[Examination of effects of alfacalcidol vitamin D supplement and renal function on improvement in the physical fitness of pre-frail elderly persons attending a nursing care prevention class].
OBJECTIVE
A characteristic condition of pre-frail elderly people is decreased mobility, which is associated with vitamin D levels and renal function. The aim of this study was to examine the association between physical fitness improvement and vitamin D levels, vitamin D supplements, and renal function in pre-frail elderly people.


METHODS
We conducted a longitudinal study in 2 towns from June 2006 to December 2009. Subjects consisted of 177 community-dwelling pre-frail elderly people aged 65 years and over (mean±standard deviation [SD]: 76.4±5.5 yrs) who attended a nursing care prevention program for 3 months. An interview was conducted based on a questionnaire. Serum levels of intact parathyroid hormone (iPTH), 25-hydroxyvitamin D(25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)(2)D), creatinine, and calcium were measured. eGFR (ml/min/1.73 m(2)) was calculated using a new formula. Alfacalcidol 1 µg/day was administered to subjects for 3 months, and we assumed that the elderly who took vitamin D (VD) of more than 80% of the recommended daily allowance to be the VD group. Walking ability, balance, and muscle strength physical fitness tests were performed.


RESULTS
The prevalence of eGFR <60.0 ml/min/1.73 m(2) was about 24.3%, and that of 25(OH)D <75 nmol/L was 86.4%. Pre-eGFR level and vitamin D supplementation with FR, pre-eGFR and pre 25(OH)D ≥45 nmol/L were associated with improvement in the timed up and go (TUG) test, pre-25(OH)D level (<50 nmol/L, ≥50 nmol/L) was associated with the tandem stance test, pre 25(OH)D level (<67.5 nmol/L, ≥67.5 nmol/L) was associated with the alternate step and 5 chair sit-to-stands tests, and post 1,25(OH)(2)D (<44 pg/ml, ≥44 pg/ml) was associated with the tandem walk tests.


CONCLUSIONS
These results suggest that the assessment of renal function and maintenance of appropriate vitamin D levels are important for the independent living of pre-frail elderly people. Ideally, a 25(OH)D level greater than 67.5 nmol/L is preferable.
Graduate School of Comprehensive Human Sciences, University of Tsukuba.
Junko
J
Okuno
Shigeo
S
Tomura
Takako
T
Fukasaku
Mi-Ji
MJ
Kim
Tomohiro
T
Okura
Kiyoji
K
Tanaka
Hisako
H
Yanagi
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D006887:Hydroxycholecalciferols / Q000494:pharmacology*; D007668:Kidney / Q000502:physiology*; D008297:Male; D010809:Physical Fitness / Q000502:physiology*; D014807:Vitamin D / Q000097:blood
D006887:Hydroxycholecalciferols; D014807:Vitamin D; C008088:alfacalcidol