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 |
| 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).