Public Health Module

VenueDate 

Unit: Public Health Aspects of Diabetes

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© 2010

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Course Aims

This unit will:

– Explore how common diabetes is;

– Familiarise students with the risk factors of diabetes

– Explore the efficacy interventions for the prevention and management of diabetes

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Outline

Part I: DIABETES AS A PUBLIC HEALTH PRIORITY 1. What is diabetes?2. Classifying diabetes 3. Epidemiology - how common is diabetes? 4. Risk factors and consequences

Part 2: PREVENTING AND MANAGING DIABETES 1. Primary prevention of diabetes2. Secondary prevention3. Screening in diabetes4. Self care 5. Monitoring diabetes care

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What is health?WB5

WHO Definition ‘a state of complete

physical, mental and social

well-being and not merely

the absence of disease or

infirmity’

Antonovosky: Salutogenic model

‘sense of coherence’

Seedhouse and Duncan: Achievement of potential

Empirical Lack of health

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What is public health?

‘the science and art of preventing disease, prolonging life and promoting health through the organized efforts of society’

C.E.A. Winslow, 1920

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The wider determinants of health

Source: Dahlgreen and Whitehead, G and Whitehead M (1991)

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The challenge for public healthWB7

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Statistical description of nation’s healthWB8

Census data

Health Inequalities data

Infant Mortality Rates

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1. What is diabetes?

Diabetes results from reduced production of the hormone

insulin, resistance of body tissues to the effect of insulin,

or both.

The result is abnormally high levels of glucose in the blood and

widespread disturbances to metabolism.

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History

• 30-90AD: Diabetes named by Greek Physician Aretaeus: means ‘a flowing through’ to describe its constant thirst, excessive urination and weight loss

• Japanese name: 'Shoukachi', the thirst disease

• 1600s: Professor Thomas Willis of Oxford University describes urine in diabetes mellitus as ‘wonderfully sweet’, distinguishing it from diabetes insipidus

• 1889: Oskar Minkowski and Joseph von Mering of University of Strasbourg remove a dog’s pancreas - it produces diabetes

• 1921: Banting & Best isolate insulin, successfully treats a patient, transforming diabetes to a treatable, chronic condition

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The Healthy Body

3. Insulin triggers liver to take up glucose and turn into glycogen

1. Glucose, produced from carbohydrates, released into bloodstream

2. The pancreas produces insulin, also released into the bloodstream

4. Insulin enables cells to take up glucose

Source: Diabetes UK, Diabetes and the Body animation (www.diabetes.org.uk/Guide-to-diabetes/Introduction-to-diabetes/What_is_diabetes/Diabetes-and-the-body/)

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2. Classification

• The WHO recognises several types of diabetes• Type 1• Type 2• Gestational diabetes• Other types

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I. Type 1 Diabetes

The pancreas unable to produce insulin

Accounts for ~15% of diabetes in the UK

Mainly diagnosed in children/young adults

Characterised by insulin deficiency

Symptoms develop quickly

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In type 1 diabetes, no insulin is available so cells are unable to take in glucose

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Symptoms of type 1 diabetes

• Frequent and excessive urination• Thirst• Dehydration• Tiredness• Urinary or genital tract [eg thrush] infections• Blurred vision• Symptoms develop quickly

• Can progress to ketoacidotic coma

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Type 2 diabetes

• Characterised by insulin resistance, though may also have deficiency [Used to be classified as Non-insulin dependent diabetes (NIDDM) but can require insulin]

• Similar acute symptoms to type 1• Compared with type 1, often develops gradually• Some have no symptoms at diagnosis • Milder forms: can be controlled by diet, and exercise• Accounts for ~85% of diabetes in the UK• Mainly diagnosed in older adults though increasingly seen in

younger age groups too

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II. Type 2 diabetes

Fat deposits affect cells’ insulin (i) sensitivity. They are less able to take in glucose (g)

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III. Gestational diabetes

• Excess blood glucose during pregnancy (both diabetes mellitus and impaired glucose regulation)

• Increased risk of diabetes related complications in pregnancy

• Health consequences for the baby include increased risk of• birth complications: caesarean sections; still births and

perinatal deaths • very high birth weight babies • birth defects• obesity and diabetes in the child.

