chronic complications of

8/7/2019 CHRONIC COMPLICATIONS OF

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P R E S E N T E D B Y N Z O M E T I A C R Y S A N T U S Y I M L E F A C K

F O U R T H Y E A R , F M B S Y A O U N D E

CHRONIC COMPLICATIONS OFDIABETES MELLITUS


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PLAN

y INTRODUCTION

y PHYSIOPATHOLOGY

y MICROVASCULAR COMPLICATIONS Retinopathy

Nephropathy

Neuropathy

y MACROVASCULAR COMPLICATIONS Coronary artery disease

Peripheral vascular disease

Cerebrovascular disease


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INTRODUCTION

y Patients on insulin therapy still have a considerablyreduced life expectancy. The major cause of death intreated patients is due to cardiovascular problems (70%),renal failure(10%) and infections (6%).

y The duration and degree of hyperglycemia also play amajor rule in the production of complications.

y Hypertension also accelerate complications

y According to DCCT, better glycemic control can reduce

the rate of progression of retinopathy and nephropathyby 60% in a study that was carried out over nine years indeveloping countries when the HbA1c was kept at about7% in type 1 diabetes.


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PATHOPHYSIOLOGY

y The best understood machanism is by non-enzymatic glucosylation (glycation) of proteins andother macromolecules. Chronic hyperglycemia

causes increased glycation of proteins, resulting inadvanced glycation end products (AGEs). These cancause damage through lost of function, turningon/off signal pathways within cells or alteration in

gene expression.


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CONTINUATION.

y e.g inOne of them is haemoglobin because it is found in the blood, itis convenient to measure as HgA1c because RBC and thus Hbsurvives in the blood for about 120days. The HbA1c provides ameans to assess glycemic control over this period.

y Abnormal microvascular blood flow prevents supply of nutrients

and oxygen. Microvascular occlusion is due to vasoconstrictors e.gendothelins and thrombogenesis that leads to endothelial damage,y Other factors include the formation of reactive oxygen species and

growth factor stimulation (TGF-b) and vascular endothelial growthfactor. These growth factors are released by ischaemic tissues andcause endothelial cells to proliferate.

y

Haemodynamic changes.e.g the kidney


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MICROVASCULAR COMPLICATIONS

y RETINOPATHY

y Diabetes can affect the eyes in a number of ways.Themost common form is Diabetic retinopathy which

usually develops mostly from the 2nd decade sincethe onset of diabetes.


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PHYSIOPATHOLOGY OF RETINOPATHY

y DM causes increased thickness of the capillarybasement membrane and increased permeability ofthe retinal capillaries.

y Aneurysmal dilatation may occur in some vessels,

while others become occluded.y Almost all Type 1 Diabetics have some retinopathy

after 20years, while the incidence is higher in Type2 Diabetics.

y These changes are detectable by fluorescentangiography


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PATHOLOGICAL CHANGES

y PERIPHERAL RETINA

y Non-proliferative

Microaneurisms(dot haemorrhages)

Blot haemorrhages

Hard exudates

y Pre-proliferative

Multiple cotton wool spots(nerve fiber layer infarcts)

Intraretinal microvascular abnormalities


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Continuation

y Proliferative

Neovascularisation(can cause Glaucoma)

Preretinal haemorrhage

Vitreous haemorrhage

y Advanced retinopathy

Retinal fibrosis

Traction retinal detachment

y CENTRAL RETINA

y Maculopathy

Hard exudates,resulting to macular edema


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THE DIABETIC KIDNEY.

Kidneys may be damaged by many ways:

Glomerular damage

y Ischaemia from hypertrophy of afferent and efferent

arterioles.

y Ascending infection.


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DIABETIC NEPHROPATHY EPIDEMIDOGY.

y Usually manifest between 15 and 25 years afterdiagnosis and affects 25-35% of patients under theage of 30years leading cause of premature death in

young diabetics.


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PATHOPHYSIOLOGY

The earliest functional abnormality is renalhypertrophy associated with a raised GFR.

y Appears soon after diagnoses and related to poor

glycemic controly Kidney damage results to dilation of afferent

arteriole to a greater extend than efferent arteriole.This increases the intraglumerular filtration pressure

further damaging the glomerular capillaries.


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continuation.

y Consequence, albuminuria ischaemic lesions

y Ischaemic lessions:

arteriolar lesions, with hypertrophy and

hyalinization of the vessels, can occur in patientswith diabetes. The appearances are similar to thoseof hypertensive disease and lead to ischaemicdamage to the kidney.


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INFECTIOUS REGIONS

y Urinary tract infections are relatively more commonin women than men.

y Ascending infections may occur because of bladder

stasis resulting from autonomic neuropathy, andinfections more easily becomes established indamaged renal tissue.


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NEUROPATHY

y Occurs in individuals with long-standing type 1 and 2DM.

y It may manifest as polyneuropathy,

mononeuropathy, radiculopathy and autonomicneuropathy, most common being distal symmetricneuropathy

y It most frequently presents with distale sensory loss;

Hyperesthesia, paresthesia and pain


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MACROVASCULAR COMPLICATIONS

y CORONARY ARTERY DISEASE

y PERIPHERAL VASCULAR DISEASE

y CEREBROVASCULAR DISEASE

chronic complications of

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