Insulin and Glucose Regulation
64 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What percentage of diabetics have Insulin-dependent diabetes mellitus (IDDM)?

  • 30-40%
  • 5-10%
  • 20-30%
  • 10-20% (correct)

    • At what percentage of β-cell destruction do symptoms of IDDM appear?

  • 70%
  • 90-100%
  • 80-90% (correct)
  • 50%

    • What is the main cause of hyperglycemia in IDDM?

  • Increased peripheral utilization
  • Increased gluconeogenesis and glycogenolysis (correct)
  • Increased glycolysis
  • Decreased insulin production

    • What is the consequence of high glucagon: insulin ratio in IDDM?

    <p>Increased lipolysis and mobilization of FA from adipose tissue</p> Signup and view all the answers

    What is a characteristic of LDL particles in IDDM?

    <p>Smaller and denser</p> Signup and view all the answers

    What is the percentage of diabetics that have NIDDM?

    <p>80-90%</p> Signup and view all the answers

    What is a complication of untreated IDDM?

    <p>Ketoacidosis</p> Signup and view all the answers

    What is the age range of IDDM patients?

    <p>Children and young adults</p> Signup and view all the answers

    What is the earliest detectable abnormality in diabetic nephropathy?

    <p>Microalbuminuria</p> Signup and view all the answers

    What is the incidence of Gestational Diabetes Mellitus (GDM) in pregnancies?

    <p>1-5% of pregnancies</p> Signup and view all the answers

    What is the term for a form of autoimmune diabetes diagnosed in individuals older than the usual age of onset of type 1 diabetes?

    <p>LADA (Latent Autoimmune Diabetes in Adults)</p> Signup and view all the answers

    What is a complication of diabetes mellitus?

    <p>Diabetic retinopathy</p> Signup and view all the answers

    What is the term for carbohydrate intolerance with onset or first recognition during pregnancy?

    <p>Gestational Diabetes Mellitus (GDM)</p> Signup and view all the answers

    What is the result of long-standing hyperglycemia?

    <p>Chronic complications of diabetes mellitus</p> Signup and view all the answers

    What is the effect of insulin on the liver?

    <p>Inhibits gluconeogenesis and glycogenolysis</p> Signup and view all the answers

    What is a macrovascular complication of diabetes mellitus?

    <p>Atherosclerosis</p> Signup and view all the answers

    What percentage of women with Gestational Diabetes Mellitus (GDM) are found to have type 2 diabetes after pregnancy?

    <p>5-10%</p> Signup and view all the answers

    What is the precursor of insulin in the process of its synthesis?

    <p>Preproinsulin</p> Signup and view all the answers

    What is the main cause of diabetes mellitus?

    <p>Defect in insulin secretion or action</p> Signup and view all the answers

    What is the effect of insulin on muscle cells?

    <p>Stimulates glucose uptake</p> Signup and view all the answers

    What is the classification of diabetes mellitus characterized by a relative or absolute deficiency in insulin?

    <p>Insulin-dependent diabetes mellitus</p> Signup and view all the answers

    What is the effect of insulin resistance on metabolic alterations?

    <p>Aggravates the metabolic alterations</p> Signup and view all the answers

    What is the function of pancreatic β-cells?

    <p>They secrete insulin in response to hyperglycemia</p> Signup and view all the answers

    What is the effect of counter-regulating hormones on glucose concentrations?

    <p>Provides sufficient energy substrates at low glucose concentrations</p> Signup and view all the answers

    What is the percentage of cardiac output that flows through the kidneys at rest?

    <p>25%</p> Signup and view all the answers

    What is the primary route of elimination for urea?

    <p>Kidneys</p> Signup and view all the answers

    What is the amount of fluid filtered into Bowman's capsule per minute?

    <p>120 ml</p> Signup and view all the answers

    Why is creatinine not a perfect substance for measuring GFR?

    <p>It does not meet all the ideal criteria</p> Signup and view all the answers

    What is the relationship between serum creatinine and GFR?

