Noncommunicable diseases A global overview David Leon Outline
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 Males Females 1 -14 25 -44 45 -64 65 -74 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% 10
Urbanisation 11
12 http: //www. indiaimages. com/street_life 2_large. jpg
Urbanisation 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. 14
Global Burden of Disease (GBD) Study 15
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 16
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_2 004 update_full. pdf 18
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 22
Combining data … Prospective studies collaboration 23
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 25
Cardiovascular mortality: Age-specific effects for 20 mm. Hg 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· 7 1· 0 Relative risk (& 95% CI) for 20 mm. Hg 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 31
% of deaths aged 35 -69 years attributable to smoking in 2000 Men Women Belarus 33% 0% Russia Ukraine 33% 32% 3% 3% Central Asia (8) Estonia Latvia Lithuania United Kingdom Germany 23% 31% 30% 29% 25% 29% 4% 3% 2% 0% 21% 11% 32 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. 33
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 34 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
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Some non-communicable diseases have infectious etiology 40
Age standardised mortality per 100, 000 Trends in stomach cancer mortality Source : WHO HFA database 41
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, Mc. Gechie DB, Glancy RJ. Attempt to fulfil Koch's postulates for pyloric Campylobacter. Med. J. Aust. 1985; 142: 436 -9. 43
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 44
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