Transcript Non-communicable diseases. A global overview

Non-communicable diseases
A global overview
David Leon
Outline
• Definition
• Non-communicable disease mortality
worldwide
• The Epidemiological Transition
• Global Burden of Disease Study
• Major risk factors
– Blood pressure
– Cholesterol
– Smoking
• Infection and non-communicable diseases
2
What are noncommunicable diseases?
3
Classifying deaths and diseases
(WHO)
• Communicable diseases [Group I]
– Those where death is directly due to the
action of a communicable agent
• Non-communicable diseases
– Diseases [Group II]
• Cancer, diseases of various organ systems (eg
respiratory, cardiovascular etc.), diabetes, mental
health etc.
– External causes (injuries, poisonings and
violence) [Group III]
4
Importance of noncommunicable diseases
mortality
5
A global problem
• In 2004 there were 59 million deaths
world-wide
• Non-communicable diseases accounted
for 60% of these deaths and injuries
and violence 10%.
• By 2020 it is estimated that noncommunicable disease will account for
73% of all deaths
GBD 2004 Update, 2008
6
The epidemiologic transition
(Omran, 1971)
Change in the balance of disease in
a population
from
communicable diseases
to
non-communicable disease
7
Decline in proportion of total
mortality due to infectious diseases
England & Wales, 1911-94, by age
0.6
0.6
Females
Males
0.5
1-14
0.5
0.4
0.4
0.3
0.3
25-44
0.2
0.2
45-64
0.1
0.1
65-74
0
0
1911 1921 1931 1941 1951 1961 1971 1981 1991
1911 1921 1931 1941 1951 1961 1971 1981 1991
8
Different countries at different
stages of the epidemiological
transition
9
Non-communicable diseases as % of all
deaths by global region
(all ages)
WORLDWIDE
59%
N.America; W Europe
88%
China, W Pacific, + some SE Asia 75%
Latin America + Caribbean
67%
S E Asia including India
51%
Sub-Saharan Africa
21%
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Urbanisation
11
12
http://www.indiaimages.com/street/street_life2_large.jpg
Urbanisation
100
90
North America
80
Europe
70
Oceania
60
WORLD
Asia
50
Africa
40
30
2007
Urban population as % of total
Latin America & Caribbean
20
10
0
1950
1960
1970
1980
1990
2000
2010
2020
2030 13
Drivers of the epidemiological
transition in low and middle
income countries
• Population ageing
• Major socio-economic changes (especially
urbanisation)
– changes in risk factors such as diet, physical
activity, smoking etc.
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Global Burden of Disease
(GBD) Study
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GBD 2001 mortality estimates
• 107 countries had collected “useable”
information on cause of death from
registration systems
• 55 countries (42 in sub Saharan Africa) no
information on adult mortality
• Estimates based on many assumptions
and extrapolations
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Global Burden of Disease Study
• First GBD study started in 1992 by World
Bank.
• Second GBD study (in collaboration with
WHO) conducted 2001
• Extensive synthesis of all available data to
give set of mortality estimates by age, sex,
region and cause worldwide – for the first
time
• 2001 GBD study covers 135 causes of
death, 17 sub-regions, based on
aggregation of country-level information 17
Global Burden of Disease
2004 Update
(published 2008)
http://www.who.int/healthinfo/glob
al_burden_disease/GBD_report_2
004update_full.pdf
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Distribution of deaths in the world
by sex, 2004
19
GBD report 2004 update, 2008
Mortality rates among men and women aged 15–
59 years, region and cause-of-death group, 2004
GBD report 2004 update, 2008
20
Projected global deaths for selected
causes, 2004–2030
21
GBD report 2004 update, 2008
Effect of key risk factors on
mortality
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Combining data …
Prospective studies collaboration
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Prospective Studies
Collaboration
• Established chiefly to investigate associations of blood
