title: Blood biomarkers and functional disability among extremely longevous individuals: a population-based study.
abstract: BACKGROUND
  Several blood biomarkers have been linked to functional disability, a health problem in general populations. However, there are limited data for evaluating the potential association of biomarkers with functional disability in an extremely longevous (95+) population.
  
  
  METHODS
  We used data from 420 extremely longevous individuals from the Rugao longevity cohort, a population-based association study conducted in Rugao, a longevity town in China. Functional disability was assessed by the Katz Index of Independence in activities of daily living. Blood biomarkers, including serum lipid, lipoprotein cholesterol, serum albumin, and lymphocyte count, were correlated with activities of daily living.
  
  
  RESULTS
  Among extremely longevous women, following the degree of functional disability, serum albumin and lymphocyte count decreased significantly (all p for trend < .001). In a univariate model, serum albumin (β = -0.279, p < .001), lymphocyte count (β = -0.187, p < .001), and neutrophil count (β = 0.140, p = .012) were found to be significantly associated with activities of daily living in women. After adjustment for other covariates, the significance remained. Notably, multivariate regression analysis revealed independent effects of all the three biomarkers on activities of daily living (β = -0.242, -0.185, and 0.143, all p < .05). We did not observe any association in men.
  
  
  CONCLUSIONS
  We found significant associations between serum albumin, lymphocyte count, and neutrophil count and physical disability even after adjustment for potential confounders in extremely longevous women, which call for further study. The findings provide preliminary but crucial clues for future studies specifically aimed at exploring the longitudinal relationships of interest before proceeding with interventions.
authors.affiliation: Unit of Epidemiology, State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
authors.forename: Zuyun
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Rugao People's Hospital, Jiangsu, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Unit of Epidemiology, State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
authors.forename: Jiapin
authors.initials: J
authors.lastname: Huang
authors.affiliation: Rugao People's Hospital, Jiangsu, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Chu
authors.affiliation: Longevity Research Institute of Rugao, Jiangsu, China.
authors.forename: Degui
authors.initials: D
authors.lastname: Qian
authors.affiliation: Rugao People's Hospital, Jiangsu, China.
authors.forename: Zhengdong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Unit of Epidemiology, State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
authors.forename: Xunming
authors.initials: X
authors.lastname: Sun
authors.affiliation: Longevity Research Institute of Rugao, Jiangsu, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Chen
authors.affiliation: Longevity Research Institute of Rugao, Jiangsu, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: Unit of Epidemiology, State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
authors.forename: Shilin
authors.initials: S
authors.lastname: Li
authors.affiliation: Unit of Epidemiology, State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
authors.forename: Li
authors.initials: L
authors.lastname: Jin
authors.affiliation: Unit of Epidemiology, State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China. xiaofengautomatic@gmail.com.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wang
mesh_terms: D000203:Activities of Daily Living; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D002681:China; D004185:Disability Evaluation; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008136:Longevity; D008297:Male
chemical_list: D015415:Biomarkers
keywords: Biomarker; Extremely longevous; Functional disability; Serum albumin.