    <p>Inversely proportional</p> Signup and view all the answers

    Why is serum creatinine not a sensitive indicator of kidney function?

    <p>Because it only increases when kidney function drops by half</p> Signup and view all the answers

    What is the source of creatinine in the body?

    <p>Skeletal muscle</p> Signup and view all the answers

    What is the theoretical concept that measurement of GFR is based on?

    <p>Clearance</p> Signup and view all the answers

    What is a characteristic of patients with DM1 in regards to insulin and C-peptide concentrations?

    <p>They have low concentrations of insulin and C-peptide.</p> Signup and view all the answers

    What is the role of autoimmune markers in patients with T1DM?

    <p>They are present in patient's blood for months or years before the onset of the disease.</p> Signup and view all the answers

    What is the purpose of monitoring blood glucose in diabetic patients?

    <p>To reduce the incidence of chronic complications of DM.</p> Signup and view all the answers

    What is the significance of HbA1c in diabetic patients?

    <p>It is an indirect indicator of glycemia over the life of erythrocytes.</p> Signup and view all the answers

    What is the limitation of urinary glucose test in diabetic patients?

    <p>It correlates with glycemia only in patients with normal GFR.</p> Signup and view all the answers

    What is the significance of glycated proteins in diabetic patients?

    <p>They are involved in the development of some chronic complications of diabetes.</p> Signup and view all the answers

    What is the current method of choice for monitoring blood glucose in diabetic patients?

    <p>Self-monitoring using a glucometer.</p> Signup and view all the answers

    What is the effect of high glucose concentration on proteins?

    <p>It leads to non-enzymatic glycation of proteins.</p> Signup and view all the answers

    Serum urea levels increase in conditions where

    <p>renal clearance decreases</p> Signup and view all the answers

    Which of the following conditions is NOT associated with increased serum urea levels?

    <p>Starvation</p> Signup and view all the answers

    What is the ratio of BUN: creatinine in pre-renal disease?

    <p>20:1</p> Signup and view all the answers

    What is the advantage of creatinine clearance over plasma creatinine?

    <p>It removes the variables of diet and muscle mass</p> Signup and view all the answers

    What is the characteristic of cystatin C that makes it a useful marker of renal function?

    <p>It is reabsorbed and metabolized by the proximal renal ducts</p> Signup and view all the answers

    Why is serum creatinine not a perfect substance for measuring GFR?

    <p>It is affected by muscle mass and diet</p> Signup and view all the answers

    What is the significance of the BUN: creatinine ratio in differentiating pre-renal from renal causes?

    <p>It is useful in differentiating pre-renal from renal causes</p> Signup and view all the answers

    Why is creatinine clearance a more sensitive indicator of renal function than plasma creatinine?

    <p>It is less affected by muscle mass and diet</p> Signup and view all the answers

    What is the primary function of the glomeruli in the nephron?

    <p>Filtration of water and low molecular weight substances</p> Signup and view all the answers

    What is the main function of the kidney in terms of calcium metabolism?

    <p>Activation of vitamin D</p> Signup and view all the answers

    What is the purpose of renal function tests?

    <p>To screen for, detect, evaluate, and monitor acute and chronic kidney diseases</p> Signup and view all the answers

    What is the functional unit of the kidney?

    <p>Nephron</p> Signup and view all the answers

    What percentage of urea is eliminated via kidneys?

    <p>85%</p> Signup and view all the answers

    What is the significance of proteinuria in urine examination?

    <p>Indicates glomerular leak and is the first sign of glomerular injury</p> Signup and view all the answers

    What is the purpose of estimating glomerular filtration rate (GFR)?

    <p>To assess kidney function</p> Signup and view all the answers

    What is the primary route of elimination for urea?

    <p>Kidneys</p> Signup and view all the answers

    What is the source of creatinine in the body?

    <p>Skeletal muscle</p> Signup and view all the answers

    What is the significance of urinary protein in urine examination?

