Table 3—

Relationship between serum surfactant-associated protein (SP)-B and respiratory parameters in older asymptomatic tobacco smokers and nonsmokers

ParameterNonsmokersSmokersCombined
rsp-valuersp-valuersp-value
VC−0.060.38−0.060.350−0.110.192
FEV1−0.220.164−0.190.115−0.230.031
PEF−0.020.470−0.460.001−0.240.029
FEF25−0.010.48−0.500.000−0.410.000
FEF50−0.210.180−0.250.054−0.310.007
FEF75−0.480.012−0.320.018−0.420.000
FEV1/VC−0.350.113−0.260.096−0.510.000
  • VC: vital capacity

  • FEV1: forced expiratory volume in one second

  • PEF: peak expiratory flow

  • FEF25, FEF50, FEF75: forced expired flow measured with a peak flow meter at 25%, 50% and 75% of expired volume respectively