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Table 4 The sex-specific association between white blood cell count and its differential count (analyzed as continuous variables) at baseline and spirometry using linear mixed-effects model a

From: Blood leukocyte count as a systemic inflammatory biomarker associated with a more rapid spirometric decline in a large cohort of iron and steel industry workers

Variable

Model b

FEV1 (ml/s)

FVC (ml)

FEV1/FVC (%)

Male (n = 5949)

Female (n = 1290)

Male (n = 5949)

Female (n = 1290)

Male (n = 5949)

Female (n = 1290)

β

SE

P

β

SE

P

β

SE

P

β

SE

P

β

SE

P

β

SE

P

WBC

1

− 38.09

6.4

 < 0.001

− 11.88

10.3

0.249

− 37.29

6.7

 < 0.001

− 12.65

11.0

0.249

− 0.14

0.1

0.089

− 0.07

0.2

0.692

WBC * TIC

2

− 4.33

0.9

 < 0.001

1.24

1.7

0.455

− 4.62

1.1

 < 0.001

1.31

1.9

0.490

− 0.02

0.01

0.128

− 0.002

0.03

0.923

NEU

1

− 33.04

6.1

 < 0.001

− 6.62

9.9

0.504

− 31.50

6.4

 < 0.001

− 5.89

10.5

0.576

− 0.13

0.1

0.083

− 0.10

0.2

0.546

NEU * TIC

2

− 3.46

0.9

 < 0.001

1.23

1.6

0.436

− 3.58

1.0

 < 0.001

1.47

1.8

0.417

− 0.02

0.01

0.082

− 0.006

0.03

0.831

LYM

1

− 30.30

6.7

 < 0.001

− 17.55

7.9

0.026

− 30.33

7.0

 < 0.001

− 17.46

8.4

0.037

− 0.10

0.1

0.248

− 0.08

0.1

0.542

LYM * TIC

2

− 3.96

1.0

 < 0.001

0.20

1.3

0.880

− 4.53

1.1

 < 0.001

0.06

1.5

0.970

− 0.002

0.01

0.859

− 0.001

0.02

0.954

MID

1

3.80

3.7

0.300

11.63

14.1

0.410

0.88

3.8

0.817

4.61

15.0

0.759

0.06

0.0

0.187

0.21

0.2

0.369

MID * TIC

2

− 1.54

0.5

0.003

− 1.03

2.3

0.647

− 1.18

0.6

0.046

− 1.94

2.6

0.452

− 0.01

0.007

0.063

0.02

0.04

0.576

  1. WBC  white blood count, NEU  neutrophilicgranulocyte, LYM  lymphocyte, MID  mid-range absolute count including monocytes, eosinophils and basophils, SE  standard error of mean, TIC  time in cohort
  2. aβ and standard error of mean was calculated using the interquartile range of WBC count and its differential at baseline as the unit of change. Inter-quartile ranges in male workers: WBC: 2.0*109/L; NEU: 1.6*109/L; LYM: 0.7*109/L; MID: 0.1*109/L. Inter-quartile ranges in female workers: WBC: 1.8*109/L; NEU: 1.4*109/L; LYM: 0.5*109/L; MID: 0.2*109/L
  3. bModel 1 assessed the associations of longitudinal lung function measurements as the outcome with baseline WBC and its differential with adjustment for age, smoking status (male only), packyears (male only), height, BMI, TIC, TWEI, and years of dust exposure. Model 2 assessed the associations of baseline WBC and its differential on lung function decline and used longitudinal lung function measurements as the outcome. In addition to all covariates adjusted in model 1, model 2 also included baseline spirometry and baseline WBC and its differential and interaction terms of TIC with TWEI, baseline spirometry, years of dust exposure, and baseline WBC and its differential. A negative β of the interaction term between TIC and baseline WBC in model 2 indicated that higher baseline WBC was associated with a more rapid decline of lung function