ENDOCRINE 1 DIABETES Flashcards
For all types of diabetes mellitus, the main feature is
chronic hyperglycemia resulting from problems with glucose regulation that include reduced insulin secretion or reduced insulin action or both.
Type 1 Diabetes (T1DM)
- Beta-cell destruction leading to absolute insuline deficiency
- autoimmune
- Idiopathic
Type 2 Diabetes (T2DM)
- Ranges from insulin resistance with relative insulin deficiency to secretory deficit with insulin resistance.
Other Conditions resulting in hyperglycemia
- genetic defects of beta-cell function
- genetic defects in insulin action
- pancreatic diseases (pancreatitis, trauma, cancer, cystic fibrosis, hemochromatosis).
- endocrine problems (acromegaly, Cushing’s disease, hyperthyroidism, aldosteronism)
- Drug-or chemical-induced hyperglycemia
- infections: congenital rubella, cytomegalovirus, human immune deficiency virus.
- genetic syndromes associated with diabetes: down syndrome, klinefelter syndrome, Turner syndrome, Hunting Disease, and others.
Gestational Diabertes Mellitus (GDM)
- glucose intolerance with onset or first recognition during pregnancy. (All pregnant women should be screened).
Islet of langerhans in pancreas, has two types of cells important to glucose regulation.
Alpha cells
beta cells
Normal blood glucose control
- blood glucose is controlled by interactions between:
- gi tract
- pancrease
- liver
- glucose is either used or stored
Fasting Glucose
74-106 mg/dL
Hypoglycemia
Blood glucose levels less than 74 mg/dl
Hyperglycemia
blood glucose levels greater than 106
Pancreas has exocrine functions
- related to digestion and endocrine functions that attempts to maintain blood glucose control.
- endocrine portion of the pancreas has 1 million islets of langerhans
alpha cells
secrete glucagon
beta cells
produce insulin and amylin
Characterization of the underlying pathophysiology is more developed in type 1 diabetes
than type 2.
Glucose is the main fuel for the
central nervous system cells.
Glucagon
is a “counterregulatory” hormone that has actions opposite those of insulin. It prevents hypoglycemia by triggering the release of glucose from storage sites in the liver and skeletal muscle.
Insulin prevents
hyperglycemia by allowing body cells to take up, use, and store carbohydrate, fat, and protein
Active insulin is a protein made up of
51 amino acids.
Insulin is secreted daily into liver circulation in a two-step manner.
- It is secreted at low levels during fasting (basal insulin secretion) and in a two-phase release after eating (prandial).
An early burst of insulin secretion occurs within
10 minutes of eating, followed by an increasing release that lasts until the blood glucose level has returned to normal.
Physiologic Response to Insufficient Insulin
- decreased glycogenesis (conversion of glucose to glycogen)
- increased glycogenolysis (conversion of glycogen to glucose)
- increased glyconeogenesis (formation of glucose from noncarbohydrate sources such as amino acids and lactate)
- increased lipolysis (breakdown of triglycerides to glycerol and free fatty acids)
- increased ketogenesis (formation of ketones from free fatty acids)
- Proteolysis (breakdown of protein with amino acid release in muscles).
glycogenesis
conversion of glucose to glycogen
glycogenolysis
conversion of glycogen to glucose
gluconeogenesis
formation of glucose from noncarbohydrate sources such as amino acids and lactate
lipolysis
breakdown of triglycerides to glycerol and free fatty acids.
ketogenesis
formation of ketones from free fatty acids
Proteolysis
breakdown of protein with amino acid release in muscles
polydipsia
excessive thirst
polyphagia
excessive eating
Insulin for glucose regulation is needed to move glucose into the many body tissues.
The lack of insulin in diabetes, from either a lack of production or a problem with insulin use at its cell receptor, prevents some cells from using glucose for energy. The body then breaks down fat and protei in an attempt to provide energy and icnreases levels of counterregulatory hormones to make glucose from other sources.
