Monday, March 31, 2008

Lecture 12

1. List three microvascular and three macrovascular complications of diabetes mellitus.
Microvascular

Diabetic Retinopathy
-Types: Non-proliferative, Pre-proliferative, Proliferative
-Leading cause of blindness in adults
-Increases the relative risk of cataracts and glaucoma by 2-3X


Diabetic Nephropathy
-occurs in 35% of patients with type 1 diabetes and 20% of patients with type 2 diabetes
-Accounts for 50% of all ESRD patients

Diabetic Neuropathy
-Common in both forms of diabetes mellitus
-One of the common causes of mortality in diabetes
-Cause of ulcers which lead to amputation


Macrovasular


Coronary Heart Disease
-2X increased risk in men 4X increased risk in women


Cerebrovascular disease
-increases stroke risk 4X

Peripheral Vascular Disease
-8% have this at diagnosis
-40-50% of non-traumatic amputations
-50% three year suurvival after amputation



2. List four risk favtors for the development of diabetic complictions
-Hyperglycemia
-Duration of Disease
-Dyslipidemia
-Blood Pressure
-tobacco
-Genetics

3. Retinopathy:
a) Given a picture of a retina, be able to recognize non-proliferative and proliferative retinopathy.

Non-proliferative
Microaneurysms
-These are red dots on exam approx 20-200microns, these are the earliest findings
-Often times they leak lipoproteins and form hard exudates



Hard Exudates
-yellow and sharply demarcated structures on fundoscopic exam
-they lead to edema



Macular Edema
-thickening of the retina less than 500 microns from te macula
-hard exudates less than 500 microns from the macula
-Macular edema causes a loss in visual acuity, and can lead to retinal ischemia

Retinal Ischemia
-cotton wool spots(soft exudates which are whitish gray areas)
-venous beading
-Intra-retinal micovascular abnormalities (IRMA), these are dilated capillaries due to retinal hypoxia
-Intra retinal hemorrhages


Pre-proliferative Retinopathy
-when the constellation of symptoms from retinal ischemia is seen together it is called pre-proliferative retinopahty
-This includes IRMA, Intra-retinal hemorrhages, Cotton wool spots, and venous beading

Proliferative Retinopathy


Neovascularization
-appearance of abnormal retinal blood vessls, usually on or near the optic nerve head or in the vicinity of other normal retinal vessels

Vitreous Hemorrhage
-as a consequence of abnormal neovasularization, vessels can often rupture into the vitreous

Fibrous Tissue
-Fibrous tissue is associated with the deelopment of new vessels.
-late in the course the blood vessels regress and the fibrous tissue may be the only sign

Traction Retinal Detachment
-When the fibrous tissue contracts it can drag the retina and cause a traction retinal detachment

b) Given a patient who has just been diagnosed with diabetes mellitus, be able to recognize whether, how often, and why that patient needs to be scheduled for an eye exam
Initially
Type 1 Diabetes patients within 3 t0 5 years after diagnosis
Type 2 Diabetes always at the time of diagnosis
Follow-up
Annually
-children and adolescents
-Adults without retinopathy
Semi-annually
-Non-proliferative retinopathy
Quarterly
-Pre-proliferative retinopathy
Individualized
-Proliferative retinopathy
-Pregnancy during each trimeseter

c) List four modifiable risk factors other than glucose control that predispose the development of diabetic retinopathy.
-Blood Pressure
-Smoking
-Pregnancy
-Nephropathy

4. Nephropathy: Given a patient with diabetes mellitus, be able to recognize diabetic nephropathy iin its early stages and recommend treatment aimed to slow its progression
Early Diagnostic findings
-Genetics
-Blood pressure elevation
-Creatinine Clearance above the upper limit of normal
-Alterations in glomerular structure
-Microalbuminuria
--measured by24 hour collection or morning urine test
--Normal less than 20micrograms/min dipstick negative
--microablbuminuria 20-200 micrograms/min (30-300mg/24hr) dipstick negative
--Overt proteinuria >200micrograms/min (>300mg/24hr) dipstick positive
--Diagnosis is made if microalbuminuria is foundin 2/3 urine samples in less than 6 months
Treatment
-Aggressive blood glucose control
-Aggressive blood pressure control
-ACE Inhibitor is the first line of therapy if they have hypertension and/or albuminuria. Ocassionally considered if there are cardiovascular problems, because of the cardiovascular benefit from ACE inhibitors
-low protein diet

5. Neuropathy
a) Given the clinical presentation of any patient with diabetes mellitus, be able to recognize the complications of distal symmetrical polyneuropathy and neuropathic ulcers.
Distal Symmetrical Polyneuropathy
-paresthesias(tingling and numbness)
-pain(dull ache, burning, lancinating)
-Impaired Sensation(vibratory, pain)
-Nocturnal exacerbation
-absent knee and ankle reflex
-motor involvemnt
Neuropathic Ulcer
-Major source of morbidity
-caused by the loss of protective sensation and repetetive trauma (i.e. walking)
-Over Areas of increased pressure( i.e. metatarsal heads or under calluses)
-Hammer-claw toe deformity of foot causes increased pressure on metatarsal heads
b) List Five risk factors for the development of diabetic neuopathy.
-Genetics
-Males
-Height
-Alcohol
-Hyperglycemia


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