Diabetes & Retinopathy Screening

Dr John DoigConsultant Diabetologist

DRS Clinical Lead Forth Valley

Diabetes & Retinopathy Screening• What is diabetes• Diagnosis• Types of Diabetes• Treatment• Complications

– Acute metabolic– Macrovascular– Microvascular

• Managing Risk Factors

What is Diabetes Mellitus• Diabetes = excessive production of urine • mellitus = honeyed

• Life-long illness associated with various complications – Blindness– Heart disease– Kidney disease– Damage to the feeling in the limbs (peripheral

neuropathy).

Diabetes Mellitus• characterised by high blood sugar levels,

disturbances of carbohydrate, fat and protein metabolism

• absolute lack or a relative deficiency in insulin action and/or insulin secretion

• Prevalence increasing– Scottish Survey 2001 = 2.1 %– Forth Valley 2007 = 4.4 %– Some practices = 5.0 %

Management of Diabetic Patient

• Main Issues– Diagnosis– Glycaemic Control– Screening

•Microvascular Complications•Macrovascular Complications

– Diabetes related issues / Education•Driving, Work, Pregnancy•Injection sites, Diet, Monitoring

Diagnosis

• Symptoms– Osmotic Symptoms & Fatigue– Weight loss / gain– Infection– Neuropathic Symptoms– Visual Upset– Cardiovascular symptoms

Diagnosis: Diagnostic Criteria

Fasting Plasma Glucose >7.0 (on 2 occasions*)

Random Plasma Glucose >11.1 (on 2 occasions*)(1 occasion if symptomatic)

Fasting Plasma Glucose 6.1 - 6.9 = IFG2 hr post 75g glucose 7.8 - 11.1 = IGT 2 hr post 75g glucose > 11.1 = DM

Type of Diabetes

• Type I– Young < 35– Thin + weight loss– Rapid onset– Ketonuria

– Autoimmune– B Cell failure– Insulin Dependent

• Type 2– Older > 35– Overweight– Onset months– Strong FH– Complications

– Insulin resistance– Late B Cell failure– Hyperinsulinaemia– Metabolic syndrome– Cardiovascular Disease

Type of Diabetes

• Type I– Young < 35– Thin + weight loss– Rapid onset– Ketonuria

– Autoimmune– B Cell failure– Insulin Dependent

• Type 2– Older > 35– Overweight– Onset months– Strong FH– Complications

– Insulin resistance– Late B Cell failure– Hyperinsulinaemia– Metabolic syndrome– Cardiovascular Disease

Other types of Diabetes

• Gestational• Drug induced

•Steroids, Atypical Neuroleptics• Metabolic

•Haemachromatosis, Cushings, Acromegaly

• Pancreatic disease• MODY (Genetic)• Stress hyperglycaemia

Treatment• Diet

• Oral Hypoglycaemic Agents– Sulphonylureas (Gliclazide, Glimepiride)– Biguanides (Metformin)– Alpha 1 glucosidase inhibitors (Acarbose)– Thiazolidinediones (Rosiglitazone, Pioglitazone)– GLP-1 agonists (Exenatide, Liragutide) – DPP4 Inhibitors (Sitagliptin, Vildagliptin)

• Insulin– Soluble, Biphasic, Intermediate / Long acting

Acute Metabolic Complications• Diabetic Ketoacidosis• Hyper Osmolor Nonketotic Coma

• Lactic Acidosis

• Hypoglycaemia

Hypoglycaemia

• Common side effect of Insulin or Sulphonylureas

• Does not occur with other oral treatments• Minor hypos often go unreported (Self

treated)• Severe hypos occurs in 25-30 % of patients

each year• Coma occurs in ~ 10 % of patients each year

~ 4.6 mmol/l Inhibition of insulinsecretion

~3.8 mmol/l Counter-regulatoryhormonal secretionbefore symptoms

Adrenaline, Growth hormone,Glucagon, Cortasol

~3.0 mmol/l Autonomic symptoms Sweating, Hunger, Palpitation,Shaking

2.8 mmol/l Neuroglycopenicsymptoms

Confusion, Drowsiness, Speechdifficulties, Incoordination,Atypical behaviour, Malaise,Nausea, Headache

< 1.0 mmol/l Coma / Convulsions

Death

Causes of hypoglycaemiaManagement Errors

Inadequate Carbohydrate

Altered Kinetics Lipohypertrophy, Site massage, Heat, Cold, Antibodies, Renal, Exercise, Human insulin

Increased Sensitivity Addison’s disease, Hypothyroidism, Hypopituitarism, Changes in gonadal steroids, Pregnancy

Factitious

Risk factors for severe hypoglycaemia

• Insulin treatment regimenIntensified High insulin doses

• Impaired awareness of hypoglycaemiaAcute (Preceding hypoglycaemic

episodes) Chronic (Central autonomic failure)

• Long duration of diabetes• Increasing age of patient• Sleep, Excessive alcohol consumption

Morbidity of hypoglycaemia

• CNS Coma and ConvulsionsTransient motor deficitsPermanent brain damageCerebral Oedema

• CVS ArrhythmiaMyocardial ischaemiaStroke

• Fractures, Vitreous haemorrhage

Treatment of hypoglycaemia• Treated immediately by oral glucose 10-20 g

• If unable to swallow / unconscious thenEnsure patient safe (ABCD, Recovery position, Get help)– Intravenous glucose 50ml 20%– Intravenous glucose 25ml 50 %– Subcutaneous glucagon 1 mg

• Patients should recover within minutes• Failure to do so may be due to cerebral oedema

• On recovery encourage consumption of complex carbohydrate

• Identify cause & take appropriate action / patient to contact diabetes care team.

