Diabetes Mellitus and Its Complications

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Questions and Answers

What is a long-term complication associated with diabetes mellitus that increases the risk of heart issues?

Pulmonary embolism

Myocardial infarction (correct)

Angina pectoris

Chronic obstructive pulmonary disease

Which component is NOT part of the metabolic syndrome cluster associated with cardiovascular diseases?

Insulin resistance

Anemia (correct)

Obesity

Hypertension

Which symptom is characterized by excessive thirst in diabetes mellitus?

Polyphagia

Polyuria

Ketonemia

Polydipsia (correct)

What role does glucose primarily serve in the body?

Providing energy Signup and view all the answers

Which of the following is NOT a key pathway in glucose metabolism?

Glucose-Fatty Acid Cycle Signup and view all the answers

What initiates the insulin signaling cascade in the body?

Binding to cell-surface receptors Signup and view all the answers

What effect do genetic variations in insulin signaling pathways primarily have?

Trigger insulin resistance Signup and view all the answers

Which condition results from an inability to regulate glucose metabolism in diabetes mellitus?

Hyperglycemia Signup and view all the answers

What is the primary effect of insulin in the body?

Increases protein synthesis in muscle Signup and view all the answers

Which hormone is considered the body's only hypoglycemic agent?

Insulin Signup and view all the answers

What is the function of glucagon in the body?

Stimulate gluconeogenesis Signup and view all the answers

In Rabson-Mendenhall syndrome, what issue arises from mutations in the INSR gene?

Decreased insulin receptor functionality Signup and view all the answers

Which of the following hormones acts to break down large molecules?

Glucagon Signup and view all the answers

What is one of the hormonal achievements in glucose metabolism?

Storage of glucose as glycogen Signup and view all the answers

What happens to glucagon levels in diabetes mellitus due to insulin deficiency?

They are elevated Signup and view all the answers

Cortisol primarily increases which process in the liver?

Gluconeogenesis Signup and view all the answers

What is the primary effect of a carbohydrate-rich meal on insulin and glucagon levels?

Stimulates insulin release and suppresses glucagon release Signup and view all the answers

Which amino acid is specifically mentioned as a precursor for gluconeogenesis in the metabolic process?

Alanin Signup and view all the answers

What is a characteristic feature of fasting in individuals with diabetes?

Increased blood free fatty acids and ketones Signup and view all the answers

What is a critical difference in glucose metabolism between type 1 and type 2 diabetes?

Type 2 diabetes does not require insulin injections Signup and view all the answers

What is the overall result of the actions of insulin and glucagon in healthy individuals?

Glucose homeostasis Signup and view all the answers

At which blood glucose level increase do nondiabetic individuals typically respond after a meal?

20% to 40% Signup and view all the answers

Which best describes the state of a diabetic individual in the absence of adequate insulin control?

State of semistarvation with reliance on triglycerides Signup and view all the answers

What is the primary cause of ketoacidosis in people with type 1 diabetes?

Insufficient insulin secretion and excess formation of ketoacids Signup and view all the answers

Which of the following conditions is NOT a known cause of secondary diabetes?

Frequent viral infections Signup and view all the answers

Impaired Glucose Tolerance (IGT) is often referred to as what?

Pre-diabetes Signup and view all the answers

Which of the following complications of diabetes are more frequent in Type 1 Diabetes (T1D) than in Type 2 Diabetes (T2D)?

Neuropathy Signup and view all the answers

What is a consequence of insulinopenia in diabetic individuals?

Increased triglyceride mobilization from adipose tissue Signup and view all the answers

What is one of the primary reasons for the development of gestational diabetes?

Increased nutritional needs for pregnancy Signup and view all the answers

Which of the following statements about diabetic ketoacidosis is correct?

It involves a decrease in blood pH due to increased ketoacids. Signup and view all the answers

Which hormone is NOT typically elevated during pregnancy and is associated with the development of gestational diabetes?

Insulin Signup and view all the answers

Which lipid profile characteristic is commonly found in individuals with Type 2 Diabetes?

Increased levels of VLDL Signup and view all the answers

How do plasma insulin levels after a glucose load differ between individuals with type 1 diabetes (T1D) and type 2 diabetes (T2D)?

T1D individuals have little or no insulin release above fasting levels. Signup and view all the answers

What is the recommended method for detecting diabetes according to recent guidelines?

Fasting plasma glucose level measurement. Signup and view all the answers

At what HbA1c level is diabetes diagnosed?

6.5% Signup and view all the answers

What condition demonstrates increased urine albumin excretion as an early sign of glomerular nephropathy?

Microalbuminuria. Signup and view all the answers

What is the primary mechanism underlying diabetes mellitus as highlighted in the content?

Insulin resistance (IR). Signup and view all the answers

For which of the following populations is the OGTT especially valuable?

