Table 1

Main characteristics of study participants, by sex and asthma status

CharacteristicsWomen (n=123 921)Men (n=132 498)
Controls (n=109 865)Asthma (n=14 056)Controls (n=118 251)Asthma (n=14 247)
Age at recruitment (years)55.4±8.054.3±8.1*56.4±8.155.3±8.4*
Caucasian ethnicity104 642 (95.3)13 301 (94.6)*112 602 (95.2)13 598 (95.4)
Annual household income < £31 00054 863 (49.9)7077 (50.4)52 906 (44.7)6172 (43.2)*
BMI (kg/m2)27.0±5.128.4±6.0*27.8±4.228.0±4.4*
 Obesity (BMI ≥30 kg/m2)25 807 (23.5)4545 (32.3)*29 624 (25.1)3919 (27.5)*
Smoking status
 Never75 812 (69.0)9506 (67.6)*69 392 (58.7)8558 (60.1)*
 Former24 056 (21.9)3258 (23.2)35 436 (30.0)4330 (30.4)
 Current9997 (9.1)1292 (9.2)13 423 (11.4)1359 (9.5)
Pack-years of smoking6.1±12.36.7±13.4*10.6±18.210.3±18.6
Current use of OC or HRT8023 (7.3)1212 (8.6)*
Had menopause75 474 (68.7)8966 (63.8)*
Free testosterone (pmol/L)11.9±8.811.4±8.6*164.9±60.1163.2±61.7*
Estradiol (pmol/L)241.4±302.7259.1±314.6*132.9±0.1133.2±0.4
FEV1 (mL)†2500±4892359±506*3368±6603099±726*
FVC (mL)†3266±5933179±606*4457±7944331±842*
FEV1/FVC (%)†76.7±5.474.1±6.6*75.5±6.370.9±8.2*
Wheeze in the last year8826 (63.7)9341 (66.5)
At least one asthma hospitalisation484 (3.6)354 (2.6)
  • Results are shown as mean±SD for continuous variables, and as N (%) for binary variables.

  • *p<0.05 for comparison of participants with current asthma versus controls.

  • †Numbers (%) may vary due to missingness.

  • BMI, body mass index; HRT, hormone replacement therapy; OC, oral contraceptives.