Macrovascular Complications• Coronary Artery Disease

• Peryipheral Vascular Disease

• Cerebro Vascular Disease

– Hyperlipidaemia– Glycaemic control– Hypertension– Obesity / Smocking / FH

Angina, MI, Heart Failure

Claudication, Risk of limb ischaemia, infection, amputation

TIA’s, Stroke disease

Cumulative Hazard for Any CVD Endpoint CARDS

Relative Risk = -36% (95% CI -45, -15)

p=0.001

Years

306287

663621

1040992

13371275

13721334

AtorvaPlacebo

14281410

Placebo189 events

Atorvastatin134 events

Cu

mu

lati

ve H

azar

d (

%)

0

5

10

15

20

0 1 2 3 4 4.75

NNT = 30

12% decrease per 10 mm Hg decrement in BP

p<0.0001

0.5

1

5

110 120 130 140 150 160 170

All Cause Mortality

Updated mean systolic blood pressure

Haz

ard

ratio

UKPDS 36. BMJ 2000; 321: 412-19

All Cause Mortality

14% decrease per 1% decrement in HbA1c

p<0.0001

0.5

1

5

0 5 6 7 8 9 10 11Updated mean HbA1c

Haz

ard

ratio

UKPDS 35. BMJ 2000; 321: 405-12

Cardiovascular Disease Prevention• Improved cardiovascular risk with:

– Improved glycaemic control (Metformin)– Improved BP control (Target < 140/80)– Addition of long acting ACEI if high risk– Lipid reduction– All secondary preventative measures

•Aspirin, B Blocker

Microvascular Complications• Diabetic Retinopathy

• Diabetic Nephropathy

• Diabetic Neuropathy

MicroalbuminuriaMacroalbuminuriaRenal impairmentEnd Stage Renal Disease

Sensory Ulceration,Neuroarthropathy

Motor Foot deformityAutonomic GI upset, Hypotension,

ED

Prevalence of Retinopathy

• In young persons with duration less than 5 yrsrare

• In patients > 30 yrs with duration 5 yrs 20 %• Duration 10 yrs 40-50 %• Duration 20 yrs 90 %

• Approx 30% of diabetic population have DR

• Prevalence of visual impairment in UK ? 2-5 %?

Diabetic Retinopathy

• Approx 10-15 % of patients progress to sight threatening retinopathy– Pre proliferative retinopathy– Proliferative retinopathy– Vitreous haemorrhage– Maculopathy

• Other sight threatening disease more common in diabetes– Cataract– Macular Degeneration– Glaucoma

Risk Factors for Diabetic Retinopathy• Duration of diabetes (age of onset)• Poor glycaemic control

• Raised blood pressure

• Microalbuminuria and proteinuria (nephropathy)

• Raised triglycerides and lowered haematocrit• Pregnancy• Genetic / ethnicity• Smoking

Modifiable Risk Factors for Prevention of Diabetic Retinopathy

• Glycaemic Control

• Blood Pressure Control

• Smoking?

Evidence For Good Control• 1993 DCCT Type 1 HbA1c 8.9 vs. 7.2 %

– Reduced risk of developing:• Retinopathy 76 %• Microalbuminuria 39 %• Clinical neuropathy 60 %

• 1998 UKPDS Type 2 HbA1c 7.9 vs. 7.0 %– Reduced risk of:

• Retinopathy 21%• Microalbuminuria 33%• Myocardial Infarction 16 %

Complication DCCT EDIC1982-1993 1994-2006

HbA1c 7.2 v 9.1% 7.9 v 8.1%Retinopathy

3-step change 63 72Proliferative 47 76Macular oedema 26* 77Laser therapy 51 77

NephropathyMicroalbuminuria (> 28mg/min) 39 53Clinical albuminuria (> 208mg/min) 54 82

Reduction in Risk for Microvascular Complications

Microvascular Endpoints

0.5

1

10

15

0 5 6 7 8 9 10 11

37% decrease per 1% decrement in HbA1c

p<0.0001

Updated mean HbA1c

Haz

ard

ratio

UKPDS 35. BMJ 2000; 321: 405-12

1148 Type 2 diabetic patients tight blood pressure 144 / 82 mmHg v standard 154/87gave reduced risk for

any diabetes-related endpoint 24% p=0.0046diabetes-related deaths 32% p=0.019stroke 44% p=0.013heart failure56% p=0.0043

microvascular disease 37% p=0.0092

retinopathy progression 34% p=0.0038deterioration of vision 47% p=0.0036

UKPDS Blood Pressure Control Study

Patients with retinopathy

• Aim for – Good glycaemic control HbA1c <

7.0%– Good BP control <130/70– Lipid control / Statin Cholesterol <4.0– Stop smoking– Correct anaemia