Table 3

 Effect of C-reactive protein (CRP, mg/l) on lung function using linear regression in two cross-sectional studies of the Nottingham Lung Health Study population in 1991 and 2000

1991 (n = 2425)2000 (n = 1298)
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; BMI, body mass index.
Basic model using FEV1 adjusted for sex, age, age2, height, age-height, body mass index and magnesium intake, smoking status (categorical) and smoking pack-years.
*1297 individuals provided data for analysis.
FEV1 (ml)–9 (–13 to –5)–7 (–13 to –2)
Stratified by smoking status
    Never–6 (–10 to –1)–3 (–11 to +4)
    Ex–27 (–39 to –15)–13 (–22 to –4)
    Current–9 (–20 to +2)–5 (–28 to +17)
pinteraction = 0.005pinteraction  = 0.494
Stratified by gender
    Male–13 (–21 to –6)–5 (–14 to +4)
    Female–5 (–9 to –1)–10 (–17 to –4)
pinteraction  = 0.022pinteraction  = 0.342
Stratified by BMI(kg/m2)
    >20–28 (–60 to +4)–77 (–247 to +94)
    20–24.9–16 (–25 to –7)+4 (–6 to +14)
    25–29.9–12 (–19 to –5)–6 (–14 to +2)
    >30–3 (–10 to +5)–20 (–31 to –10)
pinteraction  = 0.015pinteraction  = 0.033
FVC (ml)–11 (–16 to –7)–8 (–14 to –2)*
Stratified by smoking status
    Never–9 (–14 to –3)–4 (–13 to +4)
    Ex–31 (–45 to –18)–14 (–24 to –4)
    Current–7 (–18 to +5)–10 (–36 to +16)
pinteraction  = 0.003pinteraction  = 0.459
Stratified by gender
    Male–18 (–27 to –10)–5 (–15 to +5)
    Female–5 (–11 to 0)–12 (–19 to –5)
pinteraction  = 0.001pinteraction  = 0.437
Stratified by BMI(kg/m2)
    <20–20 (–53 to +13)–102 (–285 to +80)
    20–24.9–18 (–28 to –8)+4 (–8 to +16)
    25–29.9–16 (–24 to –8)–7 (–16 to +3)
    >30–4 (–11 to +4)–26 (–39 to –13)
pinteraction  = 0.025pinteraction  = 0.029