Hyperglycemia disturbs fluid and electrolyte imbalance, leading to the classic symtoms of diabetes
polyuria, polydipsia and ployphagia.
Ketone bodies
are abnormal breakdown products that collect in the blood when insulin is not available, leading to ACID-BASE Balance problems of metabolic acidosis.
Dehydrations with DM leads to hemoconcentration; hypovolemia; poor tissue perfusion and hypoxia., especially to the brain.
Hypoxic cells do not metabolize glucose efficiently, the Kreb’s cycle is blocked, and lactic acid productin increases, causing more acidosis.
The excess acids caused by absence of insulin increase hydrogen ion and carbon dioxide levels in the blood, causing an anion-grap metabolic acidosis.
These products trigger the brain to increase the rate and depth of respiration in an attempt to “blow off” carbon dioxide and acids. (Kussmaul respirations) Acetone is exhaled, giving the breath a “rotting citrus fruit” odor. When the lungs can no longer offset acidosis, the blood pH drops.
Insulin lack initially causes potassium depletion. With the increased fluid loss from hyperglycemia, excessive potassium is excreted in the urine, leading to low serum potassium levels.
High serum potassium levels may occur in acidosis because of the shift of potassium from inside the cells to the blood.
Three glucose related-emergencies can occur in patients with diabetes (DM):
- diabetic ketoacidosis (DKA) caused by the absence of insulin and generation of ketoacids.
- hyperglycemia-hyperosmolar state (HHS) caused by insulin deficiency and profound dehydration.
- Hypoglycemia from too much insulin or too little glucose.
All three require emergency treatment and can be fatal if treatment is delayed or incorrect.
Diabetes mellitus can lead to organ complications and early death because of changes in large blood vessels (macrovascular) and small blood vessels (microvascular) in tissues and organs.
These blood vessel changes lead to complication from poor tissue perfusion and cell ischemia.
Macrovascular complications
- coronary heart disease
- cerebrovascular disease
- peripheral vascular disease
Microvascular disease
- Nephropathy
- Neuropathy
- Retinopathy
Chronic high glucose levels are the main cause of microvascular complications.
Additional risk factors contributing to poor health outcomes for adults with DM include smoking, physical activity, obesity, hypertension, and high blood fat and cholesterol levels.
Patients with DM often have the traditional CVD (cardiovascular disease) risk factors of
obesity, high blood lipid levels, hypertension, and sedentary lifestyle.
Kidney Disease, indicated by albuminuria (presence of albumin in the urine), and retinopathy are markers of increase risk for coronary heart disease and motality from coronary artery disease.
Patients with DM often have higher levels of C-reactive protein (CRP), an inflammatory marker associated with increased risk for cardiovascular inflammation and death.
Cardiovascular complication rates can be reduced through
aggressive management of hyperglycemia, hypertension, and hyperlipidemia.
The American Diabetes Association recommends that BO be measured
at every routine visit and confimred on a separate day if elevated.
The ADA also recommends that BO be maintained below 140/90mm Hg, with a target of
130/80 in younger adults if that level can be achieved without excess burden.
Lipid profile screening is recommedned at the first diagnosis, at the initial medical evaluations, and/or at the age of 40 years and every 1 to 2 years thereafter.
Patients with DM who do not have overt CVD are recommended to maintain low-density lipoprotein (LDL) cholesterol below 100 and patients with indications of CVD are recommended to maintain LDLS at less than 70 mg/dl.
Lifestyle modifications that focus on reducing saturated fat, trans fat, and cholesterol intake; increasing intake of omega-3 fatty acids, fiber, and plant sterols; weight loss (if indicated); and increasing physical activity
are recommended to improve the lipid profile for patients with DM.
Cardiovascular Pharmacology Treatment
Either an ACE inhibitor or an angiotensi receptor blocker.
Multiple-drug therapy (two or more agents at maximal doses) is generally required to achieve BP targets.
