Objective:

To explore the association between hemoglobin glycation index (HGI) values and mild cognitive impairment (MCI) risk in individuals aged 45 years and older.

Approach:

• Study Design: Cohort study using data from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2018.
• Participants: Included non-MCI participants aged ≥45 years, with follow-up data collected through 2018.
• Statistical Analysis: Cox regression analyses were performed to investigate the association between HGI and MCI risk, summarized as hazard ratios with 95% confidence intervals.
• Non-linear Relationship: Restricted cubic splines (RCS) curve was applied to examine the non-linear relationship between HGI and MCI risk.

Key Findings:

• Out of 5,723 participants, 1,088 (19.01%) had MCI.
• HGI exhibited a significant U-shaped relationship with MCI risk (p < 0.05).
• Quintile analysis indicated that Q1 [HR = 1.22 (1.00–1.49), p = 0.045] and Q5 [HR = 1.26 (1.03–1.53)] were associated with higher MCI risk compared to Q2.
• Increased MCI risk was noted in subgroups of individuals aged <65 years, males, non-diabetics, and those with cardiovascular diseases (all p < 0.05).

Interpretation:

Low and high HGI values are associated with a higher risk of MCI among middle-aged and elderly individuals, suggesting HGI may help identify high-risk populations for MCI.

Limitations:

• The study's findings may not be generalizable beyond the CHARLS population.
• Potential confounding factors may not have been fully accounted for in the analysis.

Conclusion:

HGI values may be associated with MCI risk.