diabetes mellitus - endocrine 3 Flashcards
what is diabetes mellitus?
loss of control of blood glucose levels
type 1 and 2
what is type one diabetes known as?
Insulin Dependent Diabetes Mellitus (IDDM)
what causes type one diabetes?
Autoimmune destruction of the pancreatic β-cells destroys ability to produce insulin and seriously compromises patients ability to absorb glucose from the plasma.
what does untreated type 1 diabetes lead to?
Untreated type 1 diabetes leads to many complex changes in the body which ultimately cause starvation and death.
Before the discovery of insulin, survival, post-diagnosis, was between 2 weeks and 18 months.
how is type 1 diabetes managed?
Current day – patients need daily insulin injections, (peptide hormones cannot be given orally).
Type I patients have an absolute need for insulin, without it they become excessively wasted, develop ketoacidosis, coma and die.
describe the homeostatic control of blood glucose in a normal individual versus an individual with diabetes?
what is ketoacidosis?
When nutrients are scarce, body relies on stores for energy – when adipose tissue is broken down fatty acids are released. FFA’s can be readily used by most tissues to produce energy and liver will convert excess to ketone bodies which provides an additional source for muscle and brain!
HOWEVER, in poorly controlled insulin-dependent diabetes a lack of insulin depresses ketone body uptake. They build up rapidly in the plasma and because they are acidic create life threatening acidosis (ketoacidosis or ketosis) with plasma pH < 7.1. Death will occur within hours if untreated.
how can excess ketones be detected?
Ketones detectable in urine and produce distinctive acetone smell to breath.
what is type 2 diabetes known as?
Non-Insulin Dependent Diabetes Mellitus (NIDDM)
how is type 2 diabetes aquired?
Peripheral tissues become insensitive to insulin = insulin resistance. Muscle and fat no longer respond to normal levels of insulin. This is either due to an abnormal response of insulin receptors in these tissues or a reduction in their number.
β-cells remain intact and appear normal, there may even be hyperinsulinaemia.
what percent of diabetoc individuals are type one versus type 2?
90% of diabetic patients are insulin-resistant (NIDDM)
10% type 1
what is type two diabetes typically associated with?
obesity
what would a glucose tolerance test show in an individual with type one or type 2 diabetes?
Type I → inadequate insulin release →↑[BG]
Type II → inadequate tissue response →↑[BG]
what is the diagnostic criteria for diabetes?
Hyperglycaemia
how is hyperglycaemia detected?
Glucose Tolerance Test
what is a glucose tolerance test?
Patient ingests glucose load after fasting [BG] measured. [BG] will normally return to fasting levels within an hour, elevation after 2 hours is indicative of diabetes. Does not distinguish Type I from II.
