title: Dietary protein intake is associated with lean mass change in older, community-dwelling adults: the Health, Aging, and Body Composition (Health ABC) Study.
abstract: BACKGROUND
  Dietary surveys suggest that many older, community-dwelling adults consume insufficient dietary protein, which may contribute to the age-related loss of lean mass (LM).
  
  
  OBJECTIVE
  The objective of the study was to determine the association between dietary protein and changes in total LM and nonbone appendicular LM (aLM) in older, community-dwelling men and women.
  
  
  METHODS
  Dietary protein intake was assessed by using an interviewer-administered 108-item food-frequency questionnaire in men and women aged 70-79 y who were participating in the Health, Aging, and Body Composition study (n=2066). Changes in LM and aLM over 3 y were measured by using dual-energy X-ray absorptiometry. The association between protein intake and 3-y changes in LM and aLM was examined by using multiple linear regression analysis adjusted for potential confounders.
  
  
  RESULTS
  After adjustment for potential confounders, energy-adjusted protein intake was associated with 3-y changes in LM [beta (SE): 8.76 (3.00), P=0.004] and aLM [beta (SE): 5.31 (1.64), P=0.001]. Participants in the highest quintile of protein intake lost approximately 40% less LM and aLM than did those in the lowest quintile of protein intake (x+/-SE: -0.501+/-0.106 kg compared with -0.883+/-0.104 kg for LM; -0.400+/-0.058 kg compared with -0.661+/-0.057 kg for aLM; P for trend<0.01). The associations were attenuated slightly after adjustment for change in fat mass, but the results remained significant.
  
  
  CONCLUSIONS
  Dietary protein may be a modifiable risk factor for sarcopenia in older adults and should be studied further to determine its effects on preserving LM in this population.
authors.affiliation: Sticht Center on Aging, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1207, USA. dhouston@wfubmc.edu
authors.forename: Denise K
authors.initials: DK
authors.lastname: Houston
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Nicklas
authors.forename: Jingzhong
authors.initials: J
authors.lastname: Ding
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
authors.forename: Frances A
authors.initials: FA
authors.lastname: Tylavsky
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Lee
authors.forename: Nadine R
authors.initials: NR
authors.lastname: Sahyoun
authors.forename: Marjolein
authors.initials: M
authors.lastname: Visser
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism; D000368:Aged; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000378:metabolism; D005260:Female; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008460:Meat; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D009133:Muscular Atrophy / Q000517:prevention & control*; D015596:Nutrition Assessment; D014674:Plant Proteins, Dietary / Q000008:administration & dosage; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D004044:Dietary Proteins; D014674:Plant Proteins, Dietary