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.

Proteomics Analysis of Genetic Liability of Abdominal Aortic Aneurysm Identifies Plasma Neogenin and Kit Ligand: The ARIC Study.

BACKGROUND: Genome-wide association studies have reported 23 gene loci related to abdominal aortic aneurysm (AAA)-a potentially lethal condition characterized by a weakened dilated vessel wall. This study aimed to identify proteomic signatures and pathways related to these risk loci to better characterize AAA genetic susceptibility. METHODS: Plasma concentrations of 4870 proteins were determined using a DNA aptamer-based array. Linear regression analysis estimated the associations between the 23 risk alleles and plasma protein levels with adjustments for potential confounders in a race-stratified analysis of 1671 Black and 7241 White participants. Significant proteins were then evaluated for their prediction of clinical AAA (454 AAA events in 11 064 individuals), and those significantly associated with AAA were further interrogated using Mendelian randomization analysis. RESULTS: Risk variants proximal to PSRC1-CELSR2-SORT1, PCIF1-ZNF335-MMP9, RP11-136O12.2/TRIB1, ZNF259/APOA5, IL6R, PCSK9, LPA, and APOE were associated with 118 plasma proteins in Whites and 59 were replicated in Black participants. Novel associations with clinical AAA incidence were observed for kit ligand (HR, 0.59 [95% CI, 0.42-0.82] for top versus first quintiles) and neogenin (HR, 0.64 [95% CI, 0.46-0.88]) over a median 21.2-year follow-up; neogenin was also associated with ultrasound-detected asymptomatic AAA (N=4295; 57 asymptomatic AAA cases). Mendelian randomization inverse variance weighted estimates suggested that AAA risk is promoted by lower levels of kit ligand (OR per SD=0.67; P=1.4×10-5) and neogenin (OR per SD=0.50; P=0.03). CONCLUSIONS: Low levels of neogenin and kit ligand may be novel risk factors for AAA development in potentially causal pathways. These findings provide insights and potential targets to reduce AAA susceptibility.

Added sugar intake is associated with weight gain and risk of developing obesity over 30 years: The CARDIA study.

BACKGROUND AND AIMS: Numerous prospective studies have examined sugar sweetened beverage (SSB) intake associated with weight gain or incident obesity. Because SSB accounts for only 33 % of added sugar (AS) intake, we investigated the associations of AS intake with change in weight and waist circumference and risk of developing obesity. METHODS AND RESULTS: At baseline (1985-86) Black and White women and men, aged 18-30 years, enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study and were followed for 30 years (2015-16). A diet history assessed dietary intake 3 times over 20 years. Multivariable linear regression evaluated the associations of change in weight (n = 3306) and waist circumference (n = 3296) across quartiles of AS, adjusting for demographics, lifestyle factors, and anthropometrics. Proportional hazards regression analysis evaluated the associations of time-varying cumulative AS intake with risk of incident obesity (n = 4023) and abdominal obesity (n = 3449), adjusting for the same factors. Over 30 years of follow-up, greater AS intake was associated with gaining 2.3 kg more weight (ptrend = 0.01) and 2.2 cm greater change in waist circumference (ptrend = 0.005) as well as increased risk of incident obesity (HR 1.28; 95 % CI: 1.08-1.53) and incident abdominal obesity (HR 1.27; 95 % CI:1.02-1.60). CONCLUSION: Our findings are consistent with recommendations from the 2020-2025 U S. Dietary Guidelines for Americans to limit daily AS intake.

Proteomic analysis of diabetes genetic risk scores identifies complement C2 and neuropilin-2 as predictors of type 2 diabetes: the Atherosclerosis Risk in Communities (ARIC) Study.

