Diabetes Mellitus Pathology and complications By Dr. Abdelaty Shawky Assistant professor of pathology

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Diabetes Mellitus Pathology and
complicationsByDr. Abdelaty ShawkyAssistant
professor of pathology
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Diabetes Mellitus

• Metabolic disease affecting CHO, protein and fat
  metabolism due to insulin deficiency or
  inefficiency.
• Two types
• Type I (insulin dependent).
• Type II (insulin independent).

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  Type I Type II
1. Age Under 25 years. Above 40 years.
2. B. Cell mass. Reduced Not reduced.
3. Insulin secretion Reduced Not reduced
4. Etiology Hereditary. Autoimmune destruction of the B.cells. Decreased insulin specific surface receptors on most of the body cells. Premature aging of body cells including B.cells.
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Pathological lesions

• 1. Pancreas
• - In type I the pancreas is atrophic. M/P
  degranulated and destroyed B.cells, lymphocytic
  infiltration and fibrosis.
• - In type II the pancreas is normal. M/P normal
  in early stage, later on shows hyalinosis.

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• 2. Disturbance of metabolism
• A. Carbohydrate metabolism Hyperglycemia due to
  either decreased glucose utilization or due to
  glycogenolysis, leads to
• 1. Glucose retention in the tissue (increase the
  liability to infection).
• 2. Glycogen deposition in the tissues (heart,
  muscle, kidney and pancreas).
• 3. Glucosuria leads to osmotic diuresis and
  dehydration.

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• B. Fat metabolism Lipolysis Leads to
• 1. Hperlipidaemia (atheroma formation and fatty
  infiltration in the parenchymatous organs).
• 2. Formation of ketone bodies in the liver with
  keto-acidosis and coma.
• C. Protein metabolism Loss of weight.

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• 3. Vascular changes
• 1. Diabetic macroangiopathy accelerated
  atherosclerosis in aorta, large and medium sized
  arteries.
• 2. Hyaline arterioloscelrosis hyaline thickening
  of the arterioles due to deposition of hyaline
  material.
• 3. Diabetic microangiopathy diffuse thickening
  of the basement membranes due to deposition of
  hyaline material. Involves predominantly the
  capillaries of, retina, renal glomeruli, and
  peripheral nerves. Leads to diabetic
  nephropathy, retinopathy and neuropathy.

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Complications of diabetes mellitus

• Acute complications
• Diabetic ketoacidosis
• Hypoglycemic coma
• II. Chronic complications
• a. Microvascular
• Retinopathy
• Nephropathy
• Neuropathy
• b. Macrovascular
• Cerbrovascular.
• Cardiovascular.
• Peripheral vascular disease.

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Diabetic ketoacidosis (DKA)

• May be the 1st presentation of type 1 DM.
• Result from absolute insulin deficiency or
  increase requirement.
• Mortality rate around 5.

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Predisposing factors for DKA

• Infection
• Trauma
• Myocardial Infarction
• Stroke
• Surgery
• Emotional stress

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Clinical presentation of DKA

• Polyurea and polydepsia.
• Nausea and vomiting.
• Anorexia and abdominal pain.
• Tachycardia.
• Signs of dehydration.
• Hypotonia.
• Coma.

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Diagnosis of DKA

• Hyperglycemia
• Ketonuria and ketonemia
• Acidosis (PHlt 7.3 )

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Treatment of DKA

• Fluid replacement.
• Insulin therapy for hyperglycemia.
• Electrolyte correction.
• Acidosis correction.
• Treatment of precipitating cause.

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Complications of DKA

• Cerebral edema
• Vascular thrombosis
• Infection
• M I
• Respiratory distress syndrome

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Hypoglycemic coma

• Hypoglycemia is the most frequent acute
  complication in type 1 diabetes.
• Hypoglycemia is the level of blood glucose at
  which autonomic and neurological dysfunction
  begins

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Clinical manifestations of hypoglycemia

• Autonomic dysfunctions
• 1. Hunger
• 2. Tremor
• 3. Palpitation
• 4. Anxiety
• 5. Pallor
• 6. Sweating

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• Neurologic dysfunctions
• 1. Impaired thinking
• 2. Change of mood
• 3. Irritability
• 4. Headache
• 5. Convulsion
• 6. Coma

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Predisposing factors

• Missed meal
• Change in physical activity
• Alterations or errors in insulin dosage
• Alcohol ingestion

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Treatment of hypoglycemia

• In mild cases oral rapidly absorbed carbohydrate.
• In sever cases (comatose patient) I.V hypertonic
  glucose 25 or 50 concentration glucagon
  injection.

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Chronic Complications of DM

• A. Macrovascular Complications.
• B. Microvascular Complications.

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A. Macro-vascular Complications

• Accelerated atherosclerosis involving the aorta
  and large- and medium-sized arteries.
• Myocardial infarction, caused by atherosclerosis
  of the coronary arteries, is the most common
  cause of death in diabetics.
• Gangrene of the lower extremities.
• Hypertension due to Hyaline arteriolosclerosis.

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B. Microvascular Complications

• Microvascular complications are specific to
  diabetes and related to longstanding
  hyperglycaemia.
• In diabetes, the microvasculature shows both
  functional and structural abnormalities.
• The structural hallmark of diabetic
  microangiopathy is thickening of the capillary
  basement membrane.

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• Many chemical changes in basement membrane
  composition have been identified in diabetes,
  including increased type IV collagen and its
  glycosylation (i.e. binding of glucose to wall of
  blood vessels).

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• The main functional abnormalities include
  increased capillary permeability and disturbed
  platelet function.
• Increased capillary permeability is manifested in
  the retina by exudation and in the kidney by
  increased urinary losses of albumin.
• Platelets from diabetic patients show an
  exaggerated tendency to aggregate, perhaps
  mediated by altered prostaglandin metabolism.

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Diabetic retinopathy
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• Pathological lesions
• Thickening of the capillary basement membrane.
• Capillary dilatations (microaneurysms) which may
  give rise to haemorrhage or exudate (red dots
  and blots).
• Vascular occlusion leads to large ischaemic areas
  (cotton-wool spots).

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Normal Retina
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(No Transcript)
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Diabetic Retinopathy
Cotton wool spots
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Other Eye Complications

• - Cataracts.
• - Glaucoma
• Vitreous Bleeding.

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Vitreous Bleeding
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Diabetic Nephropathy (DN)
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• - Diabetic nephropathy is defined by persistent
  albuminuria (gt300 mg/day), decrease glomerular
  filtration rate and rising blood pressure.
• - About 20 30 of patients with diabetes
  develop diabetic nephropathy .

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Diabetic Neuropathy
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• 1. Sensorimotor neuropathy.
• 2. Autonomic neuropathy.

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Sensorimotor Neuropathy

• Numbness, paresthesias.
• Feet are mostly affected, hands are seldom
  affected.
• Complicated by ulceration (painless), charcot
  arthropathy, Callosities

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Complications of Sensorimotor neuropathy
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Autonomic Neuropathy

• Postural hypotension.
• Diabetic diarrhea.
• Erectile dysfunction.

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• The end