Associations of serum uric acid with incident dementia and cognitive decline in the ARIC-NCS cohort

INTRODUCTION

Elevated serum uric acid (SUA) is associated with cardiovascular risk factors, which often contribute to dementia and dementia-like morbidity, yet several cross-sectional studies have shown protective associations with cognition, which would be consistent with other work showing benefits of elevated SUA through its antioxidant properties.

METHODS

We studied 11,169 participants free of dementia and cardiovascular disease from the Atherosclerosis Risk in Communities (ARIC) cohort. SUA was measured in blood samples collected in 1990-92, baseline for this study (age range 47-70 years). Incident dementia was ascertained based on clinical assessments in 2011-13 and 2016-17, surveillance based on dementia screeners conducted over telephone interviews, hospitalization discharge codes, and death certificates. Cognitive function was assessed up to four times between 1990 and 92 and 2016-17. We estimated the association of SUA, categorized into quartiles, with incidence of dementia using Cox regression models adjusting for potential confounders. The association between cognitive decline and SUA was assessed using generalized estimating equations.

RESULTS

Over a median follow-up period of 24.1 years, 2005 cases of dementia were identified. High baseline SUA was associated with incident dementia (HR, 1.29; 95% CI, 1.12, 1.47) when adjusted for sociodemographic variables. However, after further adjustment including cardiovascular risk factors, this relationship disappeared (HR, 1.03; 95% CI, 0.88, 1.21). Elevated baseline SUA was associated with faster cognitive decline even after further adjustment (25-year global z-score difference, -0.149; 95% CI, -0.246, -0.052).

CONCLUSION

Higher levels of mid-life SUA were associated with faster cognitive decline, but not necessarily with higher risk of dementia.

Burden of pneumococcal disease: 8-year retrospective analysis from a single centre in Hong Kong

PURPOSE

Streptococcus pneumoniae is a common pathogen involved in community-acquired pneumonia. Invasive pneumococcal disease is often associated with higher co-morbidity rates, but mortality-related findings have been inconclusive. This study investigated predictors of 30-day mortality and invasive pneumococcal disease.

METHODS

This retrospective analysis included adults with pneumococcal disease who were admitted to Pamela Youde Nethersole Eastern Hospital from 1 January 2011 to 31 December 2018. Demographics, microbiological characteristics, and outcomes were compared between 30-day survivors and non-survivors, and between patients with invasive disease and those with non-invasive disease. Intensive care unit (ICU) subgroup analysis was performed. The primary outcome was 30-day all-cause mortality; secondary outcomes were ICU and hospital mortalities, and ICU and hospital lengths of stay.

RESULTS

In total, 792 patients had pneumococcal disease; 701 survived and 91 (11.5%) died within 30 days. Notably, 106 (13.4%) patients had invasive pneumococcal disease and 170 (21.5%) patients received intensive care. Vasopressor use (odds ratio [OR]=4.96, P<0.001), chronic kidney disease (OR=3.62, P<0.001), positive urinary antigen test results (OR=2.57, P=0.001), and advanced age (OR=2.19, P=0.010) were independent predictors for 30-day mortality by logistic regression analysis. Among critically ill patients, chronic kidney disease (OR=4.64, P<0.001), higher APACHE IV score (OR=3.73, P=0.016), and positive urinary antigen test results (OR=2.94, P=0.008) were predictors for 30-day mortality. Logistic regression analysis revealed that chronic kidney disease (OR=3.10, P<0.001) was a risk factor for invasive pneumococcal disease.

CONCLUSION

Advanced age, vasopressor use, chronic kidney disease, and positive urinary antigen test results were independent predictors for 30-day mortality in patients with pneumococcal disease.

Liquid Chromatographic Determination of Major Organic Acids in Apple Juice and Cranberry Juice Cocktail: Collaborative Study

Twelve laboratories collaboratively studied a liquid chromatographic method for determination of quinic, malic, and citric acids in cranberry juice cocktail and apple juice. Samples are passed through a disposable silica cartridge, filtered, and directly injected into the chromatograph. The mobile phase is 0.2M KH2PO4 (pH 2.4). Two reverse phase columns are used, with UV detection at 214 nm. Six samples of cranberry juice cocktail and 6 samples of apple juice were sent to each collaborator. Repeatability and reproducibility coefficients of variation ranged from 1.2 to 7.6% and from 2.9 to 14.7%, respectively, for quinic, malic, and citric acid levels above 0.10%. The precision of the method is satisfactory. The method has been adopted official first action.

Abstract WP479: Associations Between Vascular Risk, Amyloid Burden and Incident Dementia: The ARIC-PET Study

Background: Midlife vascular risk factors (MVRF) are associated with incident dementia. Similarly, amyloid β(Aβ) and neurodegeneration (e.g.brain volumes), as parts of the Alzheimer’s Disease (AD) ATN framework, are associated with cognition. Whether vascular and AD-associated factors contribute to dementia independently or interact synergistically to reduce cognitive ability is not well understood.

