Transcript Smoking and health - University College London

Smoking and health
Professor Martin Jarvis
Department of Epidemiology &
Public Health
Smoking as nicotine dependence
• Nicotine the driving force
• As with other drugs, complex interplay
between pharmacology, learning
mechanisms, social and economic
influences in determining patterns of
use
The major health consequences of
smoking
• Cancer
– lung
– mouth, larynx, throat, oesophagus
– bladder, cervix, kidney, pancreas
• COPD
• Coronary heart disease
• Stroke
• Peripheral vascular disease
• Pregnancy and birth complications
Mortality associated with smoking
• At least 320 deaths every day from smoking in
the UK, 120,000 per year
• 1/5 all deaths across all ages
• 1/4 all deaths in age group 35-64 years
• 1 in 2 lifetime risk for smokers
• 7.5 years average loss of life expectancy
• Over half of the difference in risk of death in
middle age between professional and unskilled
men
• 4 million deaths worldwide
Cumulative deaths from tobacco (millions)
Scenarios for future deaths from tobacco
520
500
Trend
400
300
220
200
70
100
0
1950
1975
2000
Year
Source: Peto et al
2025
2050
Smoking is highly addictive
• At least 70% of smokers want to give up
• Less than half succeed before age 65
• 40% of heart attack smokers relapse while still
in hospital within 2 days of intensive care
• 50% of patients with laryngectomies try
smoking again
• 50% of patients with lung removed for lung
cancer smoke again
• More than half of heroin and cocaine users and
alcoholics rate smoking harder to quit
Addiction
Starting point - the cigarette
“The cigarette should be conceived not as a
product but as a package. The product is
nicotine. Think of the cigarette pack as a
storage container for a day’s supply of
nicotine….Think of the cigarette as the
dispenser for a dose unit of nicotine…..Smoke
is beyond question the most optimised vehicle
of nicotine and the cigarette the most
optimised dispenser of smoke”.
William Dunn, Philip Morris, 1972
Sc h e m a tic Dia gra m
o f Arte ria l v s Ve n o u s
Nic o tin e L e v e ls
40
Ni coti ne Concentrati on (ng / ml )
35
30
Arte ri a l
25
20
Ve n o u s
15
10
5
0
- 10
0
10
20
30
40
Ti me (mi ns)
c i g a r e t t e
s m o k e d
50
60
70
Nicotine Addiction in Britain
Royal College of Physicians Feb 2000
Central conclusion: smoking is best
understood as nicotine seeking
behaviour
• “Nicotine delivered rapidly to the brain in
cigarette smoke should be recognised as a
powerfully addictive drug on a par with heroin
and cocaine, and tobacco products should
be recognised as nicotine delivery systems.”
Rating IV nicotine and cocaine:
Jones et al (1999)
• Compared 3 doses of cocaine and
nicotine given IV double-blind + saline
placebo
• Nicotine ‘high’ and ‘rush’ rated stronger
than cocaine, also ‘jittery’
• Nicotine frequently misidentified as
cocaine, and, at highest dose, an opiate
Pre v a le nc e of re gula r drug us e :
a dults a ge d 1 6 -6 4 , GB 1 9 9 3 -1 9 9 4
Ci gar et t e sm oki ng %
3 2
Dr i nki ng above
2 2
r ecom m ended l i m i t s
2
M ar i j uana
Tr anqui l l i z er s
sl eepi ng pi l l s
0
Am phet am i nes
0
O pi at es
0
Cocai ne
0
Psychedel i cs
hal l uci nogens
0
0
1 0
2 0
3 0
Regul ar dr ug user = ever y day f or 2 w eeks or m or e i n past 12 m ont hs
O PCS Psychi at r i c M or bi di t y Sur vey: M el t z er et al Base
1995 n=9792
4 0
Ne urotic dis orde r % by drink ing ha bits
GB 1 9 9 3 -1 9 9 4
45
N eurot i c di sorder %
40
35
30
25
20
15
10
5
0
Abst ai nerO ccasi onal
Li ght
M oder at Fai
e r l y heavy Heavy
Alc o h o l d rin k in g h a b its
Ver y heavy
Ne urotic dis orde r % by s m ok ing ha bits
GB 1 9 9 3 -1 9 9 4
45
N eurot i c di sorder %
40
35
30
25
20
15
10
5
0
Never sm oker Ex
3- 4
5- 6
7- 8
9- 10
11- 12
Tobacco dependence score
13- 14
Nicotine as a drug of dependence
• Blood nicotine from cigarettes, snuff
(oral and nasal) and cigars very similar
• IV nicotine suppresses smoking
• Nicotine intakes from different brands of
cigarette very similar
Nicotine as a drug of dependence
• Nicotine withdrawal syndrome
• Effect of nicotine replacement on
successful quitting
Self-assertion . . .
