Flashcards in Chapter 47 Diabetes Mellitus Deck (108)
1) Leading cause of
2) Major contributing factor
1) Leading cause of
- Adult blindness
- End-stage kidney disease
- Nontraumatic lower limb amputations
2) Major contributing factor
- Heart disease
Etiology and Pathophysiology
- Normal insulin metabolism
- Produced by beta-cells in islets of Langerhans
- Released continuously into bloodstream in small increments with larger amounts released after food
- Stabilizes glucose level in range of 70 to 120 mg/dL
Diabetes is the leading cause of?
Adult blindness, end-stage renal disease, and nontraumatic lower limb amputations. It is also a major contributing factor to heart disease and stroke.
Type 1 DM, formerly known as "juvenile-onset" or insulin dependent" diabetes, accounts for approximately 5-10% of all cases of diabetes. This type generally affects who?
Younger people than 40 years of age, although it can occur at any age
Pathophysiology: Type 1 diabetes is an autoimmune disorder in which the body develops antibodies against insulin and/or the pancreatic B-cells that produce insulin. This eventually results in?
Insufficient insulin for survival. Autoantibodies to the islet cells cause a reduction of 80-90% of normal function before hyperglycemia and other manifestations occur.
Factors that may contribute to the pathogenesis of immune-related type 1 diabetes
Genetic predisposition and exposure to a virus
Type 1 diabetes: Clinical manifestations
Once the pancreas can no longer produce sufficient amounts of glucose to maintain normal glucose the onset of symptoms is usually rapid
The patient usually has a history of a recent and sudden weight loss and the classic symptoms of polydipsia (excessive thirst), polyuria (frequent urination), and polyphagia (excessive hunger)
The individual with type 1 diabetes requires a supply of insulin from an?
outside source (exogenous insulin) to sustain life. Without insulin, the patient develops diabetic ketoacidosis (DKA), a life-threatening condition resulting in metabolic acidosis
Normal Glucose and Insulin Metabolism.
Insulin is a hormone produced by the β-cells in the islets of Langerhans of the pancreas. Under normal conditions, insulin is continuously released into the bloodstream in small increments, with increased release when food is ingested.
- Insulin lowers blood glucose and facilitates a stable, normal glucose range of approximately?
- The average amount of insulin secreted daily by an adult is approximately?
- Insulin lowers blood glucose and facilitates a stable, normal glucose range of approximately 70 to 110 mg/dL (3.9 to 6.1 mmol/L).
- The average amount of 1insulin secreted daily by an adult is approximately 40 to 50 U, or 0.6 U/kg of body weight
Normal endogenous insulin secretion. In the first hour or two after meals, insulin concentrations rise rapidly in blood and peak at about 1 hour. After meals, insulin concentrations promptly decline toward preprandial values as carbohydrate absorption from the gastrointestinal tract declines. After carbohydrate absorption from the gastrointestinal tract is complete and during the night, insulin concentrations are low and fairly constant, with a slight increase at dawn.
Insulin promotes glucose transport from the bloodstream across the cell membrane to the cytoplasm of the cell. Cells break down glucose to make energy, and liver and muscle cells store excess glucose as glycogen.
1) The rise in plasma insulin after a meal does what?
2) The fall in insulin level during normal overnight fasting facilitates the release of?
1) inhibits gluconeogenesis, enhances fat deposition of adipose tissue, and increases protein synthesis.
2) stored glucose from the liver, protein from muscle, and fat from adipose tissue.
Classes of Diabetes
- Type 1
- Type 2
- Other specific types – Due to various causes
Type 1 Diabetes Mellitus
- Formerly known as juvenile-onset or insulin-dependent diabetes
- Accounts for 5% of all cases of diabetes
- Onset in people younger than 40 years
- Incidence increasing
- More frequently in younger children
Type 1 Diabetes Mellitus Etiology and Pathophysiology
- Autoimmune destruction of β-cells
- Total absence of insulin
- Genetic predisposition and viral exposure
* HLA-DR3 and HLA-DR4
- Idiopathic diabetes
- Latent autoimmune diabetes in adults (LADA)
Type 2 Diabetes Mellitus Main Points
- Formerly known as adult-onset diabetes (AODM) or non–insulin-dependent diabetes (IDDM)
- Most prevalent type (90% to 95%)
- Risk factors: overweight, obesity, advancing age, family history
- Increasing prevalence in children
- Greater prevalence in ethnic groups
Type 2 diabetes mellitus was formerly known as adult-onset diabetes (AODM) or non–insulin-dependent diabetes (NIDDM). Type 2 diabetes is, by far, the most prevalent type of diabetes, accounting for approximately 90% to 95% of patients with diabetes.
1) Many risk factors contribute to the development of type 2 diabetes, including?
2) Although the disease is seen less frequently in children, the incidence is increasing due to?
3) Type 2 diabetes is more prevalent in some ethnic populations.
1) being overweight or obese, being older, and having a family history of type 2 diabetes.
2) the increasing prevalence of childhood obesity.
3) African Americans, Asian Americans, Hispanics, Native Hawaiians or other Pacific Islanders, and Native Americans have a higher rate of type 2 diabetes than whites
Etiology and Pathophysiology.
1) Type 2 diabetes is characterized by a combination of?
2) The pancreas usually?
3) major distinction between type 1 and type 2 diabetes
1) inadequate insulin secretion and insulin resistance.