• For the mother:• increased long term risk of type 2 diabetes (30% as opposed to

10% in the general population)• higher risk of diabetes-related complications in

subsequent pregnancies

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IV. Other types

• Monogenic diabetes• 1-2% of all diabetes, affecting 20,000-40,000 in UK• Usually develops in under 25s• Due to a single gene mutation• Runs in families – affected person has 50% chance of

passing on

• Currently 6 types of monogenic diabetes recognised• Some types managed by diet and exercise alone • Often initially misdiagnosed as type 1 or type 2 diabetes • Diagnosing correctly can help

• inform which treatments are most appropriate • give some idea of how the diabetes is likely to progress • affected families understand their risk of diabetes and/or risk to

their children

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Diabetes insipidus

• Moderately rare condition - affects 1 in 25,000

• Symptoms of excessive urination

• Distinct from diabetes mellitus: • not related to production or sensitivity to insulin• Urine not sweet• related to function of vasopressin hormone in the pituitary gland

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Classifying glucose regulation

Normoglycaemia (low risk of

diabetes/CVD)

FPG: ≤ 6.0mmol/l

Impaired glucose regulation

(higher risk of diabetes/ CVD)FPG: >6 to <7mmol/l

Diabetic

(high risk of CVD)FPG: 7.0 + mmol/l

“Healthy” “Diabetic”

DiabetesLow risk

Risk

Glucose levels

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3. Long term impact of diabetes

• Diabetes is an important cause of death and disability

• Diabetes is a leading cause of blindness, renal failure and neuropathy in the UK

• Life expectancy is reduced on average by 20 years in those

with Type 1 diabetes and up to 10 years in Type2 diabetes

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RetinopathyRetinopathyCommon cause of Common cause of blindness in peopleblindness in people

of working age in Westof working age in West

NephropathyNephropathy20% of all ESRD20% of all ESRD

Erectile DysfunctionErectile DysfunctionMay affect up to 50%May affect up to 50%

Macrovascular Macrovascular 2–4 x increased risk 2–4 x increased risk

of CVD, 75% have of CVD, 75% have hypertensionhypertension

Foot ProblemsFoot Problems15% develop 15% develop

foot ulcers; 5–15% need foot ulcers; 5–15% need amputationamputation

Source: The Audit Commission. Testing Times. A Review of Diabetes Services in

England and Wales, 2000.

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‘Macrovascular’ complications cardiovasular diseases

• Biggest cause of death in diabetes:• 75% of deaths in people with diabetes caused by

cardiovascular disease

• People with diabetes have:• 2x risk of death from heart disease• 1.5-4x risk of stroke

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‘Microvascular’ complications

Nerves (neuropathy): – affects up to 60-70% of people with diabetes– symptoms include tingling or burning, pain, numbness– increases the chance of foot ulcers and limb amputation– other conditions e.g. erectile dysfunction

Eyes (retinopathy):– biggest cause of blindness in working aged adults in UK – long-term damage to the small blood vessels in the retina– after 15 years of diabetes, ~ 2% of people become blind, and about

10% develop severe visual impairment

Kidneys: – Disease detected by protein in the urine– affects 30% of people with diabetes

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Source: Yorkshire & Humber Public Health Observatory 2008

Deaths from diabetes~ 2700 death certificates with diabetes as cause of death pa~26,000 deaths from the diseases caused by diabetes paSo death certificates underestimate diabetes attributable deaths. Variations by area too:

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Cost of diabetes

• Diabetes is a clinical area of high expenditure• eg in one year, October 2007 to September 2008, there were

31.9 million NHS items prescribed = £581.2 million

• ~ 5% of total NHS spend is used for the care of people with diabetes

• The growth in expenditure on prescribing for diabetes is greater than any other major clinical area

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4. Prevalence of diabetes

• Current prevalence• Trends• Models

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Global impact

• Diabetes accounts for estimated 5.2% all world mortality• 80% deaths occur in low & middle income countries• Prevalence increasing fastest in these countries

Source: WHO

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Diabetes prevalence in England

• 2.1 million on diabetes registers

• BUT 25% in coronary care have undiagnosed Type 2 DM

• Y&H PHO modelling estimates:• another 400,000+

not diagnosed• The estimated prevalence of

diabetes (diagnosed and undiagnosed) is 4.82% of population of England

• prevalence varies by area

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Trends

• Diabetes expected to rise in England to 6.5% by 2025

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Diabetes UK Silent Assassin Campaign

What do these images say to you about diabetes?