Pregnant women and those with borderline fasting glucose levels. Signup and view all the answers

Which statement accurately reflects the relationship between HbA1c and plasma glucose levels?

HbA1c levels are directly proportional to the average plasma glucose level. Signup and view all the answers

What blood glucose level is indicative of diabetes during a random plasma glucose test?

Greater than or equal to 200 mg/dL. Signup and view all the answers

What is the blood glucose level that characterizes Hyperglycemic Hyperosmolar Nonketotic Coma?

Above 600 mg/dL Signup and view all the answers

Which of the following symptoms is NOT characteristic of Hyperglycemic Hyperosmolar Nonketotic Coma?

Severe nausea Signup and view all the answers

At what blood glucose level do symptoms of hypoglycemia typically begin to appear?

50 mg/dL Signup and view all the answers

What is the recommended carbohydrate load preferred for the postprandial plasma glucose test?

A 75 g glucose solution Signup and view all the answers

What condition must be met for an Oral Glucose Tolerance Test to be valid?

The patient must have a minimum carbohydrate intake of 150 g/day for 3 days. Signup and view all the answers

What does a glucose level of 200 mg/dL or higher at 2 hours after the Oral Glucose Tolerance Test suggest?

Diabetes Mellitus Signup and view all the answers

In the Oral Glucose Tolerance Test, how long after glucose ingestion do healthy subjects typically peak?

30 minutes Signup and view all the answers

What is a common cause of hypoglycemia related to insulin therapy?

Aggressive use of insulin Signup and view all the answers

Study Notes

Carbohydrate Metabolism Disorders & Diabetes

Diabetes is a chronic metabolic disease marked by elevated blood glucose levels.
Type 2 diabetes is common in adults, occurring when the body resists insulin or doesn't produce enough.
Type 1 diabetes, also known as juvenile diabetes, is a condition where the pancreas makes little or no insulin.
Access to affordable treatment, including insulin, is crucial for individuals with diabetes.
Approximately 422 million people worldwide have diabetes, with the majority in low- and middle-income countries.
The prevalence of diabetes has been steadily increasing over recent decades.

Health Implications of Diabetes

Diabetes has direct effects and long-term complications, including coronary heart disease and cerebrovascular disease/stroke.
People with diabetes have a greater risk (twice as high) of myocardial infarction compared to non-diabetics of the same age and sex.

Metabolic Syndrome

Insulin resistance or glucose intolerance is a component of metabolic factors associated with cardiovascular disease, diabetes, and stroke.
Metabolic syndrome also includes: obesity (particularly abdominal weight gain), atherogenic dyslipidemia, hypertension, thromboembolic state (elevated fibrinogen), and inflammatory state (indicated by elevated CRP).

Common Symptoms of Diabetes Mellitus (DM)

Symptoms of diabetes include high blood and urine glucose levels (hyperglycemia and glucosuria), polyuria, polydipsia (excessive thirst), polyphagia (constant hunger), and sudden weight loss.
During acute episodes, individuals may experience excessive blood and urinary ketones (ketonemia and ketonuria).

Glucose Metabolism Regulation

The hormonal regulation of glucose metabolism aims to store glucose as glycogen and mobilize stored glucose to maintain stable blood glucose levels.
The primary energy source for many tissues and organs is glucose.

Anabolic and Catabolic Hormones

Important hyperglycemic agents include glucagon, epinephrine, cortisol, thyroxine, growth hormone, and certain intestinal hormones.
Insulin promotes anabolic metabolism (macro-molecule synthesis), while these hormones induce catabolic metabolism (breaking down large molecules).

Insulin Signaling Pathways

Insulin interacts with cell surface receptors initiating a cascade of phosphorylation/dephosphorylation events, second-messenger generation, and protein-protein interactions.
These interactions affect various metabolic processes in nearly every tissue.
Genetic variations and functional changes in insulin pathway proteins result in insulin resistance.

Insulin Signaling Defects

Mutations in the INSR gene can result in Rabson-Mendenhall syndrome, reducing the number or diminishing the function of insulin receptors on cells.

Hormone Regulation of Glucose Metabolism

The hormonal regulation of glucose metabolism is crucial for maintaining homeostasis in the body.

Glucose Metabolism in Diabetes

In non-diabetic individuals, insulin-to-glucagon ratio is low while blood glucose is low.
Muscle and hepatic glycogen stores are broken down to supply glucose during fasting.
Further fasting can result in protein breakdown (into amino acids) in skeletal muscle, and triglyceride breakdown in adipose tissue.
During these processes, amino acids and glycerol are converted to glucose via gluconeogenesis.
Free fatty acids also fuel the heart, skeletal muscle, and liver.

