Type 2 Diabetes and Cognitive Dysfunction: Cardiorespiratory Fitness and Physical Activity Matters

Cognitive Function Mediates the Association Between Type 2 Diabetes and Physical Performance Decline in Older Adults: A Cross-Sectional Study

Background: Elderly patients with type 2 diabetes mellitus (T2DM) often experience cognitive decline and physical function degradation. However, whether cognitive function mediates the association between T2DM and physical performance in older adults has not been previously examined. This study aimed to explore whether cognitive function was statistically associated with the relationship between T2DM and physical performance in older adults using mediation analysis. Methods: We conducted a cross-sectional study, and a total of 102 participants aged ≥60 were included (46 patients with T2DM and 56 non-diabetes controls). Cognition was assessed using standardized neuropsychological tests (global cognition, as assessed by the MoCA total score; and domain-specific measures). Physical performance was quantified by walking speed and handgrip strength. Mediation analyses were performed to test whether the cognitive function statistically accounted for part of the association between the T2DM state and the physical performance. Results: Participants with T2DM had poorer cognitive performance and lower physical performance than controls. In mediation models, the MoCA total score statistically accounted for approximately 18% of the association between T2DM and gait speed (ACME −5.19 cm/s, 95% CI −8.73 to −2.32; proportion mediated 0.18, 95% CI 0.08–0.32). For grip strength, the corresponding proportion was estimated at 60% (ACME −2.16 kg, 95% CI −3.78 to −0.81; proportion mediated 0.60, 95% CI 0.23–1.81), although this estimate should be interpreted cautiously because of the wide confidence interval. Conclusions: This study suggests that poorer cognitive performance may partially account for the observed relationship between T2DM and the decline in physical performance of the elderly. The results support the presence of concurrent cognitive and physical impairment among older adults with T2DM. Given the cross-sectional design, these findings should be regarded as exploratory and hypothesis-generating, and longitudinal studies are required to establish temporal relationships.

Cardiometabolic Risk Factors and Domain-Specific Cognitive Function in Prediabetes and Type 2 Diabetes

Background: Cardiometabolic risk factors are increasingly recognised as contributors to cognitive decline, yet their associations with domain-specific cognitive performance in adults with prediabetes or well-controlled type 2 diabetes (T2DM) remain poorly characterised. Methods: This cross-sectional study included 49 adults with prediabetes or well-controlled T2DM (managed by diet or metformin alone; HbA1c < 8%). Cognitive function was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB), Trail Making Tests (TMTs) parts A and B, Stroop, and Digit Symbol Substitution Test (DSST). Multivariable linear regression examined associations between cardiometabolic predictors (adiposity [DXA], glycaemic indices [OGTT], and serum lipids) and cognitive outcomes, adjusting for age, BMI, and education. Results: Higher HbA1c was independently associated with increased false alarms on the rapid visual processing task (RVPPFA; β = 0.04 [95% CI 0.01, 0.07]; p = 0.015); fasting and 2 h glucose were not associated with any cognitive measure. Higher triglycerides were associated with lower sustained attention accuracy (RVPA; β = −0.02 [95% CI −0.04, −0.004]; p = 0.016) and lower DSST scores (β = −4.61 [95% CI −8.81, −0.40]; p = 0.033). Higher HDL cholesterol was independently associated with better sustained attention (RVPA; β = 0.08 [95% CI 0.02, 0.15]; p = 0.017). No consistent associations were found between adiposity measures and any cognitive outcome, with no effect modification by sex or diabetes status (all Pinteraction > 0.05). Conclusions: In cognitively healthy adults with prediabetes or well-controlled T2DM, higher HbA1c and triglycerides and lower HDL were associated with poorer domain-specific cognitive performance in the absence of overt cognitive impairment. Larger longitudinal studies are needed to establish whether these associations represent early cognitive changes and to determine whether reducing cardiometabolic risk can preserve cognitive function.