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5. Risk factors

• Why consider risk factors?

• Type 1 v 2

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Type 1

• Highest prevalence in northern European populations

• Strong familial link – genetic factors

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mother

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Relative risks of type 2 diabetes

• Population factors:WB• Family history; • Age; • Socioeconomic

circumstances; • Ethnicity

• Modifiable risk factors• Obesity; • Exercise; • Smoking

0 5 10 15 20 25

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Obesity

• BMI = weight (kg)/height (m)2

• BMI categories:

• In the Nurses Health Study, compared with women with a BMI or 23 or less, diabetes was

• nearly 40 times higher with a BMI of 35+ • 20 times higher with a BMI or 30-34.9

Underweight Normal Overweight Obese Morbidly obese

<18.5 18.5-24.9 25-29.9 30-39.9 40+

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Ashwell shape chartWB34

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Physical activity, obesity and the risk of diabetes

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Age

Prevalence of doctor-diagnosed diabetes, by age

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Ethnicity

• In England, compared with the general population, rates of diabetes are:

• 3-4 x higher Bangladeshi, Pakistani and Indian men• 5 x higher in Pakistani women• 3 x higher in Bangladeshi and Black Caribbean women • 2.5 in Indian women

• When assessing risk of diabetes, need to consider ethnicity, & also need to consider gender

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Deprivation Age adjusted prevalence of known diabetes by fifths of deprivation score

• Mortality and morbidity are increased by socio-economic deprivation

• The complications of diabetes have been shown to be more prevalent in areas of high socioeconomic deprivation

J Epidemiol Community Health 2000;54:173-177

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Other risk factors

• Smoking: • small relative risk compared to obesity, but of public health

importance given prevalence of smoking, particularly in poorer socioeconomic groups

• Physical health problems

• Mental health

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Diabetes and gender

• Risk factors affect men and women differently

• Risk of death from heart disease linked to diabetes is greater in women than men:

• Is diabetes more harmful to women? and/or• Is treatment better for men? and/or??

• Gestational diabetes: numbers of diabetes cases in women of childbearing age increasing

• Risk factors: family history; pre-pregnancy obesity; advanced maternal age; gestational diabetes in previous pregnancy; ethnic background; large baby (≥ 4.5 kg) in a previous pregnancy; smoking

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Part 1 summary• Diabetes is a chronic condition

– It can lead to CVD, kidney failure, limb amputation and blindness

• Type 1 and type 2 diabetes share similar symptoms but different public health implications

• Type 2:– 85% of diabetes in UK– Obesity most important modifiable risk factor. – more common in people over 40 years, Pakistani, Bangladeshi, Indian

and African Caribbean populations • Women and poorer socioeconomic groups more at risk of diabetes

complications and death from diabetes

• Problems assessing the health burden of diabetes because: – ~20% with type 2 diabetes remain undiagnosed– diabetes seldom recorded as cause of death but its complications –

heart disease, stroke, renal failure – are leading causes of death.

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Exercise: ‘Westport’ PCT’s local diabetes Needs Assessment

• ‘Westport’ PCT needs to understand the current impact of diabetes on its population – prevalence, health consequences and effects on services - and to forecast the impact of diabetes in the future

• From what you’ve learnt in the module so far, how would you find out about the impact of diabetes on your local population?• What sources of data could you access?• What information would you collect specifically? Who would you ask?

