Metformin Use and Cognitive Dysfunction Among Patients with Diabetes Mellitus

Metformin use is associated with a reduced risk of cognitive impairment in adults with diabetes mellitus: A systematic review and meta-analysis

Objective

Controversy exists regarding the impact of metformin and whether it prevents or promotes the incidence of cognitive dysfunction. This systematic review and meta-analysis were conducted to identify the effect of metformin therapy on cognitive function in patients with diabetes.

Methods

Electronic databases (PubMed, EMBASE, PsycINFO, the Cochrane Library, and Web of Science) were systematically searched by two investigators from the date of inception until March 1, 2022. The study followed PRISMA guidelines. Inclusion criteria were defined according to the PECOSmodel. Eligible studies investigated cognitive dysfunction in metformin users compared with non-users in adults with diabetes. Only observational study designs (such as cohort, cross-section, and case-control) were included.

Results

A systematic search identified 1,839 articles, of which 28 (17 cohort, 8 case-control, and 3 cross-sectional studies) were included in the meta-analysis. Metformin reduced the occurrence of cognitive impairment in patients with diabetes [unadjusted hazard ratio (HR) = 0.67, 95% CI: 0.62–0.73; adjusted hazard ratio (aHR) = 0.92, 95% CI: 0.85–0.99]. In addition, the use of metformin was associated with a decreased risk of dementia (HR = 0.64, 95% CI: 0.59–0.69; aHR = 0.90, 95% CI: 0.84–0.96), while a random-effects meta-analysis indicated no significant effect of metformin on the risk of Alzheimer's disease (AD) (HR = 0.85, 95% CI: 0.60–1.22; aHR = 1.10, 95% CI: 0.95–1.28).

Conclusion

Metformin therapy decreased the occurrence risk of cognitive decline in patients with diabetes mellitus. Moreover, the use of metformin by adults with diabetes for the prevention of dementia, but not AD, is supported by the available evidence.

High serum amyloid A predicts risk of cognitive impairment after lacunar infarction: Development and validation of a nomogram

Background

Post-stroke cognitive impairment (PSCI) after lacunar infarction was worth attention in recent years. An easy-to-use score model to predict the risk of PSCI was rare. This study aimed to explore the association between serum amyloid A (SAA) and cognitive impairment, and it also developed a nomogram for predicting the risk of PSCI in lacunar infarction patients.

Methods

A total of 313 patients with lacunar infarction were enrolled in this retrospective study between January 2021 and December 2021. They were divided into a training set and a validation set at 70%:30% randomly. The Chinese version of the Mini-Mental State Examination (MMSE) was performed to identify cognitive impairment 3 months after discharge. Univariate and multivariate logistic regression analyses were used to determine the independent risk factors for PSCI in the training set. A nomogram was developed based on the five variables, and the calibration curve and the receiver operating characteristic (ROC) curve were drawn to assess the predictive ability of the nomogram between the training set and the validation set. The decision curve analysis (DCA) was also conducted in both sets.

Results

In total, 52/313 (16.61%) participants were identified with PSCI. The SAA levels in patients with PSCI were significantly higher than non-PSCI patients in the training set (P < 0.001). After multivariate analysis, age, diabetes mellitus, white blood count, cystatin C, and SAA were independent risk predictors of PSCI. The nomogram demonstrated a good discrimination performance between the training set (AUC = 0.860) and the validation set (AUC = 0.811). The DCA showed that the nomogram had a well clinical utility in the two sets.

Conclusion

The increased SAA is associated with PSCI in lacunar infarction patients, and the nomogram developed with SAA can increase prognostic information for the early detection of PSCI.

Exhaustive Description of the System Architecture and Prototype Implementation of an IoT-Based eHealth Biometric Monitoring System for Elders in Independent Living

In this paper, we present an exhaustive description of an extensible e-Health Internet-connected embedded system, which allows the measurement of three biometric parameters: pulse rate, oxygen saturation and temperature, via several wired and wireless sensors residing to the realm of Noncommunicable Diseases (NCDs) and cognitive assessment through Choice Reaction Time (CRT) analysis. The hardware used is based on ATMEGA AVR + MySignals Hardware printed circuit board (Hardware PCB), but with multiple upgrades (including porting from ATMEGA328P to ATMEGA2560). Multiple software improvements were made (by writing high-level device drivers, text-mode and graphic-mode display driver) for increasing functionality, portability, speed, and latency. A top-level embedded application was developed and benchmarked. A custom wireless AT command firmware was developed, based on ESP8266 firmware to allow AP-mode configuration and single-command JavaScript Object Notation (JSON) data-packet pushing towards the cloud platform. All software is available in a git repository, including the measurement results. The proposed eHealth system provides with specific NCDs and cognitive views fostering the potential to exploit correlations between physiological and cognitive data and to generate predictive analysis in the field of eldercare.

Association between metformin and neurodegenerative diseases of observational studies: systematic review and meta-analysis

BACKGROUND AND AIMS

Aging becomes a growing global concern with an increased risk of neurodegenerative diseases (NDs) that mainly consist of cognitive decline and Parkinson disease (PD). As the most commonly prescribed antidiabetic drug, metformin has been shown to have inconsistent roles in the incidence of NDs. We performed a systematic review and meta-analysis of observational studies to evaluate the effect of metformin exposure on onset of NDs.

METHODS

The observational studies that investigated the associations between metformin and the incidence of NDs were searched in MEDLINE, Embase and Cochrane Library databases. A random-effect model was performed using STATA to calculate the combined ORs.

RESULTS

In total, 23 comparisons out of 19 studies with 285 966 participants were included. Meta-analysis found there was no significant effect on incidence of all the subtypes of NDs with metformin exposure (OR 1.04, 95% CI 0.92 to 1.17). However, metformin monotherapy was associated with a significantly increased risk of PD incidence compared with non-metformin users or glitazone users (OR 1.66, 95% CI 1.14 to 2.42).

CONCLUSION

Metformin has failed to demonstrate a beneficial effect on NDs. In addition, it may increase the risk of PD development. In light of current results, how metformin would impact NDs, especially the potential risk of PD, needs to be scrutinized. The underlying mechanisms are vital to achieve some more profound understanding on the regimen.

TRIAL REGISTRATION NUMBER

CRD 42019133285.

Metformin therapy and cognitive dysfunction in patients with type 2 diabetes: A meta-analysis and systematic review

BACKGROUND

Type 2 diabetes (T2D) is a risk factor for cognitive dysfunction. The relationship between metformin therapy and cognitive function in patients with T2D is unknown. Therefore, we determined the relationship between metformin therapy and cognitive function in patients with T2D using a meta-analysis.

METHODS

We systematically searched the Cochrane library, PubMed, and Embase to identify studies showing correlations, and we calculated hazard ratios (HRs).

RESULTS

We identified 10 studies including 254,679 participants. Metformin significantly reduced the occurrence of cognitive dysfunction in patients with T2D (HR 0.90; 95% CI [0.88, 0.92]). Compared with other hypoglycemic drugs, sulfonylureas also improved cognitive dysfunction (HR 0.92; 95% CI [0.88, 0.95]). Thiazolidinediones gave no statistically significant improvement in cognitive dysfunction (HR 0.97; 95% CI [0.87, 1.07]). The use of insulin aggravated cognitive dysfunction (HR 1.34; 95% CI [1.24, 1.43]). In the subgroup analysis of various regions controlling for age, gender, education, diabetes course, complications, metformin administration and dosage, and follow-up time, metformin significantly improved cognitive dysfunction in patients in the Americas and Europe (HR 0.69; 95% CI [0.63, 0.74]), (HR 0.71; 95% CI [0.66, 0.76], respectively), while metformin did not significantly improve cognitive dysfunction in Asian patients (HR 0.99; 95% CI [0.96, 1.01]).

CONCLUSIONS

Metformin significantly improved cognitive dysfunction in patients with T2D. Sulfonylureas also improved cognitive dysfunction. Thiazolidinediones had no significant effect on cognitive dysfunction. The use of insulin aggravated cognitive dysfunction. Metformin improved cognitive dysfunction more significantly in patients in the Americas and Europe than in Asia.

Metformin Use Associated with Reduced Risk of Dementia in Patients with Diabetes: A Systematic Review and Meta-Analysis

Background:

Metformin, a first line antihyperglycemic medication, is an AMPK activator and has been hypothesized to act as a geroprotective agent. Studies on its association with various classifications of age-related cognitive decline have shown mixed results with positive and negative findings.

Objective:

To synthesize the best available evidence on the association of metformin-use with risk, progression, and severity of dementia.

Method:

Eligible research investigated the effect of metformin on dementia, Alzheimer’s disease, or any measure of cognitive impairment compared to any control group who were not receiving metformin. The initial search resulted in 862 citations from which 14 studies (seven cohort, four cross-sectional, two RCTs, and one case control) were included.

