The Association of Kidney Function with Plasma Amyloid-β Levels and Brain Amyloid Deposition

BACKGROUND

Reduced kidney function is related to brain atrophy and higher risk of dementia. It is not known whether kidney impairment is associated with higher levels of circulating amyloid-β and brain amyloid-β deposition, which could contribute to elevated risk of dementia.

OBJECTIVE

To investigate whether kidney impairment is associated with higher levels of circulating amyloid-β and brain amyloid-β deposition.

METHODS

This cross-sectional study was performed within the community-based Atherosclerosis Risk in Communities (ARIC) Study cohort. We used estimated glomerular filtration rate (eGFR) based on serum creatinine and cystatin C levels and urine albumin-to-creatinine ratio (ACR) to assess kidney function. Amyloid positivity was defined as a standardized uptake value ratios > 1.2 measured with florbetapir positron emission tomography (PET) (n = 340). Plasma amyloid-β1 - 40 and amyloid-β1 - 42 were measured using a fluorimetric bead-based immunoassay (n = 2,569).

RESULTS

Independent of demographic and cardiovascular risk factors, a doubling of ACR was associated with 1.10 (95% CI: 1.01,1.20) higher odds of brain amyloid positivity, but not eGFR (odds ratio per 15 ml/min/1.73 m2 lower eGFR: 1.08; 95% CI: 0.95,1.23). A doubling of ACR was associated with a higher level of plasma amyloid-β1 - 40 (standardized difference: 0.12; 95% CI: 0.09,0.14) and higher plasma amyloid-β1 - 42 (0.08; 95% CI: 0.05,0.10). Lower eGFR was associated with higher plasma amyloid-β1 - 40 (0.36; 95% CI: 0.33,0.39) and higher amyloid-β1 - 42 (0.32; 95% CI: 0.29,0.35).

CONCLUSION

Low clearance of amyloid-β and elevated brain amyloid positivity may link impaired kidney function with elevated risk of dementia. kidney function should be considered in interpreting amyloid biomarker results in clinical and research setting.

Cardiac Valve Disease and Prevalent and Incident CKD in Community-Dwelling Older Adults: The Atherosclerosis Risk in Communities (ARIC) Study

Rationale & Objective

Recent literature suggests improvement in kidney function after percutaneous valvular replacement therapies, implying a pathophysiological contribution of valvular heart disease to chronic kidney disease (CKD). However, this association has not been investigated epidemiologically. We aimed to assess the association of valvular abnormality with prevalent and incident CKD.

Study Design

Cross-sectional and prospective analyses.

Setting & Participants

Community-dwelling participants (mean age 75.5 [standard deviation 5.1] years) from the Atherosclerosis Risk in Communities study (2011-2013).

Exposure

Valvular abnormality defined as echocardiography-based aortic stenosis, aortic regurgitation, and mitral regurgitation.

Outcomes

Prevalent CKD was defined as estimated glomerular filtration rate (eGFR]) <60 mL/min/1.73 m2. Incident CKD was defined as progression to eGFR <60 mL/min/1.73 m2 with ≥25% decline or hospitalization/deaths with CKD diagnosis.

Analytical Approach

We cross-sectionally evaluated the association between valvular abnormality and prevalent CKD with logistic regression in 5,216 participants. Then, 3,752 participants without prevalent CKD were analyzed for incident CKD using Cox models.

Results

There were 1.4% (n = 74) with any aortic stenosis, 10.6% (n = 555) with any aortic regurgitation, and 43.1% (n = 2,249) with any mitral regurgitation. After adjustment for potential confounders, any mitral regurgitation and moderate/severe aortic regurgitation showed significant associations with prevalent CKD (adjusted OR, 1.17 [95% CI, 1.03-1.34] and 2.82 [95% CI, 1.12-7.10]), as did any aortic stenosis in a sensitivity analysis with prevalent CKD defined including albuminuria ≥30 mg/g (1.83 [95% CI, 1.10-3.05]). Only any aortic stenosis showed an independent association with incident CKD (adjusted HR, 2.12 [95% CI, 1.13-4.00]).

Limitations

Despite a relatively large study population, some subgroups had small numbers. Although we minimized reverse causation, we cannot completely rule it out.

Conclusions

Different valvular abnormality types were associated with prevalent CKD. Only aortic stenosis was robustly associated with incident CKD. These findings suggest an etiological link between valvular abnormality and CKD, highlighting the importance of clinical attention to kidney function in individuals with aortic stenosis.

Brody J, Chen H, Gottlieb DJ, Evans DS, Guo X, Gharib SA, Hale L, Hillman DR, Lutsey PL, Mukherjee S, Ochs-Balcom HM, Palmer LJ, Purcell S, Saxena R, Patel SR, Stone KL, Tranah GJ, Boerwinkle E, Lin X, Liu Y, Psaty BM, Vasan RS, Manichaikul A, Rich SS, Rotter JI, Sofer T, Redline S, Zhu X. Targeted Genome Sequencing Identifies Multiple Rare Variants in Caveolin-1 Associated with Obstructive Sleep Apnea

