The role of cerebrovascular disease and the association between diabetes mellitus and dementia among aged medicare beneficiaries

Comorbidity among inpatients with dementia: a preliminary cross-sectional study in West China

OBJECTIVE

To investigate comorbidities among hospitalized patients with dementia.

METHOD

Data were extracted from the discharge records in our hospital. Comorbidities based on ICD-10 were selected from the Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI). The distributions of these comorbidities were described in dementia inpatients and age- and sex-matched nondementia controls, as well as in inpatients with Alzheimer's disease and vascular dementia. A logistic regression model was applied to identify dementia-specific morbid conditions.

RESULTS

A total of 3355 patients with dementia were included, with a majority of 1503 (44.8%) having Alzheimer's disease, 395 (11.8%) with vascular dementia, and 441 (13.1%) with mixed dementia. The mean number of comorbidities was 3.8 in dementia patients (vs. 2.9 in controls). The most prevalent comorbidities in inpatients with dementia compared with those without dementia were cerebral vascular disease (73.0% vs. 35.9%), hypertension (62.8% vs. 56.2%), and peripheral vascular disease (53.7% vs. 31.2%). Comorbidities associated with dementia included epilepsy (OR 4.8, 95% CI 3.5-6.8), cerebral vascular disease (OR 4.1, 95% CI 3.7-4.5), depression (OR 4.0, 95% CI 3.2-5.0), uncomplicated diabetes (OR 1.5, 95% CI 1.4-1.7), peripheral vascular disease (OR 1.8, 95% CI 1.6-2.0), rheumatoid arthritis collagen vascular disease (OR 1.7, 95% CI 1.3-2.3), and anemia (OR 1.2, 95% CI 1.04-1.3). Some comorbidities suggested a protective effect against dementia. They were hypertension (OR 0.8, 95% CI 0.7-0.9), COPD (OR 0.6, 95% CI 0.5-0.6), and solid tumor without metastasis (OR 0.4, 95% CI 0.3-0.4). Vascular dementia has more cardiovascular and cerebrovascular comorbidities than Alzheimer's disease.

CONCLUSION

Patients with dementia coexisted with more comorbidities than those without dementia. Comorbidities (esp. cardio-cerebral vascular risks) in patients with vascular dementia were more than those in patients with AD. Specifically, vascular and circulatory diseases, epilepsy, diabetes and depression increased the risk of dementia.

Examination of race and gender differences in predictors of neuropsychological decline and development of Alzheimer's disease

ObjectiveBlack adults are diagnosed with Alzheimer's disease (AD) at higher rates than White adults. Biopsychosocial risk factors that differentially affect individuals by race, including health, education, and APOE e4, may explain these findings. Some research suggests that the risk for AD associated with the APOE e4 allele may differ by race. Gender differences in AD have also been identified but remain understudied. We examined race, APOE status, vascular risk factors, education, and the interaction of APOE e4 status and race as predictors of cognitive decline and the development of Alzheimer's disease between genders in a large longitudinal sample of older adults. Methods: Participants (N = 4336) were selected from the National Alzheimer's Coordinating Center's Uniform Data Set who completed measures of verbal fluency, naming, and immediate/delayed story memory across 5 years. Analyses were stratified by gender. Follow up interactions examined statistical significance of differences. Results: APOE e4 by race interactions were largely non-significant and dropped from most models. When controlling for health, education, referral source, and Uniform Data Set form (when applicable), few racial differences in cognitive performance over time emerged. Black participants obtained lower scores than White participants on a majority of baseline measures. Race findings did not differ by gender. Hypertension was more strongly predictive of decline in delayed memory among women. Conclusions: Analyses did not support that APOE e4 differentially affects Black individuals. Hypertension may be a more relevant risk factor among women. Results raise questions regarding the accuracy of baseline scores in predicting decline for Black individuals.

Dementia Risk among Coronavirus Disease Survivors: A Nationwide Cohort Study in South Korea

We aimed to investigate whether coronavirus disease (COVID-19) survivors were at a higher risk of dementia diagnosis compared to controls at 6 months follow-up. Data pertaining to the period between 1 January and 4 June 2020, were extracted from the National Health Insurance Service (NHIS)-COVID-19 database in South Korea. Data on adults (≥20 years old) with no history of dementia, obtained from the NHIS-COVID-19 database, were included in the study. The endpoint of this study was the development of dementia, which was evaluated from 1 January to 1 December 2020. A total of 306,577 adults were included in the analysis, comprising 7133 COVID-19 survivors and 299,444 individuals in the control group. Among the subjects, new-onset dementia diagnosed in 2020 was recorded in 1.2% (3546 of 306,577). In the covariate-adjusted multivariable Cox regression model, the incidence of dementia among COVID-19 survivors was 1.39-fold higher (hazard ratio: 1.39, 95% confidence interval: 1.05–1.85; p = 0.023) than that in the control group. At approximately 6 months of follow-up, COVID-19 survivors were at a higher risk of dementia compared to other populations in South Korea.