Cognitive Impairment in People with Type 2 Diabetes Mellitus: Associations with Inflammatory and Vascular Markers

Background Type 2 diabetes mellitus (T2DM) is associated with metabolic, vascular and cognitive complications. Although mild cognitive impairment (MCI) is increasingly recognised in T2DM, its relationship with inflammatory and vascular markers remains underexplored in India. Purpose This study investigated the association between high-sensitivity C-reactive protein (hs-CRP), carotid intima-media thickness (CIMT) and cognitive status in individuals with T2DM. Methods This cross-sectional study included 117 adults aged 40–65 years with T2DM of at least 5 years’ duration, recruited from a tertiary care hospital in Mysuru. Cognitive function was assessed using the Saint Louis University Mental Status Scale. Clinical, anthropometric, biochemical and vascular parameters, including hs-CRP and CIMT, were measured. Group comparisons and correlation analyses were conducted. Results MCI was present in 47.9% of participants. Education level was significantly associated with cognitive status (p = .001). Participants with MCI exhibited higher hs-CRP levels (p = .007) and greater CIMT (p = .001) compared to those with normal cognition. Correlation analyses demonstrated negative associations between SLUMS scores, hs-CRP and CIMT. Receiver operating characteristic analysis indicated fair predictive value for hs-CRP (AUC = 0.64) and CIMT (AUC = 0.70). Conclusion Lower educational attainment, higher hs-CRP levels and greater CIMT were associated with MCI among individuals with T2DM. These findings suggest that inflammatory and vascular markers may be useful in identifying individuals at greater risk of cognitive impairment. However, longitudinal studies are required to determine temporal and causal relationships.

Improving cognition through lifestyle-induced remission of type 2 diabetes: findings from DIABEPIC-2.

cognitive impairment, health status and depressive symptoms in patients with type 2 diabetes

The relationship between sedentary time, sleep quality, glycemic control, and mild cognitive impairment in older adults with type 2 diabetes mellitus.

OBJECTIVE This cross-sectional study examined associations among sedentary behavior, sleep quality, glycemic control, and mild cognitive impairment (MCI) in older adults with type 2 diabetes mellitus (T2DM), and explored latent sleep profiles and their associations with MCI. METHODS From October 2021 to October 2022, 257 patients with T2DM aged ≥ 60 years were recruited from a tertiary hospital in Jinan, China. Cognitive status was operationalized using a structured study framework that combined MoCA screening with education adjustment, assessment of daily functioning, clinical exclusion criteria, and exclusion of dementia. Participants were classified as having T2DM with MCI (T2DM-MCI; n = 146) or T2DM with normal cognitive function (T2DM-NCF; n = 111). Analyses included descriptive statistics, group comparisons, complete-case logistic regression, latent profile analysis (LPA), a PSQI cutoff plus hypnotic-medication classification, sensitivity analyses, correlation analysis, and cross-sectional indirect-effect models, including exploratory parallel and serial models. RESULTS Among the 257 participants, 146 were classified as T2DM-MCI and 111 as T2DM-NCF. LPA identified three sleep profiles: good sleep, poor sleep with low hypnotic-medication use, and poor sleep with high hypnotic-medication use. A simpler PSQI cutoff plus hypnotic-medication classification showed a broadly similar pattern. In adjusted logistic regression, the poor sleep with low hypnotic-medication use profile was associated with higher odds of MCI than the good sleep profile (OR = 2.50, p = 0.025), whereas the poor sleep with high hypnotic-medication use profile was not statistically significant. Exploratory indirect-effect models suggested significant total indirect effects through HbA1c and PSQI score, but the order-specific serial pathways were not statistically significant. These findings should not be interpreted as evidence of temporal or causal mediation. CONCLUSION Sedentary time, PSQI score, and HbA1c were associated with MCI in older adults with T2DM. These findings support further longitudinal research on multidimensional interventions addressing sedentary behavior, sleep, and glycemic management; however, causal conclusions cannot be drawn from this cross-sectional study.