Diabetes (Pathology)

Question 1

What is diabetes?

Answer 1

disorder of metabolism (carbs, proteins, fats)
due to absolute/relative deficiency in insulin
hyperglycemia

Question 2

clinical features of Diabetes?

Answer 2

Polyuria
polydypsia
polyphagia

Question 3

diabetes mellitus?

Answer 3

“sweet urine”
MC non-communicable disease
shortens lifespan by 15 years
leading cause of blindness, kidney disease

Question 4

cells in normal pancreatic islet?

Answer 4

a cells (glucagon)
B cells (insulin)

Question 5

action of insulin?

Answer 5

transmembrane transport of glucose

Question 6

insulin action on liver, muscle, fat?

Answer 6

– blood glucose

Question 7

insulin’s action on liver and skeletal muscle?

Answer 7

++ glucose in blood

Question 8

blood glucose and other hormone actions

Answer 8

insulin -
glucocortidoids +
glucagon +
growth hormone +
epinephrine +

Question 9

insulin required tissue for uptake of glucose?

Answer 9

striated muscle
cardiac muscle
fibroblasts
fat

Question 10

non-insulin required tissue for glucose uptake?

Answer 10

red cells
nerves
kidney
eye lens

Question 11

pathology of diabetes?

Answer 11

low glucose inside cell –> low metabolism

high glucose outside cell –> glycosylation damage, osmotic damage

Question 12

classes of Primary DM?

Answer 12

I - IDDM/juvenile 10%
II - NIDDM - adult 80%
MODY 5% maturity/genetic
gestational DM

Question 13

Pathogenesis of Type I DM?

Answer 13

genetic (HLA-DR3/4)
environmental
Ab to B cells (autoimmune insulitis)
B cell destruction
insulin def

Question 14

pathogenesis of Type II DM?

Answer 14

genetic/B cell defect
obesity/life style
abnormal insulin secretion/end organ resistance
relative insulin def

Question 15

Type I DM

general features

Answer 15

Less common
Children < 25 Years
Insulin- Dependent 
Duration: Weeks
Acute Metabolic complications
Autoantibody
No FHx
Insulin levels: very low
Islets: Insulitis
50% in twins

Question 16

Type II DM

general features

Answer 16

More common
Adult >25 Years
Insulin Independent * 
Months to years
Chronic Vascular complications.
No Ab
Yes FHx
Normal or high * insulin
islets - Normal / Exhaustion
60-80% in twins

Question 17

Short term Complications: (metabolic)

Answer 17

Hypoglycemia
Diabetic Ketoacidosis
Non Ketotic hyperosmolar diabetic coma
Lactic acidosis

Question 18

Long term Complications: (Angiopathy)

Answer 18

microangiopathy - Retinopathy, Nephropathy, Neurophathy, dermatopathy

Macroangiopathy – Atherosclerosis

Question 19

What will you see diabetic microangiopathy?

Answer 19

Glucose
Glycosylation 
BM damage leak
AGE = advanced glication end products
Narrow lumen
Ischemic Organ damage

Question 20

What will you see in Diabetic neuropathy?

Answer 20

Sensory –> Motor (myelin)
1. Peripheral Neuropathy (Bilateral, symmetric, Progressive, irreversible, Paraesthesia, pain, Muscle atrophy, claw foot, muscle wasting)

2. Visceral neuropathy (Cranial nerve – 4 diplopia, 7 Bell palsy, GIT- constipation, diarrhoea, CVS – orthostatic hypotension)

Question 20

Features of Neuropathic ulcers?

Answer 20

Painless
surrounded by callus
pressure points
may not be associated with gangrene
good foot pulses

Question 21

What do you see in DM retinopathy?

Answer 21

non-proliferative

proliferative

Question 22

Non-proliferative retinopathy?

Answer 22

Microaneurysms
Dot-blot hemorrhages
Hard/soft exudates
Cotton wool – infarcts
Macular edema

Question 23

Proliferative retinopathy?

Answer 23

Neovascularization
Large hemorrhages
Retinal detachment

Question 24

How do patients present with diabetic retinopathy?

Answer 24

“curtain is falling”

Question 25

How can DM retinopathy affect the lens?

Answer 25

Cataracts

sorbitol pathway

Question 26

Macrovasicular changes in diabetes?

Answer 26

Atherosclerosis

Question 27

What does DM affect the limbs?

Answer 27

gangrene

Question 28

What is macrosomia?

Answer 28

= diabetic mom –> large baby

1. glucose cross placenta and stimulates fetal pancreas –> diffused hyperplasia of islet cells
2. fetus produces insulin

Question 29

complications of big baby?

Answer 29

c section

ARDS (insulin –> – surfactant)

Question 30

Skin changes in diabetes?

Answer 30

acanthosis nigricans (paraneoplastic syndrome)
back of the neck, armpits, skin folds

insulin resistance
non-neoplastics

neoplastic - gastric cancer, breast, uterine cancers

Question 31

Nephropathy in diabetes?

Answer 31

enlarged kidney

granular surface

Question 32

Diabetic nephropathy pathologies in the kidneys?

Answer 32

KW nodules (diffused/nodular) PAS+, diastase sensitive
papillary necrosis
hyaline atherosclerosis
pyelonephritis 
ESKD (stage 4)

Question 33

Infections in diabetes?

Answer 33

– metabolism –> low immunity
– lymphocytes/neutrophils
– glycosylation of immune mediators
capillary thickening
ischemia/infarct
(immunocompromised state)

Question 34

Fungal infections in diabetes?

Answer 34

Candidiasis

Mucormycosis

Question 35

Diagnosis of diabetes?

Answer 35

1. dipstick spills after 180 (screen)
2. Random/fasting blood glucose (<11mmol)
3. OGTT (if 7-11)
4. HbA1c - for follow-up (RBCs last 120 days)
5. Fructosamine (long term maintenance)

Question 36

What is the medical emergency in diabetics?

Answer 36

hypoglycemia
(die in 30mins)
give the pt glucose!