Latent profiles of modifiable dementia risk factors in later midlife: relationships with incident dementia, cognition, and neuroimaging outcomes.

In 2020, the Lancet Commission identified 12 modifiable factors that increase population-level dementia risk. It is unclear if these risk factors co-occur among individuals in a clinically meaningful way. Using latent class analysis, we identified profiles of modifiable dementia risk factors in dementia-free adults aged 60-64 years from the UK Biobank. We then estimated associations between these profiles with incident dementia, cognition, and neuroimaging outcomes, and explored the differences across profiles in the effects of a polygenic risk score for Alzheimer's disease on outcomes. In 55,333 males and 63,063 females, three sex-specific latent profiles were identified: cardiometabolic risk, substance use-related risk, and low risk. The cardiometabolic risk profile in both males and females was associated with greater incidence of all-cause dementia (male: OR [95% CI] = 2.33 [2.03, 2.66]; female: OR [95% CI] = 1.44 [1.24, 1.68]), poorer cognitive performance, greater brain atrophy, and greater white matter hyperintensity volume compared to the low risk profile. The substance use-related risk profile in males was associated with poorer cognitive performance and greater white matter hyperintensities compared to the low risk profile, but no difference in all-cause dementia incidence was observed (OR [95% CI] = 1.00 [0.95, 1.06]). In females, the substance use-related risk profile demonstrated increased dementia incidence (OR [95% CI] = 1.58 [1.57, 1.58]) and greater brain atrophy but smaller white matter hyperintensity volume compared to the low risk profile. The polygenic risk score had larger effects among females, and differentially influenced outcomes across profiles; for instance, there were larger effects of the polygenic risk score on atrophy in the cardiometabolic profile vs. the low risk profile among males, and larger effects of the polygenic risk score on loss of white matter integrity in the cardiometabolic profile vs. the low risk profile among females. These results reveal three modifiable dementia risk profiles, their unique cognitive/neuroimaging outcomes, and their interactions with genetic risk for Alzheimer's disease. These differences highlight the need to consider population heterogeneity in risk prediction tools and in planning personalized prevention strategies.

No association between metformin initiation and incident dementia in older adults newly diagnosed with diabetes.

BACKGROUND: Metformin has been suggested to reduce dementia risk; however, most epidemiologic studies have been limited by immortal time bias or confounding due to disease severity. OBJECTIVES: To investigate the association of metformin initiation with incident dementia using strategies that mitigate these important sources of bias. METHODS: Residents of Ontario, Canada ≥66 years newly diagnosed with diabetes from January 1, 2008 to December 31, 2017 entered this retrospective population-based cohort. To consider the indication for metformin monotherapy initiation, people with hemoglobin A1c of 6.5%-8.0% and estimated glomerular filtration rate ≥45 mL/min/1.73 m2 were selected. Using the landmark method to address immortal time bias, exposure was grouped into "metformin monotherapy initiation within 180 days after new diabetes diagnosis" or "no glucose-lowering medications within 180 days." To address disease latency, 1-year lag time was applied to the end of the 180-day landmark period. Incident dementia was defined using a validated algorithm for Alzheimer's disease and related dementias. Adjusted hazard ratios (aHR) and confidence intervals (CIs) were estimated from propensity-score weighted Cox proportional hazard models. RESULTS: Over mean follow-up of 6.77 years from cohort entry, metformin initiation within 180 days after new diabetes diagnosis (N = 12,331; 978 events; 65,762 person-years) showed no association with dementia risk (aHR [95% CI] = 1.05 [0.96-1.15]), compared to delayed or no glucose-lowering medication initiation (N = 22,369; 1768 events; 117,415 person-years). CONCLUSION: Early metformin initiation was not associated with incident dementia in older adults newly diagnosed with diabetes. The utility of metformin to prevent dementia was not supported.

Cardiovascular phenotypes in type 2 diabetes: Latent class analysis of the CANVAS Program and CREDENCE trial.