Rationale: Obstructive sleep apnea (OSA) is a common disorder associated with increased risk for cardiovascular disease, diabetes, and premature mortality. There is strong clinical and epidemiologic evidence supporting the importance of genetic factors influencing OSA but limited data implicating specific genes. Objectives: To search for rare variants contributing to OSA severity. Methods: Leveraging high-depth genomic sequencing data from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program and imputed genotype data from multiple population-based studies, we performed linkage analysis in the CFS (Cleveland Family Study), followed by multistage gene-based association analyses in independent cohorts for apnea-hypopnea index (AHI) in a total of 7,708 individuals of European ancestry. Measurements and Main Results: Linkage analysis in the CFS identified a suggestive linkage peak on chromosome 7q31 (LOD = 2.31). Gene-based analysis identified 21 noncoding rare variants in CAV1 (Caveolin-1) associated with lower AHI after accounting for multiple comparisons (P = 7.4 × 10-8). These noncoding variants together significantly contributed to the linkage evidence (P < 10-3). Follow-up analysis revealed significant associations between these variants and increased CAV1 expression, and increased CAV1 expression in peripheral monocytes was associated with lower AHI (P = 0.024) and higher minimum overnight oxygen saturation (P = 0.007). Conclusions: Rare variants in CAV1, a membrane-scaffolding protein essential in multiple cellular and metabolic functions, are associated with higher CAV1 gene expression and lower OSA severity, suggesting a novel target for modulating OSA severity.

Association Between Subclinical Thyroid Dysfunction and Fracture Risk

IMPORTANCE

Clinical hyperthyroidism accelerates bone resorption without compensatory bone formation, reducing bone density and increasing the risk of fracture. The association between subclinical hyperthyroidism and fracture risk is less clear.

OBJECTIVE

To investigate the association of endogenous subclinical thyroid dysfunction and fracture risk, independent of clinical confounders.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 10 946 participants from the Atherosclerosis Risk in Communities Study, an ongoing prospective cohort study of community-dwelling individuals conducted from 1987-1989 through December 31, 2019, in Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and the suburbs of Minneapolis, Minnesota. Participants were not taking thyroid medications and had no history of fractures.

EXPOSURES

Thyrotropin and free thyroxine levels were measured at visit 2 (1990-1992). Subclinical hyperthyroidism was defined as a thyrotropin level lower than 0.56 mIU/L, subclinical hypothyroidism as a thyrotropin level higher than 5.1 mIU/L, and euthyroidism as a thyrotropin level of 0.56 to 5.1 mIU/L, with normal free thyroxine levels from 0.85 to 1.4 ng/dL.

MAIN OUTCOMES AND MEASURES

Incident fracture was ascertained using hospitalization discharge codes through 2019 and linkage to inpatient and outpatient Medicare claims through 2018.

RESULTS

Of 10 946 participants (54.3% women; mean [SD] age, 57 [5.7] years), 93.0% had euthyroidism, 2.6% had subclinical hyperthyroidism, and 4.4% had subclinical hypothyroidism. During a median follow-up of 21 years (IQR, 13.0-27.3 years), there were 3556 incident fractures (167.1 per 10 000 person-years). The adjusted hazard ratios of fracture were 1.34 (95% CI, 1.09-1.65) for those with subclinical hyperthyroidism and 0.90 (95% CI, 0.77-1.05) for those with subclinical hypothyroidism compared with individuals with euthyroidism. Among those with normal free thyroxine levels, thyrotropin levels in the lower-than-normal range were significantly associated with higher fracture-related hospitalization risk; fracture risk was greater among individuals with thyrotropin concentrations below 0.56 mIU/L.

CONCLUSIONS AND RELEVANCE

This community-based cohort study suggests that subclinical hyperthyroidism was an independent risk factor associated with fracture. The increased risk for fracture among individuals with a thyrotropin level lower than 0.56 mIU/L highlights a potential role for more aggressive screening and monitoring of patients with subclinical hyperthyroidism to prevent bone mineral disease.

Peripheral Artery Disease and Subsequent Risk of Infectious Disease in Older Individuals: The ARIC Study

OBJECTIVE

To quantify the association of peripheral artery disease (PAD) with infection risk because PAD has been understudied despite recognition of atherosclerotic cardiovascular disease as a risk factor for infection.

METHODS

Among 5082 participants of the Atherosclerosis Risk in Communities study (aged 71 to 90 years during 2011-2013), we assessed the association of PAD status, based on clinical history and ankle-brachial index (ABI), with infection-related hospitalization (through December 2019) using multivariable Cox regression. We also cross-classified participants by PAD and coronary heart disease (CHD)/stroke status at baseline, with implications for polyvascular disease.

RESULTS

During the median follow-up of 6.5 years, there were 1677 infection-related hospitalizations. Peripheral artery disease (clinical history or ABI ≤0.90) was independently associated with the risk of overall infection (adjusted hazard ratio [HR], 1.66 [95% CI, 1.42 to 1.94] vs ABI of 1.11 to 1.20), as was borderline low ABI of 0.91 to 1.00 (adjusted HR, 1.75 [95% CI, 1.47 to 2.07]). Results were consistent across major types of infection (ie, cellulitis, bloodstream infection, pneumonia, and urinary tract infection). For overall infection, PAD plus CHD/stroke had the highest HR of hospitalized infection (1.9), and PAD alone and CHD/stroke alone showed similar HRs of 1.6. For subtypes of infection, PAD alone had the highest HR of approximately 2 for bloodstream infection; PAD alone and PAD plus CHD/stroke had a similar risk of urinary tract infection with HR of approximately 1.7.

CONCLUSION

Peripheral artery disease and borderline low ABI were robustly associated with infection-related hospitalization of older adults. The contribution of PAD to infection risk was comparable to that of CHD/stroke, warranting clinical attention to PAD for the prevention of infectious diseases.

Cross-Ancestry Investigation of Venous Thromboembolism Genomic Predictors

BACKGROUND

Venous thromboembolism (VTE) is a life-threatening vascular event with environmental and genetic determinants. Recent VTE genome-wide association studies (GWAS) meta-analyses involved nearly 30 000 VTE cases and identified up to 40 genetic loci associated with VTE risk, including loci not previously suspected to play a role in hemostasis. The aim of our research was to expand discovery of new genetic loci associated with VTE by using cross-ancestry genomic resources.

