Table 1—

Baseline characteristics of men and women according to FVC (% predicted) quartile

FVC (% predicted) quartile*
I (low) (< 90.8)II (90.9–99.4)III (99.5–108.4)IV (high) (>108.4)P for trend
Men
    n1,2831,2811,2811,282
    African American26191614<0.0001
    Age at baseline (years)55 ± 5.654 ± 5.754 ± 5.653 ± 5.7<0.0001
    Education <12 years26202015<0.0001
    Parental history of diabetes121312100.11
    Smoking status
        Current36272218<0.0001
        Former42454645
        Never22283237
        Pack-years36 ± 22.931 ± 23.828 ± 20.324 ± 18.4<0.0001
    Sport index2.4 ± 0.82.6 ± 0.82.7 ± 0.82.8 ± 0.8<0.0001
    BMI (kg/m2)28.1 ± 4.627.5 ± 4.126.9 ± 3.626.6 ± 3.3<0.0001
    Waist-to-hip ratio0.96 ± 0.060.96 ± 0.050.96 ± 0.050.94 ± 0.05<0.0001
    Height (cm)176 ± 6.5176 ± 6.5176 ± 6.7177 ± 6.60.06
    Waist (cm)101 ± 11.799 ± 10.497 ± 9.896 ± 9.1<0.0001
    Metabolic syndrome§36262215<0.0001
    Fibrinogen (g/l)3.1 ± 0.73.0 ± 0.62.9 ± 0.62.8 ± 0.6<0.0001
    White blood cell count (×109/l)6.4 ± 1.96.2 ± 1.86.1 ± 2.65.9 ± 1.7<0.0001
    FVC (l)3.8 ± 0.54.4 ± 0.54.8 ± 0.55.5 ± 0.6<0.0001
    FEV1 (l)2.7 ± 0.53.3 ± 0.53.6 ± 0.54.0 ± 0.6<0.0001
    FEV1/FVC72.9 ± 9.374.3 ± 7.474.2 ± 6.873.6 ± 6.40.05
I (low) (< 95.7)II (95.8–105.3)III (105.4–114.6)IV (high) (>114.6)P for trend
Women
    n1,5881,5881,5881,588
    African American33262120<0.0001
    Age at baseline (years)54 ± 5.853 ± 5.653 ± 5.654 ± 5.60.06
    Education <12 years26191715<0.0001
    Parental history of diabetes121314130.71
    Smoking status
        Current34221915<0.0001
        Former18222425
        Never48565760
        Pack-years25.0 ± 17.820.6 ± 17.317.6 ± 15.817.3 ± 15.6<0.0001
    Sport index2.2 ± 0.72.3 ± 0.72.4 ± 0.82.5 ± 0.8<0.0001
    BMI (kg/m2)28.7 ± 6.627.3 ± 5.826.5 ± 5.126.1 ± 4.7<0.0001
    Waist-to-hip ratio0.91 ± 0.080.89 ± 0.080.87 ± 0.080.87 ± 0.08<0.0001
    Height (cm)163 ± 5.8163 ± 5.9162 ± 6.0162 ± 6.1<0.0001
    Waist (cm)98 ± 16.394 ± 14.991 ± 13.490 ± 12.8<0.0001
    Metabolic syndrome§35272116<0.0001
    Fibrinogen (g/l)3.2 ± 0.73.0 ± 0.62.9 ± 0.52.9 ± 0.6<0.0001
    WBC count (×109/l)6.3 ± 1.95.9 ± 1.95.7 ± 1.65.5 ± 1.6<0.0001
    FVC (l)2.7 ± 0.43.2 ± 0.43.5 ± 0.43.8 ± 0.5<0.0001
    FEV1 (l)2.0 ± 0.42.4 ± 0.32.6 ± 0.32.9 ± 0.4<0.0001
    FEV1/FVC76.0 ± 8.276.6 ± 6.176.2 ± 5.675.1 ± 5.80.46
  • Data are mean ± SD or percent.

  • *

    * Quartiles are sex specific.

  • P values correspond to tests for linear trend across quartiles.

  • Pack-years of cigarette smoking in ever- smokers only.

  • §

    § Metabolic syndrome was defined based on guidelines published in the National Cholesterol Education Program Adult Treatment Panel III report (46). The clinical identification of the metabolic syndrome is based upon the presence of any three of the following traits: 1) abdominal obesity, defined as a waist circumference in men >102 cm (40 in) and in women >88 cm (35 in); 2) serum triglycerides 150 mg/dl (1.7 mmol/l); 3) serum HDL cholesterol <40 mg/dl (1 mmol/l) in men and <50 mg/dl (1.3 mmol/l) in women; 4) blood pressure 130/85 mmHg; and 5) fasting plasma glucose 110 mg/dl (6.1 mmol/l).