Results:

Meta-analysis of three studies showed that cognitive impairment was significantly less prevalent in diabetic metformin (Odds ratio = 0.55, 95% CI 0.38 to 0.78), while six studies showed that dementia incidence was also significantly reduced (Hazard ratio = 0.76, 95% CI 0.39 to 0.88). Mini-Mental State Examination scores were not significantly affected by metformin-use, although both RCTs showed that metformin had a neuroprotective effect compared to placebo. Some studies found negative or neutral effects for metformin use by people with diabetes; the potential mechanism of metformin-induced vitamin B12 deficiency is discussed.

Conclusions:

Metformin should continue to be used as a first line therapy for diabetes in patients at risk of developing dementia or Alzheimer’s disease. The use of metformin by individuals without diabetes for the prevention of dementia is not supported by the available evidence.

An Overview of Cognitive Impairment

Cognitive decline occurs in all persons during the aging process. Eventually, this can result in mild cognitive impairment and dementia. There are more than 100 causes of dementia. A multifocal approach to slowing cognitive decline (Mediterranean diet, exercise, computer games, socialization, and treatment of cardiovascular risk factors) appears to be effective.

Metformin treatment prevents amyloid plaque deposition and memory impairment in APP/PS1 mice

Alzheimer'sdisease(AD) is characterized by deposition of amyloid-β (Aβ)plaques, neurofibrillary tangles, andneuronal loss, accompaniedbyneuroinflammation. Neuroinflammatoryprocesses are thought to contribute toAD pathophysiology. Metformin has been reported to have anti-inflammatory efficacy. However, whether metformin is responsible for the anti-neuroinflammationand neuroprotection on APPswe/PS1ΔE9 (APP/PS1) mice remains unclear. Here we showed that metformin attenuated spatial memory deficit, neuron loss in the hippocampus and enhanced neurogenesis in APP/PS1 mice. In addition, metformin administration decreased amyloid-β (Aβ)plaque load and chronic inflammation (activated microglia and astrocytes as well as pro-inflammatory mediators) in the hippocampus and cortex. Further study demonstrated that treatment with metformin enhanced cerebral AMPK activation. Meanwhile, metformin notably suppressed the activation of P65 NF-κB, mTOR and S6K, reduced Bace1 protein expression. Our data suggest that metformin can exert functional recovery of memory deficits and neuroprotective effect on APP/PS1 mice via triggering neurogenesis and anti-inflammation mediated by regulating AMPK/mTOR/S6K/Bace1 and AMPK/P65 NF-κB signaling pathways in the hippocampus, which may contribute to improvement in neurological deficits.

Clinical Update on Nursing Home Medicine: 2017

This is the 11th annual Clinical Update from the AMDA meeting article. This year the topics covered are hypertension after the Systolic Blood Pressure Intervention Trial; chronic obstructive pulmonary disease risk factors, diagnosis and management including end-of-life planning, and the difficulties with exacerbations such as breathlessness; diagnosis and treatment of cognitive impairment and dementia; and wound care and pressure ulcer management.

Differential effects of metformin on age related comorbidities in older men with type 2 diabetes

AIMS

To identify distinct temporal likelihoods of age-related comorbidity (ARC) diagnoses: cardiovascular diseases (CVD), cancer, depression, dementia, and frailty-related diseases (FRD) in older men with type 2 diabetes (T2D) but ARC naïve initially, and assess the heterogeneous effects of metformin on ARCs and mortality.

METHODS

We identified a clinical cohort of male veterans in the United States who were ≥65years old with T2D and free from ARCs during 2002-2003. ARC diagnoses during 2004-2012 were analyzed using latent class modeling adjusted for confounders.

RESULTS

The cohort consisted of 41,204 T2D men with age 74.6±5.8years, HbA1c 6.5±0.97%, and 8393 (20.4%) metformin users. Four ARC classes were identified. 'Healthy Class' (53.6%): metformin reduced likelihoods of all ARCs (from 0.14% in dementia to 6.1% in CVD). 'High Cancer Risk Class' (11.6%): metformin reduced likelihoods of CVD (13.3%), cancer (45.5%), depression (5.0%), and FRD (13.7%). 'High CVD Risk Class' (17.4%): metformin reduced likelihoods of CVD (48.6%), cancer (3.2%), depression (2.8%), and FRD (6.3%). 'High Frailty Risk Class' (17.2%): metformin reduced likelihoods of CVD (18.8%), cancer (3.9%), dementia (3.8%), depression (15.6%), and FRD (23.8%).

CONCLUSIONS

Metformin slowed ARC development in old men with T2D, and these effects varied by ARC phenotype.