AIMS/HYPOTHESIS: Genetic predisposition to type 2 diabetes is well-established, and genetic risk scores (GRS) have been developed that capture heritable liabilities for type 2 diabetes phenotypes. However, the proteins through which these genetic variants influence risk have not been thoroughly investigated. This study aimed to identify proteins and pathways through which type 2 diabetes risk variants may influence pathophysiology. METHODS: Using a proteomics data-driven approach in a discovery sample of 7241 White participants in the Atherosclerosis Risk in Communities Study (ARIC) cohort and a replication sample of 1674 Black ARIC participants, we interrogated plasma levels of 4870 proteins and four GRS of specific type 2 diabetes phenotypes related to beta cell function, insulin resistance, lipodystrophy, BMI/blood lipid abnormalities and a composite score of all variants combined. RESULTS: Twenty-two plasma proteins were identified in White participants after Bonferroni correction. Of the 22 protein-GRS associations that were statistically significant, 10 were replicated in Black participants and all but one were directionally consistent. In a secondary analysis, 18 of the 22 proteins were found to be associated with prevalent type 2 diabetes and ten proteins were associated with incident type 2 diabetes. Two-sample Mendelian randomisation indicated that complement C2 may be causally related to greater type 2 diabetes risk (inverse variance weighted estimate: OR 1.65 per SD; p=7.0 × 10-3), while neuropilin-2 was inversely associated (OR 0.44 per SD; p=8.0 × 10-3). CONCLUSIONS/INTERPRETATION: Identified proteins may represent viable intervention or pharmacological targets to prevent, reverse or slow type 2 diabetes progression, and further research is needed to pursue these targets.

Long-term aspartame and saccharin intakes are related to greater volumes of visceral, intermuscular, and subcutaneous adipose tissue: the CARDIA study.

BACKGROUND: Artificial sweetener (ArtSw) intakes have been previously associated with higher BMI in observational studies and may promote visceral and skeletal muscle adipose tissue (AT) accumulation. This study aimed to determine whether habitual, long-term ArtSw or diet beverage intakes are related to greater AT depot volumes and anthropometry-related outcomes. METHODS: A validated diet history questionnaire was administered at baseline, year 7, and year 20 examinations in 3088 men and women enrolled in the Coronary Artery Risk Development in Young Adults cohort (CARDIA), mean age of 25.2 years and mean BMI of 24.5 kg/m2 at baseline. Volumes of visceral (VAT), intermuscular (IMAT), and subcutaneous adipose tissue (SAT) were assessed by computed tomography at year 25. Linear regression evaluated associations of aspartame, saccharin, sucralose, total ArtSw, and diet beverage intakes with AT volumes, anthropometric measures, and 25-year change in anthropometry. Cox regression estimated associations of ArtSw with obesity incidence. Adjustments were made for demographic and lifestyle factors, total energy intake, and the 2015 healthy eating index. RESULTS: Total ArtSw, aspartame, saccharin, and diet beverage intakes were positively associated with VAT, SAT, and IMAT volumes (all ptrend ≤ 0.001), but no associations were observed for sucralose intake (all ptrend > 0.05). In addition, total ArtSw, saccharin, aspartame, and diet beverage intakes were associated with greater body mass index, body weight, waist circumference, and their increases over a 25-year period. Except for saccharin (ptrend = 0.13), ArtSw, including diet soda, was associated with greater risks of incident obesity over a median 17.5-year follow-up (all ptrend < 0.05). CONCLUSIONS: Results suggest that long-term intakes of aspartame, saccharin, or diet soda may increase AT deposition and risk of incident obesity independent of diet quality or caloric intake. Coupled with previous evidence, alternatives to national recommendations to replace added sugar with ArtSw should be considered since both may have health consequences.

Associations of ω-3 Fatty Acids With Interstitial Lung Disease and Lung Imaging Abnormalities Among Adults.