    <p>Indicates glomerular leak and is the first sign of glomerular injury</p> Signup and view all the answers

    What is the role of the kidney in erythropoiesis?

    <p>Produces erythropoietin</p> Signup and view all the answers

    Why is serum creatinine not a sensitive indicator of kidney function?

    <p>All of the above</p> Signup and view all the answers

    What is the theoretical concept that measurement of GFR is based on?

    <p>Clearance</p> Signup and view all the answers

    What is the relationship between serum creatinine and GFR?

    <p>Inversely proportional</p> Signup and view all the answers

    What is the amount of fluid filtered into Bowman's capsule per minute?

    <p>120 ml</p> Signup and view all the answers

    What percentage of cardiac output flows through the kidneys at rest?

    <p>25%</p> Signup and view all the answers

    Study Notes

    Counter-Regulating Hormones

    • Increase in concentration in blood at low glucose concentrations
    • Provide energy substrates from glycogenolysis, gluconeogenesis, lipolysis, and ketogenesis

    Insulin

    • Pancreatic β-cells function as glucose sensors, secreting insulin in response to hyperglycemia
    • Reduce insulin secretion if blood glucose decreases
    • Synthesis involves preproinsulin, proinsulin, and insulin (51 AK) with C-peptide (connecting peptide)
    • Functions:
      • Stimulate glucose uptake in muscle cells and enhance glycogenesis
      • Stimulate glucose uptake in adipose tissue cells and enhance lipogenesis
      • Inhibit gluconeogenesis and glycogenolysis in the liver

    Diabetes Mellitus

    • Systemic metabolic disorder characterized by chronic hyperglycemia with disturbances in CHO, fat, and protein metabolism
    • Caused by relative or absolute deficiency in insulin and/or insulin resistance
    • Complications:
      • Acute: diabetic ketacidosis, hyperosmolar hyperglycemic nonketotic, diabetic lactic acidosis, hypoglycemic coma
      • Chronic: macrovascular (atherosclerosis), microvascular (diabetic retinopathy, cataract, diabetic neuropathy, diabetic nephropathy)

    Insulin-Dependent Diabetes Mellitus (IDDM)

    • Type I or juvenile-onset diabetes
    • Characterized by absolute deficiency of insulin due to massive autoimmune attack on β-cells
    • Symptoms: polyuria, polydipsia, polyphagia
    • Patients rely on exogenous insulin to restore metabolic control and avoid life-threatening ketoacidosis
    • Complicated by ketoacidosis

    Non-Insulin-Dependent Diabetes Mellitus (NIDDM)

    • Type II or adult-onset diabetes
    • Most common type, constituting 80-90% of diabetic cases
    • Complications: same as IDDM, plus hypertriglyceridemia, hypercholesteremia, and low HDL

    Gestational Diabetes Mellitus (GDM)

    • Carbohydrate intolerance with onset or first recognition during pregnancy
    • Incidence: 1-5% of pregnancies
    • Patients often revert to normal glucose tolerance after delivery
    • Requires treatment to normalize maternal blood glucose levels during pregnancy

    Other Types of DM

    • Latent Autoimmune Diabetes in Adults (LADA): a form of autoimmune diabetes diagnosed in individuals older than the usual age of onset of type 1 diabetes
    • Laboratory monitoring of diabetic patients:
      • Monitoring of blood glucose: reduces incidence of chronic complications
      • HbA1c: assesses long-term compensation of a diabetic, indirect indicator of glycemia over life of erythrocytes
      • Urinary glucose test: correlates with glycemia only in patients with normal GFR
      • GFR: accurate measurement requires a substance with constant production and removal rate, such as creatinine
      • Creatinine: breakdown product of creatine and creatine phosphate, inversely proportional to GFR, but not sensitive and influenced by muscle mass and liver function
      • Blood Urea Nitrogen (BUN): formed in the liver as the end product of protein metabolism, eliminated via kidneys and GI tract