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Part 2: Preventing and managing diabetes

1. Primary prevention of diabetes

2. Secondary prevention

3. Screening in diabetes

4. Self care

5. Monitoring diabetes care

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1. Primary prevention

• Three strategies for primary prevention- • Upstream- whole population

• Midstream- special high risk groups e.g. children, elderly

• Downstream- high risk ‘individuals’

• Type 2 prevention Government priority in England:

“The NHS will develop, implement and monitor strategies to reduce the risk of developing type 2 diabetes in the population as a whole and to reduce the inequalities in the risk of developing type 2 diabetes.”

Standard 1 of the Diabetes National Service Framework, 2003

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Population measures

• Reducing obesity• Increasing physical activity

• Choosing health: choosing a healthy diet and choosing activity– 5-a-day– 5-a-week

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Identifying high risk individuals

• Why?– Can target interventions to those most at risk

• How?– Risk assessment considering

» Weight (BMI, waist circumference)» Blood pressure» Cholesterol» Blood glucose

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NHS Health Check WB46

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Interventions for high risk individuals• Lifestyle interventions significantly reduce progression rates

to diabetes in prediabetic individuals• Trials have shown that sustained lifestyle changes in diet

and physical activity can reduce the risk of developing type 2 diabetes

Study Country % risk reduction

Diabetes Prevention Programme (Tuomilehto et al, 2001)

Finland 58

DAQing (Pan et al, 1997) China 46

Diabetes prevention programme (Knowler et al, 2002)

America 58

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Programmes for high risk

• Medications & non-drug interventions to:– reduce blood pressure– lower cholesterol (eg statins)– manage blood glucose

• Community referrals for programmes on:– exercise– weight management – smoking cessation

• Specialist referrals for bariatric surgery?

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Exercise: theory…

• Chief Medical officer Report 2004: ‘5 a week’ call for action

• At least 30 minutes exercise 5 times a week can improve health, prevent diabetes and reduce overweight

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…reality?

And…people with diabetes less likely to meet exercise recommendations

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target high risk or provide for the whole population?

In public health, there is often debate about whether to target high-risk individuals or offer population wide strategies to promote health and prevent disease

Think of some of the pros and cons of these contrasting approaches for lifestyle interventions to adopt healthier diets and take more exercise to prevent diabetes

WB50Exercise 2: Encouraging healthy eating and regular exercise

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3. Screening

• Primary prevention– To identify people at increased risk of disease

• Secondary prevention– To identify early stages of disease

NSC found no evidence to implement national screening for diabetes in UK.

Better strategy to:– optimise management of blood pressure and hyperglycaemia in people with

known diabetes; and– ensure universal screening for eye disease

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4. Self care and self managementDESMOND for type 2 diabetes

• Diabetes Education and Self Management for Ongoing and Newly Diagnosed patients

• Group sessions to help new patients to– identify their own health risks – develop behaviour and health goals tailored to their

own circumstances

• Evaluation found:– greater weight loss & smoking cessation – improvements in beliefs about illness– No change in HBA1c

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5. Monitoring diabetes care

• Why?– To find out if services delivered as intended– To find out whether services reaching groups that need them

• How?– Local monitoring, checks, visits, feedback– National data

• Monitoring against targets: access• Patient survey: patient experience• Hospital admissions & procedures: outcomes

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NCHOD admissions and procedures

Age standardised rates of emergency hospital admissions for diabetic coma and ketoacidosis, by region

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Part 2 summary

• Type 2 diabetes is preventable• Complications of diabetes can be avoidable• Interventions aim to:

– encourage healthy eating and regular exercise– reduce blood pressure, cholesterol and improve glucose regulation– reduce complications

• Programmes in England to improve diabetes care focus on identifying high risk individuals, rewarding quality services, screening for retinopathy

• Monitoring indicates room for improvement in access and effectiveness

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Exercise 3: Shaping your local services

‘Westport’ PCT’s public health department has been asked to recommend how Nowhere should develop its diabetes services.

• How would you assess the impact of diabetes services

provision locally?• From what you’ve learnt in the module, how would

you decide on your top priorities for diabetes in your local area?

• Think about:– Prevention vs treatment– Evidence based programmes vs learning through doing– National policy priorities and targets

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