METHODS

We present new cross-ancestry meta-analyzed GWAS results involving up to 81 669 VTE cases from 30 studies, with replication of novel loci in independent populations and loci characterization through in silico genomic interrogations.

RESULTS

In our genetic discovery effort that included 55 330 participants with VTE (47 822 European, 6320 African, and 1188 Hispanic ancestry), we identified 48 novel associations, of which 34 were replicated after correction for multiple testing. In our combined discovery-replication analysis (81 669 VTE participants) and ancestry-stratified meta-analyses (European, African, and Hispanic), we identified another 44 novel associations, which are new candidate VTE-associated loci requiring replication. In total, across all GWAS meta-analyses, we identified 135 independent genomic loci significantly associated with VTE risk. A genetic risk score of the significantly associated loci in Europeans identified a 6-fold increase in risk for those in the top 1% of scores compared with those with average scores. We also identified 31 novel transcript associations in transcriptome-wide association studies and 8 novel candidate genes with protein quantitative-trait locus Mendelian randomization analyses. In silico interrogations of hemostasis and hematology traits and a large phenome-wide association analysis of the 135 GWAS loci provided insights to biological pathways contributing to VTE, with some loci contributing to VTE through well-characterized coagulation pathways and others providing new data on the role of hematology traits, particularly platelet function. Many of the replicated loci are outside of known or currently hypothesized pathways to thrombosis.

CONCLUSIONS

Our cross-ancestry GWAS meta-analyses identified new loci associated with VTE. These findings highlight new pathways to thrombosis and provide novel molecules that may be useful in the development of improved antithrombosis treatments.

Association of Right Ventricular Afterload With Atrial Fibrillation Risk in Older Adults: The Atherosclerosis Risk in Communities Study

BACKGROUND

Atrial fibrillation (AF) is widely perceived to originate from the left atrium (LA). Whether increases in right ventricular (RV) afterload in older adults play an etiological role in AF genesis independent of LA and left ventricular (LV) remodeling is unknown.

RESEARCH QUESTION

Is higher RV afterload associated with greater AF risk independent of LA and LV remodeling?

STUDY DESIGN AND METHODS

In this observational prospective study, we included 2,246 community-dwelling older adults (mean age, 75 years) without known cardiovascular disease, with LV ejection fraction > 50%, LA volume index < 34 mL/m2, and E/e' ratio < 14 and a measurable functional tricuspid regurgitation jet velocity. From 2D-echocardiograms, we estimated pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR). We ascertained incident AF (through 2018) from hospital discharge codes and death certificates. We estimated hazard ratios (HR) by Cox regression.

RESULTS

During follow-up (median, 6.3 years; interquartile interval, 5.5-6.9 years), 215 participants developed AF. AF risk was significantly higher in the third (vs first) tertile of PASP (HR, 1.65; 95% CI, 1.08-2.54) and PVR (HR, 1.38; 95% CI, 1.00-2.08) independent of LA and LV structure and function, heart rate, BMI, prevalent sleep apnea, systemic BP, antihypertensive medications, and lung, kidney, and thyroid function. These associations persisted after further exclusion of participants with tricuspid regurgitation jet velocity > 2.8 m/s and lateral and septal mitral annular velocity above age- and sex-specific reference limits.

INTERPRETATION

In older adults, higher RV afterload is associated with greater AF risk independent of LA and LV remodeling. Future research should focus on confirming this novel association and elucidate underlying mechanisms.

Periodontal Status, C-Reactive Protein, NT-proBNP, and Incident Heart Failure: The ARIC Study

BACKGROUND

Periodontal disease (PD), resulting from inflammatory host response to dysbiotic subgingival microbiota, has been linked to cardiovascular disease; however, its relationship to heart failure (HF) and its subtypes (heart failure with reduced ejection fraction [HFrEF] and heart failure with preserved ejection fraction [HFpEF]) is unexplored.

OBJECTIVES

The authors hypothesize that the presence of PD is associated with increased risk of incident HF, HFpEF, and HFrEF.

METHODS

A total of 6,707 participants (mean age 63 ± 6 years) of the ARIC (Atherosclerosis Risk In Communities) study with full-mouth periodontal examination at visit 4 (1996-1998) and longitudinal follow-up for any incident HF (visit 4 to 2018), or incident HFpEF and HFrEF (2005-2018) were included. Periodontal status was classified as follows: healthy, PD (as per Periodontal Profile Classification [PPC]), or edentulous. Multivariable-adjusted Cox proportional hazards models were used to calculate HRs and 95% CIs for the association between PPC levels and incident HF, HFpEF, or HFrEF. Additionally, biomarkers of inflammation (C-reactive protein [CRP]) and congestion (N-terminal brain natriuretic peptide [NT-proBNP]) were assessed.

RESULTS

In total, 1,178 incident HF cases occurred (350 HFpEF, 319 HFrEF, and 509 HF of unknown type) over a median of 13 years. Of these cases, 59% had PD, whereas 18% were edentulous. PD was associated with an increased risk for HFpEF (HR: 1.35 [95% CI: 0.98-1.86]) and significantly increased risk for HFrEF (HR: 1.69 [95% CI: 1.18-2.43]), as was edentulism: HFpEF (HR: 2.00 [95% CI: 1.37-2.93]), HFrEF (HR: 2.19 [95% CI: 1.43-3.36]). Edentulism was associated with unfavorable change in CRP and NT-proBNP, whereas PD was associated only with CRP.

