Table 2

Baseline characteristics of oral glucose tolerance test study participants

CharacteristicPlacebo (N = 96)Selenium (N = 79)Total (N = 175)P value*
Age
 Mean (SD)60.9 (8.5)62.3 (8.9)61.6 (8.7)0.28
 Median (Q1, Q3)59.5 (53.5, 68.5)64.0 (55.0, 70.0)62.0 (55.0, 69.0)
Body mass index
 Mean (SD)29.8 (5.4)28.5 (5.0)29.2 (5.2)0.11
 Median (Q1, Q3)28.9 (25.7, 32.8)27.8 (25.5, 31.6)28.3 (25.5, 32.6)
Selenium dietary intake (µg/day)†
 Mean (SD)105.5 (48.4)105.9 (54.4)105.6 (51.0)0.96
 Median (Q1, Q3)92.4 (73.6, 128.8)94.5 (72.9, 122.6)93.7 (73.3, 123.7)
Selenium supplemental intake (µg/day)†
 Mean (SD)5.6 (7.1)6.6 (7.1)6.0 (7.1)0.35
 Median (Q1, Q3)0.0 (0.0, 10.0)7.1 (0.0, 10.0)4.3 (0.0, 10.0)
Plasma selenium (ng/mL)‡
 Mean (SD)139.7 (23.8)136.8 (22.8)138.4 (23.3)0.42
 Median (Q1, Q3)136.3 (123.9, 157.7)131.3 (118.1, 155.0)133.5 (122.5, 156.1)
Gender
 Female27 (28.1%)31 (39.2%)58 (33.1%)0.12
 Male69 (71.9%)48 (60.8%)117 (66.9%)
Ethnicity
 Non-Hispanic91 (94.8%)77 (97.5%)168 (96.0%)0.37
 Hispanic5 (5.2%)2 (2.5%)7 (4.0%)
Race
 Other3 (3.1%)0 (0.0%)3 (1.7%)0.28
 White92 (95.8%)78 (98.7%)170 (97.1%)
 Mixed1 (1.0%)1 (1.3%)2 (1.1%)
Education
 Some high school0 (0.0%)5 (6.3%)5 (2.9%)0.04
 High school22 (22.9%)12 (15.2%)34 (19.4%)
 Some college24 (25.0%)26 (32.9%)50 (28.6%)
 College degree19 (19.8%)18 (22.8%)37 (21.1%)
 Postgraduate31 (32.3%)18 (22.8%)49 (28.0%)
Cigarette smoking
 Current smoker13 (13.8%)6 (7.8%)19 (11.1%)0.45
 Previous smoker42 (44.7%)36 (46.8%)78 (45.6%)
 Never Smoker39 (41.5%)35 (45.5%)74 (43.3%)
Diabetes
 No diabetes94 (97.9%)78 (98.7%)172 (98.3%)0.68
 Has diabetes2 (2.1%)1 (1.3%)3 (1.7%)
Personal history of cancer
 Never had cancer89 (92.7%)78 (98.7%)167 (95.4%)0.06
 Had cancer7 (7.3%)1 (1.3%)8 (4.6%)
Aspirin use in last 20 years
 0–1 year58 (60.4%)45 (57.0%)103 (58.9%)0.86
 1 to <5 years20 (20.8%)15 (19.0%)35 (20.0%)
 5 to <10 years5 (5.2%)5 (6.3%)10 (5.7%)
 10+ years13 (13.5%)14 (17.7%)27 (15.4%)
Non-steroidal anti-inflammatory drug use in last 20 years
 0 to <1 year93 (96.9%)72 (91.1%)165 (94.3%)0.31
 1 to <5 years2 (2.1%)3 (3.8%)5 (2.9%)
 5 to <10 years0 (0.0%)2 (2.5%)2 (1.1%)
 10+ years1 (1.0%)2 (2.5%)3 (1.7%)
Clinic
 Phoenix69 (71.9%)57 (72.2%)126 (72.0%)0.68
 Colorado11 (11.5%)7 (8.9%)18 (10.3%)
 Tucson16 (16.7%)14 (17.7%)30 (17.1%)
 Mayo0 (0.0%)1 (1.3%)1 (0.6%)
  • *t-test or analysis of variance for continuous variables, χ2 categorical variables.

  • †From Arizona Food Frequency Questionnaire.

  • ‡From baseline plasma.