Complications of diabetes mellitus

Ceri Jones Cwm Taf University LHB 2014Ceri Jones Cwm Taf University LHB 2014

Complications of diabetes mellitus

Chronic complications: Microvascular

NeuropathiesNephropathiesRetinopathies

Macrovascular complications Myocardial infarctions

Cerebrovascular accidents

Peripheral vascular disease

Aim & Objectives Understand the micro & macrovascular complications

of diabetes

Understand the factors, interventions and therapies which can prevent or delay the onset of complications

Be able to advise people with diabetes on self-care strategies to prevent and manage macrovascular complications

Facing Facts: The burden of diabetes complications

Diabetes is a progressive disease; many present with complications on diagnosis

Complications can have devastating effects on individuals lives:

human costs shortened life expectancy

Healthcare costs for diabetes, account for 9% of total healthcare expenditure

NSF for Diabetes Standard 10

Regular surveillance for the long term complications of diabetes

Standard 11

Agreed protocols and systems of care

Standard 12

All people with diabetes requiring multi agency support will receive integrated health and social care

Why do Problems Occur?Long term exposure to hyperglycaemia leads to:

Vessel closure (full or partial) – supply of oxygen and nutrients are decreased

Vessel permeability – damaged vessels dilate and leak unwanted substances

Diabetes risk factors for complications: Hyperglycaemia

Hypertension

Dyslipidaemia

Smoking

Macrovascular Complications - Risk Factors Type 2 diabetes is a strong risk factor for CV disease in both

men and women

Risk of atherosclerotic cardiovascular disease is 2-4 times higher for those with Type 2 diabetes compared to non diabetic population

CHD is the principle cause of death in people with diabetes

Normal protection afforded to pre-menopausal women is negated by diabetes

People with diabetes have the same risk as those without diabetes but who have had an MI

Acute Myocardial Infarction People with type 2 diabetes have the same risk of an

MI as people without diabetes who have already had an MI

Immediate and later mortality rates following MI are high in people with Type 2 diabetes

MIs may be silent in people with diabetes or symptoms may be atypical

Cerebrovascular Events No long term studies on stroke management to date

General consensus is to treat all vascular risk factors aggressively

ACEi

Statins

Aspirin

Evidence for Primary Prevention of Strokes

Peripheral Vascular Disease

Approx 20% of people with PVD will die within 2 yrs of symptoms

Generally PVD is asymptomatic until arterial stenosis occurs

Symptoms include: Intermittent claudication Rest pain Buttock pain

Management: Aspirin Vasodilating agents Reconstructive surgery Angioplasty Amputation & rehabilitation & foot care

Aspirin

For Secondary Prevention

People with cardiovascular disease 75 mg once daily

For Primary Prevention

British Hypertension Society recommends aspirin 75 mg once daily for those aged 50 and over, with Type 2 diabetes, with a blood pressure controlled to <150/90 mmHg (NICE suggest <145 systolic).

All people with a 10 year risk >15% to be prescribed aspirin - according to precautions and contra- indications in British National Formulary.

Microvascular Microvascular ComplicationsComplications

Nephropathy

Neuropathy

Retinopathy

Diabetic retinopathy

A silent complication with no initial symptoms

When symptoms occur, treatment is more complicated and often impossible

Screening for retinopathy is of the utmost importance

When to screen for retinopathy

Type 1 diabetes: within 5 years of diagnosis

Type 2 diabetes: at time of diagnosis

Thereafter, every 1 to 2 years, depending on the status of the retina

Diabetic eye disease

Blurred vision: common symptom of hyperglycaemia

Epidemiology: any retinopathy: 21-36% vision-threatening retinopathy:

6-13%

Risk factors

Poor glycaemic control Long duration Hypertension

Dyslipidemia Nephropathy Pregnancy

Intensive therapy

DCCT – type 1 diabetes: Primary prevention cohort:

reduced risk of developing retinopathy by 76%

Secondary intervention cohort: reduced risk of progression of retinopathy by 54%

DCCT 1993

Treatment

Blood pressure: reduces macular oedema

Blood glucose control: slows progression

Control lipids

Use of aspirin

Treatment

Laser therapy:Pan-retinal for proliferative

retinopathyFocal or grid for macular

oedema

Laser therapy

Side effects

Loss of peripheral vision, tunnel vision, night blindness

Colour blindness

Vision can get worse but “laser saves sight” in long term

Summary

100% of people with diabetes will develop some retinopathy

The higher the blood glucose level the greater the risk

Different grades of retinopathy Laser therapy saves sight Timely treatment is most effective Regular screening is a must

Diabetic nephropathy

About 20% to 30% of people with diabetes

In type 2 diabetes, a smaller fraction of these progress to CKD

People with type 2 diabetes – over half of those with diabetes starting on dialysis

Risk factors

Poor glycaemic control Hyperlipidaemia Hypertension Genetic predisposition Glomerular hyper-filtration during early

period Ethnicity Long disease duration Smoking

Type 1 diabetes

Decreasing incidence over past 35 years

Overall incidence

2.2% at 20 years duration

7.8% at 30 years duration

Finne 2005

Microalbuminuria(incipient diabetic nephropathy)

Acute renal hypertrophy-hyperfunction

Normoalbuminuria

Proteinuria(clinical overt diabetic nephropathy)

Chronic renal failure

10 to 15 years

Natural history of diabetic nephropathy

Diabetic renal assessment Urinalysis for proteinuria Spot urine for microalbuminuria

morning and resting or preferably with albumin/creatinine ratio

(normal <2.5 mg/mmol in men and <3.5 mg/mmol in women)

