Table 1

Subject characteristics and clinical outcome variables: (A) subject characteristics and (B,C) association between change in CSF biomarkers and baseline CSF ferritin

Low tau/Aβ1-42 (minimal AD pathology)High tau/Aβ1-42 (AD pathology)
(A) Subject characteristics
  Participants: n107189
  Male sex: n (%)68(64)110(58)
  APOE ε4: n (%)19(18)128(68)
  Age: mean (SD)75.5(6.7)74.7(7.0)
  Dx-CN: n (%)61(57)27(14)
  Dx-MCI: n (%)38(36)102(54)
  Dx-AD: n (%)8(7)60(32)
  CSF Aβ42: mean (SD)1190(418)566(171)
  CSF tau: mean (SD)226(70.2)374(114)
  CSF ferritin: mean (SD)6.37(2.11)7.24(2.93)
(B) Outcome: longitudinal CSF Aβ
 Covariateβ* (SE)pβ* (SE)p
  Age†−0.309 (0.122) 0.012 −0.103 (0.059)0.084
  Male sex2.640 (1.597)0.0991.226 (0.710)0.085
  APOE ε4−4.115 (2.599)0.1141.377 (0.781)0.078
  Dx-MCI−0.610 (1.549)0.6942.275 (0.824) 0.006
  Dx-AD2.730 (7.110)0.7023.498 (1.175) 0.003
  CSF tau0.158 (0.042) 0.0002 0.012 (0.008)0.140
  CSF ApoE†−15.467 (8.048)0.055−2.697 (3.403)0.429
  CSF ferritin (L<6.2<hour)0.517 (1.51)0.732−2.85 (0.71) 0.0001
(C) Outcome: longitudinal CSF tau
 Covariateβ* (SE)β† (SE)p
  Age†0.039 (0.049)0.4250.146 (0.121)0.227
  Male sex1.130 (0.632)0.074−1.870 (1.527)0.221
  APOE ε41.073 (1.030)0.298−2.394 (1.721)0.165
  Dx-MCI−0.836 (0.613)0.1732.942 (1.763)0.096
  Dx-AD0.402 (2.822)0.887−1.391 (2.416)0.565
  CSF Aβ1-42†0.006 (0.008)0.441−0.016 (0.028)0.581
  CSF ApoE†6.732 (3.049) 0.028 10.208 (6.547)0.119
  CSF ferritin (L<6.2<hour)−0.304 (0.630)0.630−2.264 (1.649)0.170

  • Separate mixed-effects linear models of annual measurements of (B) CSF Aβ1-42 and (C) CSF tau. Aβ1-42 units are pg/mL tau and ferritin units are ng/mL.

  • *Beta coefficient is annual change in biomarker associated with each covariate.

  • †Variables exhibited high multicollinearity (variance inflation factor >10) and were ultimately removed from analysis.

  • Aβ, β-amyloid; AD, Alzheimer’s disease; CN, cognitively normal; CSF, cerebrospinal fluid; Dx, diagnosis; MCI, mild cognitive impairment.