Table.
Demographic Data and Vitamin D Status in PD Patients, AD Patients, and Matched Healthy Controls
| P Valuea | ||||||
|---|---|---|---|---|---|---|
| PD Patients (n=100) |
AD Patients (n=97) |
Healthy Controls (n=99) |
PD Patients vs Controls |
AD Patients vs Controls |
PD Patients vs AD Patients |
|
| Demographic | ||||||
| Age, mean (range), y | 65.4 (37–88) | 66.4 (47–88) | 65.7 (39–89) | .84 | .59 | .47 |
| Sex, % | ||||||
| Male | 57 | 57 | 57 | … | … | … |
| Female | 43 | 43 | 43 | … | … | … |
| Race, No. | ||||||
| White | 96 | 94 | 96 | … | … | … |
| African American | 1 | 1 | 1 | … | … | … |
| Asian | 1 | 1 | 1 | … | … | … |
| Hispanic | 2 | 1 | 1 | … | … | … |
| Symptom duration, mean (SD) [range], y | 7.6 (5.4) [0–28] | 3.6 (2.6) [0–16] | … | |||
| Season sample drawn, % | .01 | .29 | .26 | |||
| Summer to fall ( July–December) | 57 | 47 | 39 | |||
| Winter to spring ( January–June) | 43 | 52 | 61 | |||
| Vitamin D statusb | ||||||
| 25(OH)D level, mean (SD) [range], ng/mL | 31.9 (13.6) [12.1–68.9] | 34.8 (15.4) [7.5–81.2] | 37.0 (14.5) [11.1–81.9] | .01 | .30 | .12 |
| Prevalence of vitamin D insufficiency (25[OH]D, ≤30 ng/mL), % | 55.0 | 41.2 | 36.4 | .008 | .48 | .05 |
| Vitamin D status by season | … | … | … | … | … | … |
| Summer to fall ( July–December)c | ||||||
| 25(OH)D, mean (SD), ng/mL | 32.3 (13.8) (n=57) | 35.1 (16.6) (n=46) | 39.85 (13.8) (n=39) | .13 | .86 | .20 |
| Prevalence of vitamin D insufficiency, % | 54 | 44 | 31 | .02 | .16 | .27 |
| Winter to spring ( January–June)d | … | … | … | … | … | … |
| 25(OH)D, mean (SD), ng/mL | 31.4 (13.5) (n=43) | 34.7 (14.6) (n=50) | 35.1 (14.8) (n=60) | .02 | .16 | .36 |
| Prevalence of vitamin D insufficiency, % | 56 | 38 | 40 | .11 | .83 | .09 |
Abbreviations: AD, Alzheimer disease; 25(OH)D, 25-hydroxyvitamin D; PD, Parkinson disease.
SI conversion factor: To convert 25(OH)D to nanomoles per liter, multiply by 2.496.
a
Except where noted, pairwise P values via pooled t test and PROC GLM procedure. Ellipses indicate statistical test not relevant.
b
25(OH)D level (P=.03, analysis of variance using PROC GLM) and prevalence (P=.02, χ2 test) irrespective of season.
c
25(OH)D level (P=.28, analysis of variance) and prevalence (P=.17, χ2 test) for summer to fall months.
d
25(OH)D level (P=.07, analysis of variance) and prevalence (P=.07, χ2 test) for winter to spring months.