airwaysdisease;forthespeciicmedicaldiagnosisof“asthma,”thisassociationisless clear
[183] .Theyoungerthechildrenaffected,themoredeinitetheassociationofpassive
smokingwiththebronchiticandasthmaticsymptoms,asalsorelectedinhospitaladmis- sions
[183–187] .Incontrasttomaternalsmoking,paternalsmokingwasnotfoundtoexert
anysigniicanteffect.AtendencyforcoldstogotothechestandforreducedFEV
75
and FEV
85
hasbeenshowntocorrelatedirectlywithsalivarycotininelevels [185]
. One sociomedical study showed an association between maternal smoking and a
medicaldiagnosisofasthmainthechildonlywherethemothershad12orfeweryearsof education
[188] .
Theuseofpulmonaryfunctionmeasurements,bronchialhyperresponsivenessmeasure- mentsandskinpricktestsasatopymarkerstopermitanobjectivediagnosisofasthmahas
yieldeddifferingconclusionsconcerningtheassociationbetweenchildhoodasthmaand passivesmoking
[155,178,179,182,185,189,190] .Themajorityofstudiesinwhich
pulmonaryfunctionhasbeenmeasuredrevealadecreaseinfunctionalindicesinpassive smokingchildren.Twostudiesshowednoassociation
[178,190] .Theinluenceofpassive
smokingonskinpricktestresultsiscontroversial [188,191,192]
.
5 27
55 Weeks after birth
50 100
Vmax FCR [mls]
150 200
250 Fig. 5.5
Maximum expiratorylowatfunctional
residualcapacityduringthe irstyearoflife.♦Healthy
controlgroup;■childrenof womenwhosmoked;
▲
total cohort
[180]
Asthma severity Lung function
FEV1 PC20; histamine [mgml]
Mother Nonsmoker
Smoker Nonsmoker
Smoker Bronchial responsiveness
Score Mother
10 100
80 60
40 20
.03 .06
125 .25
.5 1
2 4
8 16
5
Fig. 5.6
Passivesmokingandchildhoodbronchialasthma.Theigureillustratesasthmaseverity, theextentofreducedpulmonaryfunctionandtheincreasedbronchialresponsivenesstohistamine.
Studyconductedin94childrenagedbetween7and17yearswithahistoryofasthma.Ineachcase, thepairsofcolumnsrepresentnon-smokingandsmokingmothersfrom
[181]
SerumIgElevelsandprevalenceofeosinophiliawerereportedtobeincreasedinone studyin9-year-oldchildrenofsmokingparents
[193] ;likewise,elevatedIgElevelshave
beendetectedinthecordseruminchildrenofsmokingmothers [77,194]
.Childrenwhose parentssmokedduringpregnancydisplayedmoreintensereactionsfollowinghistamine
challenge [195]
. Bronchial responsiveness as tested by challenge methods was consis- tentlyincreasedinasthmatic,passivelysmokingchildren
[188,189,196,197] .
Passivesmokingalsorelectstheasthmaofaffectedchildrenincreasedoccurrenceof exacerbations,butnotthefrequencyofhospitaladmissions
[198–200] .Theassociationwas
clearbetweenmaternalsmokingnumberofcigarettesandthedeteriorationofpulmonary functiontogetherwithincreasedhistamineresponsiveness,withtheeffectonlungfunction
occurringprincipallyduringcoldwetweather [197]
.Whenparentalmaternalcigarette consumptionwasrestricted,childhoodasthmastatusandlungfunctionimproved
[181] .
Tosummarise,itmaybeconcludedthatthereisaclearassociationbetweenpassivesmok- ingandchildhoodobstructiveandnon-obstructiveairwaysdisease,withsmokeexposure
apparentlyexacerbatingpulmonaryfunctionandthecourseofasthma.However,thereisas yetnoconvincingevidencethatasthmaticdiseasesaredirectlycausedbypassivesmoking.
5.5 Bronchitis and Pneumonia
Activesmokingprovokesacuterespiratorytractdiseases.Whilerespiratorytractdiseases arenotfoundmorecommonlyinsmokersthaninnon-smokers,whentheydooccur,the
lowerrespiratorytractismoreofteninvolved,leadingtoamoreprotracteddurationof coughandmorefrequentpathologicalindingsonauscultation
[201,202] .Inonecohort
studyinmalecollegestudents,smokerswerefoundtohaveasigniicantlyhighernumber ofdoctorvisitsandanevenhighernumberofmedicalconsultationsforrespiratorytract
symptoms [203]
.Acleardose–responserelationshipwasfoundbetweensmokingdura- tionconsumptionandthenumberofdoctorvisitsforrespiratoryproblems.Inthesmoker
group,coldsweremorecommonlyassociatedwithcough,mucusproduction,shortnessof breathandrhonchi
[204] .