Docosahexaenoic acid (DHA), an ω-3 polyunsaturated fatty acid, attenuates interstitial lung disease (ILD) in experimental models, but human studies are lacking. We examined associations of circulating levels of DHA and other polyunsaturated fatty acids with hospitalization and death due to ILD over 12 years in the Multi-Ethnic Study of Atherosclerosis (MESA; n = 6,573). We examined cross-sectional associations with CT lung abnormalities in MESA (2000-2012; n = 6,541), the Framingham Heart Study (2005-2011; n = 3,917), and the Age, Gene/Environment Susceptibility-Reykjavik Study (AGES-Reykjavik) (2002-2006; n = 1,106). Polyunsaturated fatty acid levels were determined from fasting blood samples and extracted from plasma phospholipids (MESA and AGES-Reykjavik) or red blood cell membranes (Framingham Heart Study). Higher DHA levels were associated with a lower risk of hospitalization due to ILD (per standard-deviation increment, adjusted rate ratio = 0.69, 95% confidence interval (CI): 0.48, 0.99) and a lower rate of death due to ILD (per standard-deviation increment, adjusted hazard ratio = 0.68, 95% CI: 0.47, 0.98). Higher DHA was associated with fewer interstitial lung abnormalities on computed tomography (per natural log increment, pooled adjusted odds ratio = 0.65, 95% CI: 0.46, 0.91). Higher DHA levels were associated with a lower risk of hospitalization and death due to ILD and fewer lung abnormalities on computed tomography in a meta-analysis of data from population-based cohort studies.

Race-Based Differences in Lipoprotein(a)-Associated Risk of Carotid Atherosclerosis.

Objective- Lp(a) [lipoprotein(a)] is a well-described risk factor for atherosclerosis, but Lp(a)-associated risk may vary by race/ethnicity. We aimed to determine whether race/ethnicity modifies Lp(a)-related risk of carotid atherosclerotic plaque outcomes among black, white, Chinese, and Hispanic individuals. Approach and Results- Carotid plaque presence and score were assessed by ultrasonography at baseline (n=5155) and following a median 9.4 year period (n=3380) in MESA (Multi-Ethnic Study of Atherosclerosis) participants. Lp(a) concentrations were measured by immunoassay and examined as a continuous and categorical variable using clinically-based cutoffs, 30 and 50 mg/dL. Lp(a) was related to greater risk of prevalent carotid plaque at baseline in whites alone (all P<0.001): per log unit (relative risk, 1.05); Lp(a)≥30 mg/dL (relative risk, 1.16); and Lp(a)≥50 mg/dL (relative risk, 1.20). Lp(a) levels over 50 mg/dL were associated with a higher plaque score at baseline in whites (all P<0.001) and Hispanics ( P=0.04). In prospective analyses, whites with Lp(a) ≥50 mg/dL were found to have greater risk of plaque progression (relative risk, 1.12; P=0.03) and higher plaque scores (all P<0.001) over the 9.4-year follow-up. Race-based differences between whites and black participants were significant for cross-sectional associations and for carotid plaque score following the 9.4 year study period. Conclusions- Race was found to be a modifying variable in Lp(a)-related risk of carotid plaque, and Lp(a) levels may have greater influence on plaque burden in whites than in black individuals. Borderline results in Hispanics suggest that elevated Lp(a) may increase the risk of carotid plaque, but follow-up studies are needed.

Lp(a) [Lipoprotein(a)]-Related Risk of Heart Failure Is Evident in Whites but Not in Other Racial/Ethnic Groups.

Objective- Lp(a) [lipoprotein(a)] levels vary by race/ethnicity and were recently found to be associated with risk of heart failure (HF). We aimed to determine whether Lp(a)-related risk of HF is similar across different races and whether Lp(a) may further be related to HF with reduced ejection fraction or HF with preserved ejection fraction (HFpEF). Approach and Results- In 6809 participants of the MESA (Multi-Ethnic Study of Atherosclerosis), aged 45 to 84 years and free of cardiovascular disease, 308 incident HF events occurred during a median 13-year follow-up. Baseline Lp(a) concentrations were determined by immunoassay. Incident HF was adjudicated, distinguishing HF with reduced ejection fraction (ejection fraction, <45%) from HFpEF (ejection fraction, ≥45%). Cox regression assessed relations between Lp(a) and HF risk among 4 races/ethnicities. Lp(a) was examined as a continuous variable (per log unit) and using clinical cutoff values, 30 and 50 mg/dL. Lp(a) was related to greater risk of HF in whites alone: per log unit Lp(a) (hazard ratio [HR], 1.20; P=0.02); Lp(a) ≥30 mg/dL (HR, 1.69; P=0.01), Lp(a) ≥50 mg/dL (HR, 1.87; P=0.006). No significant relations were found in black, Hispanic, or Chinese participants, and significant race interactions were observed. Lp(a) was additionally related to greater risk of HFpEF in white participants: per log unit Lp(a) (HR, 1.48; P=0.001), Lp(a) ≥30 mg/dL (HR, 2.15; P=0.01), Lp(a) ≥50 mg/dL (HR, 2.60; P=0.004). Lp(a)-related risk of HF and HFpEF in whites was independent of aortic valve disease. Conclusions- In a multiethnic sample, Lp(a)-related risks of HF and HFpEF were only evident in white participants. If confirmed, these findings have implications in further Lp(a) research and clinical practice.

