Skip to main content

Table 3 Association (z-value; p trend) of FEV1 %predicted with CRP quartile classes§

From: Circulating alpha1-antitrypsin in the general population: Determinants and association with lung function

 

z-value#

ptrend (across crp quartiles)

Non-smoking men

  

FEV1 (% predicted)*

-3.91

<0.000

FEV1 (% predicted)**

-4.53

<0.000

Non-smoking women

  

FEV1 (% predicted)*

-2.32

0.02

FEV1 (% predicted)**

-2.15

0.03

Smoking men

  

FEV1 (% predicted)*

-2.44

0.015

FEV1 (% predicted)**

-4.82

<0.000

Smoking women

  

FEV1 (% predicted)*

-2.44

0.015

FEV1 (% predicted)**

-3.14

0.002

  1. *controlled for BMI, systolic blood pressure, ETS (in non smokers), packyears (in smokers), alcohol intake, study area; ** crude associations; ¶additionally adjusted for menopausal status, and intake of female hormones; subjects with crp > 10 mg/l were excluded; §CRP quartiles (Q) (mg/l): Q1 < 0.6, Q2 < 1.1, Q3 < 2.2, Q4 > 2.2; # Regression models without CRP quartiles as predictor variable were computed first. A Cuzick's trend test was then used to test whether regression residuals showed a monotonous association with CRP quartiles. Under the null hypothesis of no trend, the z-value of Cuzick's trend test statistic approximately follows a standard normal distribution, enabling the computation of approximate p-values; a negative sign indicates an inverse association between CRP and FEV1%predicted [15].