Diabetes Flashcards
Diabetes
patients w/ diabetes are classified in 2 groups
- Type 1 (insulin-dependent) 10% of cases
- 20,000 new patients
- Type 2 (non-insulin dependent) 90% of cases
- 180,000 new patients
- number of people developing type 2 diabetes increasing due to aging population, rise in obesity, lack of excercise
Diabetes Mellitus
Not a single disease, but a group of diseases caused by increased fasting blood glucose levels due to relative or absolute deficiency of insulin
- glucose remains in blood despite not having eaten
Chronic elevated blood glucose leads to
- Nerve damage, blindness, impotence, amputation
- Major cause of premature kidney failure, heart attack and stroke
- leads to blindness possibly due to improper glycosylation of proteins (not fully known)
Type 1 diabetes
- Caused by absolute deficiency of insulin as a result of autoimmune attack on the B-cells of the pancreas
- Requires both environmental stimulus and genetic determinant allowing B-cells to be targeted by immune system
- not instantaneous loss of insulin
- over time will decrease B-cells
- once reach pink line no longer enough insulin and diabetes will begin to present symptoms (abrupt)
Diagnosis of Type 1 Diabetes
- Onset occurs during childhood or puberty
- patients present with polyuria (freq. urination), polydipsia (excessive thirst) and polyphagia (escessive hunger)
- symptoms include fatigue, weight loss and weakness
- Diagnosed w/ fasting blood glucose > 126 mg/dl (normal is around 70)
Metabolic changes
- Profoundly affects metabolism in liver, muscle and adipose
- Hyperglycemia and ketoacidosis
- Liver increases glucose production, while muscle and adipose take up less glucose
- Increased mobilization of FAs from adipose combined w/ increased ox. of FAs in liver and increased ketone body synthesis
- Hypertriacylglyceridemia
- Liver cannot dispose of all FAs so packages them into VLDL
- Chylomicrons and VLDL in plasma increase because lipoprotein lipase activity is decreased; accumulate in blood
Treatment of Type 1 diabetes
- Patients not producing insulin so cannot respond to changing blood glucose levels
- rely on exogenous insulin
- Standard insulin treatment; 1 or 2 daily insulin injections
- Intensive insulin treatment; 3 or more daily injections, more freq. monitoring of blood glucose, decreases complications by 60% compared to standard
- Elevated blood glucose leads to formation of glycosylated hemoglobin (A1C) which is a marker of blood gucose
Hypoglycemia in Type 1 diabetes
- Therapeutic goal; reduce blood glucose to minimize complications of disease
- difficult to achieve approprate doses of insulin
- too much insulin. is most common complication and leads to hypoglycemia
- hypoglycemic episodes are elevated in intensive insulin therapy compared to standard insulin therapy
- Hypoglycemia is NOT a symptom of diabetes; it is strictly a complication of the therapeutic drugs
Type 2 Diabetes
- Most common form
- has a strong genetic component
Type 2 diabetes results from combination of
- Insulin resistance- inability to target tissues (liver, adipose, muscle) to respond to normal levels of insulin - most common (obesity)
- Non-functional B-cells- If B-cells are normal they can compensate by increasing amount of insulin
- can overcome barrier of resistance
Metabolic abnormalities of Type 2 diabetes
Milder than type 1
- limited insulin secretion can still slow down ketogenesis and lessen ketoacidosis
Diagnosis of type 2 Diabetes
- Develops gradually; some develop polyuria, polydipsia, polyphagia
- Diagnosis based on hyperglycemia; blood glucose conc > 126
- Patients do not require insulin injections to sustain life
- eventually B-cells fail completely leading to req. of insulin therapy
- benefit from standard therapies
Insulin rise in obese patients
- Obese patients have 3x the amount of insulin but still can compensate and have same blood glucose level as normal patient
