Genetically Predicted Sleep Traits and Functional Outcome After Ischemic Stroke: A Mendelian Randomization Study

Mendelian Randomization Reveals No Causal Association Between Periodontitis and Infective Endocarditis

OBJECTIVES

Clarifying the uncertain causal relationship between periodontitis and infective endocarditis using Mendelian randomization analysis, given their historically perceived association and clinical significance.

METHODS

Genetic variation data for acute periodontitis, chronic periodontitis, aggressive periodontitis, and infective endocarditis were obtained from published GWAS in individuals of European ancestry. Instrumental variables significantly associated with periodontitis were selected and univariable Mendelian randomization was conducted to infer the causal association between periodontitis and infective endocarditis. Multivariable Mendelian randomization was also performed to adjust for potential confounders including smoking, drinking, diabetes, and education.

RESULTS

Our analysis found no evidence of a causal association between periodontitis and infective endocarditis, with odds ratios (ORs) of 0.992 (95% CI: 0.879-1.120), 0.947 (95% CI: 0.738-1.214), and 1.056 (95% CI: 0.916-1.217) for acute periodontitis, chronic periodontitis, aggressive periodontitis, respectively. The robustness of our findings was confirmed by heterogeneity tests, pleiotropy tests, leave-one-out analyses, and MR-PRESSO. In the multivariable MR analysis, adjusting for smoking, drinking, diabetes, and education, the overall patterns between genetic liability to periodontitis and infective endocarditis remained consistent (all P > .05).

CONCLUSION

Our findings indicate that there is no genetic causal association between periodontitis and infective endocarditis.

Causal associations of fatigue and functional outcome after ischemic stroke: a mediation Mendelian randomization study

Background and objectives

Fatigue has been associated with adverse effects on recovery from ischemic stroke based on previous observational research. The purpose of our study was to explore the potential causal association of fatigue with poor functional outcome after ischemic stroke by employing Mendelian randomization (MR).

Methods

A set of instrumental variables, comprising 36 single-nucleotide polymorphisms (SNPs) that are only related to fatigue, were derived from a genome-wide association study (GWAS) that included 449,019 general individuals. The functional outcomes after ischemic stroke were derived from a GWAS (Genetics of Ischemic Stroke Functional Outcome Network) involving 6,021 survivors. Two-sample MR methods were used to assess the causal effect, including inverse variance weighted, MR-Egger, weighted median, simple mode, and weighted mode. In bidirectional MR analysis, the reverse causal association was analyzed using the Wald ratio method. The mediation effects of lipid metabolites were analyzed using two-step MR analysis.

Results

Genetic liability to fatigue was causally associated with the poor functional outcome (modified Rankin Scale ≥3 at 3 months) after ischemic stroke (OR = 4.20, 95%CI [1.11-15.99], p < 0.05). However, genetic predicted poor functional outcome after ischemic stroke was not associated with fatigue (OR = 1.00, 95%CI [0.99-1.02], p > 0.05). The results of the two-step MR showed that cholesteryl esters to total lipids ratio in large very low-density lipoprotein (VLDL) (ME = -0.13, p < 0.05); concentration of very large VLDL particles (ME = -0.13, p < 0.05); free cholesterol in large VLDL (ME = -0.13, p < 0.05); free cholesterol to total lipids ratio in very large VLDL (ME = -0.22, p < 0.05); phospholipids in large VLDL (ME = -0.15, p < 0.05); phospholipids in very large VLDL (ME = -0.13, p < 0.05); phospholipids to total lipids ratio in large high-density lipoprotein (HDL) (ME = -0.17, p < 0.05); total lipids in very large VLDL (ME = -0.14, p < 0.05); triglycerides in small VLDL (ME = -0.11, p < 0.05); and triglycerides to total lipids ratio in large HDL (ME = -0.10, p < 0.05) assumed a pivotal role in mediating the association between fatigue and poor functional outcome after ischemic stroke.

Conclusion

Our study provides evidence supporting the causal association between fatigue and the poor functional outcome after ischemic stroke, which emphasizes the importance of implementing interventions aimed at addressing fatigue. This could offer a therapeutic target to improve recovery after ischemic stroke and warrant exploration in a clinical context. One potential mechanism by which fatigue affects functional outcomes after ischemic stroke is through the action of lipid metabolites.

Incidence and Influencing Factors of Anxiety and Depression in Individuals with Acute Ischemic Stroke: A Retrospective Study

BACKGROUND

Acute ischemic stroke (AIS) is the most common type of stroke in clinical practice, and individuals with stroke are more prone to psychological disorders than healthy individuals. This study aims to explore the incidence of anxiety and depression and related influencing factors in individuals with AIS.

