Table 2

Association of alpha 1-antitrypsin protease inhibitor (PI) status with standardised lung function adjusted for age and sex

Regression coefficient (95% CI)
OutcomeCohortMS vs MMMZ vs MM†
Maximum FEV1BO−0.05 (−0.36 to 0.27)0.45 (−0.14 to 1.04)
CaPS0.07 (−0.10 to 0.24)0.11 (−0.12 to 0.33)
ELSA0.05 (−0.03 to 0.12)0.12* (0.01 to 0.23)
HAS−0.49* (−0.94 to −0.05)0.08 (−0.39 to 0.55)
HCS−0.01 (−0.10 to 0.09)0.05 (−0.10 to 0.19)
LBC1921−0.06 (−0.31 to 0.19)0.16 (−0.22 to 0.54)
NSHD0.02 (−0.09 to 0.13)0.18* (0.01 to 0.35)
WHII0.05 (−0.03 to 0.12)0.18** (0.06 to 0.29)
Combined FE0.03 (−0.01 to 0.07)0.13**** (0.07 to 0.19)
Combined RE0.03 (−0.01 to 0.07)0.13**** (0.07 to 0.19)
Estimated var‡1.20e−13 (0.00e+00 to .)1.09e−19 (0.00e+00 to .)
Maximum FVCBO0.03 (−0.26 to 0.32)0.43 (−0.11 to 0.97)
CaPS0.08 (−0.10 to 0.26)0.15 (−0.09 to 0.39)
ELSA0.02 (−0.05 to 0.09)0.12* (0.01 to 0.22)
HAS−0.35 (−0.73 to 0.03)0.33 (−0.09 to 0.74)
HCS−0.02 (−0.11 to 0.07)0.14* (0.01 to 0.27)
LBC1921−0.07 (−0.32 to 0.17)0.20 (−0.17 to 0.56)
NSHD0.02 (−0.09 to 0.13)0.20* (0.04 to 0.37)
WHII−0.01 (−0.08 to 0.07)0.19** (0.07 to 0.30)
Combined FE0.01 (−0.03 to 0.04)0.16**** (0.10 to 0.22)
Combined RE0.00 (−0.04 to 0.04)0.16**** (0.10 to 0.22)
Estimated var‡3.76e−15 (1.01e−28 to 1.40e−01)3.53e−19 (0.00e+00 to .)
  • Estimates for PI-SS, SZ and ZZ are provided in the online supplement.

  • *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001.

  • †Exact p values for PI-MZ-FEV1 were 1.7×10−5 (FE) and 1.1×10−5 (RE); for PI-MZ-FVC were 5.2×10−8 (FE) and 3.2×10−8 (RE).

  • ‡Estimated variance of the random slope on carrier status modelled by the RE model.

  • BO, Boyd Orr; CaPS, Caerphilly Prospective Study; ELSA, English Longitudinal Study of Ageing; FE, fixed effect; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; HAS; Hertfordshire Ageing Study; HCS, Hertfordshire Cohort Study; LBC1921, Lothian Birth Cohort 1921; NSHD, MRC National Survey of Health and Development; RE, random effect; WHII, Whitehall II Study.