    Serum Urea Levels

    • Increase in conditions where renal clearance decreases (acute and chronic renal failure/impairment)
    • Also increase in other conditions not related to renal diseases, such as:
      • Upper GI bleeding
      • Dehydration
      • Catabolic states
      • High protein diets
    • Decrease in:
      • Starvation
      • Low-protein diet
      • Severe liver disease

    BUN: Creatinine Ratio

    • Useful to differentiate pre-renal from renal causes when BUN is increased
    • In pre-renal disease, the ratio is close to 20:1
    • In intrinsic renal disease, the ratio is closer to 10:1
    • Upper GI bleeding can be associated with a very high BUN to creatinine ratio (sometimes >30:1)

    Creatinine Clearance

    • More sensitive than plasma creatinine at picking up small changes in renal function
    • Removes the variables of diet and muscle mass
    • Inconvenient, requiring 24hr urine collection plus serum sample
    • Calculation: Evaluation of glomerular function

    Cystatin C

    • Small polypeptide produced by all nucleated cells at a constant rate
    • Stable concentration in blood
    • Renal handling of cystatin C differs from creatinine
    • Not affected by:
      • Infections
      • Inflammatory or neoplastic states
      • Body mass
      • Diet
      • Drugs
    • Useful for monitoring progression of renal disease, assessing therapeutic response, and estimating cardiovascular risk

    Glomerular Filtration Rate (GFR)

    • Volume of blood filtered across glomerulus per unit time
    • Measurement based on a theoretical concept of clearance
    • Requires a substance that is:
      • Freely filtered by glomeruli
      • Not secreted or reabsorbed in tubules
      • Produced and removed from the body with a constant rate
    • Creatinine is close to fulfilling these criteria

    Creatinine

    • Breakdown product of creatine and creatine phosphate
    • Released from skeletal muscle at a steady rate
    • Not metabolized or excreted from the body other than by the kidney
    • Can measure its clearance from plasma or excretion in urine
    • Inversely proportional to GFR
    • Limitations:
      • Not sensitive (serum creatinine only increases above normal when kidney function drops by half)
      • Influenced by:
        • Muscle mass size
        • Food intake (meat)
        • Liver function (synthesis of creatine)

    Blood Urea Nitrogen (BUN)

    • Nitrogen-containing compound formed in the liver as the end product of protein metabolism
    • About 85% of urea is eliminated via kidneys; the rest is excreted via the GI tract
    • Hormonal functions:
      • Produces erythropoietin, which helps promote erythropoiesis in bone marrow
      • Plays a role in calcium metabolism by activating vit.D

    Renal Function Test (RFT)

    • Group of tests used to assess the functions of the kidney
    • Used to:
      • Screen for, detect, evaluate, and monitor acute and chronic kidney diseases
      • Monitor the response of kidneys to treatment or progression of renal disease
      • Evaluate kidney function in patients with other conditions that can harm the kidneys, such as diabetes or high blood pressure

    Nephron

    • Functional unit of the kidney
    • Each of the approximately one million nephrons is made up of five main functional segments
    • The principal function of the glomeruli is to filtration, which is permeable to water and low molecular weight substances, but impermeable to macromolecules like proteins.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the role of insulin in regulating blood glucose levels, including the production and secretion of insulin in response to hyperglycemia and hypoglycemia.

    More Like This

    Regulation of Blood Glucose Levels: Insulin Hormone Functions
    5 questions

    Regulation of Blood Glucose Levels: Insulin Hormone Functions

    CheaperLake avatar
    CheaperLake
    carbohydrates
    24 questions

    carbohydrates

    WonderfulSeattle avatar
    WonderfulSeattle
    Insulin and Glucagon Functions
    10 questions

    Insulin and Glucagon Functions

    CourteousPlatypus avatar
    CourteousPlatypus
    Physiology of Glucose Regulation
    21 questions

    Physiology of Glucose Regulation

    PortableSasquatch avatar
    PortableSasquatch
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser