Association of the Triglyceride-Glucose Index With Risk of Alzheimer's Disease: A Prospective Cohort Study

The triglyceride-glucose index and risk of cognitive impairment: a systematic review and meta-analysis with inclusion of two national databases

Background

To investigate the relationship between the triglyceride and glucose (TyG) index and cognitive impairment (CI).

Methods

Five authoritative databases were systematically searched for potentially relevant studies on 'TyG index' and 'CI' from inception to 27 April 2024. Two representative databases from the United Kingdom and United States were also included. We used the PICOS criteria to select available articles. All data was combined to compute Odd Ratios (ORs).

Results

15 studies were included in the meta-analysis (participants: 5604303). The pooled effect sizes demonstrate that individuals with a high TyG index exhibit a significantly elevated risk of CI compared to those with a low TyG index (OR = 2.16, 95%CI: 1.51; 3.08, p < 0.001). The subgroup analysis showed that inpatients with a high TyG index exhibited an increased risk of CI (OR = 4.56, 95%CI: 3.09; 6.74, p < 0.001). Furthermore, the risk of developing distinct types of CI differed significantly [CI: OR = 1.64, 95% CI: 1.29; 2.07, p < 0.001; Vascular Cognitive Impairment (VCI): OR = 5.39, 95% CI: 3.33; 8.70, p < 0.001].

Conclusion

A positive correlation exists between the TyG index and risk of CI, which has potential value in optimizing CI risk stratification among elderly people, especially those hospitalized.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023450336.

Exploring the Association Between Cognitive Decline and Triglyceride-Glucose Index: A Systematic Review and Meta-Analysis

BACKGROUND

Cognitive decline and dementia are debilitating conditions that compromise the quality of life and charge the healthcare system with a substantial socioeconomic burden. In this context, emerging evidence supports an association between the triglyceride-glucose index (TyG), a surrogate insulin resistance marker, and cognitive decline and dementia. Hence, we systematically reviewed the studies assessing the TyG index in patients with cognitive decline and their controls.

METHODS

Online international databases (PubMed, Scopus, Embase, and the Web of Science) were searched comprehensively for studies showing the TyG index in patients with cognitive decline/impairment. Random-effect meta-analyses were conducted to calculate the standardized mean difference (SMD), pooled odds ratio (OR), and pooled area under the curve (AUC), in addition to 95% confidence intervals (CIs) for the comparisons of groups.

RESULTS

Seventeen studies were included in our analysis. Then, we conducted a meta-analysis, demonstrating that patients with cognitive decline had significantly higher levels of TyG index than those without (SMD 0.83, 95% CI 0.16 to 1.50, p = 0.015). Moreover, our data showed that a 1-unit increase in the TyG index was associated with higher odds of cognitive decline (adjusted OR [aOR] 2.86, 95% CI 1.49 to 5.50, p = 0.002). Further, we observed that patients in the fourth TyG quartile with higher values of the TyG index than the first quartile presented with more increased cognitive decline (aOR 1.62, 95%CI 1.11 to 2.38, p = 0.013). Finally, pooled AUC data for the diagnostic performance of the TyG index resulted in an overall AUC value of 0.73 (95% CI 0.66 to 0.79). Sensitivity and specificity were also calculated as 0.695 and 0.687, respectively.

CONCLUSION

This study supports the clinical utility of the TyG index in patients with cognitive decline and solicits more focused studies to consolidate its usage in clinical settings and real-world practice.

Triglyceride-glucose index is associated with all-cause mortality in critically ill patients with alcohol use disorder: a retrospective cohort study

BACKGROUND

The relationship between Triglyceride-glucose (TyG) index and clinical outcomes in patients with alcohol use disorder (AUD) is unclear. The aim of this study was to evaluate the association between TyG index and all-cause mortality in critically ill patients with AUD.

METHODS

We used data from the multi-parameter intelligent monitoring in intensive care IV (MIMIC-IV) database. The patients were equally divided into quartiles. Kaplan-Meier curves were used for survival analysis. The primary endpoint of the study was 28-day mortality, followed by 1-year mortality. We used Cox proportional hazard models to assess the relationship between TyG index and all-cause mortality at different endpoints.

RESULTS

A total of 537 AUD patients were included. Using TyG value as a continuous variable (HR 1.460, 95% CI 1.121-1.903, p = 0.005) and categorical variable (HR 1.447-3.477 from Q2 to Q4, with Q1 as reference), elevated TyG value was significantly associated with increased 28-day mortality. TyG was positively associated with 1-year mortality in AUD patients with an HR of 1.295 (95% CI 1.011-1.659, p = 0.041).

CONCLUSION

TyG index is positively associated with different clinical outcomes of critically ill AUD patients.

Association Between Triglyceride Glucose Index with Cognitive Impairment and Dementia in Adult Population: A Meta-Analysis

The current understanding of the correlation between insulin resistance (IR) and cognitive dysfunction is limited. Therefore, the objective of this systematic review and meta-analysis was to assess the association between the triglyceride glucose (TyG) index, a recently suggested indicator of IR, and cognitive impairment and dementia in the adult population. Observational studies pertinent to our research were identified through comprehensive searches of the PubMed, Embase, and Web of Science databases. To account for potential heterogeneity, the random-effects models were employed to aggregate the findings. This meta-analysis included ten observational studies involving 5602409 participants. Compared to those with the low TyG index, subjects with the high TyG index were significantly associated with the risk of cognitive impairment [risk ratio (RR): 1.39, 95% confidence interval (CI): 1.22 to 1.59, p<0.001; I2=45%) and dementia (RR: 1.30, 95% CI: 1.06 to 1.60, p=0.01; I2=50%). The association was consistent for Alzheimer's disease (RR: 1.35, 95% CI: 1.04 to 1.76, p=0.03; I2=54%) and vascular dementia (RR: 1.18, 95% CI: 1.13 to 1.24, p<0.001; I2=0%). Subgroup analyses showed that the association between TyG index with cognitive impairment and dementia were stronger in cross-sectional studies than that in cohort studies (p for subgroup difference=0.02), but not significantly modified by age, sex, or diabetic status of the participants. In conclusion, a high TyG index may be associated with higher risk of cognitive impartment and dementia in adult population.

Association of triglyceride glucose-body mass index with Alzheimer's disease pathology, cognition and brain structure in non-demented people

The relationship between the triglyceride glucose-body mass index (TyG-BMI) index and Alzheimer's disease (AD) pathology, cognition, and brain structure remains unclear. This study aimed to investigate these associations, focusing on cerebrospinal fluid (CSF) biomarkers, cognitive measures, and brain imaging data. Eight hundred and fifty-five non-demented participants were included. Linear regression was used to explore associations between the TyG-BMI index and AD pathology, cognition, and brain structure. The association between the TyG-BMI index and AD risk was assessed using Kaplan-Meier and Cox proportional hazards models. Longitudinal relationships were assessed using linear mixed-effects models. Mediation analyses were conducted to examine AD pathology's potential mediating role between the TyG-BMI index and cognition as well as brain structure. In the linear regression analyses, higher TyG-BMI levels were associated with increased Aβ42 and decreased Tau, pTau, Tau/Aβ42, pTau/Aβ42, and pTau/Tau. Positive correlations were observed with mini-mental state examination (MMSE), memory (MEM), executive function (EF), and the volumes of the hippocampus, entorhinal cortex, and middle temporal regions, while negative correlations were found with Alzheimer's Disease Assessment Scale (ADAS). Longitudinally, the TyG-BMI index was inversely associated with ADAS, and positively with MMSE, MEM, EF, hippocampus, entorhinal, and middle temporal. High TyG-BMI levels were correlated with lower AD risk (HR 0.996 [0.994, 0.999]). Mediation analyses revealed AD pathology mediated the association between TyG-BMI index and cognition as well as brain structure. Additionally, the TyG-BMI index could mediate cognitive changes by influencing brain structure. The TyG-BMI index is associated with AD pathology, cognition, and brain structure.

Association between the triglyceride glucose index and cognitive impairment and dementia: a meta-analysis

Background

The triglyceride and glucose (TyG) index is an alternative index of insulin resistance (IR). We aimed to clarify the relationship between the TyG index and cognitive impairment and dementia.

Methods

We conducted a comprehensive search of the PubMed, Cochrane Library, and Embase databases until February 2023 to identify relevant studies. Random-effects models were used to pool effect sizes, and the Grading of Recommendations Assessment, Development, and Evaluation system (GRADE) was used to assess the quality of the evidence.

Results

Ten studies were included, with seven of which investigated the relationship between the TyG index and cognitive impairment and three exploring the association between the TyG index and dementia. When the TyG index was described as a categorical variable, it was positively associated with the risk of cognitive impairment (OR = 2.32; 95% CI 1.39-3.87) and dementia (OR = 1.14, 95% CI 1.12-1.16). The association of the TyG index with the risk of cognitive impairment (OR = 3.39, 95% CI 1.67-6.84) and dementia (OR = 1.37, 95% CI 1.03-1.83) remained significant for per 1 unit increment in the TyG index. The GRADE assessment indicated a very low certainty for cognitive impairment. Low certainty and moderate certainty were observed for dementia when the TyG index was analyzed as a categorical variable and as a continuous variable, respectively.

Conclusion

The TyG index is associated with an increased risk of cognitive impairment and dementia. Further prospective research is warranted to confirm these findings.Systematic review registration: https://www.crd.york.ac.uk/, Protocol registration number: CRD42023388028.

The link between metabolic syndrome and Alzheimer disease: A mutual relationship and long rigorous investigation

It has been illustrated that metabolic syndrome (MetS) is associated with Alzheimer disease (AD) neuropathology. Components of MetS including central obesity, hypertension, insulin resistance (IR), and dyslipidemia adversely affect the pathogenesis of AD by different mechanisms including activation of renin-angiotensin system (RAS), inflammatory signaling pathways, neuroinflammation, brain IR, mitochondrial dysfunction, and oxidative stress. MetS exacerbates AD neuropathology, and targeting of molecular pathways in MetS by pharmacological approach could a novel therapeutic strategy in the management of AD in high risk group. However, the underlying mechanisms of these pathways in AD neuropathology are not completely clarified. Therefore, this review aims to elucidate the association between MetS and AD regarding the oxidative and inflammatory mechanistic pathways.