Hypertension for nurses

29th October 2008

Cardiovascular disease

Blood pressure

Heart attack

Cholesterol Atheroma

Vascular narrowing

and/or occlusion

Stroke

Cigarettes Thrombosis Claudication

Diabetes Renal failure

Leading causes of death 2002WHO 2003 & Poole-Wilson. Clin Med JRCPL 2005; 5: 379-84.

478

496

606

735

754

929

1,398

2,399

4,692

5,823

Colo-rectal cancer

Tuberculosis

Stomach cancer

Hypertensive heart disease

Diabetes

Lung cancer

LRTI

COPD

Stroke disease

CHD

Deaths (thousands) 60 years & over

WHO global burden of disease major risk factors

Ezzati et al, Lancet 2002; 360:1347-60.

Total deaths: 55,861,000, year 2000

0 1000 2000 3000 4000 5000 6000 7000 8000

Unsafe water

Alcohol

Inactivity

High BMI

Low fruit and vegetables

Unsafe sex

Underweight

High cholesterol

Tobacco

High blood pressure

Thousands

7,141,000

4,907,000

4,915,000

3,748,000

2,886,000

2,726,000

2,591,000

1,922,000

1,804,000

1,730,000

Renfrew 1972. Arbitrary dividing linesHawthorne, Greaves & Beevers, Brit Med J 1978.

Normotensive

(89) 1846 (60.3%)

Mild Hypertensive

(90-109) 1069 (34.9%)

Moderate Hypertensive

(110-129) 130 ( 4.2%)

Severe Hypertensive

(>130) 16 ( 0.5%)

Survival of untreated hypertensionLeishman, Brit Med J 1959; 1: 1361

MHT>150130-149120-129100-119

8%

16%

36%

66%

88%

100

90

80

70

60

50

40

30

20

10

Diastolic blood pressure

Percentdead

in 2 yr

CHD mortality v usual blood pressure Prospective Studies Collaboration, Lancet 2002; 360:1903-13

Stroke mortality v usual blood pressure Prospective Studies Collaboration, Lancet 2002; 360: 1903-13.

JNC 7New classification of hypertension

J Amer Med Ass 2003; 289: 2560-72

Classification of blood pressure for adults aged 18 years or older

Systolic BP Diastolic BP

Normal <120 and <80

Pre-hypertension 120-138 or 80-89

Stage 1 hypertension 140-159 or 90-99

Stage 2 hypertension > 160 or > 100

Cardiovascular risk in “non-hypertensives”Vassan et al, New Eng J Med 2001; 345: 1291-7. Framingham.

Framingham life expectancy 2005Franco et al, Hypertension 2005; 46: 280-6.

0 10 20 30 40

Normal BP

High normal

Hypertension

Normal BP

High normal

Hypertension

Life expectancy at age 50

Free of CVD

With MI

With stroke

With other CVD

Women

Men

Metropolitan Life Insurance Company

A man age 36 with a blood pressure of 150/100 will die before he reaches the retirement age of

65.

FRAMINGHAM

Over the age of 45, systolic blood pressure is a better predictor of risk than diastolic pressure.

Kannel WB, Am J Cardiol 1971; 27: 335.

Systolic versus diastolicWere we taught wrongly?

1970s. Reliable long-term epidemiological surveys in Framingham and elsewhere.

1980s. Cox’s proportional hazard model enables differentiation.

1990s. Computer hardware and software readily available.

So the current views are based on facts rather than opinions.

The definition of hypertension

“Hypertension should be defined in terms of a blood pressure level above which investigation and treatment do

more good than harm”

Grimley Evans & Rose, Br Med Bull 1971

British Hypertension Society-IVJ Human Hypertens 2004;

Thresholds and targets for treatment

Thresholds.1. Low-risk patients: (No end-organ damage or diabetes &

CVD risk < 20%).

160/100.

2. High risk patients. (End-organ damage or diabetes or CVD

risk > 20%):

140/90.

Targets.1. Diabetics:

130//80.

2. All other patients:

140/85.

Prevalence of hypertensionPrimatesta et al, Hypertension 2001;38: 827-32.

Health Survey for England 1998.

0

25

50

75

100

16-19 20-29 30-39 40-49 50-59 60-69 70-79 >80

Men WomenPercent

SBP >140 mmHg

and/or

DBP >90 mmHg

Age

Hypertension control in seven countries

Wolf-Maier et al, Hypertension 2004; 43: 10-7

Age and gender adjusted hypertension control

0

10

20

30

40

50

60

70

USA CAN ITAL SP ENG GER SW USA CAN ITAL SP ENG GER SW

Percent atTarget 160/95

Percent atTarget 140/90

Opportunistic screening in general practiceBarber et al, Brit Med J 1979; i: 843.

Men aged 35-69 years : 1 doctor

0

100

200

300

400

500

40.4%(199)

23.3%(114)

13.9%(68)

77.5%

(381)

Screened

(80)

1st Year

2nd

Year

3rd

Year

Total Eligible

Number of patients screened

Diabetes in a BP clinicSalmasi et al, Amer J Hypertens 2004; 17: 483-8. London.

Normal GTT, n=41

IGT or IFG, n=35

Diabetes, n=24

Prevalence of hypertension and dyslipidaemia in men as a function of glucose tolerance

Isomaa et al, Diabetes Care 2001; 24: 683-9.

