"Never offer the devil a ride. He will always want to be in the driving seat…!"

Pathology of Diabetes Dr. Venkatesh M. Shashidhar Associate Professor of Pathology Fiji School of Medicine

Diabetes Mellitus Disorder of metabolism (Carb, Prot & Fat) Due to Absolute/relative deficiency of insulin. Characterized by hyperglycemia. Clinically : Polyuria, Polydypsia, Polyphagia.

Introduction Diabetes mellitus (sweet urine) 3% of world population, 100 million people Incidence is increasing alarmingly (40% in the past decade, more in future. 259 m by Most Common non communicable disease High Morbidity & mortality. DM shortens life span by 15 years. Leading cause of blindness and Kidney dis. Pacific Islands – leaders in DM & Obesity…!

World Statistics:

Normal Pancreatic Islet: ß cells α cells ß cells (Insulin) α cells (Glucagon) δ cells pp Cells δ cells (Somatostatin) pp Cells (pan prot) ß α

Insulin - Anabolic Steroid Transmembrane transport of glucose Liver, muscle & fat   blood glucose Liver & skeletal muscle -  glycogen Converts glucose to triglycerides Nucleic acid & Protein synthesis Diabetes  Increased catabolism. Diabetes  Increased catabolism. Hyperglycemia,  protein synthesis, Liplysis, wasting, weight loss.

Blood Glucose & Hormones Hormone Insulin Glucortocoids Glucagon Growth Hormone Epinephrine Action  Glucose  Glucose

Cellular Glucose Uptake Insulin Requiring Striated Muscle Cardiac Muscle Fibroblasts FAT Non-Insulin Requiring Blood Vessels Nerves Kidney Eye Lens

Pathology in Diabetes: Low glucose inside cell decreased cell metabolism (muscle, liver) High glucose outside Glycosylation damage (BV) Polyol products – osmotic damage*

Classification Primary DM – (primary - no other disease) Type I – IDDM / Juvenile – 10%. Type II – NIDDM /Adult onset – 80%. MODY – 5% maturity onset - Genetic Gestational Diabetes Secondary DM – (secondary to other dis.) Pancreatitis/tumors/Hemochromatosis. Infectious – congenital rubella, CMV. Endocrinopathy, downs. Drugs – Corticosteroids.

Pathogenesis of Type I DM GeneticHLA-DR3/4 Environment Viral infe..? Insulin deficiency Type I / IDDM Autoimmune Insulitis Ab to ß cells/insulin ß cell Destruction PS Glomerulonephritis Graves, Hashimoto thyroiditis. Rheumatic heart disease SLE, Collagen vascular disease Rheumatoid arthritis.

Progression of Type I

IDDM Genetic / ß cell defect ß cell defect Pathogenesis of Type II DM Obesity / Life style ? ß cell exhaustion Type II NIDDM Abnor. Secretion Insulin Resistance Relative Insulin Def.

“Things may come to those who wait, but only the things left by those who hustle.” – Abraham Lincoln

What type? year male obese year female following pregnancy 3. 8 year old boy year female with Cushing’s sy Year male following Carcinoma of pancreas year male with extensive tuberculosis. II NIDDM II GDM I IDDM Sec IDDM

Type-I Type-II Less common Children < 25 Years Insulin- Dependent Duration: Weeks Acute Metabolic complications Autoantibody: Yes Family History: No Insulin levels: very low Islets: Insulitis 50% in twins More common Adult >25 Years Insulin Independent * Months to years Chronic Vascular complications. No Yes Normal or high * Normal / Exhaustion 60-80% in twins

Insulitis – Type I Insulinitis

Islets in Type II Diabetes: Loss of ß cells, replaced by Amyloid deposits (hyalinization)

Islets in Type II Diabetes: Loss of ß cells, replaced by Amyloid deposits (hyalinization)

Complications: Short term Complications: (metabolic) Hypoglycemia Diabetic Ketoacidosis Non Ketotic hyperosmolar diabetic coma Lactic acidosis Long term Complications:(Angiopathy) Microngiopathy - Retinopathy, Nephropathy, Neurophathy, dermatopathy. Macroangiopathy – Atherosclerosis.

Microangiopathy Pathogenesis:  Hyperglycemia chronic.  Glycosylation of basement membrane proteins  Leaky blood vessels.  Excess deposition of proteins – glycosylation cycle.  Thick and Leaky blood vessels.  Narrow lumen  Ischemic Organ damage...

Diabetic Microangiopathy Normal Diabetic  Glucose  Glycosylation  BM damage leak  ‘AGE’ deposition

Neuropathy Sensory  Motor (myelin) Peripheral Neuropathy Bilateral, symmetric Progressive, irreversible Paraesthesia, pain, muscle atrophy Visceral neuropathy Cranial nerve – diplopia, Bell palsy GIT- constipation, diarrhoea CVS – orthostatic hypotension

Neuropathy Myelin loss in nerve

Chronic Polyneuropathy Claw foot – Dermopathy & Neuropathy

Diabetic Amyotrophy Painful muscle wasting

Diabetic Neuropathic ulcer

Neuropathic ulcer Etiology:  peripheral sensory neuropathy, Trauma & deformity. Factors:  Ischemia, callus formation, and edema.

