Table 1.
Demographic and Clinical Characteristics of the Sample Overall and Split Based on Iron Statusa
| Total sample n=115 | Iron-deficient n=16 | Iron-deplete n=52 | Iron-replete n=47 | Statistic | p value | |
|---|---|---|---|---|---|---|
| Male sex, n (%) | 100 (87) | 14 (88) | 46 (88) | 40 (85) | Fisher's exact | >0.9 |
| Age, years, mean (SD) | 11.6 (2.8) | 11.3 (0.7) | 12.2 (0.4) | 11.0 (0.4) | F=2.34 | >0.1 |
| Tanner stage I/II/III/IV/V, % | 42/15/19/22/9 | 40/13/13/20/13 | 33/12/22/24/10 | 53/15/13/15/4 | Fisher's exact | >0.5 |
| Race/Ethnicity, n (%) | ||||||
| Non-Hispanic white | 87 (76) | 12 (75) | 38 (73) | 37 (79) | Fisher's exact | |
| African American | 18 (16) | 4 (25) | 9 (17) | 5 (11) | ||
| Hispanic | 8 (7) | 0 | 5 (10) | 3 (6) | ||
| Other | 2 (2) | 0 | 0 | 2 (4) | >0.4 | |
| Age- and sex-adjusted measures, mean (SD) | ||||||
| Enrollment BMI z score | 0.57 (1.1) | 0.51 (0.28) | 0.71 (0.15) | 0.42 (0.16) | F=0.90 | >0.4 |
| Change in BMI z score | 0.46 (0.81) | 0.45 (0.22) | 0.62 (0.13) | 0.29 (0.14) | F=1.44 | >0.2 |
| Enrollment weight z score | 0.51 (1.1) | 0.47 (0.27) | 0.66 (0.15) | 0.36 (0.16) | F=0.89 | >0.4 |
| Change in weight z score | 0.44 (0.65) | 0.53 (0.17) | 0.51 (0.10) | 0.33 (0.11) | F=0.73 | >0.4 |
a
Iron status was defined based on a combination of serum ferritin and transferrin receptor concentration (see Methods) (World Health Organization 2011).
For continuous variables, means (SD) are reported for the total sample and means (SE) are reported for the three “iron status” groups.
BMI, body mass index.