2) produces some endogenous (self-made) insulin. However, the body either does not produce enough insulin or does not use it effectively, or both.
3) The presence of endogenous insulin is a major distinction between type 1 and type 2 diabetes. (In type 1 diabetes, there is an absence of endogenous insulin.)
Type 1 diabetes mellitus role of the pancreas
- Autoimmune destruction of B-cells
- Autoantibodies present for months to years before clinical symptoms
- Insufficient production of insulin
Type 2 diabetes mellitus role of the pancreas, liver, adipose tissue, muscle
- Defective B cell secretion of insulin
- Insulin resistance stimulates increase in insulin secretion
- Eventual exhaustion of B cells in many people
- Increase glucagon secretion
- Excess glucose production
- Inappropriate regulation of glucose production
3) Adipose Tissue
- Decrease adiponectin and Increase leptin
- Results in altered glucose and fat metabolism
- Defective insulin receptors
- Insulin resistance
- Decreased uptake of glucose by cells resulting in hyperglycemia
Type 2 Diabetes Mellitus Etiology and Pathophysiology Main Points
- Pancreas continues to produce some endogenous insulin
- Insulin insufficient or poorly utilized
- Multiple etiologic factors
- Obesity is greatest risk factor
- Genetic component increases insulin resistance and obesity
Type 2 Diabetes Mellitus Etiology and Pathophysiology
Four major metabolic abnormalities
- Insulin resistance
- Decreased insulin production by pancreas
- Inappropriate hepatic glucose production
Type 2 Diabetes: Genetic mutations that lead to insulin resistance and a higher risk for obesity have been found in many people with type 2 diabetes. Individuals with a first-degree relative with the disease are 10 times more likely to develop type 2 diabetes. Four major metabolic abnormalities play a role in the development of type 2 diabetes
1) The first factor is insulin resistance, which describes a condition in which body tissues do no respond to the action of insulin because insulin receptors are unresponsive, insufficient in number, or both. Entry of glucose into the cell in impeded, resulting in hyperglycemia
2) A second factor is a marked decrease in the ability of the pancreas to produce insulin as the B-cells become fatigue from the compensatory overproduction of insulin or when B-cell mass is lost
3) A third factor is inappropriate glucose production by the liver. Instead of properly regulating the release of glucose in response to blood levels, the liver does so in a haphazard way that does not correspond to the body's needs at the time
4) A fourth factor is alteration in the production of hormones and cytokines by adipose tissue (adipokines). Adipokines play a role in glucose and fat metabolism and likely contribute to the pathophysiology of type 2 diabetes
Individuals with metabolic syndrome are at an increased risk for the development of type 2 diabetes. Overweight indidivuals with metabolic syndrome can reduce their risk for diabetes by?
through a program of weight loss and regular physical activity
Disease onset in type 2 diabetes is usually gradual, with signs and symptoms of hyperglycemia developing when about 50% to 80% of B-cells no longer secrete insulin. Many people are diagnosed on?
routine laboratory testing or when they undergo treatment for other conditions and elevated glucose or glycosylated hemoglobin (A1C) levels are found
1) The fasting blood glucose level of a patient with prediabetes may range from?
2) The normal blood glucose level ranges from?
3) A blood glucose level of what indicates hypoglycemia?
4) A blood glucose level of what indicates hyperglycemia?
1) 100 to 125 mg/dL.
2) 70 to 130 mg/dL.
3) A blood glucose level less than 70 mg/dL indicates hypoglycemia.
4) A blood glucose level greater than 200 mg/dL indicates hyperglycemia.
A patient is admitted with diabetic ketoacidosis. Which signs/symptoms would the nurse expect to find upon physical examination?
Blood sugar 200 mg/dL and bradypnea
Hypotension and blood sugar 68 mg/dL
Diaphoresis and extreme hunger
Dry skin and ketonuria
Dry skin and ketonuria
In diabetic ketoacidosis, the lungs try to compensate for the acidosis by blowing off volatile acids and carbon dioxide. This leads to a pattern of Kussmaul respirations, which are deep and nonlabored. The patient also will present with dry, loose skin. Blood pressure will not be low and respiratory rate will be increased, not decreased.
Which hormone regulates the normal blood glucose level in the body?
Insulin is a hormone secreted by beta cells in the Islet of Langerhans of the pancreas. It helps in regulating the blood glucose level. Glucagon is a hormone secreted by the alpha cells of the Islet of Langerhans. It increases the blood glucose level by counteracting the mechanism of insulin. Epinephrine is a hormone secreted by the adrenal gland. It may not be helpful in maintaining the blood glucose level. Growth hormone is secreted by the pituitary gland and it helps in growth of all tissues and bones in the body.
The nurse is preparing an educational session on Type 2 diabetes for the public. Which symptoms of type 2 diabetes would the nurse include in the presentation? Select all that apply.
The onset of type 2 diabetes usually is delayed, resulting in chronic complications having already manifested. The patient will have slower wound healing and infection healing, fatigue, and visual changes as a result of the disease progression. Some patients with type II diabetes may have polyuria. Weight loss is typically seen with type I diabetes.
Which is an insulin-dependent tissue?
Red blood cells
Skeletal muscles have specific receptors that are activated by insulin that permit the transportation of glucose into the cells. The brain, kidney, and red blood cells do not have receptors; instead they require only a specific amount of glucose for normal functioning.