Metabolism and DIabetes

Question 1

glucose for cornea

Answer 1

all glucose is utilized in corneal metabolism is supplied by the aqueous humor, mainly anaerobic and pentose phosphate shunt

Question 2

corneal epithelium and endothelium

Answer 2

epithelium: uses pentose phosphate shunt because it needs nucleic acids
endothelium: needs more energy because of NA+/K+ pump

Question 3

glucose for ocular lens

Answer 3

low energy demands, obtained from aqueous humor, uses anaerobic

Question 4

glucose for retina

Answer 4

very high energy demands, uses more aerobic glycolysis than other parts of the eye
- able to undergo aerobic and anaerobic simultaneously

Question 5

diabetes for the eye

Answer 5

leading cause of blindness in US adults, estimated 1/3 of diabetics will develop retinopathy

Question 6

diabetes definition

Answer 6

group of syndromes characterized by elevated fasting blood glucose caused by relative or absolute insulin deficiency

Question 7

2 causes of insulin deficiency

Answer 7

1. autoimmune destruction of pancreatic B-cells
2. resistance of insulin action

Question 8

Type I vs Type II symptoms

Answer 8

type I: show abrupt onset of hyperglycemia symptoms
type II: develops gradually, without obvious symptoms

Question 9

what does insulin deficiency lead to?

Answer 9

dysfunction in carb metabolism, lipid metabolism, and protein metabolism
life-threatening: ketoacidosis

Question 10

ketoacidosis in DM

Answer 10

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

Question 11

DM metabolic changes

Answer 11

look at slides

Question 12

type I DM

Answer 12

• caused by autoimmune destruction of pancreatic B-cells
• insulin-dependent
• prone to ketoacidosis

Question 13

Type II DM

Answer 13

• most prevalent form of DM
• insulin resistance
• causes: obesity, leads to dysfunctional B-cells and insulin resistance
• has environmental and strong genetic factors

Question 14

type II DM management

Answer 14

lifestyle modifications and pharmacological measures

Question 15

Goal for Hb A1C levels

Answer 15

less than 7%

Question 16

diagnosis of DM (one of the options)

Answer 16

• 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

Question 17

Gestational DM definition

Answer 17

glucose intolerance that is first recognized during pregnancy

Question 18

risks from gestational DM

Answer 18

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

Question 19

long term complications of DM

Answer 19

microvascular disease:
- retinopathy w/ vision lost/blindness
- nephropathy w/ end-stage renal disease
- neuropathy w/ limb amputations
macrovascular disease:
- cardiovascular disease
- stroke

Question 20

Diabetic cornea

Answer 20

1. decreased adhesion of the epithelium
2. loss of neural sensitivity (diabetic neurotrophic keratopathy)
3. keratitis
4. increased corneal thickness

Question 21

diabetic lens

Answer 21

• sorbitol accumulates faster than it can be converted to fructose
• causing light scatter from cellular debris (cataracts)

Question 22

diabetic retina

Answer 22

sorbitol accumulation from DM can cause retinal hemorrhages, retinal edema, and hypoxia
- ultimately leads to diabetic retinopathy