“To account for the fact that the beginning
smoker will tolerate the unpleasantness
we must invoke a psychosocial motive.
Smoking a cigarette for the beginner is a
symbolic act. The smoker is telling his
world, 'This is the kind of person I am.'
Surely there are variants of this theme, 'I
am no longer my mother's child,' 'I am
tough,' 'I am not a square.' Whatever the
individual intent, the act of smoking
remains a symbolic declaration of
personal identity . . .” Philip Morris (Bates no. 1003287836)
. . . and addiction
“ . . . As the force from the
psychosocial symbolism subsides,
the pharmacological effect takes
over to sustain the habit . . .”
Philip Morris 1969 document (Bates no. 1003287836)
Addiction -
Factors favouring study of smoking as
compared with other drug taking
behaviours
• High prevalence
• Legal
• Little stigma, so self-reports largely
accurate
• Unlike alcohol, excellent biomarker
of intake available
Cotinine as a biomarker of nicotine
intake
• Main nicotine metabolite (70-80% converted)
• Half-life 16-20 hours
• Measurable in saliva, blood or urine
• Quantitative measure of nicotine intake:
10ng/ml cotinine in blood ~ 1mg nicotine
daily
Brief dependence scale
1. How soon after waking do you smoke your
first cigarette of the day?
Less than
5 minutes
Between
5 and 15
minutes
Between
15 and 30
minutes
Between
30 min.
and 1 hr
Between
1 and 2
hours
Longer
than 2
hours
2. How easy or difficult would you find it to go
without smoking for a whole day?
Very easy
Fairly easy
Fairly difficult
Very difficult
3. How many cigarettes do you usually smoke
each day?
1-10
11-20
21-30
31+
DI STRI BUTI O N O F TI M E TO FI RST CI G ARETTE
I N SM O KERS I N PRI M ARY CARE
Per cent age of sm oker s
30
" Ho w
y our
soon af t er w aki ng do you sm oke
f i r s t c i ga r e t t e of t he da y ?"
25
20
15
10
5
0
Sal i va cot i ni ne ( ng/ m l )
15- 30 30 m i n 1 t o M
2 or e t han
Less t han 5 - 1 5
5 m i n u t ems i n u t e sm i n u t e s t o 1 h r h o u r s 2 h o u r s
450
400
350
300
250
200
150
M
100
e a n
+
-
9 5 %
C I
50
L e s s
t h a n5 - 1 5
1 5 - 3 0 3 0
5
m i n um
t e is n u t me s i n u t e t s o
n = 2 6 0
T I M
E
T O
n = 3 2 2
n = 2 0 5
F I RS T
CI G
m
1
i n1
t o M2 o r e
t h a n
h rh o u r s 2
h o u r s
n = 2 1 4
ARE T T E
n = 1 8 2
O
F
n = 3 0 7
T HE
DAY
Sa liv a c otinine (ng/m l)
SALIVA COTININE BY DEPENDENCE IN
SM OKERS IN PRIM ARY CARE
550
440
330
220
110
M ean + 95% CI
0
N =
0
1
130
108
2
96
3
99
4
5
6
7
8
9
10
11
120
149
136
143
160
108
73
38
DEPENDENCE SCALE SCORE
3
Plasma cotinine (ng/ml)
2
1
0 .5
Geometri c mean ± 95%CI
0
0
1 -4
5 -9
1 0 -1 4
1 5 -1 9
2 0 -2 4
2 5 -2 9
P ar tner 's daily cigar ette consum ption
30+
Pla s m a c otinine (ng/m l)
PASSI VE SMOKI NG: COTI NI NE I N ADULTS
BY PARTNER'S CI GARETTE CONSUMPTI ON
2. 5
Heal t h Survey f or Engl and
1994 &1996
2. 0
1. 5
1. 0
0. 5
G eomet ri c mean + 95%CI
0. 0
0
1- 4
5- 9
10- 14
15- 19
20- 24
25- 29
30+
Part ner's dai l y ci garet t e consumpt i on
n=
8328
234
231
259
155
294
60
79
CI GARETTE SMOKI NG 1972- 1998:
GB: General Househol d Survey
% pre v a le nc e
60
Men
50
40
Women
30
20
10
0
1972
1976
1980
1984
1988
1992
1996
Disadvantage and Smoking
