Table 1.
Baseline characteristics of study participants, overall and by subgroup, i.e., participants with ≥1 risk allele versus none at the TCF7L2 locus
| Characteristic | All subjects, N = 244 | ≥1 risk allele, N = 135 | No risk alleles, N = 109 | P value |
|---|---|---|---|---|
| Sex | 0.93 | |||
| Female | 128 (52.5) | 70 (51.9) | 58 (53.2) | |
| Male | 116 (47.5) | 65 (48.1) | 51 (46.8) | |
| Age at confirmed single Ab+ (years) | 0.50 | |||
| Median | 12.8 | 13.45 | 12.5 | |
| Range | 1.22–45.9 | 1.22–45.9 | 1.3–45.7 | |
| Islet Ab+ type | 0.71 | |||
| GAD65 | 158 (64.8) | 87 (64.4) | 71 (65.1) | |
| IA-2 | 17 (6.7) | 11 (8.1) | 6 (5.5) | |
| mIAA | 69 (28.3) | 37 (27.4) | 32 (29.4) | |
| Race | 0.46 | |||
| White | 220 (96.5) | 119 (96) | 101 (97.1) | |
| Black/African American | 3 (1.3) | 2 (1.6) | 1 (1.0) | |
| Asian | 1 (0.4) | 1 (0.8) | 0 (0.0) | |
| Multiracial | 4 (1.8) | 2 (1.6) | 2 (1.9) | |
| Unknown/missing | 16 | 1 | 5 | |
| Ethnicity | 0.45 | |||
| Hispanic/Latino | 23 (9.7) | 12 (9.0) | 11 (10.4) | |
| Non-Hispanic/Latino | 214 (90.3) | 121 (91.0) | 93 (89.4) | |
| Unknown/missing | 7 | 2 | 5 | |
| Fasting C-peptide (ng/mL) | 0.71 | |||
| Median | 1.52 | 1.56 | 1.49 | |
| Range | 0.38–7.3 | 0.38–5.13 | 0.43–7.3 | |
| Missing | 2 | 2 | 0 | |
| C-peptide AUC | 0.10 | |||
| Median | 649.9 | 628.5 | 681.8 | |
| Range | 197.8–3,089.4 | 197.8–1,652.3 | 242.4–3,089.4 | |
| Missing | 12 | 9 | 3 | |
| OGTT status | 0.44 | |||
| Normal | 196 (81.7) | 105 (79.5) | 91 (84.6) | |
| Abnormal | 44 (18.3) | 27 (20.5) | 17 (15.7) | |
| Missing time point | 4 | 3 | 1 | |
| HLA DR3 and DR4 | 0.21 | |||
| No | 217 (92.3) | 117 (90.0) | 100 (95.2) | |
| Yes | 18 (7.7) | 13 (10.0) | 5 (4.8) | |
| Missing | 9 | 5 | 4 | |
| HLA DR3 and/or DR4 | 0.999 | |||
| No | 74 (31.5) | 41 (31.5) | 33 (31.4) | |
| Yes | 161 (68.5) | 89 (68.5) | 72 (68.6) | |
| Missing | 9 | 5 | 4 | |
| BMI category | 0.033 | |||
| Normal | 131 (58.2) | 78 (61.9) | 53 (53.5) | |
| Overweight | 48 (21.3) | 18 (14.3) | 28 (28.3) | |
| Obese | 46 (20.4) | 30 (23.8) | 18 (18.2) | |
| Missing | 19 | 9 | 10 |
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.