Administer 1 or more antihypertensive medications at bedtime
Achieve low lipid values:
- LDL <70 mg/dl
- HDL > 50 mg/dl
- Triglycerides < 150 mg/dl
Patients with blood pressure >120/80 mmHg should be advised on lifestyle changes to reduce blood pressure.
Patient’s confirmed with blood pressure higher than 140/80, need lifestype therapy and drug treatment.
Teach patietns to report subtle indications of ischemia,
such as dyspnea with or without cough, extreme fatigue, and sudden onset of nausea and vomiting, to their primary health care provider for evaluation.
Peripheral Vascular Disease
- due to poor circulation diabetics are at higher risk of developing:
- dry cracked skin
- foot deformities
- foot ulcers
Diabetes mellitus
- chronic disorder of impaired carbohydrate, protein, and lipid metabolism caused by a deficiency of insulin.
- an absolute or relative deficiency of insulin results in hyperglycemia.
Type 1 diabetes mellitus ia nearly absolute deficiency of insulin (primary beta cell destruction);
if insulin is not given, fats are metabolized for energy for energy, resulting in ketonemia (acidosis).
Type 2 diabetes mellitus is a relative lack of insulin or resistance to the action of insulin;
usually, insulin is sufficient to stablize fat and protein metabolism but not carbohydrate metabolism.
metabolic syndrome is also known as syndrome X, and the individual has coexisiting risk factors for developing type 2 diabetes mellitus;
these risk factors include abdoninal obesity, hyperglycemia, hypertension, high triglyceride level, and a lower HDL cholesterol level.
Diabetes mellitus can lead to chronic health problems and early death as a result of
complications that occur in the large and small blood vessels in tissues and organs,
Macrovascular complications include
coronary artery disease, cardiomyopathy, hypertension, cerebrovascular disease, and peripheral vascular disease.
Microvascular complications include
retinopathy, nephropathy, and neuropathy.
Infection is a concern
because of reduced healing ability.
Male erectile dysfunction can also occur
as a result of the disease.
Obesity
is a major risk factor for diabetes mellitus.
diabetes signs and symptoms
- polyuria, polydipsia, polyphagia (more common in type 1 diabetes mellitus).
- hyperglycemia
- weight loss (common in type 1 diabetes mellitus, rare in type 2 diabetes mellitus).
- blurred vision
- slow wound healing
- vaginal infections
- weakness and parenthesias
- signs of inadequate circulation to the feet
- signs of accelerated atherosclerosis (renal, cerebral, cardiac, peripheral).
The diabertic client’s diet should take into account weight, medication, activity level, and other health problems.
Day-to-day consistency in timing and amount of food intake helps control the blood glucose level.
As prescirbed by the PHCP or endocrinologist, the client
may be advised to follow the recommendations of the American Diabetic Association diet or the US dietary guideling issued by the US Deptarment of Agriculture and Health and Human Services.
Carbohydrate counting may be a simpler approach for some clients; it focuses on the total grams of carbohydrates eaten per meal.
The client may be more compliant with carbohydrate counting, resulting in better glycemic control; it is usually necessary for clients undergoing intense insulin therapy.
Incorporate the diet into the indidual client
needs, lifestyle, and cultural and socioeconomic patterns.
Exercise lowers the blood glucose level, encourages weight loss, reduces cardiovascular risks, improves circulation and muscle tone,
decreases total cholesterol and trigylceride levels, and decreases insulin resistance and glucose tolerance.
Instruct the client in dietary adjustments when exercising; dietary adjustments are individualized.
If the client requires extra food during exercise to prevent hypoglycemia, it need not be deducted from the regular meal plan.
If the blood glucose level is higher than 250 mg/dL and urinary ketones (type 1 diabetes mellitus) are present,
the client is instructed not to exercise until the blood glucose level is closer to normal and urinary ketones are absent.
The client should try to exercise at the same time each day
and should exercise when insulin or glucose-lowering medications are peaking.
Insulin should not be injected into an area of the body that will be exercised following injection,
as exercise speeds absorption.