Methods: Recruited from 3 U.S. communities, ARIC-PET participants were followed from 1987-89 (45-64 yo) through 2016-17 (74-94 yo). Cognition was evaluated in 2011-13 (ages 69-88), and twice more, every 2-3 years. In 2011-13, nondemented ARIC-PET participants had a brain MRI, with measurement of white matter hyperintensities (WMH) and brain volumes, with florbetapir (Aβ) PET scans in 2012-14; global cortical standardized uptake value ratio (SUVR) was log-transformed and standardized. Dementia was classified by expert review, as well as phone and medical record surveillance. The relative contributions of vascular risk (MVRF, WMH volume) and AD pathology (elevated Aβ SUVR, smaller AD signature region volumes) to incident dementia were evaluated with Cox proportional hazards regression.

Results: In 298 individuals, 36 developed dementia. In models with key MVRF, demographics, and Aβ SUVR, hypertension and Aβ each independently predicted dementia risk (per SD of Aβ SUVR: HR 2.57, 95% CI 1.72-3.84; hypertension: HR 2.57, 95% CI 1.16-5.67), but didn’t interact on dementia risk. WMH (per SD: HR 1.51, 95% CI 1.03-2.20) and Aβ SUVR (per SD: HR 2.52, 95% CI 1.83-3.47) each contributed to incident dementia but WMH lost significance when MVRF were added to the model. Smaller AD signature regions were associated with incident dementia, independent of Aβ SUVR, and remained significant after adjustment for MVRF (HR per SD 2.18, 95% CI 1.18-4.01).

Conclusions: Midlife hypertension and late-life Aβ independently contribute to dementia risk, but don’t synergize on a multiplicative scale. Neurodegeneration (e.g.smaller AD signature region volume) is also associated with incident dementia, independent of Aβ and MVRF. Multiple pathways leading to dementia should be considered when evaluating risk factors and interventions to reduce the burden of dementia.

Imaging of spindle cell lipoma

AIM

To review the evaluation, diagnosis, and treatment of spindle cell lipoma (SCL) with emphasis on the location of these tumours and the spectrum of magnetic resonance imaging (MRI) and computed tomography (CT) appearances.

MATERIALS AND METHODS

The MRI and CT findings of 27 histopathologically proven SCLs were evaluated retrospectively. Imaging features evaluated included margins, percentage visible fat, MRI signal characteristics, oedema, and contrast enhancement patterns.

RESULTS

Patient ages ranged from 18 to 80 years with an average age of 56.5 years. Men were affected twice as frequently as women (M=18, F=9). SCLs ranged in size from 2 to 10 cm, with an average greatest dimension of 5.5 cm. Five lesions (19%) contained no visible fat on CT or MRI, and the leading differential diagnosis of high-grade soft-tissue sarcoma diagnosis was suggested by referring surgeons. Five lesions (19%) had <50% fatty areas, nine lesions (52%) demonstrated >50% but <90% fat at MRI or CT. Only three of 25 lesions (12%) had an appearance of a typical lipoma on unenhanced MRI sequences. All SCLs that were imaged with contrast medium (n = 18) demonstrated some degree of enhancement, with eight (44%) showing marked enhancement, four (22%) showing moderate, and six (33%) minimal enhancement.

CONCLUSION

SCLs have considerably variable imaging appearances and may have minimal or no visible fat at MRI or CT. Imaging features may make it difficult to distinguish this benign tumour from a potentially higher-grade malignant tumour.

Adherence to Dietary Patterns and Risk of Incident Dementia: Findings from the Atherosclerosis Risk in Communities Study

BACKGROUND

Previous studies have suggested that adherence to healthy dietary patterns during late life may be associated with improved cognition. However, few studies have examined the association between healthy dietary patterns during midlife and incident dementia.

OBJECTIVE

Our study aimed to determine the association between adherence to healthy dietary patterns at midlife and incident dementia.

METHODS

We included 13,630 adults from the Atherosclerosis Risk in Communities (ARIC) Study in our prospective analysis. We used food frequency questionnaire responses to calculate four dietary scores: Healthy Eating Index-2015 (HEI-2015), Alternative Healthy Eating Index-2010 (AHEI-2010), alternate Mediterranean (aMed) diet, and Dietary Approaches to Stop Hypertension (DASH). Participants were followed until the end of 2017 for incident dementia. Cox regression models adjusted for covariates were used to estimate risk of incident dementia by quintile of dietary scores.

RESULTS

Over a median of 27 years, there were 2,352 cases of incident dementia documented. Compared with participants in quintile 1 of HEI-2015, participants in quintile 5 (healthiest) had a 14% lower risk of incident dementia (hazard ratio, HR: 0.86, 95% confidence interval, CI: 0.74-0.99). There were no significant associations of incident dementia with the AHEI-2010, aMed, or DASH scores. There were no significant interactions by sex, age, race, education, physical activity, hypertension, or obesity.

CONCLUSION

Adherence to the HEI-2015, but not the other dietary scores, during midlife was associated with lower risk of incident dementia. Further research is needed to elucidate whether timing of a healthy diet may influence dementia risk.

