Pathology Diabetes Mellitus Question And Answers

Diabetes Mellitus Important Notes

1. Etiology of Diabetes Mellitus

• Reduced insulin secretion
• Decreased glucose use by the body
• Increased glucose production

2. Complications of Diabetes Mellitus

• Ketoacidosis
• Nonketotic coma
• Hypoglycemia
• Atherosclerosis
• Nephropathy
• Neuropathy
• Microangiopathy
• Retinopathy
• Infections

Diabetes Mellitus Long Essays

Question 1. Define diabetes mellitus. Discuss laboratory diagnosis and complications of diabetes mellitus.
Answer:

Diabetes Mellitus Definition: Diabetes mellitus is defined as a heterogenous metabolic disorder characterized by the common feature of chronic hyperglycaemia with disturbance of carbohydrate, fat and protein metabolism

Diabetes mellitus Laboratory Diagnosis:

• Urine testing
  • Glucosuria
    • The Dipstick method is used
    • In this method, enzyme coated paper strip is used which turns purple when dipped in urine containing glucose
  • ketonuria
    • Rothera’s test is used to detect ketone bodies in urine
• Single blood sugar estimation
  • O-toluidine, Somogyi-Nelson and glucose oxidase methods are used
  • A fasting plasma glucose value above 126 mg/dl is certainly indicative of diabetes
• Screening by fasting glucose test
  • It is a screening test for type 2 diabetes mellitus
  • Done for individuals above 45 years
• Oral glucose tolerance test

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Diabetes Mellitus Method:

• Intake of a high carbohydrate diet 3 days prior to the test
• Overnight fasting on the day of the test
• A fasting blood sugar sample is collected
• 75 gms of glucose dissolved in 300 ml of distilled water is given to the individual
• Blood and urine samples are collected at half-hour intervals for atleast 2 hours

Diabetes Mellitus Result:

Diabetes Mellitus Complications:

• Acute metabolic complications
  • Diabetic ketoacidosis
    • Develop in patients with severe insulin deficiency
    • Pathogenesis

• • • Diabetic ketoacidosis Clinical Features:
      • Nausea, vomiting, anorexia
      • Deep and fast breathing
      • Mental confusion
      • Coma
  • Hyperosmolar hyperglycaemia non-ketotic coma
    • It is a complication of type 2 diabetes mellitus
    • Caused by severe dehydration which leads to sustained hyperglycaemia diuresis
      • Hyperglycaemia non-ketotic coma Clinical Features:
        • High blood sugar
        • High plasma osmolality
        • Thrombotic and bleeding complications
  • Hypoglycaemia
    • Develop in type 1 diabetes mellitus
    • Occurs due to
      • Excessive administration of insulin
      • Missing a meal
      • Stress
    • It produces
      • Permanent brain damage
      • Worsening of diabetic control
      • Rebound hyperglycaemia

• Late systemic complications
  • Atherosclerosis
    • Common in both type 1 and type 2 diabetes mellitus
    • Its contributory factors are
      • Hyperlipidaemia
      • Reduced HDL levels
      • Non-enzymatic glycosylation
      • Increased platelets adhesiveness
      • Obesity
      • Hypertension
    • Atherosclerosis may lead to
      • Myocardial infarction
      • Cerebral stroke
      • Gangrene of toes and feet
  • Diabetic microangiopathy
    • It is the basement membrane thickening of small blood vessels and capillaries of different organs and tissues
    • Occurs due to increased glycosylation of haemoglobin and other proteins
  • Diabetic nephropathy
    • It is a severe complication of diabetes mellitus
    • Occurs in both types
      • Diabetic nephropathy Features:
        • Asymptomatic proteinuria
        • Nephrotic syndrome
        • Progressive Renal failure
        • Hypertension
  • Diabetic neuropathy
    • Effects all parts of the nervous system
      • Pathological Changes:
        • Segmental demyelination
        • Schwann cell injury
        • Axonal damage
  • Diabetic retinopathy
    • It is the cause of blindness
    • Other retinal complications include
      • Glaucoma
      • Cataract
      • Corneal disease
  • Infections
    • Diabetic patients are more susceptible to infections like tuberculosis, pyelonephritis, otitis, carbuncles and diabetic ulcers

Diabetes Mellitus Short Essays

Question 1. Aetiopathogenesis of Diabetes Mellitus.
Answer:

1. Genetic susceptibility Diabetes mellitus involves inheritance of multiple genes

2. Autoimmune factors

• Presence of islet cell antibodies against insulin
• Occurrence of CD8+ T lymphocytes with a variable number of CD4+ T lymphocytes and macrophages
• Selective destruction of beta cells by T-cell mediated cytotoxicity or by apoptosis

3. Constitutional factors

• Obesity, hypertension and level of physical activity
• Presence of viral infection

4. Insulin resistance

• It leads to
  • Impaired glucose uptake by tissues
  • Increased glucose synthesis by the liver
  • Hyperglycaemia

5. Impaired insulin secretion

• In diabetes mellitus, initially, there is increased secretion of insulin
• Later beta cells fail to secrete adequate insulin

6. Increased hepatic glucose synthesis

• In diabetes mellitus gluconeogenesis process remains unaffected
• Thus there is increased glucose synthesis in the liver.

Diabetes Mellitus Short Question And Answers

Question 1. Glycosuria.
Answer:

• It is the condition of glucose excretion in urine.
• Glucose appears in urine when the plasma glucose concentration exceeds the renal threshold for glucose.

Glycosuria Types:

1. Renal glycosuria.

• It is a benign condition.
• Occurs due to a reduced renal threshold for glucose.
• It is unrelated to diabetes.

2. Alimentary glycosuria.

• In certain individuals, blood glucose rapidly Increases after meals which get excreted in the urine.
• This is known as alimentary glycosuria.
• It is observed in.
  • Normal individuals.
  • Individuals with.
    • Hepatic diseases
    • Hyperthyroidism
    • Peptic ulcer.