Relationship between glycemic control, microalbuminuria and cognitive functions in elderly type 2 diabetic patients

The association between sodium-glucose cotransporter 2 inhibitors and incident dementia: A nationwide population-based longitudinal cohort study

BACKGROUND

The association of the use of sodium-glucose cotransporter 2 (SGLT2) inhibitor and incident dementia remains unclear. This study aimed to evaluate the risk of incident dementia with the use of SGLT2 inhibitor.

METHODS

This is a population-based cohort study utilizing Taiwan's National Health Insurance Research Database. Each patient who took SGLT2 inhibitors was assigned to the SGLT2 inhibitor group, whereas 1:1 propensity score-matched randomly selected patients who were nonusers of SGLT2 inhibitors were assigned to the non-SGLT2 inhibitor group. The study outcome was incident dementia.

RESULTS

A total of 976,972 patients newly diagnosed with type 2 diabetes mellitus (DM) between 2011 and 2018 were included in this study. After the patients' propensity score matching by age, sex, duration of DM, comorbidities and drug index date of the patients, a total of 103,247 patients in the SGLT2 inhibitor group and 103,247 in the non-SGLT2 inhibitor group were enrolled for analysis. The SGLT2 inhibitor group was associated with a lower risk of incident dementia (adjusted hazard ratio: 0.89, 95% confidence interval: 0.82-0.96; p = .0021). Diabetic complications were significantly lower in the SGLT2 inhibitor group compared with the non-SGLT2 group. Sensitivity analysis was also consistent with the main analysis.

CONCLUSIONS

Patients with type 2 DM who were prescribed SGLT2 inhibitors were associated with a lower risk of incident dementia compared with those not prescribed SGLT2 inhibitors in real-world practice.

Cognitive function in diabetic persons with peripheral neuropathy: a systematic review and meta-analysis

OBJECTIVES

The aim of this study is to improve our knowledge of cognitive function in individuals with type 1 (T1DM) or type 2 (T2DM) diabetes mellitus and with peripheral diabetic neuropathy (DPN).

METHODS

A systematic review and meta-analysis was performed of publications included in PubMed, Scopus, PsycInfo and Web of Science databases until November 2021. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) with reference number: CRD42021229163.

RESULTS

A total of 832 articles were identified, 19 of which were selected. The presence of DPN was associated with global cognitive impairment in the T1DM persons in two studies (p=0.046; p=0.03) and T2DM persons in four (p<0.001; p<0.02; p=0.011; p=<0.05). Differences in specific dimensions - memory, attention, and psychomotor speed - were found in both kinds of diabetes. The meta-analysis showed that the individuals with T2DM and DPN presented a lower mean cognitive performance than those without DPN (-1.0448; 95% CI: -1.93%; -0.16%). Depression was associated with impaired cognitive function in these diabetic persons (p<0.01).

CONCLUSION

The review reveals the great variability in instruments and methodologies, while providing results that support the presence of both global and domain-specific cognitive impairment in diabetic persons with DPN.

Spot Urine Albumin Creatinine Ratio can be a Predictor of Cognitive Function in Type 2 Diabetes Mellitus

Introduction

In diabetes mellitus (DM), the underlying pathophysiology of albuminuria and cognitive dysfunction is similar. So, we hypothesized that urinary albumin excretion (UAE) could be linked to cognitive dysfunction in type 2 diabetes mellitus.

Methods and Materials

It was a hospital-based observational study. Patient aged 40-60 years with type 2 DM were included in this study. Complete assessment with detailed history, physical examination, and necessary biochemical investigations including spot urine albumin creatinine ratio (uACR) was done. Cognitive status was determined in all the individuals with the application of Hindi translated version of the mini-mental status examination (MMSE) questionnaire.

Results

In 80 patients, the mean MMSE score was 25.37 ± 3.34. Cognitive dysfunction (score <26) was present in 45% of individuals. Spot uACR, estimated glomerular filtration rate (eGFR), glycated hemoglobin (HbA1c), presence of retinopathy and dyslipidemia were significantly different between the normal and subnormal scoring groups. On multivariate analysis spot uACR was found to be independently predicting odds of developing cognitive dysfunction (OR 1.01, CI 1.004-1.022; P = 0.001). The mean MMSE scores in normo-albuminuric (n = 15), moderately increased albuminuric (n = 48) and severely albuminuric (n = 17) patients were 28.00 ± 1.60, 25.54 ± 3.33 and 22.58 ± 2.31, respectively, which were significantly different among the three groups (P < 0.001).

Conclusions

Spot uACR could be helpful in predicting cognitive decline in people with type 2 DM.

