Table 2.
Sex differences in AD-related fluid biomarkers.
| CSF | Plasma/Serum | |||
|---|---|---|---|---|
| Aβ42 or Aβ42/40 | F = M | No differences found88,240–244 | ○ | unknown |
| sAPPα and sAPPβ | F ⩾ M | Most studies have not assessed it. One study found higher levels in AD women.248 | ○ | unknown |
| t-tau | F ⩾ M | Most studies have not reported differences. A few showed higher levels in women (controls, MCI, and AD)243,245 | F = M | Most studies have not assessed it. One study reported no differences59 |
| p-tau | F = M | Most studies have not reported differences240–243,249 | ○ | unknown |
| NfL | F ⩽ M | Most studies have not assessed it. A few had reported no differences,69,250 but a recent study found higher levels in men.186 | F = M | Only a few studies available and no differences found72,78 |
| VILIP-1 | F = M | Most studies have not assessed it. A study reported no sex differences in controls and AD88 | ○ | unknown |
| VCAM1 | F ⩽ M | Most studies have not assessed it. A few have found higher levels in men.124,242 | F ⩽ M | One study found higher levels in men.125. |
| ICAM1 | F ⩽ M | Most studies have not assessed it. One study found higher levels in men171 | ○ | unknown |
| sTREM2 | F ⩽ M | Most studies have not reported differences.150,151 One study found higher levels in men (controls and AD)148 | F = M | Only one study available and did not find differences148 |
| Progranulin | F ⩽ M | A number of studies have reported higher levels in men (controls, MCI, and AD)174,175,178 | F ⩾ M | Very few studies available. One study found higher levels in women while another did not find differences174,175 |
| YKL-40 | F = M | A number of studies have assessed it and no differences have been reported183,186,251–253 | F = M | Few studies have assessed it and reported no differences183,193 |
| MCP-1 | F = M | Most studies have not assessed it. One study reported no differences251 | F = M | Most studies have not assessed it. A few have reported no differences194,254 |
| α -synuclein | F = M | Most studies have not assessed it. Few have reported no differences226,255,256 | ○ | unknown |
The table depicts the differences found in AD-related biomarkers between women and men in AD (prodromal, dementia, or both), the controls or both. ○ indicates unknown. We reviewed all studies available in AlzBiomarker for GFAP, MCP-1, neurogranin, NfL, sAPPα, sAPPβ, sTREM2, VILIP-1, YKL-40, and α -synuclein. For Aβ, t-tau, and p-tau we reviewed those studies in AlzBiomarker with a total number of individuals >300. CSF/Serum Albumin ratio, GFAP, and neurogranin are not included in the table because there is no data available on sex differences either in CSF or blood. In addition, we included biomarkers where there is evidence of sex differences.
Aβ, β-amyloid; CSF, cerebrospinal fluid; ICAM-1, intercellular adhesion molecule-1; MCP-1, Monocyte chemoattractant protein-1; NfL, neurofilament light; p-tau, phosphorylated tau; sAPP, soluble N-terminal fragment of APP; sTREM2, soluble triggering receptor expressed on myeloid cells 2; t-tau, total tau; VILIP-1, visinin-like protein 1; YKL-40, chitinase 3-like protein 1.