Association of Dietary Patterns in Midlife and Cognitive Function in Later Life in US Adults Without Dementia

Importance

The association of dietary patterns, or the combinations of different foods that people eat, with cognitive change and dementia is unclear.

Objective

To examine the association of dietary patterns in midlife with cognitive function in later life in a US population without dementia.

Design, Setting, and Participants

Observational cohort study with analysis of data collected from 1987 to 2017. Analysis was completed in January to February 2019. Community-dwelling black and white men and women from Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and suburban Minneapolis, Minnesota, participating in the Atherosclerosis Risk in Communities (ARIC) study were included.

Exposures

Two dietary pattern scores were derived from a 66-item food frequency questionnaire using principal component analysis. A Western, or unhealthy, dietary pattern was characterized by higher consumption of meats and fried foods. A so-called prudent, or healthier, dietary pattern was characterized by higher amounts of fruits and vegetables.

Main Outcomes and Measures

Results of 3 cognitive tests (Digit Symbol Substitution Test, Word Fluency Test, and Delayed Word Recall) performed at 3 points (1990-1992, 1996-1998, and 2011-2013) were standardized and combined to represent global cognitive function. The 20-year change in cognitive function was determined by tertile of diet pattern score using mixed-effect models. The risk of incident dementia was also determined by tertile of the diet pattern score.

Results

A total of 13 588 participants (7588 [55.8%] women) with a mean (SD) age of 54.6 (5.7) years at baseline were included; participants in the top third of Western and prudent diet pattern scores were considered adherent to the respective diet. Cognitive scores at baseline were lower in participants with a Western diet (z score for tertile 3 [T3], -0.17 [95% CI, -0.20 to -0.14] vs T1, 0.17 [95% CI, 0.14-0.20]) and higher in participants with a prudent diet (z score for T3, -0.09 [95% CI, -0.12 to -0.06] vs T1, -0.09 [95% -0.12 to -0.06]). Estimated 20-year change in global cognitive function did not differ by dietary pattern (difference of change in z score for Western diet, T3 vs T1: -0.01 [95% CI, -0.05 to 0.04]; and difference of change in z score for prudent diet, T3 vs T1: 0.02 [95% CI, -0.02 to 0.06]). The risk of incident dementia did not differ by dietary pattern (Western hazard ratio for T3 vs T1, 1.06 [95% CI, 0.92-1.22]; prudent hazard ratio for T3 vs T1, 0.99 [95% CI, 0.88-1.12]).

Conclusions and Relevance

This study found that the dietary pattern of US adults at midlife was not associated with processing speed, word fluency, memory, or incident dementia in later life.

ABCA1 transporter reduces amphotericin B cytotoxicity in mammalian cells

Amphotericin B (AmB) belongs to a group of polyene antibiotics commonly used in the treatment of systemic mycotic infections. A widely accepted mechanism of action of AmB is based on the formation of an oligomeric pore structure within the plasma membrane (PM) by interaction with membrane sterols. Although AmB binds preferentially to ergosterol, it can also bind to cholesterol in the mammalian PM and cause severe cellular toxicity. The lipid content and its lateral organization at the cell PM appear to be significant for AmB binding. Several ATP-binding cassette (ABC) transporters, including ABCA1, play a crucial role in lipid translocation, cholesterol redistribution and efflux. Here, we demonstrate that cells expressing ABCA1 are more resistant to AmB treatment, while cells lacking ABCA1 expression or expressing non-active ABCA1MM mutant display increased sensitivity. Further, a FLIM analysis of AmB-treated cells reveals a fraction of the antibiotic molecules, characterized by relatively high fluorescence lifetimes (> 6 ns), involved in formation of bulk cholesterol-AmB structures at the surface of ABCA1-expressing cells. Finally, lowering the cellular cholesterol content abolishes resistance of ABCA1-expressing cells to AmB. Therefore, we propose that ABCA1-mediated cholesterol efflux from cells induces formation of bulk cholesterol-AmB structures at the cell surface, preventing AmB cytotoxicity.

Association of white matter microstructural integrity with cognition and dementia

Late-life measures of white matter (WM) microstructural integrity may predict cognitive status, cognitive decline, and incident mild cognitive impairment (MCI) or dementia. We considered participants of the Atherosclerosis Risk in Communities study who underwent cognitive assessment and neuroimaging in 2011-2013 and were followed through 2016-2017 (n = 1775 for analyses of prevalent MCI and dementia, baseline cognitive performance, and longitudinal cognitive change and n = 889 for analyses of incident MCI, dementia, or death). Cross-sectionally, both overall WM fractional anisotropy and overall WM mean diffusivity were strongly associated with baseline cognitive performance and risk of prevalent MCI or dementia. Longitudinally, greater overall WM mean diffusivity was associated with accelerated cognitive decline, as well as incident MCI, incident dementia, and mortality, but WM fractional anisotropy was not robustly associated with cognitive change or incident cognitive impairment. Both cross-sectional and longitudinal associations were attenuated after additionally adjusting for likely downstream pathologic changes. Increased WM mean diffusivity may provide an early indication of dementia pathogenesis.