METHODS

In brief, 680 individuals with AIS admitted to Chun'an County First People's Hospital from January 2021 to January 2023 were selected as the research subjects, and their clinical data were retrospectively analyzed. All patients were evaluated with the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS) to observe the occurrence of anxiety and depression, and single-factor and multi-factor logistic regression were used to analyze the influencing factors of anxiety and depression.

RESULTS

Among the 680 individuals with AIS, there were 63 cases of mild anxiety (9.26%), 25 cases of moderate anxiety (3.68%), and 8 cases of severe anxiety (1.18%), with a total of 96 cases (14.12%) with anxiety symptoms. Additionally, there were 74 cases of mild depression (10.88%), 28 cases of moderate depression (4.12%), and 10 cases of severe depression (1.47%), with a total of 112 cases with depression (16.47%). The results of univariate analysis showed that there was a weak correlation between age, body mass index, disease duration, marital status, and the development of anxiety and depression in individuals with AIS (p > 0.05). Educational level, underlying diseases, family income, and place of residence were found to influence the development of anxiety and depression in individuals with AIS (p < 0.05). The results of multivariate logistic regression analysis showed that educational level (no higher education), underlying diseases (with), family income (<50,000 yuan/year, the average exchange rate of RMB to USD was 6.7261), and place of residence (rural area) were influencing factors for the development of anxiety and depression in individuals with AIS (p < 0.05).

CONCLUSION

Depression and anxiety are common psychological disorders in patients with AIS. The level of education (no higher education), underlying diseases (with), family income (<50,000 yuan/year), and place of residence (rural area) were risk factors that may lead to anxiety and depression in individuals with AIS. For those with risk factors for anxiety and depression, reasonable intervention should be continually provided to guide early disease prediction and treatment of anxiety and depression in individuals with AIS.

Sleep disorders as both risk factors for, and a consequence of, stroke: A narrative review

BACKGROUND AND PURPOSE

Sleep disorders are increasingly implicated as risk factors for stroke, as well as a determinant of stroke outcome. They can also occur secondary to the stroke itself. In this review, we describe the variety of different sleep disorders associated with stroke and analyze their effect on stroke risk and outcome.

METHODS

A search term-based literature review ("sleep," "insomnia," "narcolepsy," "restless legs syndrome," "periodic limb movements during sleep," "excessive daytime sleepiness" AND "stroke" OR "cerebrovascular" in PubMed; "stroke" and "sleep" in ClinicalTrials.gov) was performed. English articles from 1990 to March 2023 were considered.

RESULTS

Increasing evidence suggests that sleep disorders are risk factors for stroke. In addition, sleep disturbance has been reported in half of all stroke sufferers; specifically, an increase is not only sleep-related breathing disorders but also periodic limb movements during sleep, narcolepsy, rapid eye movement (REM) sleep behavior disorder, insomnia, sleep duration, and circadian rhythm sleep-wake disorders. Poststroke sleep disturbance has been associated with worse outcome.

CONCLUSION

Sleep disorders are risk factors for stroke and associated with worse stroke outcome. They are also a common consequence of stroke. Recent guidelines suggest screening for sleep disorders after stroke. It is possible that treatment of sleep disorders could both reduce stroke risk and improve stroke outcome, although further data from clinical trials are required.

Causal effects of gut microbiota on the prognosis of ischemic stroke: evidence from a bidirectional two-sample Mendelian randomization study

Background

Increasing research has implicated the possible effect of gut microbiota (GM) on the prognosis of ischemic stroke (IS). However, the precise causal relationship between GM and functional outcomes after IS remains unestablished.

Methods

Data on 211 GM taxa from the MiBioGen consortium and data on prognosis of IS from the Genetics of Ischemic Stroke Functional Outcome (GISCOME) network were utilized as summary-level data of exposure and outcome. Four kinds of Mendelian randomization (MR) methods were carried out to ascertain the causal effect of GM on functional outcomes following IS. A reverse MR analysis was performed on the positive taxa identified in the forward MR analysis to determine the direction of causation. In addition, we conducted a comparative MR analysis without adjusting the baseline National Institute of Health Stroke Scale (NIHSS) of post-stroke functional outcomes to enhance confidence of the results obtained in the main analysis.

Results

Four taxa were identified to be related to stroke prognosis in both main and comparative analyses. Specifically, genus Ruminococcaceae UCG005 and the Eubacterium oxidoreducens group showed significantly negative effects on stroke prognosis, while the genus Lachnospiraceae NK4A136 group and Lachnospiraceae UCG004 showed protective effects against stroke prognosis. The reverse MR analysis did not support a causal role of stroke prognosis in GM. No evidence of heterogeneity, horizontal pleiotropy, and outliers was found.

Conclusion

This MR study provided evidence that genetically predicted GM had a causal link with post-stroke outcomes. Specific gut microbiota taxa associated with IS prognosis were identified, which may be helpful to clarify the pathogenesis of ischemic stroke and making treatment strategies.

