title: Concomitant lower serum albumin and vitamin D levels are associated with decreased objective physical performance among Japanese community-dwelling elderly.
abstract: BACKGROUND
  Previous studies have shown that serum albumin or vitamin D is associated with physical performance. We hypothesized that older adults with concomitant lower serum albumin and vitamin D (25-hydroxyvitamin D, 25OHD) levels are associated with decreased physical performance compared to those with 1 or none of the 2 risk factors.
  
  
  OBJECTIVE
  To investigate the association of combined serum albumin and 25OHD levels with physical performance (muscle strength and balance capability) in community-dwelling elderly.
  
  
  METHODS
  A cross-sectional study in a community-based population in the province of Tokyo, Japan, was performed. For the study, 1,094 community-dwelling people aged 70 and older underwent an interview, anthropometric measurements, blood analysis and physical performance testing. The subjects were classified into 4 types by combining serum albumin and 25OHD levels: lower albumin only, lower vitamin D only, lower albumin and lower vitamin D, higher albumin and higher vitamin D.
  
  
  RESULTS
  Men with concomitant lower albumin and lower 25OHD levels had significantly decreased knee extension power, usual timed Up & Go and maximal timed Up & Go, even after adjusting for age and body mass index (BMI). In women, concomitant lower albumin and lower vitamin D was associated with significantly decreased handgrip strength and functional reach, even after adjusting for age and BMI. Subjects with combined lower albumin and lower vitamin D levels showed a significant decline in muscle strength and balance capability compared to higher albumin and higher vitamin D, even after adjusting for age, current drinking or smoking status, physical activity, history of chronic disease, basic activities of daily living, instrumental activities of daily living, BMI and bone mineral density.
  
  
  CONCLUSIONS
  Concomitant lower serum albumin and lower vitamin D levels are associated with decreased muscle strength and balance capability in both men and women. These results suggest that serum albumin and 25OHD together may be an important target for strategies aiming to achieve a healthy life and prevent loss of independence in community-dwelling elderly.
authors.affiliation: Research Team for Promoting Independence of the Elderly, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan. kwounjh@hanmail.net
authors.forename: Jinhee
authors.initials: J
authors.lastname: Kwon
authors.forename: Takao
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hideyo
authors.initials: H
authors.lastname: Yoshida
authors.forename: Hunkyung
authors.initials: H
authors.lastname: Kim
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Hajime
authors.initials: H
authors.lastname: Iwasa
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D015999:Multivariate Analysis; D053580:Muscle Strength / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D012709:Serum Albumin / Q000032:analysis*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D012709:Serum Albumin; D014807:Vitamin D; C104450:25-hydroxyvitamin D