Download Chapter 18

Pathophysiology:
A Clinical Approach
Chapter 18: Combining Complex
Pathophysiologic Concepts:
Diabetes Mellitus
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Pancreas
• Endocrine
• Exocrine
• Islets of Langerhans
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Insulin
• Anabolic hormone
• Required for the uptake of glucose by many
cells, particularly those of the liver, muscle,
and adipose cells
• Promotes protein synthesis and
formation/storage of lipids
• Facilitates transport of potassium, phosphate,
and magnesium into the cells
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Feedback Mechanisms
• Insulin increases when these increase:
– Blood glucose, amino acids, glucagon,
and gastrin
• Insulin decreases when there is:
– Low blood glucose, high insulin levels,
and stimulation of alpha cells
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Diabetes Mellitus
• Demonstrates the inability to regulate
glucose, leading to the inadequate
metabolism of macronutrients
• Type 1
• Type 2
• Gestational
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Type 1 Diabetes Mellitus
• Absolute or significant deficit of insulin; cellmediated immunodestruction of beta cells in the
pancreas
• Multifactorial: genetic-environmental influences
• Approximately 10% of those with diabetes
mellitus
• Hyperglycemia, hyperketonemia, ketoacidosis
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Type 1 Diabetes Mellitus
Clinical Manifestations
• Polydipsia
• Fatigue, lethargy
• Polyuria
• Nocturia
• Polyphagia
• Visual changes
• Weight loss
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Type 1 Diabetes Mellitus
Diagnostic Criteria
• History and physical examination
• Blood glucose levels
– Fasting
– Random
• Glycosylated hemoglobin (HbA1C)
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Type 1 Diabetes Mellitus
Treatment
• Carbohydrate (nutrient) intake
• Exercise
• Insulin replacement therapy
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Type 2 Diabetes Mellitus
• Insulin resistance and a reduction in
adequate insulin secretion
• Obesity is greatest risk factor
• More common than type 1 (90% of those
with diabetes)
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Type 2 Diabetes Mellitus
Clinical Manifestations
• Often asymptomatic
• Manifestations can be vague
– Visual changes
– Nephropathy
– Coronary artery disease
– Peripheral vascular disease
– Recurrent infections
– Neuropathy
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Type 2 Diabetes Mellitus
Diagnostic Criteria
• Blood glucose level
• Distinguish type 1 from type 2
• Test for presence of long-term complications
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Type 2 Diabetes Mellitus
Treatment
• Weight control: diet, exercise
• Oral glycemic agents
• Goal: maintain optimal blood glucose levels
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Gestational Diabetes
• Glucose intolerance with onset during
pregnancy
• Occurs in 4-14% of pregnancies
• Requires diet modifications, exercise, and
possibly insulin
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Acute Complications of
Diabetes Mellitus
• Hypoglycemia
• Diabetic ketoacidosis (DKA)
• Hyperglycemia hyperosmolar nonketotic
syndrome (HHNK)
• The Somogyi Effect and Dawn Phenomenon
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Chronic Complications of
Diabetes Mellitus
• Microvascular Complications
• Macrovascular Complications
• Neuropathies
• Infection
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Chronic Complications of Diabetes
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