CONCLUSIONS

Periodontal status was associated with incident HF, HFpEF, and HFrEF, as well as unfavorable changes in CRP and NT-proBNP.

Abstract 038: The Association Of Supine Hypertension Versus Standing Hypotension With Adverse Cardiovascular Events Among Middle-aged Adults

Background: Clinical management of orthostatic hypotension (OH) prioritizes the prevention of standing hypotension (HYP), sometimes at the expense of supine hypertension (HTN). It is unclear whether supine HTN is associated with adverse outcomes relative to standing HYP.

Objectives: To compare supine HTN and standing HYP among middle-aged adults with and without OH.

Methods: The Atherosclerosis Risk in Communities Study measured supine and standing blood pressure (BP) in adults aged 45-64 between 1987-1989. We defined OH as a positional drop in systolic BP ≥20 mmHg or diastolic BP ≥10 mmHg, supine HTN as a BP≥140/≥90 mmHg, and standing HYP as a BP≤105/≤65 mmHg. ARIC participants were followed >30 years. Coronary heart disease (CHD) and mortality were adjudicated; falls and syncope were based on hospital claims. We used adjusted Cox models that included both supine HTN and standing HYP.

Results: Of 12,580 participants (55% female, 26% Black, mean age 54±6) 5% had OH. Among those without OH (N=11936), 19% had supine HTN and 21% had standing HYP, while among those with OH (N=644), 11% had supine HTN and 34% had standing HYP. Supine HTN was associated with CHD (HR 1.49; 1.36, 1.63), syncope (HR 1.26; 1.15, 1.39), and all-cause mortality (HR 1.47; 1.38, 1.57), while standing HYP was only associated with all-cause mortality (HR 1.08; 1.00, 1.16) and to a lesser extent than supine HTN (P comparing coefficients <0.001) (Table). Associations did not differ for those with OH (P-interactions>0.25).

Conclusion: Supine HTN was associated with more adverse events than standing HYP, regardless of OH status, questioning conventional practices of prioritizing standing HYP among adults with OH.

Physical Function and Subsequent Risk of Cardiovascular Events in Older Adults: The Atherosclerosis Risk in Communities Study

Background

Reduced physical function, a representative phenotype of aging, has been associated with cardiovascular disease (CVD). However, few studies have comprehensively investigated its association with composite and individual CVD outcomes in community‐dwelling older adults and its predictive value for CVD beyond traditional risk factors.

Methods and Results

We studied 5570 participants (mean age 75 [SD 5] years, female 58%, Black 22%) at visit 5 (2011–2013) of the ARIC (Atherosclerosis Risk in Communities) study. Physical function was evaluated with the Short Physical Performance Battery (SPPB), which incorporates a walk test, chair stands, and balance tests. The SPPB score was modeled categorically (low [0–6], intermediate [7–9], and high [10–12]) and continuously. We assessed the associations of SPPB score with subsequent composite (coronary heart disease, stroke, or heart failure) and individual CVD outcomes (components within composite outcome) using multivariable Cox models adjusting for major CVD risk factors and history of CVD. We also evaluated improvement in C‐statistics by adding SPPB to traditional CVD risk factors in the Pooled Cohort Equation. Among the study participants, 13% had low, 30% intermediate, and 57% high SPPB scores. During a median follow‐up of 7.0 (interquartile interval 5.3–7.8) years, there were 930 composite CVD events (386 coronary heart disease, 251 stroke, and 529 heart failure cases). The hazard ratios of composite CVD in low and intermediate versus high SPPB score were 1.47 (95% CI, 1.20–1.79) and 1.25 (95% CI, 1.07–1.46), respectively, after adjusting for potential confounders. Continuous SPPB score demonstrated independent associations with each CVD outcome. The associations were largely consistent across subgroups (including participants with prevalent CVD at baseline). The addition of SPPB to traditional CVD risk factors significantly improved the C‐statistics of CVD outcomes (eg, ΔC‐statistic 0.019 [95% CI, 0.011–0.027] for composite CVD).

Conclusions

Reduced physical function was independently associated with the risk of composite and individual CVD outcomes and improved their risk prediction beyond traditional risk factors in community‐dwelling older adults. Although confirmatory studies are needed, our results suggest the potential usefulness of SPPB for classifying CVD risk in older adults.

Clinically Recognized Varicose Veins and Physical Function in Older Individuals: The ARIC Study

BACKGROUND

Although a few studies reported an association between varicose veins and physical function, this potentially bidirectional association has not been systematically evaluated in the general population.

METHOD

In 5 580 participants (aged 71-90 years) from the Atherosclerosis Risk in Communities study, varicose veins were identified in outpatient and inpatient administrative data prior to (prevalent cases) and after (incident cases) visit 5 (2011-2013). Physical function was evaluated by the Short Physical Performance Battery (SPPB, score ranging from 0 to 12). We evaluated (i) cross-sectional association between prevalent varicose veins and physical function, (ii) association of prevalent varicose veins with subsequent changes in physical function from visit 5 to visits 6 (2016-2017) and 7 (2018-2019), and (iii) association of physical function at visit 5 with incident varicose veins during a median follow-up of 3.6 years (105 incident varicose veins among 5 350 participants without prevalent cases at baseline).

RESULTS

At baseline, varicose veins were recognized in 230 (4.1%) participants and cross-sectionally associated with reduced physical function. Longitudinally, prevalent varicose veins were not significantly associated with a decline in SPPB over time. In contrast, a low SPPB ≤6 was associated with a greater incidence of varicose veins compared to SPPB ≥10 (adjusted hazard ratio 2.13 [95% confidence interval = 1.19, 3.81]).