0

10

20

30

40

50

60

Normal glucosetolerance

Impaired fastingglucose

Type 2 diabetes

Pat

ien

ts (

%)

Dyslipidaemia

Hypertension

STROKE

38% SD 4

8.7<0.0001

CHD

16% SD 4

38.80.0001

REMAINING VASCULAR

DEATHS

ALL VASCULAR DEATHS*

4.8<0.00021

ALL OTHER

DEATHS

1200

1000

800

600

400

200

T

T

C

C

T C

T C

CT

Total numbers of individuals affected

% reduction in odds:

No. of SD:2P=value

* includes any deaths from unknown causes

= fatal events

T = treatment

C = control

Brit. Med. Bull. 1994: 50: 272-90

525

140

835

234

934

470

1104

560

158 170

768

964

667 670

BP control in general practiceHudson. Practice Nurse 1993; 1: 14. Holmes Chapel

0%

25%

50%

75%

100%

General practitioner Practice nurse

Good (<160/90) Fair (160-180/90-110) Poor (>180/110)

Nurse run BP clinicCurzio et al, J Human Hypertens 1990; 4: 665-70. Western Infirmary, Glasgow

80

100

120

140

160

180

0 1 2 3 4Years follow up

SBP

DBP

Nurse run clinic: (n=198) – drop out rate = 8%Conventional clinic: (n-198) – drop out rate = 34%

Nurse management of hypertensionRudd et al, Amer J Hypertens 2004; 17: 921-7. California

Early counselling and telephone follow-up

p<0.01

p<0.01

Nurse-run hypertension OP clinicCurzio et al. J Human Hypertens 1990; 4: 665.

Nurse-run clinic Conventional clinic

Moved away 4% 0

To other clinic 11% 6%

Discharged 1% 15%

Died 9% 9%

Defaulted 8% 34%

Weight loss 2.8 kg 0.5 kg

Nurse management of hypertensionRudd et al, Amer J Hypertens 2004; 17: 921-7. California

Early counselling and telephone follow-up

P<0.05

Part 2

What causes the bloody thing?

The aetiology of hypertensionRenal disease

Renovascular disease

Secondary hypertension (2-3%) Aldosterone excess

Phaeochromocytoma

Others

Salt

Low fruit & vegetables

High fat diet

Essential hypertension (97-98% Weight

Alcohol

Exercise

Genetic factors

Drug-induced hypertension and interactions with antihypertensive drugs

Oestrogen-only oral contraceptives

LiquoriceOral & topical

corticosteroidsCold cures & nasal

decongestantsCyclosporinErythropoetin

Methysergide

Monoamine oxidase inhibitors

Narcotic abuse

Alcohol excess

Sibutramine

NSAIDS & coxibs

Lithium

Ever popular terms like “ idiopathic” and “essential” are actually

nonsensical as all diseases must have causes

Geoffrey Rose, Reflections on changing times. Brit Med J 1990; 301: 683-7

Family history and hypertensionStamler et al, JAMA 1979; 241: 43-6.

Percent of population with DBP 95 mmHg or more.Whites Blacks

Men Women Men Women All

Positive family history (%)

36.9 33.6 50.5 40.0 35.9

Negative family history (%)

22.1 19.5 36.3 22.2 21.8

Montreal Adoption StudyMongeau et al, Clin Exper Hypertens 1986; 8: 653-60

Correlation coefficients;

* p<0.001, † p<0.01

0.38*

Diastolic BP

0.53*

Systolic BP

0.26*

0.27* 0.29*

0.13†

0.21† 0.10

0.18

0.160.19

0.27*

0.24* 0.08

0.09

AANN

AANN

0.15*

Stress and hypertension

Whilst acutely stressful stimuli cause an acute rise in blood

pressure,

there is no convincing evidence that chronic stress causes

hypertension

Meta-analysis of salt intake v systolic BP Law et al, BMJ 1991; 302: 811

Age 20-29

SBP

Age 40-49

Age 60-69

0 100 200 300 400

Sodium Intake (mmol/24h)

Developed

Underdeveloped100

120

140

160

180

100

120

140

160

100

120

140

160

The effect on systolic BP (A) and diastolic BP (B) of reduced sodium intake and the DASH Diet.

Sacks FM, New Eng J Med 2001; 344: 3-10

412 subjects - normotensive + hypertensive - randomised to diet rich in veg & low fat & 3 levels of salt intake.7.1 mmHg normotensives11.5 mmHg hypertensives

Exercise and blood pressureWallace et al, Amer J Hypertens 1997; 10: 728-34. Indiana

25 untreated mildly hypertensive patients

Kaiser Permanente multiphasic health examination data

Klatsky et al, New Eng J Med 1977; 296 1194-2000.

Effects of obesityWestern Europe

Haslam & James. Lancet 2005; 366: 1197-209.

0 500 1000 1500 2000

Women

Men

Disability-adjusted life-years lost due to obesity x103

CHD

Hypertension

Stroke

Diabetes

Colon cancer

Endometrial cancer

Breast cancer

Osteoarthritis

Obesity and hypertensionHaemodynamic profile

Weir et al, Amer J Med 1991; 90 (suppl A): 5-14

1. High cardiac output2. Expanded plasma volume3. Increased salt sensitivity and intake4. Normal or decreased renin-angiotensin activity5. Normal or decreased peripheral resistance6. Raised sympathetic nervous system activity,

plasma adrenalin & noradrenalin 7. Insulin resistance

Blood pressure change with dietReisin et al, Ann Intern Med 1983; 98: 315-9

-20 -15 -10 -5 0 5 +10 +15

Change in weight (kg)

Change in MAP(mmHg)

+15

+10

+5

0

-5

-10

-15

-20

r = .49p < 0.05

SummaryCauses of hypertension

Unmodifiable

Family history

ModifiableSalt salt salt

Fruit & vegetablesAnimal fatObesity

Alcohol excessLack of exercise

Underlying renal adrenal diseases

Millions of undiagnosed, untreated & undertreated hypertensives

The existing structure of health-care delivery has failed to solve the problem

The primary health-care team can potentially improve things.

It’s time the nurses took over.

……but only if they receive adequate postgraduate training.