Metabolism and DIabetes Flashcards
glucose for cornea
all glucose is utilized in corneal metabolism is supplied by the aqueous humor, mainly anaerobic and pentose phosphate shunt
corneal epithelium and endothelium
epithelium: uses pentose phosphate shunt because it needs nucleic acids
endothelium: needs more energy because of NA+/K+ pump
glucose for ocular lens
low energy demands, obtained from aqueous humor, uses anaerobic
glucose for retina
very high energy demands, uses more aerobic glycolysis than other parts of the eye
- able to undergo aerobic and anaerobic simultaneously
diabetes for the eye
leading cause of blindness in US adults, estimated 1/3 of diabetics will develop retinopathy
diabetes definition
group of syndromes characterized by elevated fasting blood glucose caused by relative or absolute insulin deficiency
2 causes of insulin deficiency
- autoimmune destruction of pancreatic B-cells
- resistance of insulin action
Type I vs Type II symptoms
type I: show abrupt onset of hyperglycemia symptoms
type II: develops gradually, without obvious symptoms
what does insulin deficiency lead to?
dysfunction in carb metabolism, lipid metabolism, and protein metabolism
life-threatening: ketoacidosis
ketoacidosis in DM
lack of insulin presence doesn’t suppress beta-oxidation
- severe accumulation of keto acids within the blood plasma lowers the pH to dangerous levels = metabolic acidosis
DM metabolic changes
look at slides
type I DM
- caused by autoimmune destruction of pancreatic B-cells
- insulin-dependent
- prone to ketoacidosis
Type II DM
- most prevalent form of DM
- insulin resistance
- causes: obesity, leads to dysfunctional B-cells and insulin resistance
- has environmental and strong genetic factors
type II DM management
lifestyle modifications and pharmacological measures
Goal for Hb A1C levels
less than 7%
diagnosis of DM (one of the options)
- A1C over 6.5%
- FPG over 126 mg/dl
- 2-h plasma glucose over than or equal to 200mg/dl
-hyperglycemic symptoms and random plasma test over 200 mg/dl
Gestational DM definition
glucose intolerance that is first recognized during pregnancy
risks from gestational DM
for the baby: respiratory distress syndrome, increase chance of type II DM when older
for the mother: increased risk of type II DM after pregnancy
long term complications of DM
microvascular disease:
- retinopathy w/ vision lost/blindness
- nephropathy w/ end-stage renal disease
- neuropathy w/ limb amputations
macrovascular disease:
- cardiovascular disease
- stroke
Diabetic cornea
- decreased adhesion of the epithelium
- loss of neural sensitivity (diabetic neurotrophic keratopathy)
- keratitis
- increased corneal thickness
diabetic lens
- sorbitol accumulates faster than it can be converted to fructose
- causing light scatter from cellular debris (cataracts)
diabetic retina
sorbitol accumulation from DM can cause retinal hemorrhages, retinal edema, and hypoxia
- ultimately leads to diabetic retinopathy
