Module 15 Flashcards
What is diabetes?
Diabetes is a chronic disease characterized by elevated blood levels of glucose (i.e. sugar).
- Normally glucose is efficiently reabsorbed in the proximal tubule of the kidney so it is not found in the urine.
- In untreated diabetes, blood glucose rises so high that the transporters that reabsorb it are saturated and significant amounts of glucose are found in the urine.
Many years ago, how was diabetes diagnosed?
By the sweet smell and taste of the urine.
High blood sugar in diabetes results from what?
Either not enough insulin produced in the body or because the body’s cells do not respond to the insulin that is produced.
(therefore there are primarily two main types of diabetes)
What are the classic symptoms of diabetes?
- polyuria (increased urination)
- polydipsia (increased thirst)
- polyphagia (increased hunger)
- weight loss
What is insulin?
Insulin is a hormone produced by the pancreas that is involved in tightly regulating blood glucose.
- Diabetes occurs when insulin levels are too low or when the body’s cells are resistant to the effects of insulin.
What are the three distinct groups that diabetes can be classified into?
- Type I diabetes – Also called insulin dependent diabetes mellitus.
- Type II diabetes – Also called non-insulin dependent diabetes mellitus.
- Gestational diabetes – Diabetes that occurs in pregnancy.
Insulin is a _____ hormone synthesized by the _____ cells of the _____ of the pancreas.
peptide, β (beta), islets of Langerhans
Insulin is rapidly released from the pancreas into the blood in response to what?
increases in blood glucose
When insulin is secreted, it causes glucose uptake into where?
muscle, liver, and fat cells
In liver cells, glucose uptake results in what?
glycogen synthesis (a storage form of glucose)
In muscle cells, glucose is used as energy and promotes what?
protein synthesis
In fat cells, insulin causes increased synthesis of fatty acids, which results in what?
increased triglyceride synthesis
Extracellular potassium is important in the action of insulin as it helps insulin to do what?
drive glucose into the cell
Approximately how many people with diabetes have type 1 diabetes?
10%
Type 1 diabetes is usually diagnosed when?
In children (aged 4-7) or adolescents (aged 10-14); however, symptoms may not appear until early adulthood.
What is type 1 diabetes believed to be caused by?
It is believed to be caused by an autoimmune reaction where the body’s own immune cells attack and destroy the insulin secreting β cells.
- As a result, the body makes too little or no insulin at all and requires insulin replacement.
Is type 1 diabetes preventable?
No, and therefore it is not caused by eating too much sugar
Approximately how many people with diabetes have type 2 diabetes?
90%
In type II diabetes the pancreas makes sufficient insulin, however, the insulin produced is what?
The insulin produced is resistant to use.
- Over the course of the disease, insulin synthesis may also decrease.
What are some of the many risk factors for developing type 2 diabetes?
age, having a family member with diabetes, previous gestational diabetes, lack of exercise, heart disease, obesity, ethnicity (African and Native descent are at higher risk)
In Canada, what percentage of all patients with type II diabetes are obese or overweight?
~ 80%
When is type 2 diabetes typically diagnosed?
It is typically diagnosed later in life but there is a trend towards younger people getting the disease.
What is gestational diabetes?
Gestational diabetes is diabetes that first starts during pregnancy.
- Usually begins ~ halfway through pregnancy.
- All women should have an oral glucose tolerance test between weeks 24-28 of pregnancy to test for gestational diabetes.
- Usually diet and exercise are sufficient to keep blood glucose levels within normal ranges.
- Pregnant women with gestational diabetes tend to have larger babies and babies with hypoglycemia in the first few days of life.
- After birth, the blood sugar of the mother usually returns to normal however; blood glucose should be continually monitored as many patients develop diabetes 5 – 10 years later.
What is diabetic retinopathy?
- Diabetic retinopathy is the most common cause of blindness in people under the age of 65.
- Hyperglycemia causes damage to retinal capillaries.
- Tightly controlling blood sugar minimizes the risk of retinopathy.
- Patients with type I or type II diabetes should have an eye exam once a year.
Define hyperglycemia
an excess of glucose in the bloodstream, often associated with diabetes mellitus
Define hypoglycemia
Low blood glucose, also called low blood sugar or hypoglycemia, occurs when the level of glucose in your blood drops below what is healthy for you.
Describe diabetic nephropathy?
- Diabetic nephropathy is the leading cause of morbidity and mortality in patients with type I diabetes.
- Tight control of blood glucose both delays and reduces the severity of diabetic nephropathy.
- ACE inhibitors and ARBs are useful in preventing diabetic nephropathy. Experts suggest patients with type I diabetes take an ACE inhibitor or ARB regardless of their blood pressure.
What is diabetic nephropathy characterized by?
proteinuria (protein in the urine), decreased glomerular filtration and increased blood pressure
What is the earliest sign of diabetic nephronpathy?
proteinuria
What are the leading causes of morbidity and mortality in patients with type 2 diabetes?
CVD including heart attack and stroke
What develops much earlier in patients with diabetes?
Atherosclerosis
CVD in diabetes results from what?
A combination of hyperglycemia and altered lipid metabolism.
What reduce cardiovascular events in patietns with diabetes, regardless of their LDL cholesterol levels?
Statins
What is the most common cause of hospitalization for people with diabetes?
Diabetic foot ulcers
- Diabetes accounts for approximately half of all lower limb amputations every year due to infection.
- All people with diabetes should have regular foot exams.
What are the three main tests used to diagnose diabetes?
- Fasting Plasma Glucose Test
- Casual Plasma Glucose Test
- Oral Glucose Tolerance Test (OGTT)
Describe the Fasting Plasma Glucose Test
- Patients fast for at least 8 hours and then have a blood sample drawn to measure blood glucose.
- If the fasting plasma glucose is > 7.0 mmol/L then diabetes is diagnosed.
- The fasting plasma glucose test is the preferred test for diagnosing diabetes.
Describe the Casual Plasma Glucose Test
- Blood can be drawn at any time no matter what the interval was since the last meal.
- For a diagnosis of diabetes, the casual plasma glucose is > 11.1 mmol/L AND the patient displays classic signs of diabetes including polyuria, polydipsia and weight loss.
- If an initial casual plasma glucose test suggests diabetes, it is often followed up by a fasting plasma glucose test.