Correlation between time in range and mild cognitive impairment in older adults with type 2 diabetes mellitus

To investigate the association between time in range (TIR) and mild cognitive impairment (MCI) in older adult patients with type 2 diabetes mellitus (T2DM) and the contributions of various indicators to MCI.

Two hundred and three participants received continuous glucose monitoring and cognitive assessments. Relative weight analysis assessed TIR and other factors' contributions to MCI. Binary logistic analysis explored TIR-MCI associations across the sample and by age and sex.

TIR showed a stronger association with MCI than diabetes duration, education, systolic blood pressure (SBP), urinary albumin-creatinine ratio (UACR), and C-peptide (25.59% relative weight). Multivariable-adjusted odds ratios (ORs) for MCI declined with increasing TIR quartile (Q) (Q1 [reference group], ≤40%; Q2, 40.3-51.1%, OR 0.402, 95% confidence interval [CI] 0.094-1.717; Q3, 51.2-61.2%, OR 0.113, 95% CI 0.023-0.565; Q4, ≥61.3%, OR 0.050, 95% CI 0.007-0.343). This protective association remained when TIR was treated as a continuous variable and adjusted for covariates (OR 0.917, 95% CI 0.867-0.969, P = 0.002). Women with TIR ≥61.3% had lower MCI risk. Men with TIR 51.2-61.2% had lower MCI risk.

Besides hemoglobin A1c, clinicians should consider low TIR as a risk factor for MCI in older T2DM patients. Women potentially require a higher TIR target to prevent MCI.