Association of metabolic syndrome severity with cognitive decline among Chinese older adults: evidence from two prospective cohort studies

Ming Chen; Lu Liu; Na Liu; Ji-Wen Che; Yuan-Yuan Peng; Yan Zeng

doi:10.3389/fnins.2026.1780804

Association of metabolic syndrome severity with cognitive decline among Chinese older adults: evidence from two prospective cohort studies

Front Neurosci. 2026 Mar 17:20:1780804. doi: 10.3389/fnins.2026.1780804. eCollection 2026.

Authors

Ming Chen^{1

2}, Lu Liu^{1

2}, Na Liu^{1

2}, Ji-Wen Che^{1

2}, Yuan-Yuan Peng^{1

2}, Yan Zeng^{1

2}

Affiliations

¹ Hubei Provincial Clinical Research Center for Alzheimer's Disease, Tianyou Hospital, School of Medicine, Wuhan University of Science and Technology, Wuhan, China.
² Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China.

Abstract

Introduction: The relationship between metabolic syndrome (MetS) severity and cognitive decline is not well understood, largely because the traditional binary diagnosis of MetS is unable to capture its continuous nature.

Methods: This longitudinal study included 1,191 participants aged ≥ 60 years from the Hubei Memory and Aging Cohort Study (HMACS, 2016-2024) and 2,281 participants from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2020). Annual rates of cognitive decline were calculated using standardized z-scores. An age-sex-ethnicity-specific MetS score model was used to calculate the MetS score for assessing MetS severity. The Cumulative MetS score was defined as (baseline MetS score + final MetS score)/2 × follow-up duration. The association between baseline and cumulative MetS score and annual rates of cognitive decline was evaluated using linear mixed models. Results from the two cohorts were pooled through random-effects meta-analysis. Sensitivity analyses included re-clustering of MetS trajectories and exclusion of participants with younger than 65 years and baseline cognitive impairment.

Results: A higher baseline MetS score was associated with a faster rate of global cognitive decline [β _HMACS = -0.052 (-0.073, -0.031); β _CHARLS = -0.028 (-0.041, -0.015); pooled β = -0.038 (-0.062, -0.015) z-score/year]. Participants in the highest quartile (Q4) of cumulative MetS score showed a more rapid annual decline in memory compared with those in the lowest quartile (Q1) [β _HMACS = -0.100 (-0.16, -0.041); β _CHARLS = -0.118 (-0.149, -0.086); pooled β = -0.114 (-0.142, -0.086) z-score/year]. These associations remained stable across all sensitivity analyses.

Discussion: Greater MetS severity is linked to a faster rate of cognitive decline in Chinese older adults, underscoring the urgent need for early detection of MetS and targeted interventions to mitigate the risk of cognitive deterioration.

Keywords: CHARLS; cognitive decline; dual-cohort study; longitudinal study; metabolic syndrome severity.