Sleep Characteristics and Risk of Stroke and Dementia: An Observational and Mendelian Randomization Study

BACKGROUND AND OBJECTIVES

Sleep disturbances are implicated as risk factors of both stroke and dementia. However, whether these associations are causal and whether treatment of sleep disorders could reduce stroke and dementia risk remain uncertain. We aimed to evaluate associations and ascertain causal relationships between sleep characteristics and stroke/dementia risk and MRI markers of small vessel disease (SVD).

METHODS

We used data sets from a multicenter population-based study and summary statistics from genome-wide association studies (GWASs) of sleep characteristics and outcomes. We analyzed 502,383 UK Biobank participants with self-reported sleep measurements, including sleep duration, insomnia, chronotype, napping, daytime dozing, and snoring. In observational analyses, the primary outcomes were incident stroke, dementia, and their subtypes, alongside SVD markers. Hazard ratios (HRs) and odds ratios (ORs) were adjusted for age, sex, and ethnicity, and additional vascular risk factors. In Mendelian randomization (MR) analyses, ORs or risk ratios are reported for the association of each genetic score with clinical or MRI end points.

RESULTS

Among 502,383 participants (mean [SD] age, 56.5 [8.1] years; 54.4% female), there were 7,668 cases of all-cause dementia and 10,334 strokes. In longitudinal analyses, after controlling for cardiovascular risk factors, participants with insomnia, daytime napping, and dozing were associated with increased risk of any stroke (HR 1.05, 95% CI 1.01-1.11, p = 8.53 × 10-3; HR 1.09, 95% CI 1.05-1.14, p = 3.20 × 10-5; HR 1.19, 95% CI 1.08-1.32, p = 4.89 × 10-4, respectively). Almost all sleep measures were associated with dementia risk (all p < 0.001, except insomnia). Cross-sectional analyses identified associations between napping, snoring, and MRI markers of SVD (all p < 0.001). MR analyses supported a causal link between genetically predicted insomnia and increased stroke risk (OR 1.31, 95% CI 1.13-1.51, p = 0.00072), but not with dementia or SVD markers.

DISCUSSION

We found that multiple sleep measures predicted future risk of stroke and dementia, but these associations were attenuated after controlling for cardiovascular risk factors and were absent in MR analyses for Alzheimer disease. This suggests possible confounding or reverse causation, implying caution before proposing sleep disorder modifications for dementia treatment.

Investigating the shared genetic architecture between frailty and insomnia

Background

The epidemiological association between frailty and insomnia is well established, yet the presence of a common genetic etiology is still uncertain. Further exploration is needed to ascertain the causal relationship between frailty and insomnia.

Methods

Utilizing data obtained from genome-wide association studies (GWAS) summaries, we utilized the linkage disequilibrium score regression (LDSC) to determine the genetic correlation existing between frailty and insomnia. The determination of causality was achieved through the application of two-sample Mendelian randomization. We investigated the enrichment of single nucleotide polymorphism (SNP) at various tissue types utilizing stratified LD score regression (S-LDSC) and multimarker analysis of genome annotation (MAGMA). Common risk SNPs were identified using Multi-Trait Analysis of GWAS (MTAG) and Cross-Phenotype Association (CPASSOC). We further investigated the expression profiles of risk genes in tissues using Summary-data-based Mendelian randomization(SMR) based on pooled data, to explore potential functional genes.

Results

Our findings indicated a significant genetic correlation between frailty and insomnia, highlighting SNPs sharing risk (rs34290943, rs10865954), with a pronounced correlation in the localized genomic region 3p21.31. Partitioned genetic analysis revealed 24 functional elements significantly associated with both frailty and insomnia. Furthermore, mendelian randomization revealed a causal connection between frailty and insomnia. The genetic correlation between frailty and insomnia showed enrichment in 11 brain regions (S-LDSC) and 9 brain regions (MAGMA), where four functional genes (RMB6, MST1R, RF123, and FAM212A) were identified.

Conclusion

This study suggests the existence of a genetic correlation and common risk genes between frailty and insomnia, contributing to a deeper comprehension of their pathogenesis and assists in identifying potential therapeutic targets.

Exploring causal association between circulating inflammatory cytokines and functional outcomes following ischemic stroke: A bidirectional Mendelian randomization study

OBJECTIVES

Previous observational studies have indicated correlations between various inflammatory cytokines and functional outcomes following ischemic stroke (IS); however, the causality remains unclear. We aimed to further evaluate the causal association between 41 circulating inflammatory cytokines and functional outcomes following IS.

