Diabetes Mellitus Overview and Classification

Questions and Answers

Both rosiglitazone and pioglitazone are rapidly absorbed and have a peak concentration of less than 2 hours.

True

The elimination half-life of rosiglitazone and pioglitazone is longer than 7 hours.

False

Bile acid sequestrants are primarily used as antihypertensive agents.

False

GLP-1 receptor agonists amplify insulin secretion in a glucose-dependent manner.

True Signup and view all the answers

Dipeptidyl peptidase-4 (DPP-4) inhibitors include drugs like metformin and glipizide.

False Signup and view all the answers

Colesevelam is a type of GLP-1 receptor agonist.

False Signup and view all the answers

Weight gain is a common side effect associated with the use of rosiglitazone and pioglitazone.

True Signup and view all the answers

GLP-1 receptor agonists can lead to an increase in appetite.

False Signup and view all the answers

The mechanism of action for DPP-4 inhibitors includes reducing glucagon levels.

True Signup and view all the answers

Sitagliptin is an example of a bile acid sequestrant.

False Signup and view all the answers

Study Notes

Diabetes Mellitus Overview

Chronic metabolic disorder leading to hyperglycemia.
Caused by defects in insulin secretion or action affecting carbohydrate, fat, and protein metabolism.

Classification of Diabetes Mellitus

Type 1 DM: Insulin-dependent; requires insulin for survival due to absence of insulin.
Type 2 DM: Non-insulin dependent; insulin is present but ineffective due to:
- Insulin resistance in cells.
- Secretory defects in insulin production.
Gestational Diabetes Mellitus: Occurs during pregnancy, often resolves postpartum.
Other Specific Types:
- MODY (Maturity Onset Diabetes of the Young) types 1-6.
- Fibrocystic pancreatic diabetes (drug-induced by thiazides, diuretics, steroids).
- Endocrinopathies (e.g., acromegaly, Cushing syndrome).

Clinical Significance

Common Symptoms:
- Polyuria (increased urination).
- Polydipsia (increased thirst).
- Polyphagia (increased hunger).
- Weight loss.
- Blurred vision.
- Tingling or burning sensations.
- Recurrent infections (e.g., boils).

Diagnosis Criteria

Fasting plasma glucose ≥ 7.0 mmol/L (126 mg/dL) indicates diabetes.
Random plasma glucose ≥ 11.1 mmol/L (200 mg/dL) confirms diabetes.
Symptomatic individuals require one abnormal lab value; asymptomatic individuals require two.

Management Strategies

Key Components:
- Patient education.
- Dietary modifications.
- Drug therapy.
- Rehabilitation services.

Drug Therapy Insights

Type 1 DM: Requires insulin for survival.
Insulin Structure: Small protein, molecular weight of 5808 Da, composed of 51 amino acids in two chains linked via disulfide bridges.
Side Effects of Insulin: Weight gain, gastrointestinal disturbances, allergic reactions, bone marrow damage.

Drug Interactions Enhancing Hypoglycemia

NSAIDs, Coumarins, Alcohol, Sulfonamides, Primethoprim, Chloramphenicol, Imidazoles, Antifungal agents.

Sulfonylureas

First Generation: Tolbutamide, Chlorpropamide, Tolazamide.
Second Generation: Glyburide, Glipizide, Glimepiride; offer fewer adverse effects and interactions.

Biguanides

Examples: Metformin, Phenformin (discontinued due to lactic acidosis risk).
Mechanism of Action:
- Increases glucose removal from blood.
- Decreases hepatic gluconeogenesis.
- Slows glucose absorption from the gastrointestinal tract.
- Reduces plasma glucagon levels.
Metformin Characteristics: Half-life of 1.5-3 hours, kidney-excreted, no protein binding.
Contraindications: Renal or hepatic disease, pulmonary disease, heart failure.

Thiazolidinediones (Glitazones)

Mechanism: Activates PPAR-gamma nuclear receptor, enhancing insulin sensitivity in adipose tissue, muscle, and liver.
Pharmacokinetics: Rapid absorption, reaches peak in < 2 hours, liver metabolized, elimination half-life < 7 hours.
Side Effects: Weight gain, fluid retention, headache, fatigue, potential hepatotoxicity.

Bile Acid Sequestrants

Example: Colesevelam.
Mechanism: Affects enterohepatic circulation, decreases fornesoid X receptor activation.

GLP-1 Receptor Agonists

Function: Amplifies glucose-dependent insulin secretion, inhibits glucagon release, reduces appetite.
Examples: Exenatide, Liraglutide.

Dipeptidyl Peptidase-4 (DPP-4) Inhibitors

Examples: Sitagliptin, Saxagliptin, Linagliptin.
Action: Elevates levels of natural GLP-1, enhances insulin secretion, lowers glucagon levels.

Description

This quiz provides an overview of Diabetes Mellitus, a chronic metabolic disorder characterized by hyperglycemia. It covers the classification of diabetes types, including Type 1, Type 2, and Gestational Diabetes, along with common symptoms and clinical significance of the condition.