Classification and Diagnosis of Diabetes

Exeter Diabetes Care Team

Introduction

Prevelance Definition Diagnosis Different types of diabetes Action of insulin Treatment Brief overview of complications

UK Prevalence of Diabetes

1.4 million with diagnosed diabetes

1 million with undiagnosed diabetes

3 million predicted by 2010 in the UK

221 million predicted worldwide by 2010

Definition

Diabetes – The term diabetes mellitus describes a metabolic disorder of multiple aetiology which is characterized by hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action or both.

Diagnosis

Glucose Tolerant Population: FPG <6mmol/l OGTT 2hour value <7.8mmol/lo Non Glucose Tolerant Population Impaired fasting glucose FPG 6-7mmol/l Impaired glucose tolerance OGTT 2-hour value 7.8-11.1mmol/lo Type 2 Diabetes FPG >7mmol/l Random plasma glucose >11.1mmol/l

What Is a Normal Blood Sugar Level?

Normal range 4 – 7 mmol/l

Aim for normoglycaemia

Prevent diabetes complications

Encourage self management

Classification of Diabetes

Type 1

Type 2

Gestational

Other specific types (genetic)

P e r ip h e r a l

g lu c o s eu p t a k e

G lu c o s ea b s o r p t io n

G lu c o s ep r o d u c t i

o n

B lo o d

g lu c os e

Liver M u s c le

In t e s t in e Ad ip o s e

Blood glucose levels

Insulin structure

51 amino acids arranged as a two chained molecule connected by two disulphide bridges:

A chain 21 amino acidsB chain 30 amino acids

Effects of insulin

Glucose metabolism

Suppresses hepatic gluconeogenesis Suppresses hepatic glycogenolysis Stimulates uptake of glucose into

skeletal muscle & fat Suppresses breakdown of protein & fat

D e c r e a s e d h e p a t ic g lu c o s e p r o d u c t io n

In c r e a s e d p e r ip h e r a l g lu c o s e u p t a k e

Primary effects of insulin on blood glucose

MuscleL iv e r

P a n c r e a s

Effects of insulin

Protein metabolism

May increase protein synthesis – especially in muscular tissue

Inhibits protein breakdown (proteolysis)

Effects of insulin

Lipid metabolism

Increases triglyceride synthesis (lipogenesis)

Inhibits breakdown of triglycerides in adipose tissue (lipolysis)

Glucose uptake

Glucose transporters required for glucose to cross cell membrane

Transporters accelerate transport along glucose concentration gradient – does not require energy

Transporters in brain, liver, kidneys are insulin independent or very slightly insulin dependent

GLUT4-transporter: highly insulin sensitive located on fat, muscle, heart cells

Without insulin:

Hepatic glucose production permitted

Uptake of glucose into muscle and fat cells is restricted

Lipids and protein are broken down

Hyperglycaemia aggravated by food intake

Type 1 Diabetes

Onset typically <40 years Usually normal weight or slim No endogenous insulin production Onset “dramatic” Family history less common Insulin required to sustain life

Type 1 diabetes

• : U s e d t o b e k n o w n a s

IDDMtype Ijuvenile-onset diabetes

Symptoms of Type 1

Frequent urination Thirst Weight loss Fatigue Ketones (acetone on breath)

Type 1 diabetes• Onset typically childhood & adolescence• Usually normal weight or slim• Pancreatic β cells destroyed• Onset often “dramatic”• Family history less common – first degree

relatives• Autoimmune disease• Insulin required to sustain life

Type 1 Diabetes - Symptoms

Frequent urination (polyuria/nocturia)

Thirst Fatigue Ketones(acetone on breath) Weight loss-can be dramatic Other minor symptoms-skin

infections, muscle cramps,blurred vision, puritis

Management of Type 1

Diet and exercise

Insulin

Aim is to normalise blood glucose level

Type 2 Diabetes

Onset typically>40 years Genetic predisposition Associated with obesity Slow onset of symptoms Insulin not required to sustain life

but often used to maintain health Wrongly perceived as “mild

diabetes”

Features of Type 2 Diabetes

Reduced insulin secretion from the pancreas

The body is also resistant to the insulin that it is producing

Symptoms of Type 2

Excessive thirst Frequent urination Fatigue Blurred vision Recurrent infections Sometimes weight loss Sometimes ketones Some, all or none of the above!!

Review

Type 1 diabetes – no insulin production

Type 2 diabetes – Insufficient insulin Resistance to insulin

Diagnosis

More prone to diabetes if: Obese Asian or afro-Caribbean Over 65 years Family history of diabetes History of gestational diabetes Other auto-immune disease

Diagnostic Criteria

Fasting Blood Glucose >7.0

Random Blood Glucose >11.1

Treatment of Type 2

Diet alone – low fat, low sugar, high fibre = healthy

Diet and tablets

Diet, tablets and insulin

Diet and insulin

Monitoring Diabetes

Urine testing – All results should be negative

Only shows positive when blood sugar level is above 10 mmolls

Monitoring Diabetes

Home blood glucose monitoring Using a meter

Gives accurate level of sugar at time of testing

Quick and easy to do

Monitoring Diabetes

Blood test for Glycated haemoglobin

Aim to achieve HbA1c 7% or below

HbA1c – reviews an average over the last 3 months

Possible Complications

Small vessel complications: Retinopathy = affect on the small

blood vessels on the back of the eye Nephropathy = affect on the

kidneys Neuropathy = affect on the nerves

and circulation

Possible Complications

Large vessel complications: Heart disease

Poor circulation leading to foot problems

Stroke

How to Prevent

Aspirin is commonly prescribed

Aim for HbA1c of 7% or less

Aim for blood pressure no greater than 140/80

Aim for cholesterol level of less than 4.0mmol/l

Advice to Patients

Maintain healthy weight Regular exercise Reduce salt intake Healthy intake of fruit and vegetables Limit alcohol consumption Stop smoking Reduce intake of saturated fat Increase intake of oily fish

Symptoms of Hypoglycaemia

A ‘hypo’ is any blood sugar level below normal i.e.. 4 mmol/l

Sweating Shaking Change in mood i.e.. Confusion,

aggression Extreme hunger Numbness/tingling around lips

Management of Hypoglycaemia

Should be treated immediately with: 5-6 dextrose sweets or half glass

lucozade or sugar in water, etc Followed by carbohydrate snack Blood sugar level should then be

checked again in 10 minutes to check response

Summary

Discussed definition and diagnosis of diabetes.

Its prevalence Types Treatment Brief review of complications