pressure and cholesterol with cause-specific mortality
• Individual data on 900 000 participants without any
previous history of vascular disease from 61 prospective
cohort studies
• 55 000 vascular deaths (34 000 ischaemic heart disease
[IHD], 12 000 stroke, 10 000 other)
Blood pressure and
cardiovascular mortality
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Cardiovascular mortality: Age-specific
effects for 20 mmHg lower usual SBP
55 345 deaths at ages 40-89
Age
Stroke 40-49
50-59
60-69
70-79
80-89
IHD
Number
deaths
414
1372
2939
4327
2636
40-49
1322
50-59
5594
60-69 10 450
70-79 10 852
80-89
5649
Other 40-49
vascular
50-59
60-69
70-79
80-89
386
1377
2549
3227
2251
0·36 (0·32-0·40)
0·38 (0·35-0·40)
0·43 (0·41-0·45)
0·50 (0·48-0·52)
0·67 (0·63-0·71)
0·49 (0·45-0·53)
0·50 (0·49-0·52)
0·54 (0·53-0·55)
0·60 (0·58-0·61)
0·67 (0·64-0·70)
0·43 (0·38-0·48)
0·50 (0·47-0·54)
0·53 (0·51-0·56)
0·64 (0·61-0·67)
0·70 (0·65-0·75)
0·25 0·35 0·5 0·7 1·0
Relative risk (& 95% CI) for
20 mmHg lower usual systolic BP
December 02
26
Cholesterol and
cardiovascular mortality
27
Ischaemic Heart Disease mortality (33 744 deaths)
and total cholesterol
Age at
risk
256
80-89
128
70-79
Hazard ratio
( 95% CI)
64
60-69
32
50-59
16
40-49
8
4
2
1
0·5
4·0
5·0
6·0
7·0
8·0
Usual total cholesterol (mmol/L)
Different for stroke
29
Stroke mortality (11 663 deaths) and total cholesterol by age
64
Age
80-89
32
Hazard ratio
(& 95% CI)
16
70-79
8
4
60-69
2
40-59
1
4·0
5·0
6·0
7·0
8·0
Usual total cholesterol (mmol/L)
Smoking
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% of deaths aged 35-69 years
attributable to smoking in 2000
Men
Women
Belarus
33%
0%
Russia
33%
3%
Ukraine
Central Asia (8)
Estonia
32%
23%
31%
3%
4%
3%
Latvia
Lithuania
30%
29%
2%
0%
United Kingdom
Germany
25%
29%
21%
11%
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Source : http://www.deathsfromsmoking.net/
Odds Ratio of Myocardial Infarction
Risk of myocardial infarction increases with
every single cigarette smoked per day
INTERHEART study
52 countries
12 461 cases, 14 637 controls
Never
1-2
3-4
5-6
7-8
9-10 11-12 13-14 15-16 17-18 19-20
>=21
Number of cigarettes smoked per day
Source : K. K. Teo et al Tobacco use and risk of myocardial infarction in 52 countries in the INTERHEART study
Lancet 368 (9536):647-658, 2006.
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Smoking causes more deaths from
cardiovascular disease than cancer
Deaths attributed to smoking
among men (all ages) in Russia, 2000
All cancers = 77,000
Cardiovascular disease = 148,000
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Source : http://www.deathsfromsmoking.net/
Things are getting worse
not better
35
Smoking in men in Russia
is not declining
Rural
Urban
St Petersburgh/Moscow
Source : Perlman et al Tob.Control 16 (5):299-305, 2007
Russian Longitudinal Monitoring Survey
36
Smoking in women in Russia
is increasing
Source : Perlman et al Tob.Control 16 (5):299-305, 2007
St Petersburgh/Moscow
Urban
Rural
Russian Longitudinal Monitoring Survey
37
Giving up smoking reduces risk
38
39
Some non-communicable
diseases have infectious
etiology
40
Age standardised mortality per 100,000
Trends in stomach cancer mortality
41
Source : WHO HFA database
Helicobacter pylori bacterium - a causal factor for stomach cancer
42
The Helicobacter pylori story …...
Marshall BJ,.Warren JR. Unidentified curved bacilli in the
stomach of patients with gastritis and peptic ulceration.
Lancet 1984;1:1311-5.
Marshall BJ, Armstrong JA, McGechie DB, Glancy RJ.
Attempt to fulfil Koch's postulates for pyloric
Campylobacter. Med.J.Aust. 1985;142:436-9.
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Summary
• Non-communicable diseases are now the most
common cause of death world wide
• Increasing rates in low and middle income
countries because of change in lifestyles
(urbanisation)
• Key risk factors have very large effects
• Interventions are effective and can reduce
burden
• The need to combine results and have large
studies
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