smoking and health professor martin jarvis department of epidemiology & public health
TRANSCRIPT
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
1950 1975 2000 2025 2050
Year
0
100
200
300
400
500
Cu
mu
lati
ve d
eath
s fr
om
to
bac
co (
mil
lio
ns)
Scenarios for future deaths from tobacco
Trend
520
70
220
Source: Peto et al
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
-10 0 10 20 30 40 50 60 70
Time (mins)
0
5
10
15
20
25
30
35
40
Nic
oti
ne C
on
cen
trati
on
(n
g/m
l)
Schematic Diagramof Arterial vs Venous
Nicotine Levels
Venous
Arterial
cigarette
smoked
Nicotine Addiction in Britain
Royal College of Physicians Feb 2000
• “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.”
Central conclusion: smoking is best understood as nicotine seeking behaviour
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
0 10 20 30 40
Prevalence of regular drug use:adults aged 16-64, GB 1993-1994
32
22
2
0
0
0
0
0
Cigarette smoking %
Drinking above
recommended limits
Marijuana
Tranquillizers
sleeping pills
Amphetamines
Opiates
Cocaine
Psychedelics
hallucinogens
OPCS Psychiatric Morbidity Survey: Meltzer et al 1995 Base n=9792
Regular drug user = every day for 2 weeks or more in past 12 months
Abstainer Occasional Light Moderate Fairly heavy Heavy Very heavy0
5
10
15
20
25
30
35
40
45
Ne
uro
tic
dis
ord
er
%Neurotic disorder % by drinking habits
GB 1993-1994
Alcohol drinking habits
Never smoker Ex 3-4 5-6 7-8 9-10 11-12 13-140
5
10
15
20
25
30
35
40
45
Ne
uro
tic
dis
ord
er
%Neurotic disorder % by smoking habits
GB 1993-1994
Tobacco dependence score
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 yourfirst cigarette of the day?
Less than Between Between Between Between Longer5 minutes 5 and 15 15 and 30 30 min. 1 and 2 than 2
minutes minutes and 1 hr hours hours
2. How easy or difficult would you find it to gowithout smoking for a whole day?
Very easy Fairly easy Fairly difficult Very difficult
3. How many cigarettes do you usually smokeeach day?
1-10 11-20 21-30 31+
0
5
10
15
20
25
30
Per
cen
tag
e o
f sm
oke
rs
DISTRIBUTION OF TIME TO FIRST CIGARETTEIN SMOKERS IN PRIMARY CARE
"How soon after waking do you smokeyour first cigarette of the day?"
Less than
5 minutes
5-15
minutes
15-30
minutes
30 min
to 1 hr
1 to 2
hours
More than
2 hours
50
100
150
200
250
300
350
400
450
Sal
iva
coti
nin
e (n
g/m
l)
Mean + 95% CI-
TIME TO FIRST CIGARETTE OF THE DAY
Less than
5 minutes5-15
minutes
15-30
minutes
30 min
to 1 hr
1 to 2
hours
More than
2 hours
n=307n=182n=214n=205n=322n=260
0 1 2 3 4 5 6 7 8 9 10 110
110
220
330
440
550
Sa
liv
a c
oti
nin
e (
ng
/ml)
SALIVA COTININE BY DEPENDENCE INSMOKERS IN PRIMARY CARE
Mean + 95% CI
DEPENDENCE SCALE SCORE
N = 160 108 381431361491209996108130 73
0 1 -4 5 -9 1 0 -1 4 1 5 -1 9 2 0 -2 4 2 5 -2 9 3 0 +0
1
3
Pla
sma
cotin
ine
(ng/
ml)
P ar tner 's daily cigar ette consum ption
Geometric mean ± 95%CI
0 .5
2
0 1-4 5-9 10-14 15-19 20-24 25-29 30+0.0
0.5
1.0
1.5
2.0
2.5
Pla
sm
a c
oti
nin
e (
ng
/ml)
PASSIVE SMOKING: COTININE IN ADULTSBY PARTNER'S CIGARETTE CONSUMPTION
Partner's daily cigarette consumption
Geometric mean + 95%CI
Health Survey for England
1994 &1996
8328 234 231 259 155 294 79n= 60
1972 1976 1980 1984 1988 1992 1996
0
10
20
30
40
50
60
% p
reva
len
ceCIGARETTE SMOKING 1972-1998:
GB: General Household Survey
Men
Women
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
0 1 2 3 4 50
10
20
30
40
50
60
70
80
% p
rev
ale
nc
e
CIGARETTE SMOKING BY DEPRIVATIONIN GREAT BRITAIN: GHS 1973 & 1998
1973
1998
DEPRIVATION SCOREMost affluent Poorest
0 1 2 3 4 50
10
20
30
40
50
60
70
80
% q
uit
SMOKING CESSATION BY DEPRIVATIONIN GREAT BRITAIN: GHS 1973 & 1998
1973
1998
DEPRIVATION SCOREMost affluent Poorest
0 1 2 3 4
200
250
300
350
Pla
sm
a c
oti
nin
e (
ng
/ml)
Plasma cotinine by deprivationin adult smokers: HSE 1993-1996
1993
1994
1996
DEPRIVATION SCORE
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
0 - .1 .1- .2- .4- .5- .6- .7- .8- .9- 1.0 +
Cigarette nicotine yield (mg)
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Nic
oti
ne
in
tak
e p
er
cig
are
tte
(m
g)
Predicted and actual nicotine intakes per cigarettesmoked by nominal nicotine yield of usual brand
Predicted
Health Survey for England 1998
0 - .1 .1- .2- .4- .5- .6- .7- .8- .9- 1.0 +
Cigarette nicotine yield (mg)
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Nic
oti
ne
in
tak
e p
er
cig
are
tte
(m
g)
Predicted and actual nicotine intakes per cigarettesmoked by nominal nicotine yield of usual brand
Actual Predicted
Health Survey for England 1998
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%
1950 1975 2000 2025 2050
Year
0
100
200
300
400
500
Cu
mu
lati
ve d
eath
s fr
om
to
bac
co (
mil
lio
ns)
Scenarios for future deaths from tobacco
Trend
520
70
220
Source: Peto et al
1950 1975 2000 2025 2050
Year
0
100
200
300
400
500
Cu
mu
lati
ve d
eath
s fr
om
to
bac
co (
mil
lio
ns)
Scenarios for future deaths from tobacco
If smokinguptake halves
by 2020
Trend
520
70
220
500
Source: Peto et al
1950 1975 2000 2025 2050
Year
0
100
200
300
400
500
Cu
mu
lati
ve d
eath
s fr
om
to
bac
co (
mil
lio
ns)
Scenarios for future deaths from tobacco
If adult smokinghalves by 2020
If smokinguptake halves
by 2020
Trend
520
70
220
190
500
340
Source: Peto et al
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