Serum creatinine; preferably with adjustment of body size

Estimated glomerular filtration rate Repeat the tests at about yearly intervals if

normal If GFR <60 ml/min test 3-6 monthly

Microalbuminuria

Type 1 diabetes indicates incipient nephropathy

Type 2 diabetes marker of increased cardiovascular morbidity

and mortality

Presence of microalbuminuria is an indication for screening of vascular disease and intensive intervention

Interventions: glycaemic control

Diabetes Control and Complications Trial (DCCT) occurrence of microalbuminuria by 40% occurrence of macroalbuminuria by 50%

United Kingdom Prospective Diabetes Study (UKPDS)

overall microvascular complication rate by 25%

Diabetic nephropathy

Treatment intensive treatment of blood

pressure

target <130/80 mmHg

reduce salt in diet

reduce alcohol

Sacks, 2001

Management of people with elevated creatinine

Caution should be taken when using the following:

metformin

non-steroidal anti-inflammatory drugs

glibenclamide

radiographic contrast

Management of people with elevated creatinine Insulin dosage may need adjustment

due to change in insulin half life and dialysis

Anaemia is common and may need treatment – measure haemoglobin every 6 months if eGFR is <60 ml/min/1.73 m2

Refer to nephrologist when eGFR <30 ml/min/1.73m2

Estimated Glomerular Filtration Rate (eGFR) May underestimate actual renal

function especially in women, the young and the obese

More accurate in lower ranges <60 ml/min

If eGFR is <60 ml/min, 30% risk of CVD

Most common cause of death in CKD is cardiac arrest (22%)

Summary

Diabetes is a common cause of CKD

Various grades of nephropathy

The higher the A1c the higher the risk

Control matters

Blood pressure

Diabetic foot disease –the high-risk foot

Peripheral vasculardisease

Peripheral neuropathy

Peripheral neuropathy andperipheral vascular disease

Some statistics

• Half of all limb amputations are caused by diabetes

• Risk is 40 times increased in diabetes

• 70% of people die five years following an amputation

• Foot problems account for 40% of healthcare resources in developing countries; 15% in developed countries

Some statistics• 85% of all amputations begin with an ulcer

• 49-85% of amputations can be prevented

Peripheral neuropathy – sensory motor

Most common form of neuropathy Affects approximately 50% after 15 years Affects long nerves (feet and legs) first

glove and stocking distribution

Bilateral Equal symptoms in both limbs

Diabetic peripheral neuropathy – risk factors

Poor glycaemic control

Long duration

Age

Height

Excessive alcohol

Nerve damage – neuropathy

Symptoms:burningpins and needlespain

No symptoms

Painless nature of diabetic foot disease

Sensory nerve damage

Motor nerve damage

Autonomic nerve damage

Take off the shoes!Take off the shoes!

Diabetic peripheral neuropathyscreening tests

Test sensation BiothesiometerTuning fork10 gm

monofilament

Ankle reflexes

Assessment of high risk characteristics

Peripheral vascular disease

Symptoms Intermittent claudicationRest pain

No symptoms

InactivityNeuropathy

Signs of vascular disease

Diminished or absent pedal pulses

Coolness of the feet and toes

Poor skin and nails

Absence of hair on feet and legs

Vascular assessment

Palpation of foot pulses

Dorsalis pedis (10% absent due to anatomical reasons)

Tibialis posterior

Peripheral vascular diseasenon-invasive evaluation

Methods Doppler pressure studies (ABI) Duplex arterial imaging

Rationale Identify and confirm presence of

disease Predict healing of ulcers or determine

need for early surgical intervention

Peripheral vascular disease

Treatment

• Quit smoking

• Walk through pain

• Surgical intervention

Cause of diabetic amputation

Pecararo

Trauma

Ulcer

Failure to heal

Infection

Amputation

Neuropathy or vascular disease

An amputation every 30 secondsdue to diabetes

Modifiable Risk FactorsHyperglycaemia

Hypertension

Dyslipidaemia

Smoking

Excess visceral adiposity

Lifestyle

Why Treat to Target?

Many people with Type 2 diabetes have both microvascular and

macrovascular complications (1)

UKPDS showed that treating to target levels helped reduce the

complications of Type 2 diabetes (2,3)

HbA1c and blood pressure are modifiable cardiovascular risk factors in

Type 2 diabetes (2,3)

Treating to target levels reduces complications and reduces the burden

of Type 2 diabetes (2,3)

Each 1% reduction in HbA1c for 10 years was associated with 37%

reduction in microvascular problems.1.UKPDS 6. Diabetes Research 1990;13:1–11

2. UKPDS 33. Lancet1998;352:837–835 .

3, UKPDS 38. BMJ 1998;317:703–713

UKPDSUKPDS

The risk of each of the macrovascular and microvascular complications in type 2 diabetes was strongly associated with hyperglycaemia, as measured by HbA1c.

Good glycaemic control reduces the risk of complications.

DCCTDCCT This landmark diabetes study established that good

control prevents and delays the progression of chronic complications in people with type 1 diabetes.

Retinopathy and nephropathy (urine albumin excretion) were reduced by 35-75% in the group with tight control.

In those with initial early retinopathy, risk of progression reduced by about 50%.

The tight control group experienced 3x more severe hypos than the control group.

Conclusion

Macrovascular complications of diabetes can have a profound and devastating affect on the quality of life and life expectancy of people with diabetes.

Many factors, interventions and therapies which can prevent or delay the onset of complications are available.

Ongoing and new research strive to reach more positive outcomes for people with diabetes.

As healthcare professionals our roles are to advise people with diabetes on self-care strategies to prevent and manage macrovascular complications.