TABLE 1.
Sample Characteristics
| Group | P | Group Differences | |||
|---|---|---|---|---|---|
| Nonsnorers | Transient Snorers | Persistent Snorers | |||
| Sample size, n | 170 | 57 | 22 | ||
| Boys, n, % | 78, 45.9 | 29, 50.9 | 9, 40.9 | .69 | |
| African American, n, % | 23, 13.5 | 19, 33.3 | 12, 54.6 | <.0001 | NS < TS, PS |
| Gestational age, wk | 39.2 ± 1.7 | 38.9 ± 1.3 | 39.1 ± 1.5 | .46 | |
| Birth weight, lbs | 7.6 ± 1.4 | 7.3 ± 1.4 | 7.7 ± 1.2 | .30 | |
| Age at 2-y evaluation, y | 2.08 ± 0.08 | 2.10 ± 0.09 | 2.09 ± 0.09 | .52 | |
| Age at 3-y evaluation, y | 3.10 ± 0.11 | 3.10 ± 0.12 | 3.11 ± 0.13 | .93 | |
| Family income, thousands of US dollars | 84.1 ± 40.6 | 62.5 ± 49.6 | 49.3 ± 45.6 | <.0001 | NS > TS, PS |
| Mother’s education, y | 16.2 ± 2.8 | 14.9 ± 3.1 | 13.4 ± 3.2 | <.0001 | NS > TS, PS |
| Father’s education, y | 16.0 ± 2.9 | 14.6 ± 2.9 | 13.5 ± 2.6 | <.0001 | NS > TS, PS |
| BMI z-score at 2-y evaluation, mean ± SD | −0.04 ± 1.03 | −0.21 ± 1.00 | 0.49 ± 1.27 | <.05 | PS > TS |
| BMI z score at 3-y evaluation, mean ± SD | 0.01 ± 1.09 | −0.10 ± 1.11 | 0.55 ± 1.37 | .07 | |
| Prenatal (maternal) cotinine, median (25th, 75th percentile) | 0.009 (0.002, 0.033) | 0.032 (0.007, 0.189) | 0.157 (0.035, 0.922) | <.0001 | NS < TS, PS |
| Serum cotinine at 2-y evaluation, median (25th, 75th percentile) | 0.036 (0.019, 0.076) | 0.153 (0.027, 0.461) | 1.230 (0.034, 2.07) | <.001 | NS < TS, PS |
| Serum cotinine at 3-y evaluation, median (25th, 75th percentile) | 0.022 (0.009, 0.047) | 0.063 (0.027, 0.474) | 0.710 (0.103, 2.14) | <.0001 | NS < TS, PS |
Unless otherwise indicated, group values are presented as mean ± SD. Statistical significance (P) values are based on χ2, analysis of variance, or Kruskal-Wallis H test. Follow-up tests of group differences were Tukey honestly significant difference for normally distributed variables and χ2 or Mann-Whitney U tests with Bonferroni corrections for categorical or nonnormal variables. NS, nonsnorers; TS, transient snorers; PS, persistent snorers.