Body Mass Index Trajectories in Relation to Change in Lean Mass and Physical Function: The Health, Aging and Body Composition Study

Ilse Reinders*, Rachel A. Murphy, Kathryn R. Martin, Ingeborg A. Brouwer, Marjolein Visser, Daniel K. White, Anne B. Newman, Denise K. Houston, Alka M. Kanaya, Daniel S. Nagin, Tamara B. Harris

*Corresponding author for this work

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Objectives

To examine body mass index (BMI) trajectories with change in lean mass and physical function in old age.

Design

Prospective cohort study.

Setting

Health, Aging and Body Composition Study.

Participants

Black and white men (n=482) and women (n=516) aged 73.12.7 and initially free of disability.

Measurements

A group-based trajectory model was used to determine BMI trajectories, the path a person's BMI followed over 9years. Lean mass, gait speed, grip strength, and knee extension strength were assessed at baseline and after 9years, and relative changes were calculated. Multivariable linear regression was used to determine associations between trajectories and relative change in lean mass and physical function.

Results

Four BMI trajectories were identified for men and four for women. Although all demonstrated a decline in BMI, the rate of decline differed according to trajectory for women only. Men in Trajectory 4 (mean BMI at baseline 33.9 +/- 2.3kg/m(2)) declined more than those in Trajectory 1 (mean BMI at baseline 22.9 +/- 1.6kg/m(2)) in gaitspeed (-9.91%, 95% confidence interval (CI)=-15.15% to -4.67%) and leg strength (-8.63%, 95% CI=-15.62% to -1.64%). Women in Trajectory 4 (mean BMI at baseline 34.9 +/- 3.0kg/m(2)) had greater losses than those in Trajectory 1 (mean BMI at baseline 20.5 +/- 1.6kg/m(2)) in lean mass in the arms (-3.19%, 95% CI=-6.16% to -0.23%). No other associations were observed.

Conclusion

Obese men had the highest risk of decline in physical function despite similar weight loss between trajectories, whereas overweight and obese women who lost the most weight had the greatest risk of lean mass loss. The weight at which a person enters old age is informative for predicting loss in lean mass and physical function, illustrating the importance of monitoring weight.

Original languageEnglish
Pages (from-to)1615-1621
Number of pages7
JournalJournal of the American Geriatrics Society
Volume63
Issue number8
Early online date20 Aug 2015
DOIs
Publication statusPublished - Aug 2015

Keywords

  • aging
  • body mass index
  • lean mass
  • physical function
  • trajectories
  • FAT-FREE MASS
  • OLDER-ADULTS
  • WEIGHT-LOSS
  • MUSCLE MASS
  • AGE
  • OVERWEIGHT
  • PATTERNS
  • ABC

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Reinders, I., Murphy, R. A., Martin, K. R., Brouwer, I. A., Visser, M., White, D. K., Newman, A. B., Houston, D. K., Kanaya, A. M., Nagin, D. S., & Harris, T. B. (2015). Body Mass Index Trajectories in Relation to Change in Lean Mass and Physical Function: The Health, Aging and Body Composition Study. Journal of the American Geriatrics Society, 63(8), 1615-1621. https://doi.org/10.1111/jgs.13524