17β-oestradiol alleviates endoplasmic reticulum stress injury induced by chronic cerebral hypoperfusion through the Haemoglobin/HIF 1α signalling pathway in ovariectomized rats

Endoplasmic reticulum stress (ERS) is known to be an essential target in protecting against ischaemic brain injury. In this study, using a vascular dementia (VaD) animal model induced by bilateral common carotid artery occlusion (BCCAO), we evaluated the effect and mechanism of 17β-oestradiol (E2) against VaD by inhibiting ERS at the early stage (14 d, 21 d, 28 d) and late stage (3 m) after BCCAO in the hippocampal CA1 region of ovariectomized rats. The results showed that the activation of the PERK-eIF2α-ATF4-CHOP axis, a typical ERS pathway, was significantly increased at the early and late stages after BCCAO. JNK (c-Jun N-terminal kinase)-cJun, a pro-death pathway, also displayed the same pattern as the ERS axis. E2 treatment profoundly suppressed the impairments caused by BCCAO. Further mechanistic studies revealed that cerebral blood flow (CBF) was sharply decreased at 14 d and returned to the normal level at 21 d after BCCAO. E2 could not change CBF, while it unexpectedly enhanced the ability to carry oxygen. This is evidenced by the fact that the protein expression of haemoglobin α/β (Hα/β), an oxygen carrier, robustly increased at BCCAO 21 d and 3 m after E2 treatment. The oxygen carrier increased strongly after 21 d and 3 m of BCCAO treated with E2. Moreover, E2 correspondingly enhanced the protein expression of hypoxia-inducible factor 1α (HIF 1α) in both the early and late stage after BCCAO in the hippocampal CA1 region. Finally, E2 administration markedly decreased the activities of caspase-8, caspase-3, and caspase-12 and increased the number of NeuN-positive cells. These findings suggest that E2 serves as a neuroprotectant to alleviate VaD by suppressing ERS injury involving the haemoglobin/HIF 1α signalling pathway.

Midlife Modifiable Risk Factors for Dementia: A Systematic Review and Meta-analysis of 34 Prospective Cohort Studies

OBJECTIVE

The aim of this study is to assess the association between midlife risk factors and dementia.

METHODS

PubMed and Cochrane library were systematically searched on May 24, 2018, to retrieve prospective cohort studies. The summary Relative Risk (RR) and 95% Confidence Interval (CI) were calculated by the random-effect model to explore the association between midlife risk factors and dementia. Sensitivity analysis and meta-regression were conducted to explore the source of heterogeneity. Publication bias was examined using Begg's and Egger's tests.

RESULTS

Thirty-four prospective cohort studies were included, among which 24 were eligible for metaanalysis. A total of 159,594 non-demented adults were enrolled at baseline before 65 years and 13,540 people were diagnosed with dementia after follow-up. The pooled results revealed that five factors could significantly increase the dementia risk by 41 to 78%, including obesity (RR, 1.78; 95% CI: 1.31-2.41), diabetes mellitus (RR, 1.69; 95% CI: 1.38-2.07), current smoking (RR, 1.61; 95%, CI: 1.32-1.95), hypercholesterolemia (RR, 1.57; 95% CI: 1.19-2.07), and hypertension (borderline blood pressure RR, 1.41; 95% CI: 1.23-1.62 and high Systolic Blood Pressure (SBP) RR, 1.72; 95% CI: 1.25-2.37). However, the sensitivity analyses found that the results of hypercholesterolemia and high SBP were not reliable, which need to be confirmed by more high-quality studies. No influences due to publication bias were revealed. In the systematic review, another three factors (hyperhomocysteinemia, psychological stress, and heavy drinking) were found to be associated with elevated dementia risk. In addition, physical exercise, a healthy diet, and hormone therapy in middle age were associated with the reduction of dementia risk.

CONCLUSIONS

Middle-aged people with obesity, diabetes, hypertension, or hypercholesterolemia, and current smokers in midlife are at higher risk of developing dementia later in life.