METHODS

Two-sample bidirectional Mendelian randomization (MR) analysis was used in this study. The genetic variation of 41 circulating inflammatory cytokines were derived from genome-wide association study (GWAS) data of European ancestry (n = 8293). The corresponding genetic association of functional outcomes following IS were derived from European ancestry GWAS data (n = 6021).

RESULTS

Inverse variance weighted (IVW) analysis showed that genetically predicted increased levels of regulation and activation in normal T-cell expression and secretion factor (RANTES/CCL5) and eosinophilic chemotactic factor (EOTAXIN/CCL11) were positively correlated with the increased adverse functional outcomes (modified Rankin Scale [mRS≥3] following IS (OR: 1.40, 95% CI: 1.002-1.96, p = 0.049; OR: 1.33, 95% CI: 1.15-1.54, p = 0.0001). Interleukin 18 (IL-18) level might be the downstream consequence of adverse functional outcomes following IS (β: -0.09, p = 0.039). Other inflammatory cytokines and functional outcomes following IS did not appear to be causally related.

CONCLUSIONS

This study suggests a causality between inflammation and adverse functional outcomes following IS. RANTES (CCL5) and EOTAXIN (CCL11) may be the upstream factors of adverse functional outcomes following IS, while IL-18 may be the downstream effect of adverse functional outcomes following IS. Whether these cytokines can be used to predict or improve adverse functional outcomes after IS requires further researches.

Genetic liability to migraine and functional outcome after ischemic stroke

BACKGROUND AND PURPOSE

To evaluate the association of genetic liability to migraine with functional outcome after ischemic stroke using Mendelian randomization.

METHODS

Genetic proxies for migraine were obtained from the largest genome-wide association study meta-analysis of 102,084 migraine cases and 771,257 controls. Genetic associations with functional outcome after ischemic stroke were obtained from the Genetics of Ischemic Stroke Functional Outcome network study (N = 6021). Poor functional outcome after ischemic stroke was defined as a score of 3-6 on the modified Rankin scale at 3 months (N = 2280). The inverse-variance weighted method was used to estimate the association of genetic liability to migraine with functional outcome, and we performed sensitivity analyses to assess the robustness of results.

RESULTS

Genetic liability to migraine was associated with poor functional outcome after ischemic stroke (odds ratio of poor functional outcome per doubling in migraine odds 1.22, 95% confidence interval 1.02-1.45, p = 0.031). This association remained directionally consistent across sensitivity analyses.

CONCLUSIONS

This study provides genetic support that migraine is associated with poor functional outcome after ischemic stroke. These findings warrant further follow-up and, if replicated, may have clinical implications for post-stroke recovery.

Effect of hyperbaric oxygen on post-stroke depression

BACKGROUND

In patients with post-stroke depression (PSD) in diabetes, the situation may be more complex, requiring simultaneous treatment of blood glucose, depressive symptoms, and neurological dysfunction. Hyperbaric oxygen (HBO) therapy can improve tissue oxygen content and improve the situation of ischemia and hypoxia, thus playing a role in protecting brain cells and restoring the function of brain cells. However, there are few studies on HBO therapy for patients with PSD. This study explores the clinical efficacy of such therapy for stroke complicated with depression and diabetes mellitus, and to provide reference and basis for clinical treatment and development through the application of relevant rating scales and laboratory test indicators.

AIM

To evaluate the clinical effects of HBO therapy on patients with diabetes with PSD.

METHODS

A total of 190 diabetic patients with PSD were randomly divided into observation and control groups (95 patients per group). The control group received escitalopram oxalate 10mg once a day for eight weeks. In addition, the ob-servation group was also given HBO therapy, once a day, five times a week, for eight weeks. The Montgomery Depression Rating Scale (MADRS), National Institutes of Health Stroke Scale (NIHSS), hypersensitive C-reactive protein, tumor necrosis factor (TNF)-α, and fasting glucose levels were compared.

RESULTS

There were no significant differences in age, sex, or depression course between the groups (P > 0.05). After HBO treatment, MADRS scores in both groups decreased significantly (14.3 ± 5.2), and were significantly lower in the control group (18.1 ± 3.5). After HBO treatment, NIHSS scores in both groups decreased significantly, and scores in the observation group (12.2 ± 4.0) decreased more than in the control group (16.1 ± 3.4), the difference was statistically significant (P < 0.001). The levels of hypersensitive C-reactive protein and TNF-α in both groups were significantly decreased, and the observation group was significantly lower than the control group (P < 0.001). Fasting blood glucose levels in both groups decreased significantly, and those in the observation group decreased more (8.02 ± 1.10) than in the control group (9.26 ± 1.04), with statistical significance (t = -7.994, P < 0.001).

CONCLUSION

HBO therapy can significantly improve depressive symptoms and neurological dysfunction in patients with PSD, and reduce the levels of hypersensitive C-reactive protein, TNF-α and fasting blood glucose.