CONCLUSION

In community-dwelling older adults, varicose veins and low physical function were associated cross-sectionally. Longitudinally, low physical function was a risk factor for incident varicose veins, but not vice versa. Our findings suggest an etiological contribution of low physical function to incident varicose veins.

Incidence and Risk Factors of Pulmonary Hypertension After Venous Thromboembolism: An Analysis of a Large Health Care Database

Background

Pulmonary hypertension (PH) is a devastating potential complication of pulmonary embolism, a manifestation of venous thromboembolism (VTE). The incidence of and risk factors for PH in those with prior VTE are poorly characterized.

Methods and Results

International Classification of Diseases ( ICD ) codes from inpatient and outpatient medical claims from MarketScan administrative databases for years 2011 to 2018 were used to identify cases of VTE, comorbidities before the VTE event, and PH occurring subsequent to the VTE event. Cumulative incidence and hazard ratios (HR), and their 95% CI, were calculated. The 170 021 VTE cases included in the analysis were on average (±SD) 57.5±15.8 years old and 50.5% were female. A total of 5943 PH cases accrued over an average follow‐up of 1.94 years. Two years after incident VTE, the cumulative incidence (95% CI) of PH was 3.5% (3.4%–3.7%) overall. It was higher among older individuals, among women (3.9% [3.8%–4.1%]) than men (3.2% [3.0%–3.3%]), and among patients presenting with pulmonary embolism (6.2% [6.0%–6.5%]) than those presenting with deep vein thrombosis only (1.1% [1.0%–1.2%]). Adjusting for age and sex, risk of PH was higher among patients with VTE with underlying comorbidities. Using the Charlson comorbidity index, there was a dose–response relationship, whereby greater scores were associated with increased PH risk (score ≥5 versus 0: HR, (2.50 [2.30–2.71])). When evaluating individual comorbidities, the strongest associations were observed with concomitant heart failure (HR, 2.17 [2.04–2.31]), chronic pulmonary disease (2.01 [1.90–2.14]), and alcohol abuse (1.66 [1.29–2.13]).

Conclusions

In this large, real‐world population of insured people with VTE, 3.5% developed PH in the 2 years following their initial VTE event. Risk was higher among women, with increasing age, and in those with additional comorbidities at the time of the VTE event. These data provide insights into the burden of PH and risk factors for PH among patients with VTE.

Risk Factors for Dementia in Patients With Atrial Fibrillation

Although dementia and atrial fibrillation (AF) are common in older adults, risk factors for dementia have not been sufficiently characterized in patients with AF. We studied 621,773 patients with AF without dementia at the time of AF diagnosis who were enrolled in the MarketScan Commercial and Medicare Supplemental databases from 2007 to 2015. Dementia incidence and presence of predictors at the time of AF diagnosis (cardiometabolic conditions, mental and neurologic disorders, and other chronic conditions) were based on International Classification of Diseases, Ninth Revision, Clinical Modification codes in outpatient and inpatient claims, whereas medication usage was based on outpatient pharmacy claims. A frailty score was calculated using a previously established algorithm. The associations between the predictors of interest and dementia were assessed with multivariable Cox models. Patients had a mean age of 68 years (SD 14 years) and 41% were women. During a mean follow-up of 2.0 years, there were 16,073 cases of dementia. The strongest predictors of dementia were frailty (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.40 to 1.45, per 1-SD increase in the score), cognitive impairment (HR 1.50, 95% CI 1.36 to 1.65), mood disorders (HR 1.49, 95% CI 1.32 to 1.70), schizophrenia (HR 1.86, 95% CI 1.75 to 1.98), and substance abuse (HR 1.58, 95% CI 1.39 to 1.80). Among cardiometabolic conditions, only stroke (HR 1.17, 95% CI 1.13 to 1.22) and diabetes mellitus (HR 1.14, 95% CI 1.11 to 1.18) were associated with small increases in dementia risk after adjusting for demographics, frailty, co-morbidities, and medications. We have identified several risk factors for dementia in patients with AF.

Variation in Population Attributable Fraction of Dementia Associated With Potentially Modifiable Risk Factors by Race and Ethnicity in the US

IMPORTANCE

Identifying modifiable risk factors that are associated with dementia burden across racial and ethnic groups in the population can yield insights into the potential effectiveness of interventions in preventing dementia and reducing disparities.

OBJECTIVE

To calculate the population attributable fraction (PAF) of dementia associated with 12 established modifiable risk factors for all US adults, as well as separately by race and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used survey data from nationally representative samples of US adults. PAFs were calculated using relative risks and prevalence estimates for 12 risk factors. Relative risks were taken from meta-analyses, as reported in a 2020 systematic review. Prevalence estimates for risk factors were derived from nationally representative cross-sectional survey data collected between 2011 and 2018. Combined PAFs were adjusted for risk factor communality using weights derived from the Atherosclerosis Risk in Communities (ARIC) study (1987-2018). Analyses were conducted May through October 2021.

EXPOSURES

Low education, hearing loss, traumatic brain injury, hypertension, excessive alcohol consumption, obesity, smoking, depression, social isolation, physical inactivity, diabetes, and air pollution.

MAIN OUTCOMES AND MEASURES

PAF for each dementia risk factor, a combined PAF, and the decrease in the number of prevalent dementia cases in 2020 that would be expected given a 15% proportional decrease in each exposure.

