Table 1

 Studies examining risk of COPD in α1-antitrypsin PI MZ heterozygotes

AuthorYearCountrySource of casesSource of controlsCOPD definitionCases PI MZ/PI MMControls PI MZ/PI MMAdjustment for smoking
PI, protease inhibitor; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; PEFR, peak expiratory flow rate; PFT, pulmonary function test; MMEF, maximum mid-expiratory flow; Tlco, carbon monoxide transfer factor.
(A) Case-control studies
Fagerhol181969NorwayHospital patientsHospital patients with other chest diseasesClinical diagnosis (emphysema, chronic bronchitis)5/1359/268None
Talamo311972USAHospital pulmonary clinicHealthy prison inmates, employeesFEV1/FVC <0.72,
>PEFR <80% predicted
Kueppers241974GermanyRetired workers, hospital inpatientsBlood donorsCombination of PFTs and blood gases12/1381/193None
Barnett171975USAPatients seen at the University of North CarolinaPatients with non-pulmonary diseases, patients’ spouses,
>hospital employees
MMEF <50%
Cox141976CanadaHospital pulmonary clinic, hospital inpatientsHealthy hospital employees, school childrenClinical diagnosis (bronchitis), Tlco <80% predicted (emphysema)6/10114/644None
Kueppers251977USAHospital pulmonary clinic, local physiciansHospital patients with fractures or dental extractionsFEV1 <70% predicted9/976/98Matched on smoking status
Abboud121979CanadaHospital pulmonary clinicHealthy hospital staff, patients’ spousesFEV1/FVC <0.505/420/26None
Bartmann131985GermanyRehabilitation clinicBlood donors, hospital employeesClinical diagnosis, including PFTs and x ray31/4298/583None
Lieberman261986USAPatients undergoing carotid body surgeryJunior high school studentsClinical diagnosis57/59534/1213None
Poller291990GermanyHospital clinicPatients without pulmonary disease or family historyClinical diagnosis, plethysmography16/1377/130None
Sandford301999CanadaPatients undergoing lobar or lung resectionPatients undergoing lobar or lung resectionFEV1 <80% predicted, FEV1/FVC <0.712/1630/66Logistic regression
(B) Cross sectional studies
Author Year Country Study population COPD diagnosis No. COPD/total PI MZ No. COPD/total PI MM Adjustment for smoking
Klayton231975USARandom selection of employees in research facilities, age >40FEV1 <2 SD below predicted13/2769/262Stratified by smoking status
Matzen271977USAClinic patients without previous diagnosis of pulmonary diseaseClinical diagnosis2/1227/427None
Chan-Yeung111978CanadaCaucasian employees of sawmills and grain elevator terminalsFEV1 <80% predicted,
>FEV1/FVC <0.7
0/3198/1006Stratified by smoking status
Gulsvik201979NorwayCommunity survey, ages 15-70, oversampled those with symptomsClinical diagnosis, including PFTs and chest x ray7/51123/1054None
Dahl152002DenmarkRandomly selected adults from Danish general populationFEV1 <80% predicted,
>FEV1/FVC <0.7
86/4501053/7018Logistic regression