Association of Midlife to Late-Life Blood Pressure Patterns With Incident Dementia

Importance

The association between late-life blood pressure (BP) and cognition may depend on the presence and chronicity of past hypertension. Late-life declines in blood pressure following prolonged hypertension may be associated with poor cognitive outcomes.

Objective

To examine the association of midlife to late-life BP patterns with subsequent dementia, mild cognitive impairment, and cognitive decline.

Design, Setting, and Participants

The Atherosclerosis Risk in Communities prospective population-based cohort study enrolled 4761 participants during midlife (visit 1, 1987-1989) and followed-up over 6 visits through 2016-2017 (visit 6). BP was examined over 24 years at 5 in-person visits between visits 1 and 5 (2011-2013). During visits 5 and 6, participants underwent detailed neurocognitive evaluation. The setting was 4 US communities: Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and Minneapolis, Minnesota. Follow-up ended on December 31, 2017.

Exposures

Five groups based on longitudinal patterns of normotension, hypertension (>140/90 mm Hg), and hypotension (<90/60 mm Hg) at visits 1 to 5.

Main Outcomes and Measures

Primary outcome was dementia onset after visit 5, based on Ascertain Dementia-8 informant questionnaires, Six-Item Screener telephone assessments, hospital discharge and death certificate codes, and the visit 6 neurocognitive evaluation. Secondary outcome was mild cognitive impairment at visit 6, based on the neurocognitive evaluation.

Results

Among 4761 participants (2821 [59%] women; 979 [21%] black race; visit 5 mean [SD] age, 75 [5] years; visit 1 mean age range, 44-66 years; visit 5 mean age range, 66-90 years), there were 516 (11%) incident dementia cases between visits 5 and 6. The dementia incidence rate for participants with normotension in midlife (n = 833) and late life was 1.31 (95% CI, 1.00-1.72 per 100 person-years); for midlife normotension and late-life hypertension (n = 1559), 1.99 (95% CI, 1.69-2.32 per 100 person-years); for midlife and late-life hypertension (n = 1030), 2.83 (95% CI, 2.40-3.35 per 100 person-years); for midlife normotension and late-life hypotension (n = 927), 2.07 (95% CI, 1.68-2.54 per 100 person-years); and for midlife hypertension and late-life hypotension (n = 389), 4.26 (95% CI, 3.40-5.32 per 100 person-years). Participants in the midlife and late-life hypertension group (hazard ratio [HR], 1.49 [95% CI, 1.06-2.08]) and in the midlife hypertension and late-life hypotension group (HR, 1.62 [95% CI, 1.11-2.37]) had significantly increased risk of subsequent dementia compared with those who remained normotensive. Irrespective of late-life BP, sustained hypertension in midlife was associated with dementia risk (HR, 1.41 [95% CI, 1.17-1.71]). Compared with those who were normotensive in midlife and late life, only participants with midlife hypertension and late-life hypotension had higher risk of mild cognitive impairment (37 affected individuals (odds ratio, 1.65 [95% CI, 1.01-2.69]). There was no significant association of BP patterns with late-life cognitive change.

Conclusions and Relevance

In this community-based cohort with long-term follow-up, sustained hypertension in midlife to late life and a pattern of midlife hypertension and late-life hypotension, compared with midlife and late-life normal BP, were associated with increased risk for subsequent dementia.

Adherence to the Healthy Eating Index-2015 (HEI-2015), Cognitive Function, and Incident Dementia in the Atherosclerosis Risk in Communities (ARIC) Study (OR32-01-19)

Objectives

The Healthy Eating Index-2015 (HEI-2015) score was created to measure adherence to the 2015–2020 Dietary Guidelines for Americans. It remains undetermined whether adherence to the newly released guidelines is associated with improved cognitive function or reduced incident dementia.

Methods

We assessed the diet of 13,632 participants from the Atherosclerosis Risk in Communities (ARIC) study who were recruited from 1987–1989 and calculated their HEI-2015 scores (0–100) using responses to food frequency questionnaires. Baseline cognitive function was assessed using the Delayed Word Recall, Digit Symbol Substitution, and Word Fluency Tests. We used linear regression models to assess the cross-sectional association of adherence to HEI-2015 and standardized cognitive test scores. Incident dementia was ascertained through the end of 2017. Dementia status at the ARIC Neurocognitive Study visits (2011–13, 2016–17) was determined by detailed neurocognitive battery, informant interviews, and adjudicated review as well as through dementia screening by phone interview and informant review, or by ICD-9 dementia code for a hospitalization or death. We used Cox proportional hazards regression models adjusted for demographic, lifestyle, genetic, and clinical covariates to estimate the association between HEI-2015 score and risk of incident dementia.