Cognitive Dysfunction in Older Adults with Type 2 Diabetes: Links, Risks, and Clinical Implications

The prevalence of comorbid diabetes and cognitive dysfunction increases as the population ages. Diabetes increases the risk of progression of cognitive dysfunction through a spectrum of cognitive decline to mild cognitive impairment then to dementia. Cognitive dysfunction, especially impairment in the executive domain, has a negative impact on patients' self-care tasks. With further progression of dementia and the development of behavioral problems, the challenge to carers and health care professionals looking after these patients is significant. Therefore, clinical trials are needed to explore the impact of novel hypoglycemic therapy on cognitive function as an important outcome in this population.

Diabetes Mellitus and Cause-Specific Mortality: A Population-Based Study

BACKGROUND

To investigate whether diabetes contributes to mortality for major types of diseases.

METHODS

Six National Health and Nutrition Examination Survey data cycles (1999 to 2000, 2001 to 2002, 2003 to 2004, 2005 to 2006, 2007 to 2008, and 2009 to 2010) and their linked mortality files were used. A population of 15,513 participants was included according to the availability of diabetes and mortality status.

RESULTS

Participants with diabetes tended to have higher all-cause mortality and mortality due to cardiovascular disease, cancer, chronic lower respiratory diseases, cerebrovascular disease, influenza and pneumonia, and kidney disease. Confounder-adjusted Cox proportional hazard models showed that both diagnosed diabetes category (yes or no) and diabetes status (diabetes, prediabetes, or no diabetes) were associated with all-cause mortality and with mortality due to cardiovascular disease, chronic lower respiratory diseases, influenza and pneumonia, and kidney disease. No associations were found for cancer-, accidents-, or Alzheimer's disease-related mortality.

CONCLUSION

The current study's findings provide epidemiological evidence that diagnosed diabetes at the baseline is associated with increased mortality risk due to cardiovascular disease, chronic lower respiratory diseases, influenza and pneumonia, and kidney disease, but not with cancer or Alzheimer's disease.

Practical considerations for managing patients with diabetes and dementia

Diabetes and dementia appear to be linked epidemiologically and share a common pathogenetic mechanism. The development of dementia in older people with diabetes will have a significant impact on diabetes self-care and will increase the risk of hypoglycaemia and frailty which ultimately lead to disability and poor outcome. Areas covered: We performed a Medline and Embase search from 1997 to present on relevant dementia and diabetes studies published in English language. Expert commentary: Older people with comorbid diabetes and dementia are functionally heterogeneous and interventions should be proportionate to patients 'functional capacity. Metabolic targets can be tightened in fit persons and relaxed when cognitive abilities continue to decline and overall function deteriorates. A holistic multidisciplinary team approach that involves patients, their carers and integrated primary and secondary care services at one point of care that focuses on improving function and maintaining quality of life is needed.

Diabetes in a Large Dementia Cohort: Clinical Characteristics and Treatment From the Swedish Dementia Registry

OBJECTIVE

We aimed to investigate the differences in clinical characteristics and pharmacological treatment associated with the presence of diabetes in a large cohort of patients with dementia.

RESEARCH DESIGN AND METHODS

A cross-sectional registry-based study was conducted using data from the Swedish Dementia Registry (SveDem). Data on dementia diagnosis, dementia type, and demographic determinants were extracted from SveDem. Data from the Swedish Patient Register and Prescribed Drug Register were combined for the diagnosis of diabetes. Data on antidiabetic, dementia, cardiovascular, and psychotropic medications were extracted from the Swedish Prescribed Drug Register. Logistic regression was used to determine whether the variables were associated with diabetes after adjustment for confounders. In total, 29,630 patients were included in the study, and 4,881 (16.5%) of them received a diagnosis of diabetes.

RESULTS

In the fully adjusted model, diabetes was associated with lower age at dementia diagnosis (odds ratio [OR] 0.97 [99% CI 0.97-0.98]), male sex (1.41 [1.27-1.55]), vascular dementia (1.17 [1.01-1.36]), and mixed dementia (1.21 [1.06-1.39]). Dementia with Lewy bodies (0.64 [0.44-0.94]), Parkinson disease dementia (0.46 [0.28-0.75]), and treatment with antidepressants (0.85 [0.77-0.95]) were less common among patients with diabetes. Patients with diabetes who had Alzheimer disease obtained significantly less treatment with cholinesterase inhibitors (0.78 [0.63-0.95]) and memantine (0.68 [0.54-0.85]).

CONCLUSIONS

Patients with diabetes were younger at dementia diagnosis and obtained less dementia medication for Alzheimer disease, suggesting less optimal dementia treatment. Future research should evaluate survival and differences in metabolic profile in patients with diabetes and different dementia disorders.