Table 1.
Clinical characteristics of participants according to serum 25OHD concentrations (n = 359)
| Serum 25OHD concentrations (ng/mL) | P valuea | ||||||
|---|---|---|---|---|---|---|---|
| <10 (n = 56) |
10–30 (n = 256) |
>30 (n = 47) |
Overall | <10 versus 10–30 |
<10 versus >30 |
10–30 versus >30 |
|
| Age, mean ± SD (years) | 70.9 ± 5.3 | 70.5 ± 4.9 | 69.4 ± 4.1 | 0.268 | – | – | – |
| Female, n (%) | 23 (41.1) | 101 (39.5) | 22 (46.8) | 0.639 | – | – | – |
| Number of drugs daily taken, mean ± SD | 3.0 ± 2.7 | 2.6 ± 2.4 | 2.7 ± 3.1 | 0.548 | – | – | – |
| Use of psychoactive drugsb, n (%) | 48 (85.7) | 215 (84.0) | 36 (76.6) | 0.399 | – | – | – |
| Body mass index (kg/m2), mean ± SD | 27.3 ± 5.4 | 26.5 ± 4.1 | 25.3 ± 3.5 | 0.057 | – | – | – |
| Visual acuityg (/10), mean ± SD | 6.8 ± 2.6 | 7.6 ± 2.3 | 7.6 ± 2.3 | 0.080 | – | – | – |
| Lower limb proprioceptionf (/8), mean ± SD | 5.6 ± 1.6 | 5.9 ± 1.3 | 6.3 ± 1.2 | 0.042 | 0.398 | 0.035 | 0.240 |
| Handgrip strengthe (N/m2), mean ± SD | 30.8 ± 11.1 | 31.4 ± 10.9 | 30.6 ± 11.2 | 0.867 | – | – | – |
| Depression symptomsc, n (%) | 17 (30.4) | 59 (23.0) | 9 (19.1) | 0.373 | – | – | – |
| Cognitive impairmentd, n (%) | 20 (35.7) | 78 (30.5) | 11 (23.4) | 0.399 | – | – | – |
| Timed "Up & Go" test (seconds), mean ± SD | |||||||
| Performed | 11.2 ± 3.5 | 10.0 ± 2.6 | 10.0 ± 2.8 | 0.010 | 0.009 | 0.078 | 1.00 |
| Imagined | 6.3 ± 2.5 | 6.4 ± 2.4 | 6.5 ± 2.1 | 0.884 | – | – | – |
| TUG delta timeh (%), mean ± SD | 56.6 ± 28.5 | 44.5 ± 27.5 | 43.3 ± 28.4 | 0.010 | 0.010 | 0.048 | 1.00 |
Significant P value (i.e., P < 0.05) indicated in italics
25OHD 25-hydroxyvitamin D, SD standard deviation
aComparison based on one-way ANOVA, with Bonferroni corrections or chi-square test, as appropriate
bUse of benzodiazepines or antidepressants or neuroleptics
cFour-item Geriatric Depression Scale score >1
dParticipants with impaired Clock Drawing Test
eMean value of maximal isometric voluntary contraction strength measured with computerized dynamometers expressed in Newton per square meter
fMean value from left and right sides, based on graduated tuning fork placed on the lower limb
gBinocular visual acuity at a distance of 5 m with a Snellen letter test chart
hCalculated from the following formula: "[ (Performed Timed "Up & Go" − Imagined Timed "Up & Go") / ((Performed Timed "Up & Go" + Imagined Timed "Up & Go") / 2) ] × 100