Plasma n-3 and n-6 Fatty Acids Are Differentially Related to Carotid Plaque and Its Progression: The Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: ω-3 (n-3) fatty acids (FAs) have long been considered healthful dietary components, yet recent clinical trials have questioned their cardiovascular benefits. By contrast, the ω-6 (n-6) FAs have been considered harmful, proatherogenic macronutrients, despite an absence of empirical evidence supporting this hypothesis. We aimed to determine whether plasma n-3 and n-6 FAs are related to risk of carotid plaque and its progression in 3327 participants of MESA (Multi-Ethnic Study of Atherosclerosis). APPROACH AND RESULTS: Carotid plaque was assessed using ultrasonography at baseline and after a median period of 9.5 years. Plasma phospholipid n-3 and n-6 FAs were determined using gas chromatography-flame ionization detection. Relative risk regression analyses assessed the relations of FAs with the presence or progression of carotid plaque adjusted for typical cardiovascular disease risk factors. At baseline, it was found that participants in the fourth quartile of n-3 docosahexaenoic acid showed a 9% lower risk of carotid plaque (P=0.05), whereas those in the second quartile of n-3 α-linolenic acid showed an 11% greater risk compared with respective referent quartiles (P=0.02). In prospective analyses, individuals in the top quartile of docosahexaenoic acid showed a 12% lower risk of carotid plaque progression during 9.5 years compared with those in the referent quartile (P=0.002). No significant relations were observed among n-6 FAs and plaque outcomes. No significant race/ethnicity interactions were found. CONCLUSIONS: These findings support docosahexaenoic acid as an atheroprotective macronutrient, whereas null findings for n-6 FAs challenge the view that they promote atherosclerosis.

Evaluation of Lipoprotein(a) Electrophoretic and Immunoassay Methods in Discriminating Risk of Calcific Aortic Valve Disease and Incident Coronary Heart Disease: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: A number of lipoprotein(a) [Lp(a)] analytical techniques are available that quantify distinct particle components, yet their clinical efficacy has not been comprehensively evaluated. This study determined whether Lp(a) mass [Lp(a)-M], Lp(a) cholesterol content [Lp(a)-C], and particle concentration [Lp(a)-P] differentially discriminated risk of calcific aortic valve disease (CAVD) or incident coronary heart disease (CHD) among 4679 participants of the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS: Lp(a)-M, Lp(a)-C, and Lp(a)-P were measured in individuals without clinical evidence of CHD at baseline. Relative risk regression and Cox proportional analysis determined associations between Lp(a) and the presence of CAVD or 12-year risk of CHD, respectively. To control for the relatively high lower limits of quantification for Lp(a)-C and Lp(a)-P assays, the upper 25th and 15th percentiles were selected as analytical cutoff points. RESULTS: Regardless of method or analytical cutoff, high Lp(a) concentrations were significantly associated with CAVD and CHD in MESA participants following adjustment for typical cardiovascular risk factors. Stratifying by race/ethnicity rendered most associations nonsignificant after correction for multiple comparisons, but Lp(a) remained associated with CAVD in whites irrespective of method (all P < 0.0001). CONCLUSIONS: Associations of Lp(a)-C, Lp(a)-P, and Lp(a)-M with CAVD or incident CHD were similar in this entire MESA sample using a dichotomized statistical approach. However, the high lower limits of quantification and imprecision of the Lp(a)-C and Lp(a)-P assays limited their usefulness in our analyses and would likely do so in research and clinical settings.