Forchildren,passivesmokinghaslongbeenregardedasariskfactorforthedevelop- mentoflowerrespiratorytractdiseases.IntheUSA,eachyear,150,000–300,000children
belowtheageof18monthsarereportedtosufferfromrespiratorytractinfectionsbron- chitisorpneumoniaasaresultofpassivesmokingathome
[4] .
Activecigarettesmokingisassociatedwithahighercomplicationriskforpneumonia, especiallyinluenzapneumonia:inonegroupof250,000veterans,mortalityfrominlu-
enzapneumoniawas1.78timeshigheramongsmokersthanamongnon-smokers [142]
. TheincidenceandseverityofinluenzaAH1-N1arealsoincreasedinsmokers50vs.
30fornon-smokers [46]
.Duringasevereinluenzaepidemic,theincidenceofclinical aswellassubclinicalinfectionsbasedonantibodytitreswasincreasedamongsmokers
[205] ;whilesmokingexertednoeffectondiseaseseverity,thepersistenceofantibody
titresinsmokerswasreduced.Thismaybeonereasonforincreasedsusceptibilitytoinlu- enzainfections
[206] .
5.6 Other Lung Diseases Influenced by Cigarette Smoking
Thiscategoryprincipallyincludesarespiratorybronchiolitis-associatedinterstitiallungdis- ease
[207] andpulmonaryLangerhanscellgranulomatosis
[208,209] .Pulmonaryhaemor-
rhage associated with Goodpasture’s syndrome type is also signiicantly associated with cigarettesmoking
[50] .Womenwithbreastcancerwhosmoketendtodeveloplungmetas-
tasesmorefrequentlythannon-smokers [210]
.Incontrast,sarcoidosis [211]
andallergic pneumonitisoccurmorerarelyinsmokersthaninnon-smokers.Idiopathicpulmonaryibro-
sisiscommonamongheavysmokersthanformersmokersOR=−2.3;CI:1.3–3.8vs.1.9 CI:1.3–2.9,andthediseasemayevenhaveitsonsetaftersuddensmokingcessation
[73] .
Obviously,explanationsforthevariousdiseasesaretobesoughtintheeffectsofsmokingon theinlammatoryprocessesinthelung,onimmunefunctionandonvascularpermeability.
Smokersarepresumedtohaveahigherriskthannon-smokersfordeveloping-varicella pneumonia
[110,212] .Radiologically,pneumoniacanbedetectedonthebasisofdiffuse
interstitialorpatchyiniltratesinupto20ofadultcases [213]
,thoughoftenwithout clinicalsymptoms.Thepulmonarysymptomsusuallysetinduringtheirstdaysafterthe
onsetofrash,andconsistofcough,dyspnoeaandvaryingdegreesofhypoxaemiacaused byinlammationandswellingofthebronchialepithelium
[206,214] .Inuntreatedadults,
themortalityratefromvaricellapneumoniaisapproximately10,butmaybeashighas 50wherethereisseverepulmonaryinvolvementleadingtopulmonaryfailure
[206] .
5.7 Concluding Remarks
•
Currentknowledgeindicatesthatthereisanestablishedassociationbetweensmokingand variousformsoflungcancer.Exposureovermonthsandyearstothevariousinhalational
productsoftobacco,suchasbenzo[a]pyrene,nitrosaminesNNK,NNN,solventsben- zene,crotonaldehyde,formaldehydeand
210
polonium,isanimportantaetiologicalfactor. TheorganiccompoundsaremetabolisedactivatedbyvariousenzymesintheCYPsys-
temandthenformadductswithDNAinlungtissueandwithleucocytes.Inaddition,the activityoftheGSTsystemplaysanimportantroleinthedetoxiicationeliminationof
carcinogens.
•
Asigniicantriskforthedevelopmentoflungcancerhasbeenidentiiedinindividuals with high inducibility of CYP1A1 and reduced activity of glutathione S-reductase
GSTM100.Theriskforbronchialcarcinomaisparticularlyincreasedincarriersofthe GSTM100system.Bronchialcarcinomaiscommonlyencounteredandsome90of
casesaresmoking-related;worldwide,itsprevalenceisincreasingmoreamongwomen thanmen.
•
Asthepracticeofsmokinglightcigaretteshasbecomemorewidespread,therehasbeen anincreaseintheprevalenceofAC,aformoflungcancerthatislessamenabletotreat-
mentthanSCC.