Albertine Donker

Chapter 7 242 Table 4. Results of multivariable linear regression analyses for serum hepcidin concentrations (nmol/L) stratified by sex Males 95% CI Variable Beta a Lower limit Upper limit p Age, years <12 12-<18 -0.579 -0.736 -0.423 0.000 Time Blood sampling 7.30 AM-12 PM ref ref ref 12 -3 PM 0.143 -0.008 0.295 0.063 3- 6 PM 0.369 0.158 0.580 0.001 Ferritin, µg/L b 1.014 0.604 1.425 0.000 TIBC, µmol/L 0.000 -0.009 0.010 0.950 ALT, IU/L b 0.091 -0.440 0.622 0.736 CRP, mg/L b, c 0.107 -0.017 0.230 0.091 BMI d Normal weight ref ref ref Underweight 0.538 0.027 1.048 0.039 Overweight 0.106 -0.125 0.337 0.366 Adipose 0.081 -0.335 0.497 0.702 a Beta expresses the change in the dependent variable -log-transformed hepcidin- that is associated with a 1-unit change in the independent variable. Independent variables marked with b were log- transformed as well; the interpretation of the regression coefficients for these variables is as follows: a 1% change in the independent variable corresponds to a beta % change in serum hepcidin c CRP levels of children were between > 0.1 and < 5 mg/L d BMI was assessed according to international standards established by Cole et al 36 Abbreviations: na denotes not applicable; ref, reference category