Diabetes and Insulin Flashcards
Endogenously insulin is produced in
the beta cells
Endogenously glucagon is produced in
the alpha cells
Insulin promotes
storage of glucose, fatty acids, and amino acids
daily insulin secreted is equivalent
to 40-50 units
Activation of Na+/K+ ATPase in cell membranes by insulin
moves K+ into cells and decreases concentration of K+ in plasma
The primary source of endogenous glucose production following glycogenolysis and gluconeogenesis is
the liver
How is insulin secretion regulated?
via negative feedback effect of the blood glucose concentration in the pancreas
Glycogenesis is
glycogen formation
Glycogenolysis is
glycogen breakdown
The body will not secrete insulin when
blood glucose levels <50 mg/dL
The body secretes maximum insulin at concentrations of
> 300 mg/dL
Blood glucose concentrations are
maintained within a narrow range
____ glucose is more effective than ____ glucose in evoking the release of insulin
Oral, IV
Insulin receptor expression is
highest in the tissues
promotes use of carbohydrates for energy
Relationship between glucagon and insulin
They are reciprocally secreted
glucagon acts to mobilize glucose, fatty acids, and amino acids into systemic circulation
Glucagon secretion occurs
during hypoglycemia
Glucagon acts by
activating adenylate cyclase for cAMP formation
exogenous administration can lead to enhanced myocardial contractility
Diabetes mellitus can affect vascular system because
it impairs vasodilation–> chronic proinflammatory, prothrombic and proatherogenic state–> vascular complications
Goals of therapy for diabetes
prevent adverse consequences of hypo/hyperglycemia
avoid weight gain
reduce micro/macrovascular complications
HbA1c <6-7% associated with fewer microvascular complications
symptoms often resolve when blood glucose < 200 mg/dL
Diagnosis of diabetes is based on
elevated fasting plasma glucose greater than 126 mg/dL or hemoglobin of 6.5% or greater
Long term complications of diabetes include
retinopathy, kidney disease, HTN, CAD, peripheral/cerebral vascular disease, and peripheral/autonomic neuropathies
T1DM diagnosis is based on
random glucose >200 mg/dL + HbA1C >7%
Hypoglycemia treatment
each 1 mL of 50% glucose will increase blood glucose of 70 kg patient by 2 mg/dL
Hyperosmolar nonketotic coma is due to
dehydration/hyperosmolality
DKA is
decreased insulin activity allows catabolism of free fatty acids into ketone bodies leading to accumulation
infection is a common precipitating factor
Treatment: correct hypovolemia, hyperglycemia and total body potassium deficit
The treatment for type 1 DM
insulin therapy (necessary for survival)
Circulating insulin levels are altered more by
renal dysfunction than hepatic disease
The duration of action of insulin is
30-60 minutes after IV administration
Alpha-adrenergic stimulation will
decrease basal secretion of insulin
Beta-adrenergic or parasympathetic nervous system will
increase basal secretion of insulin
Insulin response to glucose is greater after
oral ingestion than IV infusion
Type 1 DM need
at least two daily SQ injections of intermediate or long-acting insulin + rapid acting insulin following meals
The basic principle of insulin administration is to
provide slow, long-acting, continuous supply of insulin that mimics basal secretion
Insulin formulations include:
basal insulin-intermediate acting & long acting
short acting- meal time
rapid acting- meal time (preferred for prandial coverage)
The most commonly used commercial preparation of insulin is
U-100 (100 U/mL)
Typical daily exogenous dose for T1Dm is around
0.5 to 1 U/kg/day
Insulin requirements can be increased dramatically by
stress, sepsis, or trauma
Rapid acting insulins include:
lispro, insulin aspart, and glulisine
The onset, peak and duration for rapid acting insulin is
onset: 5-15 minutes, peak 45-75 minutes, duration 2-4 hours
Intermediate acting insulins include
NPH
The onset, peak, and duration for intermediate acting insulin is
2 hours, peak 4-12 hours, duration 18-28 hours
Short acting insulin includes
regular insulin
The onset, peak, and duration for short acting insulin
onset: 30 minutes, peak 2-4 hours, duration 6-8 hr
Long acting insulins include
glargine and detemir (have a similar onset, peak, and duration to intermediate acting insulins)