes is characterized by insulin deficiency (10% of cases) and is an autoimmune process.
• Type 2 Diabetes is characterized by insulin resistance (90% of cases).
• Glucose levels increase (hyperglycemia).
• Glucose can non-enzymatically glycosylate protein, causing further complications.
• Diabetes affects various body systems, impacting both physical and psychological needs.

Learning Outcomes

• Define Diabetes Mellitus
• Compare and contrast the pathophysiology of Type 1 and Type 2 Diabetes
• Discuss the principles of diagnosis and classification of diabetes
• List the cardinal symptoms and signs of diabetes
• Identify risk factors for the rising prevalence of Type 2 Diabetes
• Recognize the importance of prevention and early intervention in the management of Type 2 Diabetes
• Outline the overarching principles of investigation and management of diabetes
• Evaluate the implications of diabetes, including the impact on quality of life and healthcare costs
• Identify the role of interdisciplinary care in the management of diabetes

Patient MF

• A 22-year-old male presented to A&E with worsening polyuria, polydipsia, fatigue, and unintentional weight loss (4 kg).
• He reported drinking approximately 2 liters of soda and fruit punch daily.
• He is 175 cm tall and weighs 66 kg (BMI 21.5 kg/m²).
• He has a maternal history of hypothyroidism but no family history of diabetes.
• His plasma glucose was 26 mmol/L (4-7.8 mmol/L).
• He presented with blurry vision, nausea, and a fruity-smelling breath.

What is Diabetes Mellitus?

• Chronic disease
• Several distinct types
  • Type 1 Diabetes (T1D): characterized by insulin deficiency (10% of cases). An autoimmune process where the body's immune system attacks the insulin-producing beta cells in the pancreas.
  • Type 2 Diabetes (T2D): characterized by insulin resistance (90% of cases). A metabolic disorder with multiple contributing factors affecting carbohydrate, fat, and protein metabolism, often accompanied by defects in insulin secretion and/or action.
• Glucose levels increase (hyperglycemia)
• Glucose glycosylates proteins, causing long-term complications
• Significant burden of morbidity and mortality
• Significant resource utilization

Health Impact of the Disease

• 5th leading cause of death
• Life expectancy ↓5 to 10 years
• Cardiovascular disease ↑2X to 4X
• Nerve damage in 60-70% of patients
• Diabetes is the no. 1 cause of renal failure, new cases of blindness, and nontraumatic amputations

Prevalence

• Approximately 537 million adults (20-79 years) are living with diabetes.
• Projected to rise to 643 million by 2030 and 783 million by 2045.
• Three in four adults with diabetes live in low- and middle-income countries.
• Global prevalence is increasing. Significant regional differences in prevalence exist.

Type 1 Diabetes (T1D)

• Autoimmune process: Body's immune system attacks insulin-producing beta cells in the pancreas.
• Under the microscope:
  • Lymphocytes attack beta cells (insulitis).
  • Beta cells die.
  • Area heals with fibrosis.
• Causes: Not fully understood. Likely a combination of genetic susceptibility and environmental trigger (e.g., viral infection).
• Occurs most often in children and young adults.

Pathogenesis of T1D

• Diagram showing the interplay of the hypothalamus, adrenal gland, adipose tissue, and liver, highlighting the role of insulin and related hormones in regulating glucose levels.

Pancreas

• The pancreas contains islets of Langerhans.
• The islets of Langerhans constitute 2% of the total pancreas.
• Three important cell types in the islets are:
  • Beta cells (60-80%): insulin
  • Alpha cells (20-30%): glucagon
  • Delta cells: somatostatin

B-Cell Histology

• Normal histology: Red stains for insulin in beta cells, brown stains for glucagon in alpha cells
• Type 1 histology: Reduced red staining (reduced insulin).

Insulin

• A peptide hormone secreted by beta cells in the pancreatic islets of Langerhans.
• Key role in glucose uptake, utilization, lipid & protein synthesis, and normal development.
• Insulin function requires islet B-cell mass, insulin synthesis, insulin signaling, and glucose-dependent insulin secretion.
• Lack of insulin, or inability of cells to respond to it, causes hyperglycemia.

Importance of Beta Cell

• Diagram illustrating the feedback loop between glucose levels, beta cells, insulin secretion, and alpha cells/glucagon.

Normal Insulin Metabolism

• Glucose is the major regulator of insulin secretion.
• Insulin release occurs immediately upon increase in blood glucose, and active synthesis follows with prolonged stimuli.
• Insulin secretagogues (including intestinal hormones GLP-1 and certain amino acids like leucine & arginine) enhance insulin release.

Functions of Insulin

• Insulin is a major anabolic hormone required for transmembrane transport of glucose and amino acids.
• Involved in formation of glycogen in the liver and skeletal muscles.
• Converts glucose to triglycerides.
• A crucial anabolic hormone for nucleic acid and protein synthesis.

Classification of Diabetes Mellitus

... (previous information)

T1D vs T2D

• Type 1: Absolute insulin deficiency; abrupt onset, propensity for DKA, lifelong insulin required, associated with auto-antibodies, diagnosed in individuals <30.
• Type 2: Insulin resistance with relative insulin deficiency; gradual onset (initially silent), can be treated with oral medications, associated with increased age and obesity, can lead to HHNK.

Comparison of Types 1 & 2

... (previous information)

Hormonal Response to Carbohydrate Load

• Graph showing the response of insulin, glucagon, and glucose to a carbohydrate meal in healthy individuals.

Diagnosis

• Various criteria for diagnosis of diabetes.
  • Fasting plasma glucose
  • HbA1c
  • Two-hour plasma glucose (after OGTT)
  • Random plasma glucose

Hemoglobin A1c (HbA1c)

... (previous information)

Clinical Presentation

... (previous information)

Epidemiology of T1D

... (previous information)

...and so on (rest of the summary points).