AIM: To identify unique clinical phenotypes in type 2 diabetes (T2D) and investigate their treatment response to canagliflozin using latent class analysis. METHODS: This was a pooled latent class analysis of the individuals in the CANVAS Program and CREDENCE trial. The co-primary endpoints were hospitalization for heart failure (HHF) and the composite of cardiovascular death (CVD) or HHF. Secondary endpoints included three-point major adverse CV events, its individual components, and all-cause mortality. We completed Cox proportional hazards models to evaluate the effect of canagliflozin across phenotypes. RESULTS: Four distinct phenotypes were identified: Phenotype 1 (n = 966, 6.6%), with the lowest prevalence of heart failure, kidney dysfunction and hypertension; Phenotype 2 (n = 4169, 28.7%), primarily comprising females with a high prevalence of atherosclerotic vascular disease (ASCVD); Phenotype 3 (n = 7108, 48.9%), predominately males with a high prevalence of ASCVD; and Phenotype 4 (n = 2300, 15.8%), possessing the highest prevalences of HF and renal dysfunction. A hierarchical increase in the risk of the primary endpoint was observed across the phenotypes, with the highest CV risk observed for Phenotype 4 (hazard ratio for HHF: 7.57 [95% CI: 4.19-13.69]). Canagliflozin significantly reduced HHF and the composite CVD or HHF across phenotypes (all P values for interaction > .05). CONCLUSION: We identified four clinically distinct T2D phenotypes with differential CV risks. Canagliflozin reduced the risk of CV events, irrespective of the phenotype, emphasizing its broad therapeutic acceptability.

Assessing cardiovascular disease risk in women with a history of hypertensive disorders of pregnancy: A guidance paper for studies using administrative data.

BACKGROUND: Hypertensive disorders of pregnancy (HDP) are a major cause of maternal morbidity and mortality, and their association with increased cardiovascular disease (CVD) risk represents a major public health concern. However, assessing CVD risk in women with a history of these conditions presents unique challenges, especially when studies are carried out using routinely collected data. OBJECTIVES: To summarise and describe key challenges related to the design and conduct of administrative studies assessing CVD risk in women with a history of HDP and provide concrete recommendations for addressing them in future research. METHODS: This is a methodological guidance paper. RESULTS: Several conceptual and methodological factors related to the data-generating mechanism and study conceptualisation, design/data management and analysis, as well as the interpretation and reporting of study findings should be considered and addressed when designing and carrying out administrative studies on this topic. Researchers should develop an a priori conceptual framework within which the research question is articulated, important study variables are identified and their interrelationships are carefully considered. CONCLUSIONS: To advance our understanding of CVD risk in women with a history of HDP, future studies should carefully consider and address the conceptual and methodological considerations outlined in this guidance paper. In highlighting these challenges, and providing specific recommendations for how to address them, our goal is to improve the quality of research carried out on this topic.

Maternal Health Outcomes After Pregnancy-Associated Stroke: A Population-Based Study With 19 Years of Follow-Up.

BACKGROUND: Pregnancy-associated stroke carries high short-term morbidity and mortality, but data on subsequent maternal outcomes are limited. We evaluated long-term maternal health outcomes after pregnancy-associated stroke. METHODS: In this retrospective cohort study, we used administrative data to identify pregnant adults aged ≤49 years with stroke between 2002-2020 in Ontario, Canada and 2 comparison groups: (1) non-pregnant female patients with stroke and (2) pregnant patients without stroke. Patients who survived the index admission were followed until 2021. After propensity score matching, we used Cox regression with a robust variance estimator to compare pregnant patients with stroke and the 2 comparison groups for the composite outcome of death and all-cause non-pregnancy readmission. Where proportional hazard assumption was not met, we reported time-varying hazard ratios (HR) with 95% CIs by modeling the log-hazard ratio as a function of time using restricted cubic splines. RESULTS: We identified 217 pregnant patients with stroke, 7604 non-pregnant patients with stroke, and 1 496 256 pregnant patients without stroke. Of the 202 pregnant patients with stroke who survived the index stroke admission, 41.6% (6.8 per 100 person-years) subsequently died or were readmitted during follow-up. Median follow-up times were 5 years (pregnancy-associated stroke), 3 years (non-pregnant stroke), and 8 years (pregnant without stroke). Pregnant patients with stroke had a lower hazard of death and all-cause readmission compared with non-pregnant patients with stroke at 1-year follow-up (HR, 0.64 [95% CI, 0.44-0.94]), but this association did not persist during longer-term follow-up. Conversely, pregnant patients with stroke had higher hazard of death and readmission compared with pregnant patients without stroke at 1-year follow-up (HR, 5.70 [95% CI, 3.04-10.66]), and this association persisted for a decade. CONCLUSIONS: Stroke during pregnancy is associated with long-term health consequences. It is essential to transition care postpartum to primary or specialty care to optimize vascular health.