Results

Compared to participants in the lowest quintile of HEI-2015 score, participants in the highest quintile scored higher on the Digit Symbol Substitution Test (β: 0.07, 95% CI: 0.03 to 0.11, P for trend < 0.001), Word Fluency Test (β: 0.07, 95% CI: 0.02 to 0.12, P for trend < 0.001) and global cognitive score (β: 0.05, 95% CI: 0.01 to 0.10, P for trend = 0.003) (Table). In total, there were 2354 cases of incident dementia over a median follow-up of 25 years. Compared to participants in the lowest quintile, participants in other quintiles had a lower risk of incident dementia after adjusting for covariates. Participants in the highest quintile had a 19% lower risk of dementia compared to those in the lowest (HR: 0.81, 95% CI: 0.71–0.93, P for trend = 0.01).

Conclusions

Higher adherence to the 2015–2020 Dietary Guidelines for Americans was associated with higher baseline cognitive function and lower risk of incident dementia.

Funding Sources

NHLBI, NIDDK, NIA, NINDS, NIH, HHS.

Supporting Tables, Images and/or Graphs

Association of Brain Magnetic Resonance Imaging Signs With Cognitive Outcomes in Persons With Nonimpaired Cognition and Mild Cognitive Impairment

IMPORTANCE

Brain atrophy and vascular lesions contribute to dementia and mild cognitive impairment (MCI) in clinical referral populations. Prospective evidence in older general populations is limited.

OBJECTIVE

To evaluate which magnetic resonance imaging (MRI) signs are independent risk factors for dementia and MCI.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included 1553 participants sampled from the Atherosclerosis Risk in Communities Study who had brain MRI scans and were dementia free during visit 5 (June 2011 to September 2013). Participants' cognitive status was evaluated through visit 6 (June 2016 to December 2017).

EXPOSURES

Brain regional volumes, microhemorrhages, white matter hyperintensity (WMH) volumes, and infarcts measured on 3-T MRI.

MAIN OUTCOMES AND MEASURES

Cognitive status (dementia, MCI, or nonimpaired cognition) was determined from in-person evaluations. Dementia among participants who missed visit 6 was identified via dementia surveillance and hospital discharge or death certificate codes. Cox proportional hazards models were used to evaluate the risk of dementia in 3 populations: dementia-free participants (N = 1553), participants with nonimpaired cognition (n = 1014), and participants with MCI (n = 539). Complementary log-log models were used for risk of MCI among participants with nonimpaired cognition who also attended visit 6 (n = 767). Models were adjusted for demographic variables, apolipoprotein E ε4 alleles, vascular risk factors, depressive symptoms, and heart failure.

RESULTS

Overall, 212 incident dementia cases were identified among 1553 participants (mean [SD] age at visit 5, 76 [5.2] years; 946 [60.9%] women; 436 [28.1%] African American) with a median (interquartile range) follow-up period of 4.9 (4.3-5.2) years. Significant risk factors of dementia included lower volumes in the Alzheimer disease (AD) signature region, including hippocampus, entorhinal cortex, and surrounding structures (hazard ratio [HR] per 1-SD decrease, 2.40; 95% CI, 1.89-3.04), lobar microhemorrhages (HR, 1.90; 95% CI, 1.30-2.77), higher volumes of WMH (HR per 1-SD increase, 1.44; 95% CI, 1.23-1.69), and lacunar infarcts (HR, 1.66; 95% CI, 1.20-2.31). The AD signature region volume was also consistently associated with both MCI and progression from MCI to dementia, while subcortical microhemorrhages and infarcts contributed less to the progression from MCI to dementia.

CONCLUSIONS AND RELEVANCE

In this study, lower AD signature region volumes, brain microhemorrhages, higher WMH volumes, and infarcts were risk factors associated with dementia in older community-based residents. Vascular changes were more important in the development of MCI than in its progression to dementia, while AD-related signs were important in both stages.

Neural stem cells promote glioblastoma formation in nude mice

PURPOSE

Neural stem cells (NSCs) have been characterized with the ability of self-renewal and neurogenesis, which has inspired lots of studies to clarify the functions of NSCs in neural injury, ischemic stroke, brain inflammation and neurodegenerative diseases. We focused on the relationship of NSCs with glioblastoma, since we have discovered that recurrent glioblastomas were inclined to be derived from subventricular zone (SVZ), where NSCs reside. We want to clarify whether NSCs are involved in glioblastoma relapse.

METHODS

Immunocytochemistry was used to confirm the stemness of NSCs. The Cell Counting Kit-8 was used to measure the proliferation of cells. Migration abilities were examined by wound healing and transwell assays, and tumor formation abilities were confirmed in nude mice.

RESULTS

We found in experiments that NSCs promoted proliferation of a glioblastoma cell line-Ln229, the migration ability of Ln229 cells was motivated by co-cultured with NSCs. Tumor formation of Ln229 cells was also accelerated in nude mice when co-transplanted with NSCs. In immunohistochemistry, we found that the Sox2- and Ki67-positive cells were much higher in co-transplanted groups than that of control groups.