Lipoprotein(a) Levels Are Associated With Subclinical Calcific Aortic Valve Disease in White and Black Individuals: The Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: Lipoprotein(a) [Lp(a)] is a risk factor for calcific aortic valve disease (CAVD) but has not been evaluated across multiple races/ethnicities. This study aimed to determine whether Lp(a) cutoff values used in clinical laboratories to assess risk of cardiovascular disease identify subclinical CAVD and its severity and whether significant relations are observed across race/ethnicity. APPROACH AND RESULTS: Lp(a) concentrations were measured using a turbidimetric immunoassay, and subclinical CAVD was measured by quantifying aortic valve calcification (AVC) through computed tomographic scanning in 4678 participants of the Multi-Ethnic Study of Atherosclerosis. Relative risk and ordered logistic regression analysis determined cross-sectional associations of Lp(a) with AVC and its severity, respectively. The conventional 30 mg/dL Lp(a) clinical cutoff was associated with AVC in white (relative risk: 1.56; confidence interval: 1.24-1.96) and was borderline significant (P=0.059) in black study participants (relative risk: 1.55; confidence interval: 0.98-2.44). Whites with levels ≥50 mg/dL also showed higher prevalence of AVC (relative risk: 1.72; confidence interval: 1.36-2.17) than those below this level. Significant associations were observed between Lp(a) and degree of AVC in both white and black individuals. The presence of existing coronary artery calcification did not affect these associations of Lp(a) and CAVD. There were no significant findings in Hispanics or Chinese. CONCLUSIONS: Lp(a) cutoff values that are currently used to assess cardiovascular risk seem to be applicable to CAVD, but our results suggest race/ethnicity may be important in cutoff selection. Further studies are warranted to determine whether race/ethnicity influences Lp(a) and risk of CAVD incidence and its progression.

Sex and ethnic differences in the associations between lipoprotein(a) and peripheral arterial disease in the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: Higher lipoprotein(a) [Lp(a)] has been linked with peripheral arterial disease (PAD). Also, elevated Lp(a) serum levels have been observed in women and African Americans (AAs). It remains uncertain if sex and ethnicity modify the association between Lp(a) and PAD. METHODS: Lp(a) mass concentration was measured with a latex-enhanced turbidimetric immunoassay, from blood collected at baseline clinic visits after a 12-hour fast, in a multiethnic cohort. Also at baseline, the ankle-brachial index was measured. PAD was defined as an ankle-brachial index <1.0. Multivariable logistic regression was used to determine sex and ethnic differences in associations of log-transformed Lp(a) and the presence of PAD. RESULTS: In 4618 participants, the mean age was 62 ± 10 years; Lp(a) mean was 30 ± 32 mg/dL and median (interquartile range) was 18 (8-40 mg/dL); 48% were male; 36% were European American, 29% were AA, 23% were Hispanic American (HA), and 12% were Chinese American; and 11% had PAD. Across all ethnic groups, serum Lp(a) was higher among women compared with men and highest among AAs compared with other ethnicities. After adjustments for traditional cardiovascular disease risk factors (age, sex, ethnicity, hypertension, diabetes, smoking, total cholesterol, and high-density lipoprotein cholesterol) as well as interleukin-6, fibrinogen, D-dimer, and homocysteine levels, one log unit increase in Lp(a) was associated with greater odds for PAD (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.01-1.25). In fully adjusted models, significant gender(∗)ln[Lp(a)] and ethnicity(∗)ln[Lp(a)] interactions were observed (P = .08 for both). The association between higher Lp(a) and PAD was strongest in HA men (OR, 1.73; 95% CI, 1.07-2.80) and HA women (OR, 1.49; 95% CI, 1.07-2.08). Nonsignificant associations were observed for European American, AA, and Chinese American men and women. CONCLUSIONS: We observed a significant and independent association between elevated Lp(a) and PAD only among HA women and men, despite higher serum Lp(a) levels among AAs. Future studies are needed to determine the role that lowering of Lp(a) may have on the burden of PAD in HAs.