Dynamic relationships between depressive symptoms and insulin resistance over 20 years of adulthood.

BACKGROUND: Bidirectional longitudinal relationships between depression and diabetes have been observed, but the dominant direction of their temporal relationships remains controversial. METHODS: The random-intercept cross-lagged panel model decomposes observed variables into a latent intercept representing the traits, and occasion-specific latent 'state' variables. This permits correlations to be assessed between the traits, while longitudinal 'cross-lagged' associations and cross-sectional correlations can be assessed between occasion-specific latent variables. We examined dynamic relationships between depressive symptoms and insulin resistance across five visits over 20 years of adulthood in the population-based Coronary Artery Risk Development in Young Adults (CARDIA) study. Possible differences based on population group (Black v. White participants), sex and years of education were tested. Depressive symptoms and insulin resistance were quantified using the Center for Epidemiologic Studies Depression (CES-D) scale and the homeostatic model assessment for insulin resistance (HOMA-IR), respectively. RESULTS: Among 4044 participants (baseline mean age 34.9 ± 3.7 years, 53% women, 51% Black participants), HOMA-IR and CES-D traits were weakly correlated (r = 0.081, p = 0.002). Some occasion-specific correlations, but no cross-lagged associations were observed overall. Longitudinal dynamics of these relationships differed by population groups such that HOMA-IR at age 50 was associated with CES-D score at age 55 (ß = 0.076, p = 0.038) in White participants only. Longitudinal dynamics were consistent between sexes and based on education. CONCLUSIONS: The relationship between depressive symptoms and insulin resistance was best characterized by weak correlations between occasion-specific states and enduring traits, with weak evidence that insulin resistance might be temporally associated with subsequent depressive symptoms among White participants later in adulthood.

Discriminative Utility of Transcranial Magnetic Stimulation-Derived Markers of Cortical Excitability for Transient Ischemic Attack.

BACKGROUND: Several guidelines currently recommend acute diffusion weighted imaging (DWI) for the detection of ischemia in transient ischemic attack (TIA). However, DWI hyperintensities resolve early and only 30%-50% with clinically defined TIA show acute DWI positivity. A recent meta-analysis reported an unexplained 7-fold variation in DWI positivity in TIA across studies, concluding that DWI does not provide a consistent basis for defining ischemia. Intracortical excitability, measured using transcranial magnetic stimulation (TMS), has previously been shown to be altered after TIA and associated with ABCD2 scores; however, whether altered cortical excitability is associated with clinical and DWI-based definitions of TIA remains unclear. METHODS: Individuals with TIA symptoms (N = 23; mean age = 61 ± 12) were prospectively recruited and underwent DWI and paired-pulse TMS. Multivariate linear regression was used to estimate associations between TMS-derived excitability thresholds, and clinical TIA diagnosis, and imaging-based evidence of cerebral ischemia (DWI positivity). Area under the curve (AUC) analyses was used to compare the discriminability of TMS-derived thresholds and clinical TIA diagnoses. RESULTS: Thresholds for intracortical inhibition in the TIA-unaffected hemisphere were significantly associated with the clinical diagnosis of TIA. No associations between TMS-derived thresholds and DWI positivity were observed. TMS thresholds showed low-moderate discriminability and values differed by age (65+) and sex. CONCLUSIONS: In this small sample, TMS-derived markers of intracortical excitability were associated with clinical TIA diagnoses but not DWI positivity. Our results provide preliminary evidence for the potential discriminative utility of TMS for the diagnosis of TIA and highlight the need for future work in larger cohorts.

The new frontline: exploring the links between moral distress, moral resilience and mental health in healthcare workers during the COVID-19 pandemic.