CONCLUSIONS

These results imply the potential role that NSCs play in speeding up tumor formation in the process of glioblastoma relapse, providing the basis for dealing with newly diagnosed glioblastoma patients, which may help postpone the recurrence of glioblastoma as far as possible through preprocessing the tumor-adjacent SVZ tissue.

Early internationalization of students in a German medical school in the former German Democratic Republic

The growing influence and importance of internationalization in higher education, especially in medical education, inspired anatomists at Columbia University New York, USA and at the Martin Luther University Halle-Wittenberg, Germany, to start a novel international preclinical collaboration project. As part of the anatomy dissection course a group of volunteer medical students from Halle dissected selected areas of the human body with the help of an English, illustrated, iPad-run dissection script (American Dissector). Meanwhile the rest of the students worked with a traditional German text-based dissector. Additionally, participating German students were matched with US students, with whom they connected via video-conferencing and discussed subjects like differences between their health care systems, structure and content of the anatomy course and the differences in their medical education systems. Questionnaires were sent for feedback and checklists confirmed dissection findings. Results indicated that the American Dissector was successfully shared internationally. The majority (62%) found it easier to find structures using the American Dissector compared to the standard dissector and also 62% needed the atlas two times less when using the American Dissector. Furthermore, students enjoyed their interaction with their international peers and the vast majority (77%) wished there were more interactions like this in the medical curriculum. This publication describes an approach to embed internationalization in the preclinical medical curriculum based in the gross anatomy course in a German Medical school, located in East Germany. Considering its history as a former German Democratic Republic faculty this is a meaningful step towardglobalization of medical education in this part of Germany.

Systemic inflammation during midlife and cognitive change over 20 years: The ARIC Study

OBJECTIVE

To examine the association between systemic inflammation measured during midlife and 20-year cognitive decline.

METHODS

Within the Atherosclerosis Risk in Communities cohort study, inflammatory biomarkers were measured during middle adulthood. We created an inflammation composite score using 4 blood biomarkers measured at visit 1 (fibrinogen, white blood cell count, von Willebrand factor, and factor VIII); we measured C-reactive protein (CRP) at visit 2. Cognition was assessed over 3 visits spanning 20 years using measures of memory, executive function, and language.

RESULTS

A total of 12,336 participants (baseline age 56.8 [5.7], 21% black, 56% women) were included. After adjusting for demographic variables, vascular risk factors, and comorbidities, each standard deviation (SD) increase in midlife inflammation composite score was associated with an additional 20-year decline of -0.035 SD (95% confidence interval: -0.062 to -0.007) on the cognitive composite score. We found a similar association between each SD increase in midlife CRP level and additional 20-year cognitive decline (-0.038 SD, 95% confidence interval: -0.057 to -0.019). Participants with a midlife inflammation composite score in the top quartile had a 7.8% steeper cognitive decline, compared to participants in the lowest quartile; CRP in the top quartile was associated with an 11.6% steeper cognitive decline. In cognitive domain-specific analyses, elevated midlife inflammatory markers were most consistently associated with declines in memory. Results were similar after adjusting for attrition using inverse probability weighting.

CONCLUSIONS

Our findings highlight what may be an early pathogenic role for systemic inflammation as a driver of cognitive decline in the decades leading up to older adulthood.

Hospitalisation of adults with Down syndrome: lesson from a 10-year experience from a community hospital

BACKGROUND

Life expectancy of individuals with Down syndrome (DS) has improved significantly over the past decades. However, there are sparse data documenting the co-morbidities and hospitalisation of adult patients with DS in the literature. The aim of this study was to characterise the co-morbidities and pattern of hospitalisation in adult patients with DS during a 10-year period at the community hospital as well as to compare hospitalisation parameters with the general adult population during the same years.

METHOD

We reviewed the medical records of 81 hospitalisations from 37 patients with DS aged 21 to 68 years at Metrowest Medical Center during a 10-year period and compared with those of the general adult population during the same time. Co-morbidities were also described.

RESULTS

Adults with DS had a mean age at admission of 48.6 ± 8.8 years with the median length of stay of 3 days (interquartile range 4 days). Male patients were hospitalised longer than female patients (mean 5.0 vs. 2.8 days; P < 0.05), and patients who lived at home were admitted at earlier ages than those who came from residential healthcare facility (mean 41.5 vs. 52.2 years; P < 0.001). The most common cause of hospitalisation was pneumonia/aspiration syndrome (29.6%), and the most common co-morbidity was gastroesophageal reflux disease (GERD)/dysphagia (70.3%). Presence of GERD/dysphagia or seizure disorder was significantly associated with multiple admission and readmission within 1 month (P < 0.05). The mortality rate was 4.9%, and the rate of intensive care unit admission was 8.6%.

CONCLUSIONS

Our cohort did not show statistically significant different hospitalisation parameters such as inpatient mortality and average length of stay when compared with general adult population hospitalised at the same years. The care of adult patients with DS presents challenges in internal medicine due to its unique co-morbid profile and signifies the importance of multidisciplinary approach. In order to improve the care of this patient population, their co-morbidities, particularly GERD/dysphagia and seizure disorder, should be optimally managed and comprehensively addressed when patients are hospitalised.

