Multi-trajectories of intrinsic capacity and their effect on higher-level functional capacity, life satisfaction, and self-esteem in community-dwelling older adults: the NILS-LSA

OBJECTIVES: Variability in intrinsic capacity (IC) changes among community-dwelling older adults and their effect on health outcomes remain understudied. We examined the variability in IC trajectories and their impact on higher-level functional capacity (HLFC), life satisfaction, and self-esteem. DESIGN: Longitudinal study. SETTING: Data from the second to seventh waves (2000-2012) of the National Institute for Longevity Sciences-Longitudinal Study of Aging project. PARTICIPANTS: 934 community dwellers (aged ≥60). MEASUREMENTS: We used group-based multi-trajectory modeling to obtain IC trajectories across six domains: cognition, locomotion, vitality, vision, hearing, and psychological well-being. We employed multivariable regression to investigate the associations between IC trajectories and a decline in HLFC (assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence TMIG-IC; baseline TMIG-IC - follow-up TMIG-IC ≥ 2; logistic regression model), life satisfaction (assessed using the Life Satisfaction Index-K LSI-K; linear mixed model), and self-esteem (assessed using the Rosenberg Self-Esteem Scale RSES; linear mixed model). RESULTS: We identified four IC trajectories: the "healthy aging group" (63.7%), the "hearing decline group" (15.1%), the "vision and cognitive decline group" (12.7%), and the "comprehensive deterioration group" (8.5%). Compared to the healthy aging group, the vision and cognitive decline group and the comprehensive deterioration group displayed a significantly greater risk of a decline in the TMIG-IC score (multivariable-adjusted odds ratio aOR, 95% confidence interval CI = 2.05 1.11, 3.79, 2.74 1.41, 5.30, respectively), the LSI-K score (multivariable-adjusted β standard error = -0.46 0.08, -0.52 0.10, respectively), and the RSES score (multivariable-adjusted β standard error = -0.85 0.16, -0.66 0.20, respectively). The "hearing decline group" did not show a significantly increased risk for these outcomes. CONCLUSION: Older adults with different IC trajectories may differ in HLFC, life satisfaction, and self-esteem. Public health officials should be aware of this and provide targeted interventions.