RESULTS

Among all US adults, an estimated 41.0% (95% CI, 22.7%-55.9%) of dementia cases were attributable to 12 risk factors. A 15% proportional decrease in each risk factor would reduce dementia prevalence in the population by an estimated 7.3% (95% CI, 3.7%-10.9%). The estimated PAF was greater for Black and Hispanic than it was for White and Asian individuals. The greatest attributable fraction of dementia cases was observed for hypertension (PAF, 20.2%; 95% CI, 6.3%-34.4%), obesity (PAF, 20.9%; 95% CI, 13.0%-28.8%), and physical inactivity (PAF, 20.1%; 95% CI, 9.1%-29.6%). These factors were also highest within each racial and ethnic group, although the proportions varied.

CONCLUSIONS AND RELEVANCE

A large fraction of dementia cases in the US were associated with potentially modifiable risk factors, especially for Black and Hispanic individuals. Targeting and reducing these risk factors may curb the projected rise in dementia cases over the next several decades.

Venous thrombosis risk during and after medical and surgical hospitalizations: The medical inpatient thrombosis and hemostasis (MITH) study

BACKGROUND

Thirty to seventy percent of all venous thromboembolism (VTE) events are associated with hospitalization. The absolute and relative risks during and after hospitalization are poorly characterized.

OBJECTIVES

Quantify the absolute rate and relative risk of VTE during and up to 3 months after medical and surgical hospitalizations.

PATIENTS/METHODS

We conducted an observational cohort study between 2010 and 2016 of patients cared for by the University of Vermont (UVM) Health Network's primary care population. Cox proportional hazard models with hospitalization modeled as a time-varying covariate were used to estimate VTE risk.

RESULTS

Over 4.3 years of follow-up, 55 220 hospitalizations (156 per 1000 person-years) and 713 first venous thromboembolism events (2.0 per 1000 person-years) occurred. Among individuals not recently hospitalized, the rate of venous thromboembolism was 1.4 per 1000 person-years and 71.8 per 1000 person-years during hospitalization. During the first, second, and third months after discharge, the rates of venous thromboembolism were 35.1, 11.3, and 5.2 per 1000 person-years, respectively. Relative to those not recently hospitalized, the age- and sex-adjusted HRs of venous thromboembolism were 38.0 (95% CI 28.0, 51.5) during hospitalization, and 18.4 (95% CI 15.0, 22.6), 6.3 (95% CI 4.3, 9.0), and 3.0 (95% CI 1.7, 5.4) during the first, second, and third months after discharge, respectively. Stratified by medical versus surgical services the rates were similar.

CONCLUSION

Hospitalization and up to 3 months after discharge were strongly associated with increased venous thromboembolism risk. These data quantify this risk for use in future studies.

Changes in Serum Intact Fibroblast Growth Factor 23 Concentrations From Midlife to Late Life and Their Predictors in the Community: The ARIC Study

Objective

To investigate longitudinal changes in the blood concentration of fibroblast growth factor 23 (FGF23) from midlife to late life and their major predictors in the general population.

Patients and Methods

In 14,444 participants of the Atherosclerosis Risk in Communities Study, we analyzed the association of 31,095 measurements of serum intact FGF23 with age using data from 3 visits (visit 2 [N=13,460; mean age, 57 years]; visit 3 [N=12,323; mean age, 60 years]; and visit 5 [N=6122; mean age, 76 years]) and a linear mixed-effects model. Among 5804 participants who had FGF23 measurements at both visits 3 and 5, we explored predictors of FGF23 change from midlife to late life using linear regression models. Prespecified risk factors were estimated glomerular filtration rate, body mass index, ever smoking, ever drinker, diabetes, hypertension, history of cardiovascular disease, total cholesterol, and high-density lipoprotein cholesterol.

Results

Median FGF23 concentrations were 41.9 pg/mL (interquartile interval [IQI], 33.9 to 51.8 pg/mL) at visit 2, 38.3 pg/mL (IQI, 30.6 to 48.3 pg/mL) at visit 3, and 55.0 pg/mL (IQI, 44.4 to 70.3 pg/mL) at visit 5. A linear mixed-effects model showed that the association of FGF23 with age was nonlinear, with a slight decline or no change in age 45-60 years and a monotonic increase in age greater than or equal to 65 years (FGF23, +10 to 15 pg/mL per 10 years of age). In a multivariable linear regression model, significantly greater increases in FGF23 were noted, with midlife estimated glomerular filtration rate less than 60 mL/min per 1.73 m2 vs more than or equal to 60 mL/min per 1.73 m2 (ΔFGF23, +4.4 pg/mL [95% CI, 0.9 to 8.0]), diabetes vs no diabetes (ΔFGF23, +6.2 pg/mL [95% CI, 4.1 to 8.3]), and hypertension vs no hypertension (ΔFGF23, +4.1 pg/mL [95% CI, 2.7 to 5.4]).

Conclusion

FGF23 did not show any major changes in midlife but increased linearly in late life. Reduced kidney function, diabetes, and hypertension were robustly associated with a greater increase in FGF23. Further investigations are needed to understand the potential mechanisms linking these conditions to an increase in FGF23 concentrations.

