Table 1

Baseline characteristics of study participants, overall and by subgroup, i.e., participants with ≥1 risk allele versus none at the TCF7L2 locus

CharacteristicAll subjects, N = 244≥1 risk allele, N = 135No risk alleles, N = 109P value
Sex0.93
 Female128 (52.5)70 (51.9)58 (53.2)
 Male116 (47.5)65 (48.1)51 (46.8)
Age at confirmed single Ab+ (years)0.50
 Median12.813.4512.5
 Range1.22–45.91.22–45.91.3–45.7
Islet Ab+ type0.71
 GAD65158 (64.8)87 (64.4)71 (65.1)
 IA-217 (6.7)11 (8.1)6 (5.5)
 mIAA69 (28.3)37 (27.4)32 (29.4)
Race0.46
 White220 (96.5)119 (96)101 (97.1)
 Black/African American3 (1.3)2 (1.6)1 (1.0)
 Asian1 (0.4)1 (0.8)0 (0.0)
 Multiracial4 (1.8)2 (1.6)2 (1.9)
 Unknown/missing1615
Ethnicity0.45
 Hispanic/Latino23 (9.7)12 (9.0)11 (10.4)
 Non-Hispanic/Latino214 (90.3)121 (91.0)93 (89.4)
 Unknown/missing725
Fasting C-peptide (ng/mL)0.71
 Median1.521.561.49
 Range0.38–7.30.38–5.130.43–7.3
 Missing220
C-peptide AUC0.10
 Median649.9628.5681.8
 Range197.8–3,089.4197.8–1,652.3242.4–3,089.4
 Missing1293
OGTT status0.44
 Normal196 (81.7)105 (79.5)91 (84.6)
 Abnormal44 (18.3)27 (20.5)17 (15.7)
 Missing time point431
HLA DR3 and DR40.21
 No217 (92.3)117 (90.0)100 (95.2)
 Yes18 (7.7)13 (10.0)5 (4.8)
 Missing954
HLA DR3 and/or DR40.999
 No74 (31.5)41 (31.5)33 (31.4)
 Yes161 (68.5)89 (68.5)72 (68.6)
 Missing954
BMI category0.033
 Normal131 (58.2)78 (61.9)53 (53.5)
 Overweight48 (21.3)18 (14.3)28 (28.3)
 Obese46 (20.4)30 (23.8)18 (18.2)
 Missing19910
  • Data are n or n (%) unless otherwise indicated. P values are given for the comparison of the characteristic between groups. Continuous measures were compared using Wilcoxon rank sum test. Categorical variables were compared using χ2 tests (or Fisher exact tests if cell sizes too small). Ab+, autoantibody positivity; AUC, area under the curve; OGTT, oral glucose tolerance test.