Classification of Diabetes

Type 1 diabetes accounts for 5-10% of diagnoses and is caused by insufficient insulin secretion.
Insulin injection is necessary for type 1 diabetics. Type 1 individuals are prone to ketoacidosis.
Type 2 diabetes is more common and typically occurs in individuals over 40 years old, but is increasingly prevalent among younger individuals.
Type 2 diabetics generally aren't dependent on insulin injections, and are not prone to ketoacidosis.
Secondary diabetes is a diabetes type caused by other underlying issues such as pancreatic disease, growth hormone excess, Cushing's syndrome, glucagonoma, somatostatinoma, severe liver disease, or drug administration.

Impaired Glucose Tolerance (IGT)

Impaired glucose tolerance is an intermediate step in the development of type 2 diabetes.
Individuals with IGT have abnormally high glucose tolerance but don't experience fasting hyperglycemia. IGT is a condition referred to as pre-diabetes.

Gestational Diabetes (GD)

Gestational diabetes (GD) is a temporary form of diabetes that develops during pregnancy.
GD often progresses to type 2 diabetes in the woman.
Nutritional needs increase during pregnancy, and adipose cells increase, leading to a higher need for insulin secretion.

Complications of Diabetes

Complications of diabetes include retinopathy (damage to the retina), neuropathy (nerve damage), angiopathy (vessel damage), nephropathy (kidney damage), susceptibility to infections, hyperlipidemia (high lipid levels), ketoacidosis (high ketone levels), HHNC (hyperglycemic hyperosmolar nonketotic coma).
Complications occur more frequently in type 1 diabetes, except for HHNC (occurs in type 2).

Hyperlipidemia and Atherosclerosis

Abnormal triglyceride, cholesterol, and very-low-density lipoprotein (VLDL) levels are often associated with type 2 diabetes.
HDL levels tend to be lower in diabetics than non-diabetics.

Diabetic Ketoacidosis (DKA)

Ketoacid production increases in diabetics due to insulin deficiency and triggered triglycerides mobilization in adipose tissues.
Increased production of ketoacids reduces blood pH, leading to keto-acidosis.
The mortality rate for diabetic keto-acidosis is between 1-8%.

Hyperglycemic Hyperosmolar Nonketotic Coma (HHNC)

HHNC is an emergency medical condition triggered by very high blood glucose levels, serum osmolality, and intense thirst.
People with HHNC have frequent urination and may experience lethargy and/ or coma.
HHNC has a mortality rate of between 10-20%.

Hypoglycemia

Hypoglycemia causes neurogenic problems ranging in severity from mild to severe coma, seizures, and death. Symptoms often manifest when blood glucose is around 50 mg/dL.
Aggressive insulin use is a common cause of hypoglycemia in people who are maintaining normal blood sugar levels.

Function Tests

Postprandial plasma glucose (PPPG) tests measure glucose clearance rates from the blood after a carbohydrate load (often 75g of glucose solution). This test is helpful in diagnosing diabetes. Two tests are recommended for accurate diagnosis.
Oral glucose tolerance test (OGTT) evaluates glucose clearance under controlled conditions. It's standardized by the ADA to help diagnose people with diabetes. A minimum 8-hour fast before testing is crucial. The glucose load is usually 75g and levels are measured 2 hours after ingestion. Results are consistent with values above 200 after a 2hr measurement.
A fasting blood glucose (FPG) test measures blood glucose after an 8-hour fast; this is now the preferred blood glucose test to diagnose people with diabetes, particularly when diagnosing diabetes in people who are over 40 years old.
A random plasma glucose (RPG) test measures blood glucose at any time of day, helping diagnose severe diabetes symptoms. A blood glucose of 200 mg/dL or higher is suggestive of diabetes in this test.

Glycated Hemoglobin (HbA1c)

HbA1c, formed by glucose binding to hemoglobin, reflects average plasma glucose levels for the preceding 120 days in red blood cells.
Diagnostic criteria for diabetes using HbA1c are above 6.5%.

Urinary Glucose

While sometimes helpful in screening, urinary glucose is a less reliable marker for diabetes diagnosis than other tests.

Urinary Protein

Microalbuminuria, the presence of albumin in urine, is an early sign of glomerular nephropathy, frequently associated with diabetes. This measured is most helpful when monitoring in a patient population.
Urine albumin/creatinine ratio is a useful screening test for microalbuminuria, an indicator for early kidney disease associated with diabetes.

Insulin Resistance (IR)

Insulin resistance is a significant factor in diabetes mellitus, impacting the effectiveness of insulin to regulate blood sugar.
Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) is a widely used estimation of insulin resistance, calculated as (fasting plasma insulin (FPI) multiplied by fasting plasma glucose (FPG)) divided by the constant 22.5.
High HOMA-IR usually means greater insulin resistance.

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Description

This quiz tests your knowledge on the long-term complications associated with diabetes mellitus, particularly focusing on cardiovascular issues. It explores various aspects of metabolism, insulin signaling, and the hormonal regulation of glucose in the body. Enhance your understanding of how diabetes affects health and the body's response to glucose.