Table 1.

Characteristics of study subjects

Demographic and risk factorsCases n (%), n = 300Controls n (%), n = 416P*
Age (tertile), y
    ≤61111 (37.0)150 (36.0)
    62-6999 (33.0)138 (33.2)
    ≥7090 (30.0)128 (30.8)0.96
Sex
    Male199 (66.3)269 (64.7)
    Female101 (33.7)147 (35.3)0.64
Education levels
    Low141 (47.0)154 (37.0)
    Medium102 (34.0)144 (34.6)
    High57 (19.0)118 (28.4)0.005
Family history of cancer
    No family history175 (58.3)275 (66.1)
    Stomach cancer36 (12.0)17 (4.1)
    Other cancers77 (25.7)117 (28.1)
    Unknown12 (4.0)7 (1.7)<0.001
H. pylori status
    Negative50 (16.7)63 (15.2)
    Positive250 (83.3)352 (84.8)0.59
Smoking status
    Nonsmoker85 (28.5)166 (39.9)
    Former smoker90 (30.2)133 (32.0)
    Current smoker123 (41.3)117 (28.1)<0.001
Pack-years of smoking
    085 (28.6)166 (40.0)
    0.1-30100 (33.7)137 (33.0)
    >30112 (37.7)112 (27.0)0.002
Alcohol drinking status
    Nondrinker105 (35.8)136 (32.7)
    Former drinker95 (32.5)62 (14.9)
    Current drinker93 (31.7)218 (52.4)<0.001
Total years of drinking alcohol
    Nondrinker105 (35.7)136 (32.9)
    <1074 (25.2)137 (33.1)
    10-2951 (17.3)85 (20.5)
    >2964 (21.8)56 (13.5)0.008
Fruit intake
    Daily/weekly131 (46.3)202 (48.7)
    Several times/month101 (35.7)137 (33.0)
    Rarely/never51 (18.0)76 (18.3)0.75
Vegetables intake
    Daily/weekly141 (49.7)250 (60.7)
    Several times/month108 (38.0)122 (29.6)
    Rarely/never35 (12.3)40 (9.7)0.02
Mean (SD) RTL1.25 (0.34)1.34 (0.35)0.0008§
  • *P value obtained from a Fisher's exact test comparing cases and controls.

  • Negative, tested negative for IgG antibodies both to H. pylori and to cagA; positive, tested positive for either IgG antibodies to H. pylori or cagA antibody or both.

  • Division into nonsmokers and low and high numbers of pack-years used the median of pack-years among smokers.

  • §P value obtained from a Student’s t test comparing telomere length in cases and controls.