Neuropathic ulcers FEATURES: Painless, surrounded by callus At pressure points. associated with good foot pulses May not be associated with gangrene

Nephropathy Nodular Glomerulo Sclerosis. Common morbidity & mortality. Deposition of ‘AGE’ Advanced Glycosylation End-products as nodules. Nephrotic syndrome Pyelonephritis End stage renal failure

Diabetic Nephropathy Microangiopathy, atherosclerosis & infections: Diffuse or nodular diabetic glomerulosclerosis (Kimmelstiel Wilson Sy) Renal arteriolosclerosis & atherosclerosis Necrotizing renal papillitis. Pyelonephritis. End stage kidney.

Nodular Glomerulosclerosis – KW lesion.

Diabetic Glomerulosclerosis Hyaline nodules

Diabetic Glomerulosclerosis

Normal Retina

Non Proliferative Retinopathy Venous dilation and small red dots posterior retinal pole - capillary micro-aneurysms. Dot and blot retinal hemorrhages and deep-lying edema and lipid exudates impair macular function. Late generalized diminution of vision due to ischemia and macular edema - common cause of visual defect (best detected by fluorescein angiography) Cotton-wool spots (soft exudates) - microinfarcts due to ischemia. They are white and obscure underlying vessels. Hard exudates are caused by chronic edema. They are yellow and generally deep to retinal vessels.

Proliferative Retinopathy Neovascularization - which grows into the vitreous cavity. In advanced disease, neovascular membranes can occur, resulting in a traction retinal detachment. Vitreous hemorrhages may result. sudden severe loss of vision can occur when there is intravitreal hemorrhage. Poor visual prognosis if severe retinal ischemia, extensive neovascularization, or extensive fibrous tissue formation. Panretinal photocoagulation may diminish or eliminate proliferative retinopathy

Retinopathy Non Proliferative Microaneurysms, Dot blot hemorrhages Hard and soft exudates Cotton wool – infarcts Macular edema. Proliferative. Neovascularization Large hemorrhages Retinal detachment.

Diabetic Retinopathy Neovascularization Cotton wool spots

Diabetic Retinopathy Dot blot – Hemorrhages (Microaneurysms)

Diabetic Retinopathy Pre retinal Hemorrhage - detachment

Diabetic Retinopathy Advanced fibrous plaques

“The past cannot be changed, but the future can.. by actions in the present time.” --BK Past is history, Future is mystery Present is the gift…!

Label the diagram Hard dep. Optic disc Macula Blot hem Cotton wool

Macroangiopathy Atherosclerosis Dyslipidemia  HDL Non-Enzymatic Glycosylation  Platelet Adhesiveness  Thromboxane A 2  Prostacyclin Endothelial damage  Atherosclerosis MI, CVA, Gangrene of Leg (PVD), Renal Insufficiency

Atherosclerosis:

Slide Show

Diabetic Gangrene

Fungal infections: Candidiasis

Macrosomia With Polycythemia

Blood vessel calcification: Amputated thumb

Cataract

Acanthosis Nigricans  Insulin resistance…

Acanthosis Nigricans  Insulin resistance…

Label the diagram Capillary Nodule – AGE Bowman caps Hyaline arteriolo sclerosis in arteriole.

Infections in Diabetes: Decreased metabolism – low immunity. Decreased function of lymphocytes & neutrophils – glycosylation. Glycosylation of immune mediators. Ab Capillary thickening – impaired inflammation. Ischemia & infarctions. Increased glucose (alone is not the cause*) Diabetes  State of immunosuppression.

Laboratory Diagnosis: Urine glucose - dip-stick –Screening Random or fasting blood glucose (<11) Fasting > 7mmol, Random >11mmol If Fasting level is between 7-11 then OGTT HbA1c - for follow-up, not for diagnosis Fructosamine - for long term maintenance.

Points to remember: Disorder of metabolism – Insulin Type-I Children, Acute, Metabolic compl. Type-II Adults, Chronic, Vascular compl. Angiopathy (micro/macro), Heart, Brain, Kidney, Retina, Skin, BV. Increased Infections – know reasons. Hypoglycemia is more dangerous. Not hyper Glucose control is critical * FBS, GTT & HbA1C.

Questions.. How – Ketoacidosis? How – hypoglycemia ? Angiopathy – Macro & Micro ? Infections in Types of retinopathy ? Diabetes insipidus ? Nephrotic / Nephritic syndrome ? Kidney damage in Diabetes ?

The best gift of Nature to man is the briefness of his life…! Latin quote

“It's not that I'm so smart, it's just that I stay with problems longer” --Albert Einstein