Insulin Types and Functions Quiz

Introduction to Diabetes Mellitus (DM)

• DM is a group of metabolic disorders characterized by chronically elevated blood glucose (BG), abnormal carbohydrate, fat, and protein metabolism.
• It affects the body's ability to produce and/or utilize insulin.
• DM has categories including Type 1 and Type 2.
• Without effective treatment, DM can lead to acute complications like diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic syndrome (HHS).
• Chronic hyperglycemia can cause microvascular, macrovascular, and neuropathic complications.

Pathophysiology of Type 1 DM

• Type 1 DM affects 5%-10% of cases.
• The pancreas does not produce insulin.
• It usually results from autoimmune destruction of pancreatic ẞ-cells, leading to absolute insulin deficiency.
• This condition can occur in children and adolescents but can also occur at any age.
• Amylin, a hormone co-secreted with insulin from pancreatic ẞ-cells, is also deficient in type 1 DM due to ẞ-cell destruction.
• Amylin suppresses inappropriate glucagon secretion, slows gastric emptying, and causes central satiety.

Pathophysiology of Type 2 DM

• Type 2 DM affects 90%-95% of cases.
• It usually occurs in people age 45 or older.
• It is characterized by insulin resistance, manifested by excessive hepatic glucose production, decreased skeletal muscle uptake of glucose, and increased lipolysis and fatty acid production.
• Over time, impaired insulin secretion occurs, with reduced ẞ-cell mass and function.
• The failure and decline in ẞ-cells is progressive.
• Incretin effects are also reduced in Type 2 DM; gut incretin hormones are reduced or are not secreted as effectively, decreasing insulin secretion and increasing glucagon release in response to a meal.

Clinical Presentation of Type 1 DM

• Patients often have symptoms in the days or weeks before diagnosis.
• Common initial symptoms include polyuria, polydipsia, polyphagia, weight loss, fatigue, and lethargy.
• Individuals with type 1 DM are often thin and prone to develop DKA in the absence of adequate insulin supply; many patients initially present with DKA.
• Symptom onset can be triggered by infection, trauma, or psychological stress.

Clinical Presentation of Type 2 DM

• Most patients are asymptomatic or have only mild fatigue at diagnosis.
• Many are incidentally diagnosed after routine lab testing (plasma glucose or A1C) or developing complications like myocardial infarction or stroke.
• Hemoglobin A1C (HbA1c) is an important blood test that provides an average of blood sugar (glucose) control over the past 2-3 months.
• Because mild hyperglycemia can exist for years before diagnosis, microvascular and macrovascular complications are often present at the time of diagnosis.
• Most patients are overweight or obese with an elevated waist-to-hip ratio.

Diagnosis of Diabetes Mellitus

• Diagnosis is based on criteria for A1C, fasting plasma glucose, and/or two-hour post-load plasma glucose.

Goals of Treatment

• The primary goal is to prevent or delay progression of long-term microvascular and macrovascular complications.
• Additional goals are alleviating symptoms of hyperglycemia, minimizing hypoglycemia, minimizing treatment burden, and maintaining quality of life.
• General glycemic targets for most nonpregnant adults with DM are listed in Table 19-1.

Treatments: Insulin

• Endogenous insulin moves glucose from blood into cells.
• Two main types exist: regular insulin and insulin analogues such as insulin aspart, lispro, glulisine, detemir.
• Advantages: can achieve various glucose targets and allows individualized dosage based on glucose levels.
• Disadvantages: potential hypoglycemia, need for injections, weight gain, and treatment burden.
• Insulin products are typically administered through subcutaneous injections or inhaled products (except inhaled human insulin).

Treatments: Insulin (Specifics)

• Most insulin products are administered (SC) for chronic diabetes management.
• Different types of insulin have varying onset, peak, and duration of action.
• This includes rapid-acting insulins, short-acting insulins, intermediate-acting insulins, long-acting insulins, ultra-long-acting insulins, and mixed insulins.
• Insulin doses, mixtures, type, and administration are tailored to the needs of individual patients.

Treatments: Biguanides

• Metformin is an oral medicine for type 2 diabetes.
• It decreases hepatic glucose production, enhances insulin sensitivity in peripheral tissues, and allows for increased glucose uptake into muscle cells.
• Metformin is generally recommended as first-line pharmacotherapy for patients with DM, unless contraindicated.

Treatments: Sulfonylureas

• Sulfonylureas are oral medicines for type 2 diabetes.
• They enhance or stimulate insulin secretion by binding to the sulfonylurea receptor on pancreatic ẞ-cells.
• Sulfonylureas are used as monotherapy or in combination with other oral or injectable medications (e.g., Glimepiride and Glyburide).

Treatments: Thiazolidinediones (TZDs)

• TZDs reduce insulin resistance and improve glycemic control in patients with type 2.
• They improve insulin sensitivity in muscle, liver, and fat tissues.
• Common TZDs include pioglitazone and rosiglitazone.

Treatments: Alpha-glucosidase Inhibitors

• Alpha-glucosidase inhibitors (e.g., acarbose and miglitol) are used to delay carbohydrate absorption after a meal to lower postprandial glucose levels.

Treatments: Amylin Analogs

• Pramlintide (Symlin) is a synthetic amylin analog reducing glucagon secretion, slowing gastric emptying, and increasing satiety.
• It is used as an adjunctive therapy to improve postprandial glucose levels and A1C in patients with type 1 or type 2 DM.

Treatments: Glucagon-like Peptide-1 Receptor Agonists (GLP-1 RAs)

• GLP-1 RAs are incretin hormones, stimulating insulin secretion, reducing postprandial glucagon secretion, and decreasing hepatic glucose output.
• Common GLP-1 RAs include dulaglutide, exenatide, exenatide XR, lixisenatide, liraglutide, and semaglutide.
• Short acting agents predominately lower postprandial glucose, whereas long acting agents lower both fasting and postprandial glucose.

Adverse Effects

• Common adverse effects of medications for diabetes management are reviewed, including hypoglycemia, weight gain, injection site reactions, and respiratory issues.

Storage

• Diabetic medications, including insulin, should be stored appropriately.

Other important considerations

• The information presented is a brief summary, and individuals should consult a healthcare professional for any health concerns or medical advice.
• It is crucial to note that the suggested doses, administration techniques, and other recommendations are not exhaustive and should be tailored based on individual patient's needs and medical conditions.