• A whole range of indicators of
disadvantage predict who smokes
• Cigarette smoking prevalence tightly
linked to deprivation, mainly because of
low rates of quitting in disadvantaged
groups
Indicators of socio-economic
status
•
•
•
•
•
•
•
•
Occupational class
Educational level
Housing tenure
Car ownership
Unemployment
Living in crowded accommodation
Single parenthood
Divorced or separated
Disadvantage and smoking
• Poor people are:
– More likely to take up smoking
– Less likely to quit
– More heavily exposed to other people’s
smoke
– Become more nicotine dependent
– Much more likely to die prematurely
from smoking
CIGARETTE SMOKING BY DEPRIVATION
IN GREAT BRITAIN: GHS 1973 & 1998
80
% prevalence
70
60
50
1973
40
1998
30
20
10
0
0
Most affluent
1
2
3
DEPRIVATION SCORE
4
5
Poorest
SMOKING CESSATION BY DEPRIVATION
IN GREAT BRITAIN: GHS 1973 & 1998
80
70
% quit
60
50
1973
40
1998
30
20
10
0
0
Most affluent
1
2
3
DEPRIVATION SCORE
4
5
Poorest
Pla s m a c otinine by de priv a tion
in a dult s m ok e rs : HSE 1 9 9 3 -1 9 9 6
P l asma cot i ni ne ( ng/ ml )
350
300
1993
1994
250
1996
200
0
1
2
3
DEPRI VATI O N SCO RE
4
Some implications of nicotine addiction for
cessation and harm reduction
• Ineffective
• cutting down
• switching to cigars or a pipe
• switching to low tar
• Effective
• Nicotine replacement products
N i cot i ne i nt ake per ci garet t e ( mg)
Pre dic te d a nd a c tua l nic otine inta k e s pe r c ig
s m ok e d by nom ina l nic otine y ie ld of us ua l
1. 6
Heal t h Survey f or Engl and 1998
1. 4
1. 2
1. 0
0. 8
0. 6
0. 4
0. 2
0 - .1
. 1-
. 2-
. 4-
. 5-
. 6-
. 7-
. 8-
Ci garet t e ni cot i ne yi el d ( mg)
Pr edi ct ed
. 9-
1. 0 +
N i cot i ne i nt ake per ci garet t e ( mg)
Pre dic te d a nd a c tua l nic otine inta k e s pe r c ig
s m ok e d by nom ina l nic otine y ie ld of us ua l
1. 6
Heal t h Survey f or Engl and 1998
1. 4
1. 2
1. 0
0. 8
0. 6
0. 4
0. 2
0 - .1
. 1-
. 2-
. 4-
. 5-
. 6-
. 7-
. 8-
Ci garet t e ni cot i ne yi el d ( mg)
Act ual
Pr edi ct ed
. 9-
1. 0 +
One year success rates by intensity of
intervention:
• Unaided quit attempt …………………...…..….1-2%
• Brief GP advice ……………………………...……5%
• Brief GP advice + NRT ……………………….…10%
• Intensive clinic support ………………………...15%
• Intensive clinic support + NRT……………..20-30%
Cumulative deaths from tobacco (millions)
Scenarios for future deaths from tobacco
520
500
Trend
400
300
220
200
70
100
0
1950
1975
2000
Year
Source: Peto et al
2025
2050
Cumulative deaths from tobacco (millions)
Scenarios for future deaths from tobacco
520
500
500
If smoking
uptake halves
by 2020
Trend
400
300
220
200
70
100
0
1950
1975
2000
Year
Source: Peto et al
2025
2050
Cumulative deaths from tobacco (millions)
Scenarios for future deaths from tobacco
520
500
500
If smoking
uptake halves
by 2020
Trend
400
340
300
220
200
If adult smoking
halves by 2020
190
70
100
0
1950
1975
2000
Year
Source: Peto et al
2025
2050
Conclusions
• Nicotine’s legal status and lack of
adverse effects on performance have
hampered recognition of its status as a
drug of dependence
• Nicotine is pharmacologically a hard
drug, on a par with heroin and cocaine
• Cigarette smoking is by far the biggest
problem of drug dependence in the UK