Neural correlates of domain-specific cognitive decline: The ARIC-NCS Study

OBJECTIVE

To evaluate the association of cognitive declines in the domains of memory, language, and executive function with brain gray matter (GM) volume in old age.

METHODS

This was a prospective study of 1,846 participants in the Atherosclerosis Risk in Communities (ARIC) Study who underwent 3T brain MRI scans in 2011 to 2013. Participants were categorized by cognitive domain performance trajectory over the prior 20 years (cut point to define decline: 20th percentile). Associations between GM volume and cognitive declines were assessed at the voxel level with voxel-based morphometry and at the regional level with atlas-defined GM volumes of specific regions of interest.

RESULTS

Participants were an average age of 76 years; 60% were female; and 28% were black. Participants in the top 20th percentile for decline in the memory domain had smaller GM volumes in the medial temporal lobe (-3.3%, 95% confidence interval [CI] -4.6% to -2.1%), amygdala (-2.7%, 95% CI -4.1% to -1.3%), entorhinal cortex (-4.1%, 95% CI -6.0% to -2.2%), and hippocampus (-3.8%, 95% CI -5.2% to -2.4%) compared to participants who were in the lowest 80th percentile for decline in all domains. In contrast, among participants who were in the top 20th percentile for decline in the language or executive function domains, GM volumes were smaller in more brain regions.

CONCLUSIONS

Declines in memory function were associated with brain volume loss in the medial temporal and hippocampal formations. Declines in language and executive function were associated with decreases in brain volumes across more noncontiguous brain regions.

Elevated Vancomycin Trough Levels in a Tertiary Health System: Frequency, Risk Factors, and Prognosis

OBJECTIVE

To investigate the frequency of, risk factors for, and outcomes after elevated levels of vancomycin.

PATIENTS AND METHODS

We identified hospitalizations among 21,285 individuals in which intravenous vancomycin was given between August 29, 2007, and October 10, 2014. We investigated frequency and risk factors for elevated vancomycin levels (trough levels >30 mg/L) as well as associations with subsequent acute kidney injury (AKI), length of stay, and in-hospital mortality.

RESULTS

Among the 21,285 patients, the mean age was 62.9 years, and 10,478 (49.2%) were female. Trough levels of vancomycin were checked in 7422 patients, and 755 elevated levels were detected. Compared with patients with trough levels checked but no elevated levels found, those with elevated levels had longer duration of vancomycin therapy (median, 6.0 days vs 3.4 days; P<.001) and slightly higher doses (mean, 1.72 g vs 1.58 g; P<.001). Patients with higher body mass index or lower estimated glomerular filtration rate had more elevated levels. In propensity-matched analyses, patients had higher risk of incident AKI after elevated levels compared with patients without elevated levels (hazard ratio, 1.55; 95% CI, 1.09-2.20; P=.02), as well as longer subsequent length of stay (relative risk, 1.14; 95% CI, 1.02-1.28; P=.03) but similar in-hospital mortality.

CONCLUSION

In this study, elevated vancomycin levels were common, particularly in patients with higher body mass index and lower estimated glomerular filtration rate, and were associated with greater subsequent AKI and length of stay.

Association of Hospitalization, Critical Illness, and Infection with Brain Structure in Older Adults

OBJECTIVES

To examine the association between hospitalization, critical illness, and infection occurring during middle- and late-life and structural brain abnormalities in older adults.

DESIGN

Prospective cohort study.

SETTING

Atherosclerosis Risk in Communities (ARIC) Study.

PARTICIPANTS

A community sample of adults who were 44 to 66 years of age at study baseline.

MEASUREMENTS

Active surveillance of local hospitals and annual participant contact were used to gather hospitalization information (including International Classification of Diseases, Ninth Revision, codes) on all participants over a 24-year surveillance period. Subsequently, a subset of participants underwent 3-Tesla brain magnetic resonance imaging (MRI) to quantify total and regional brain volumes, white matter hyperintensity (WMH) volume, and white matter microstructural integrity (fractional anisotropy (FA) and mean diffusivity (MD) as measured using diffusion tensor imaging (DTI)).

RESULTS

Of the 1,689 participants included (mean age at MRI 76±5), 72% were hospitalized, 14% had a major infection, and 4% had a critical illness during the surveillance period. Using covariate-adjusted regression, hospitalization was associated with 0.12-standard deviation (SD) greater WMH volume (95% confidence interval (CI)=0.00-0.24) and poorer white matter microstructural integrity (0.17-SD lower FA, 95% CI=-0.27 to -0.06; 0.16-SD greater MD, 95% CI=0.07-0.25) than no hospitalization. There was a dose-dependent relationship between number of hospitalizations, smaller brain volumes, and lower white matter integrity (p-trends ≤.048). In hospitalized participants, critical illness was associated with smaller Alzheimer's disease (AD) signature region (-1.64 cm³ , 95% CI=-3.16 to -0.12); major infection was associated with smaller AD signature region (-1.28 cm³ , 95% CI=-2.21 to -0.35) and larger ventricular volume (3.79 cm³ , 95% CI= 0.81-6.77).