Associations between endogenous sex hormones and FGF-23 among women and men in the Multi-Ethnic Study of Atherosclerosis

Elevated levels of testosterone and fibroblast growth factor 23 (FGF-23) are both independently associated with a higher risk of cardiovascular disease (CVD). However, the relationship between sex hormones and FGF-23 is not well established. We explored the association between sex hormones and FGF-23 among middle-aged to older men and women in MESA. We studied 3,052 men and 2,868 postmenopausal women free of CVD at the time of enrollment with baseline serum sex hormones [total testosterone (T), free T, estradiol (E2) and sex hormone binding globulin (SHBG)] and intact FGF-23. In sex-stratified analyses, we examined the cross-sectional associations between log-transformed sex hormones (per 1 SD) and log-transformed FGF-23 using multiple linear regression adjusted for socio-demographics, CVD risk factors, estimated glomerular filtration rate and mineral metabolites (25-hydroxyvitamin D, calcium, phosphorus and parathyroid hormone). The mean (SD) age of study participants was 64 (10) years. The median (IQR) of FGF-23 was similar in women and men [38 (30-46) vs 38 (31-47) pg/mL]. In adjusted analyses, among women, 1 SD increment in free T was associated with 3% higher FGF-23 while SHBG was associated with 2% lower FGF-23. In men, 1 SD increment in E2 was associated with 6% higher FGF-23 whereas total T/E2 ratio was associated with 7% lower FGF-23. In conclusion, this exploratory analysis found that a more androgenic sex hormone profile was directly associated with FGF-23 in women and inversely associated with FGF-23 in men. Longitudinal studies are required to determine whether FGF-23 mediates the relationship between sex hormones and CVD risk.

18-year change in serum intact fibroblast growth factor 23 from midlife to late life and risk of mortality: the ARIC Study

Objective

Fibroblast growth factor 23 (FGF23) concentration increases in response to declining kidney function to preserve normal phosphate concentrations. However, the etiological association of change in FGF23 concentration with mortality has not been examined in the general population.

Design and methods

We analyzed 5458 participants of the Atherosclerosis Risk in Communities Study who had intact FGF23 and estimated glomerular filtration rate (eGFR) assessed during midlife (visit 3, 1993-1995, mean age: 58 years) and late life (visit 5, 2011-2013, 76 years) to examine the association of FGF23 change over 18 years from mid-life to late life with the subsequent risk of mortality in late life using Cox regression models.

Results

The median 18-year change in intact FGF23 was +17.3 pg/mL. During a median follow-up of 7.2 years following visit 5, 1176 participants died. In multivariable Cox models, elevated mortality was seen in the highest quartile of FGF23 change (ΔFGF23: ≥31.3 pg/mL) (adjusted hazard ratio (aHR): 1.61 (95%CI: 1.36-1.90), or 1.37 (1.15-1.64) after additionally adjusting for eGFR change, compared with the lowest quartile (≤6.4 pg/mL)). When both FGF23 change and FGF23 in late life were simultaneously entered into the Cox model, FGF23 in late life, but not FGF23 change, was an independent predictor of mortality; however, we observed a high correlation between FGF23 change from midlife to late life and FGF23 in late life (r = 0.77).

Conclusions

Serum intact FGF23 change from midlife to late life was associated with subsequent risk of mortality independent of decline in kidney function. Our findings further support the implications of FGF23 beyond its association with kidney function.

Association of Carotid Intima-Media Thickness with Brain MRI Markers in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

OBJECTIVE

Elevated carotid intima-media thickness (cIMT) and carotid plaque are markers of arterial injury and may be linked to structural brain injury. We hypothesized cIMT or presence of carotid plaque at midlife are associated with presence of infarcts and cerebral microbleeds, greater white matter hyperintensity (WMH) volume, and smaller regional brain volumes in late-life.

METHODS

We included 1,795 Atherosclerosis Risk in Communities (ARIC) Study participants (aged 57±6 years, 57% female, 23% Black) with carotid ultrasounds in 1990-1992 and brain MRI scans in 2011-2013. Weighted linear regression was used for brain volume outcomes, while logistic regression was used for infarcts and cerebral microbleeds.

RESULTS

After multivariable adjustments, the highest cIMT quintile was associated with smaller deep gray matter (β [95% CI]: -0.11 [-0.22, -0.01]) and cortical volume in a temporal-parietal meta region of interest (ROI) (β [95% CI]: -0.10 [-0.20, -0.01]) in late-life. Similarly, those with carotid plaque had smaller regional brain volumes than those without (βs [95% CIs]: -0.05 [-0.12, 0.03] and -0.06 [-0.13, 0.01] for deep gray matter and temporal-parietal meta ROI). No significant relations were observed with WMH volume, infarcts, or cerebral microbleeds.

CONCLUSION

Over a median follow-up of 21 years, greater midlife cIMT and presence of carotid plaque were associated with smaller deep gray matter volume and cortical volume in a meta ROI involving temporal and parietal lobe regions typically involved in neurodegeneration, including Alzheimer's disease, in later life. Contrary to our hypothesis, associations between measures of arterial injury and markers of vascular brain injury were null.

Relationship Between Age at Menopause, Obesity, and Incident Heart Failure: The Atherosclerosis Risk in Communities Study

Background The mechanisms linking menopausal age and heart failure (HF) incidence are controversial. We investigated for heterogeneity by obesity on the relationship between menopausal age and HF incidence. Methods and Results Using postmenopausal women who attended the Atherosclerosis Risk in Communities Study Visit 4, we estimated hazard ratios of incident HF associated with menopausal age using Cox proportional hazards models, testing for effect modification by obesity and adjusting for HF risk factors. Women were categorized by menopausal age: <45 years, 45 to 49 years, 50 to 54 years, and ≥55 years. Among 4441 postmenopausal women, aged 63.5±5.5 years, there were 903 incident HF events over a mean follow-up of 16.5 years. The attributable risk of generalized and central obesity for HF incidence was greatest among women who experienced menopause at age ≥55 years: 11.09/1000 person-years and 7.38/1000 person-years, respectively. There were significant interactions of menopausal age with body mass index and waist circumference for HF incidence, Pinteraction 0.02 and 0.001, respectively. The hazard ratios of incident HF for a SD increase in body mass index was elevated in women with menopausal age <45 years [1.39 (1.05-1.84)]; 45-49 years [1.33, (1.06-1.67)]; and ≥55 years [2.02, (1.41-2.89)]. The hazard ratio of incident HF for a SD increase in waist circumference was elevated only in women with menopausal age ≥55 years [2.93, (1.85-4.65)]. Conclusions As obesity worsened, the risk of developing HF became significantly greater when compared with women with lower body mass index and waist circumference, particularly among those who had experienced menopause at age ≥55 years.

