Table 2.
Results of linear regression analyses for serum hepcidin concentration by site adjusted for age
| Variable | Gambian children | Kenyan children | ||||
|---|---|---|---|---|---|---|
| β (95% CI)* | P* | R2, % | β (95% CI)* | P* | R2, % | |
| Age, y | 0.07 (0.03, 0.11) | .001 | 1.2 | −0.07 (–0.02, −0.12) | .003 | 2.7 |
| BMI, kg/m2 | −0.01 (–0.06, 0.03) | .51 | 3.3 | 0.02 (–0.05, 0.09) | .51 | 3.3 |
| Gender, female | −0.03 (–0.12, 0.07) | .59 | 1.2 | −0.05 (–0.24, 0.14) | .61 | 2.7 |
| Ethnicity, minority group | −0.04 (–0.22, 0.13) | .63 | 1.2 | 0.26 (–0.03, 0.55) | .08 | 3.6 |
| Hb type, HbAS | −0.04 (–0.19, 0.11) | .62 | 1.1 | −0.09 (–0.36, 0.17) | .49 | 2.8 |
| G6PDd, A- type | 0.11 (–0.12, 0.34) | .33 | 1.2 | −0.15 (–0.36, 0.06) | .16 | 3.2 |
| Iron status | ||||||
| Log-ferritin, µg/L | 0.98 (0.88, 1.08) | <.0005 | 28.7 | 1.43 (1.26, 1.60) | <.0005 | 43.8 |
| Log-sTfR, mg/L | −2.26 (–2.57, −1.96) | <.0005 | 22.3 | −3.26 (–3.60, −2.93) | <.0005 | 37.3 |
| Hematologic status | ||||||
| Hb, g/dL | 0.18 (0.15, 0.21) | <.0005 | 14.3 | 0.37 (0.24, 0.50)† | <.0005 | 28.1 |
| MCV, fL | 0.03 (0.03, 0.04) | <.0005 | 10.5 | 0.07 (0.05, 0.10)† | <.0005 | 36.4 |
| Inflammation | ||||||
| Log-ACT, g/L or log-CRP, mg/L | 1.86 (1.49, 2.22) | <.0005 | 8.4 | 0.65 (0.46, 0.84) | <.0005 | 14.4 |
| Malaria | ||||||
| Season, end of malaria season | −0.45 (–0.40, −0.51) | <.0005 | 10.2 | −0.46 (–0.35, −0.56) | <.0005 | 9.1 |
| P. falciparum parasitemia | −0.15 (–0.27, −0.03) | .01 | 1.8 | 0.50 (0.28, 0.71) | <.0005 | 5.9 |
*
The dependent variable hepcidin was log-transformed before inclusion in the linear regressions models, and all analyses (except for age) were adjusted for age. Ninety-five percent CIs and P values were adjusted to take account of potential within-subject clustering of events using the sandwich estimator.34
†
These data were available for only 82 children at the end of the season and should be interpreted with caution. The dependent variable for these models was log-transformed hepcidin at the end of the malaria season (because Hb and MCV were not available at the start of the season).