Diabetes, Albuminuria and the Kidney-Brain Axis

Cognitive decline and kidney disease are significant public health problems that share similar characteristics and risk factors. The pathophysiology of the kidney-brain axis is not completely understood, and studies analysing the relationship between the biomarkers of kidney damage and cognitive impairment show different results. This article focuses on the epidemiological and clinical aspects concerning the association of albuminuria, a marker for endothelial dysfunction and microvascular disease, and cognitive impairment in patients with chronic kidney disease, diabetic kidney disease and end-stage kidney disease. Most studies show a positive relationship between albuminuria and cognitive impairment in all groups, but evidence in type 2 diabetes (T2D) patients is limited. We briefly discuss the mechanisms underlying these associations, such as damage to the microvascular circulation, leading to hypoperfusion and blood pressure fluctuations, as well as increased inflammation and oxidative stress, both in the brain and in the kidneys. Further clinical and epidemiological studies developed to understand the interplay between the kidneys and brain diseases will hopefully lead to a reduction in cognitive impairment in these patients.

Albuminuria in Association with Cognitive Function and Dementia: A Systematic Review and Meta-Analysis

OBJECTIVES

Cerebral microvascular disease is considered to contribute to cognitive dysfunction. We opted to explore whether albuminuria, a marker of systemic microangiopathy, is associated with cognitive impairment, dementia, and cognitive function.

DESIGN

Systematic review; independent reviewers screened 2359 articles, derived through the search strategy, for identification of observational studies quantifying an association of albuminuria with the outcomes of interest, abstracted data on study characteristics and results and evaluated studies on quality using the Newcastle-Ottawa scale.

SETTING

Community.

PARTICIPANTS

Adults.

MESUREMENTS

Cognitive impairment and dementia, defined by validated neuropsychological tests or clinical guidelines, respectively, and cognitive function, assessed by validated instruments.

RESULTS

Thirty-two eligible studies were identified. Albuminuria was associated with cognitive impairment (Odds Ratio (OR): 1.35, 95% Confidence Interval (CI): 1.19-1.53; 7,852 cases), dementia (OR: 1.35, 95% CI: 1.10-1.65; 5,758 cases), clinical Alzheimer's disease (OR: 1.37, 95% CI: 1.11-1.69; 629 cases) and vascular dementia (OR: 1.96, 95% CI: 1.16-3.31; 186 cases); the effect remained significant among longitudinal, population-based and high quality studies. Time-to-event analysis on prospective studies of non-demented at baseline individuals also showed a significant association with incident dementia (Risk Ratio: 1.52, 95% CI: 1.16-1.99; 971 cases). Worse global cognitive performance (Hedge's g: -0.13, 95% CI: -0.18, -0.09; 68,348 subjects) and accelerated cognitive decline (g: -0.20, 95% CI: -0.34, -0.07; 31,792 subjects) were noted among subjects with albuminuria, who also scored lower in executive function, processing speed, verbal fluency, and verbal memory.

CONCLUSIONS

Albuminuria was independently associated with cognitive impairment, dementia and cognitive decline. The stronger effects for vascular dementia and cognitive performance in domains primarily affected by microvascular disease support that the association could be mediated by shared microvascular pathology in the kidney and the brain.

High rate of hypoglycemia in 6770 type 2 diabetes patients with comorbid dementia: A multicenter cohort study on 215,932 patients from the German/Austrian diabetes registry

AIMS

Dementia and type 2 diabetes (T2D) are two major phenomena in older people. To compare anti-hyperglycemic therapy and diabetes-related comorbidities between elderly T2D patients with or without comorbid dementia.

METHODS

215,932 type 2 diabetes patients aged ≥ 40 years (median [Q1;Q3]: 70.4 [61.2;77.7] years) from the standardized, multicenter German/Austrian diabetes patient registry, DPV, were studied. To identify patients with comorbid dementia, the registry was searched by ICD-10 codes, DSM-IV/-5 codes, respective search terms and/or disease-specific medication. For group comparisons, multiple hierarchic regression modeling with adjustments for age, sex, and duration of diabetes was applied.

RESULTS

3.1% (n=6770; 57% females) of the eligible T2D patients had clinically recognized comorbid dementia. After adjustment for demographics, severe hypoglycemia (insulin group: 14.8 ± 0.6 vs. 10.4 ± 0.2 events per 100 patient-years, p<0.001), hypoglycemia with coma (insulin group: 7.6 ± 0.4 vs. 3.9 ± 0.1 events per 100 patient-years, p<0.001), depression (9.9 vs. 4.7%, p<0.001), hypertension (74.7 vs. 72.2%, p<0.001), stroke (25.3 vs. 6.5%, p<0.001), diabetic foot syndrome (6.0 vs. 5.2%, p=0.004), and microalbuminuria (34.7 vs. 32.2%, p<0.001) were more common in dementia patients compared to T2D without dementia. Moreover, patients with dementia received insulin therapy more frequently (59.3 vs. 54.7%, p<0.001), but metabolic control (7.7 ± 0.1 vs. 7.7 ± 0.1%) was comparable to T2D without dementia.

CONCLUSIONS

In T2D with dementia, higher rates of hypoglycemia and other diabetes-related comorbidities were observed. Hence, the risks of a glucocentric and intense diabetes management with insulin and a focus on tight glycemic control without considering other factors may outweigh the benefits in elderly T2D patients with comorbid dementia.