The prospective association between periodontal disease and brain imaging outcomes: The Atherosclerosis Risk in Communities study

AIM

We investigate if periodontal disease is prospectively associated with cerebrovascular and neurodegenerative markers of dementia and Alzheimer's pathology.

MATERIALS AND METHODS

N = 1306 participants (Visit 5 mean age = 76.5 [standard deviation = 5.4] years) in the Atherosclerosis Risk in Communities study with completed dental exams at Visit 4 underwent brain magnetic resonance imaging scans at Visit 5 while N = 248 underwent positron emission tomography scans. Participants were classified as edentulous or, among the dentate, by the modified Periodontal Profile Class. Brain volumes were regressed on periodontal status in linear regressions. Cerebrovascular measures and β-amyloid positivity were regressed on periodontal status in logistic regressions.

RESULTS

Periodontal disease was not associated with brain volumes, microhaemorrhages, or elevated β-amyloid. Compared with periodontally healthy individuals, odds ratios [95% confidence interval] for all-type infarcts were 0.37 [0.20, 0.65] for severe tooth loss and 0.56 [0.31, 0.99] for edentulous participants.

CONCLUSIONS

Within the limitations of this study, periodontal disease was not associated with altered brain volumes, microhaemorrhages, or β-amyloid positivity. Tooth loss was associated with lower odds of cerebral infarcts.

Direct Oral Anticoagulants and Warfarin for Atrial Fibrillation Treatment: Rural and Urban Trends in Medicare Beneficiaries

BACKGROUND

Data are needed on the use of oral anticoagulation in patients with atrial fibrillation (AF) in rural versus urban areas, including the initiation of direct oral anticoagulants (DOACs).

OBJECTIVE

We used Medicare data to examine rural/urban differences in anticoagulation use in patients with AF.

METHODS

We identified incident AF in a 20% sample of fee-for-service Medicare beneficiaries (aged ≥ 65 years) from 2011 to 2016 and collected ZIP code and covariates at the time of AF. We identified the first anticoagulant prescription filled, if any, following AF diagnosis. We categorized beneficiaries into four rural/urban areas using rural-urban commuting area codes and used Poisson regression models to compare anticoagulant use.

RESULTS

We included 447,252 patients with AF (mean age 79 ± 8 years), of which 82% were urban, 9% large rural, 5% small rural, and 4% isolated. The percentage who initiated an anticoagulant rose from 34% in 2011 to 53% in 2016, paralleling the uptake of DOACs. In a multivariable-adjusted analysis, those in rural areas (vs. urban) were more likely to initiate an anticoagulant. However, rural beneficiaries (vs. urban) were less likely to initiate a DOAC; those in isolated areas were 17% less likely (95% confidence interval [CI] 13-20), those in small rural areas were 12% less likely (95% CI 9-15), and those in large rural areas were 10% less likely (95% CI 8-12).

CONCLUSION

Among Medicare beneficiaries with AF, anticoagulation use was low but increased over time with the introduction of DOACs. Rural beneficiaries were less likely to receive a DOAC.

Proteomic profiling identifies novel proteins for genetic risk of severe COVID-19: the Atherosclerosis Risk in Communities Study

BACKGROUND

Genome-wide association studies have identified six genetic variants associated with severe COVID-19, yet the mechanisms through which they may affect disease remains unclear. We investigated proteomic signatures related to COVID-19 risk variants rs657152 (ABO), rs10735079 (OAS1/OAS2/OAS3), rs2109069 (DPP9), rs74956615 (TYK2), rs2236757 (IFNAR2) and rs11385942 (SLC6A20/LZTFL1/CCR9/FYCO1/CXCR6/XCR1) as well as their corresponding downstream pathways that may promote severe COVID-19 in risk allele carriers and their potential relevancies to other infection outcomes.

METHODS

A DNA aptamer-based array measured 4870 plasma proteins among 11 471 participants. Linear regression estimated associations between the COVID-19 risk variants and proteins with correction for multiple comparisons, and canonical pathway analysis was conducted. Cox regression assessed associations between proteins identified in the main analysis and risk of incident hospitalized respiratory infections (2570 events) over a 20.7-year follow-up.

RESULTS

The ABO variant rs657152 was associated with 84 proteins in 7241 white participants with 24 replicated in 1671 Black participants. The TYK2 variant rs74956615 was associated with ICAM-1 and -5 in white participants with ICAM-5 replicated in Black participants. Of the 84 proteins identified in the main analysis, seven were significantly associated with incident hospitalized respiratory infections including Ephrin type-A receptor 4 (hazard ratio (HR): 0.87; P = 2.3 × 10-11) and von Willebrand factor type A (HR: 1.17; P = 1.6x10-13).

CONCLUSIONS

Novel proteomics signatures and pathways for COVID-19-related risk variants TYK2 and ABO were identified. A subset of these proteins predicted greater risk of incident hospitalized pneumonia and respiratory infections. Further studies to examine these proteins in COVID-19 patients are warranted.