Table 3. Serum and CSF levels of calcium, PTH, and 25-hydroxyvitamin D (25OHD) in the study population of 52 patients with cognitive impairment (AD, n=28; other dementias, n=12; SMCI, n=12) and 17 healthy matched controls.
| AD | Other dementias | SMCI | Controls | P-value* | |
|---|---|---|---|---|---|
| Serum levels | |||||
| Calcium (mmol/L) | 2.37 (2.30-2.45) | 2.39 (2.33-2.45) | 2.35 (2.32-2.43) | 2.37 (2.35-2.39) | 0.92 |
| PTH (ng/L) | 54.5 (46.5-71.5) | 54.0 (38.0-56.5) | 54.0 (46.5-74.0) | 45.0 (41.5-58.8) | 0.15 |
| 25OHD (nmol/L) | 44.0 (36.0-54.5) | 42.0 (37.0-49.0) | 41.0 (37.8-55.8) | 56.0 (46.8-57.3) | 0.31 |
| CSF levels | |||||
| 25OHD (nmol/L) | 11.0 (10.0-11.5)a,b | 12.0 (11.5-12.5) | 11.0 (10.0-12.0) | 12.0 (11.0-13.0) | 0.03 |
| Calcium (mmol/L) | 1.16 (1.14-1.20) | 1.15 (1.11-1.19) | 1.19 (1.18-1.23) | 1.19 (1.15-1.20) | 0.16 |
| Ratios | |||||
| CSF/serum 25OHD | 0.23 (0.19-0.28) | 0.28 (0.23-0.32) | 0.26 (0.19-0.27) | 0.22 (0.21-0.23) | 0.13 |
| CSF/serum calcium | 0.49 (0.48-0.50) | 0.48 (0.47-050) | 0.50 (0.49-0.51) | 0.50 (0.49-0.51) | 0.09 |
PTH was only measurable in serum.
*
P-values for differences between all groups were assessed using the Kruskal-Wallis test for multiple variables. Post hoc testing was then performed using the Mann-Whitney U test for pair-wise comparisons.
Values are given as the median (25th-75th percentile).
a P = 0.03 vs. controls; b P = 0.01 vs. other dementias