CONCLUSIONS

Whereas all-cause hospitalization was primarily associated with lower white matter integrity, critical illness and major infection were associated with smaller brain volume, particularly within regions implicated in AD.

Association of Metformin Use With Risk of Lactic Acidosis Across the Range of Kidney Function: A Community-Based Cohort Study

Importance

Approximately 1 million patients in the United States with type 2 diabetes mellitus and mild-to-moderate kidney disease do not receive guideline-directed therapy with metformin. This may reflect uncertainty regarding the risk of acidosis in patients with chronic kidney disease.

Objective

To quantify the association between metformin use and hospitalization with acidosis across the range of estimated glomerular filtration rate (eGFR), accounting for change in eGFR stage over time.

Design, Setting, and Participants

Community-based cohort of 75 413 patients with diabetes in Geisinger Health System, with time-dependent assessment of eGFR stage from January 2004 until January 2017. Results were replicated in 67 578 new metformin users and 14 439 new sulfonylurea users from 2010 to 2015, sourced from 350 private US health systems.

Exposures

Metformin use.

Main Outcomes and Measures

Hospitalization with acidosis (International Classification of Diseases, Ninth Revision, Clinical Modification code of 276.2).

Results

In the primary cohort (n = 75 413), mean (SD) patient age was 60.4 (15.5) years, and 51% (n = 38 480) of the participants were female. There were 2335 hospitalizations with acidosis over a median follow-up of 5.7 years (interquartile range, 2.5-9.9 years). Compared with alternative diabetes management, time-dependent metformin use was not associated with incident acidosis overall (adjusted hazard ratio [HR], 0.98; 95% CI, 0.89-1.08) or in patients with eGFR 45 to 59 mL/min/1.73 m2 (adjusted HR, 1.16; 95% CI, 0.95-1.41) and eGFR 30 to 44 mL/min/1.73 m2 (adjusted HR, 1.09; 95% CI, 0.83-1.44). On the other hand, metformin use was associated with an increased risk of acidosis at eGFR less than 30 mL/min/1.73 m2 (adjusted HR, 2.07; 95% CI, 1.33-3.22). Results were consistent when new metformin users were compared with new sulfonylurea users (adjusted HR for eGFR 30-44 mL/min/1.73 m2, 0.77; 95% CI, 0.29-2.05), in a propensity-matched cohort (adjusted HR for eGFR 30-44 mL/min/1.73 m2, 0.71; 95% CI, 0.45-1.12), when baseline insulin users were excluded (adjusted HR for eGFR 30-44 mL/min/1.73 m2, 1.16; 95% CI, 0.87-1.57), and in the replication cohort (adjusted HR for eGFR 30-44 mL/min/1.73 m2, 0.86; 95% CI, 0.37-2.01).

Conclusions and Relevance

In 2 real-world clinical settings, metformin use was associated with acidosis only at eGFR less than 30 mL/min/1.73 m2. Our results support cautious use of metformin in patients with type 2 diabetes and eGFR of at least 30 mL/min/1.73 m2.

Lower Extremity Peripheral Artery Disease and Quality of Life Among Older Individuals in the Community

Background

Evidence regarding the association of lower extremity peripheral arterial disease with quality of life (QOL) is mainly from selected clinical populations or relatively small clinical cohorts. Thus, we investigated this association in community‐derived populations.

Methods and Results

Using data of 5115 participants aged 66 to 90 years from visit 5 (2011‐2013) of the Atherosclerosis Risk in Communities Study, we quantified the associations of ankle‐brachial index (ABI) with several QOL parameters, including 12‐item Short‐Form Health Survey (SF‐12), after accounting for potential confounders using linear and logistic regression models. Peripheral arterial disease defined by an ABI <0.90 (n=402), was independently associated with a low SF‐12 Physical Component Summary score (−3.26 [95% CI −5.60 to −0.92]), compared to the ABI reference 1.10 to 1.19 (n=1900) but not with the Mental Component Summary score (−0.07 [−2.21 to 2.06]). A low ABI was significantly associated with poorer status of all SF‐12 physical domains (physical functioning, role‐physical, bodily pain, and general health) but only vitality out of 4 mental domains. Similarly, low ABI values were more consistently associated with other physically related QOL parameters (leisure‐time exercise/activity/walking) than mentally related parameters (significant depressive symptoms and hopeless feeling). Lower physical QOL was observed even in individuals with borderline low ABI (0.90 to 0.99; n=426).

Conclusions

Low ABI (even borderline) was independently associated with poor QOL, especially for physical components, in community‐dwelling older adults. QOL is a critical element for older adults, and thus, further studies are warranted to assess whether peripheral arterial disease‐specific management can improve QOL in older populations.