BACKGROUND: Global health crises, such as the COVID-19 pandemic, confront healthcare workers (HCW) with increased exposure to potentially morally distressing events. The pandemic has provided an opportunity to explore the links between moral distress, moral resilience, and emergence of mental health symptoms in HCWs. METHODS: A total of 962 Canadian healthcare workers (88.4% female, 44.6 + 12.8 years old) completed an online survey during the first COVID-19 wave in Canada (between April 3rd and September 3rd, 2020). Respondents completed a series of validated scales assessing moral distress, perceived stress, anxiety, and depression symptoms, and moral resilience. Respondents were grouped based on exposure to patients who tested positive for COVID-19. In addition to descriptive statistics and analyses of covariance, multiple linear regression was used to evaluate if moral resilience moderates the association between exposure to morally distressing events and moral distress. Factors associated with moral resilience were also assessed. FINDINGS: Respondents working with patients with COVID-19 showed significantly more severe moral distress, anxiety, and depression symptoms (F > 5.5, p < .020), and a higher proportion screened positive for mental disorders (Chi-squared > 9.1, p = .002), compared to healthcare workers who were not. Moral resilience moderated the relationship between exposure to potentially morally distressing events and moral distress (p < .001); compared to those with higher moral resilience, the subgroup with the lowest moral resilience had a steeper cross-sectional worsening in moral distress as the frequency of potentially morally distressing events increased. Moral resilience also correlated with lower stress, anxiety, and depression symptoms (r > .27, p < .001). Factors independently associated with stronger moral resilience included: being male, older age, no mental disorder diagnosis, sleeping more, and higher support from employers and colleagues (B [0.02, |-0.26|]. INTERPRETATION: Elevated moral distress and mental health symptoms in healthcare workers facing a global crisis such as the COVID-19 pandemic call for the development of interventions promoting moral resilience as a protective measure against moral adversities.

Profiles of sleep changes during the COVID-19 pandemic: Demographic, behavioural and psychological factors.

This study aimed to evaluate changes in sleep during the COVID-19 outbreak, and used data-driven approaches to identify distinct profiles of changes in sleep-related behaviours. Demographic, behavioural and psychological factors associated with sleep changes were also investigated. An online population survey assessing sleep and mental health was distributed between 3 April and 24 June 2020. Retrospective questions were used to estimate temporal changes from before to during the outbreak. In 5,525 Canadian respondents (67.1% females, 16-95 years old: Mean ± SD = 55.6 ± 16.3 years), wake-up times were significantly delayed relative to pre-outbreak estimates (p < .001, ηp2  = 0.04). Occurrences of clinically meaningful sleep difficulties significantly increased from 36.0% before the outbreak to 50.5% during the outbreak (all p < .001, g ≥ 0.27). Three subgroups with distinct profiles of changes in sleep behaviours were identified: "Reduced Time in Bed", "Delayed Sleep" and "Extended Time in Bed". The "Reduced Time in Bed" and "Delayed Sleep" subgroups had more adverse sleep outcomes and psychological changes during the outbreak. The emergence of new sleep difficulties was independently associated with female sex, chronic illnesses, being employed, family responsibilities, earlier wake-up times, higher stress levels, as well as heavier alcohol use and television exposure. The heterogeneity of sleep changes in response to the pandemic highlights the need for tailored interventions to address sleep problems.

Emerging New Psychiatric Symptoms and the Worsening of Pre-existing Mental Disorders during the COVID-19 Pandemic: A Canadian Multisite Study: Nouveaux symptômes psychiatriques émergents et détérioration des troubles mentaux préexistants durant la pandémie de la COVID-19: une étude canadienne multisite.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has caused global disruptions with serious psychological impacts. This study investigated the emergence of new psychiatric symptoms and the worsening of pre-existing mental disorders during the COVID-19 pandemic, identified factors associated with psychological worsening, and assessed changes in mental health service use. METHODS: An online survey was circulated between April 3 and June 23, 2020. Respondents were asked to complete mental health questionnaires based on 2 time referents: currently (i.e., during the outbreak) and in the month preceding the outbreak. A total of 4,294 Canadians between 16 and 99 years of age were subdivided based on the presence of self-reported psychiatric diagnoses. RESULTS: The proportion of respondents without prior psychiatric history who screened positive for generalized anxiety disorder and depression increased by 12% and 29%, respectively, during the outbreak. Occurrences of clinically important worsening in anxiety, depression, and suicidal ideation symptoms relative to pre-outbreak estimates were significantly higher in those with psychiatric diagnoses. Furthermore, 15% to 19% of respondents reported increased alcohol or cannabis use. Worse psychological changes relative to pre-outbreak estimate were associated with female sex, younger age, lower income, poorer coping skills, multiple psychiatric comorbidities, previous trauma exposure, deteriorating physical health, poorer family relationships, and lower exercising. Reductions in mental health care were associated with increased suicidal ideation. CONCLUSION: The worsening in mental health symptoms and the decline in access to care call for the urgent development of adapted interventions targeting both new mental disorders and pre-existing psychiatric conditions affected by the COVID-19 pandemic.