Use of lipoprotein particle measures for assessing coronary heart disease risk post-American Heart Association/American College of Cardiology guidelines: the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: The American College of Cardiology and American Heart Association have issued guidelines indicating that the contribution of apolipoprotein B-100 (ApoB) to cardiovascular risk assessment remains uncertain. The present analysis evaluates whether lipoprotein particle measures convey risk of coronary heart disease (CHD) in 4679 Multi-Ethnic Study of Atherosclerosis (MESA) participants. APPROACH AND RESULTS: Cox regression analysis was performed to determine associations between lipids or lipoproteins and primary CHD events. After adjustment for nonlipid variables, lipoprotein particle levels in fourth quartiles were found to convey significantly greater risk of incident CHD when compared to first quartile levels (hazard ratio [HR]; 95% confidence interval [CI]): ApoB (HR, 1.84; 95% CI, 1.25-2.69), ApoB/ApoA-I (HR, 1.91; 95% CI, 1.32-2.76), total low-density lipoprotein-particles (LDL-P; HR, 1.77; 95% CI, 1.21-2.58), and the LDL-P/HDL-P (high-density lipoprotein-P) ratio (HR, 2.28; 95% CI, 1.54-3.37). Associations between lipoprotein particle measures and CHD were attenuated after adjustment for standard lipid panel variables. Using the American Heart Association/American College of Cardiology risk calculator as a baseline model for CHD risk assessment, significant net reclassification improvement scores were found for ApoB/ApoA-I (0.18; P=0.007) and LDL-P/high-density lipoprotein-P (0.15; P<0.001). C-statistics revealed no significant increase in CHD event discrimination for any lipoprotein measure. CONCLUSIONS: Lipoprotein particle measures ApoB/ApoA-I and LDL-P/high-density lipoprotein-P marginally improved net reclassification improvement scores, but null findings for corresponding c-statistic are not supportive of lipoprotein testing. The attenuated associations of lipoprotein particle measures with CHD after the adjustment for lipids indicate that their measurement does not detect risk that is unaccounted for by the standard lipid panel. However, the possibility that lipoprotein measures may identify CHD risk in a subpopulation of individuals with normal cholesterol, but elevated lipoprotein particle numbers cannot be ruled out.

Race is a key variable in assigning lipoprotein(a) cutoff values for coronary heart disease risk assessment: the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: We aimed to examine associations of lipoprotein(a) (Lp(a)) concentrations with coronary heart disease (CHD) and determine whether current Lp(a) clinical laboratory cut points identify risk of disease incidence in 4 races/ethnicities of the Multi-Ethnic Study of Atherosclerosis (MESA). APPROACH AND RESULTS: A subcohort of 1323 black, 1677 white, 548 Chinese American, and 1044 Hispanic MESA participants were followed up during a mean 8.5-year period in which 235 incident CHD events were recorded. Lp(a) mass concentrations were measured using a turbidimetric immunoassay. Cox regression analysis determined associations of Lp(a) with CHD risk with adjustments for lipid and nonlipid variables. Lp(a) concentrations were continuously associated with risk of CHD incidence in black (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.09-2.04] and white participants (HR, 1.22; 95% CI, 1.02-1.45). Examining Lp(a) risk by the 50 mg/dL cut point revealed higher risks of incident CHD in all races except Chinese Americans: blacks (HR, 1.69; 95% CI, 1.03-2.76), whites (HR, 1.82; 95% CI, 1.15-2.88); Hispanics (HR, 2.37; 95% CI, 1.17-4.78). The lower Lp(a) cut point of 30 mg/dL identified higher risk of CHD in black participants alone (HR, 1.87; 95% CI, 1.08-3.21). CONCLUSIONS: Our findings suggest that the 30 mg/dL cutoff for Lp(a) is not appropriate in white and Hispanic individuals, and the higher 50 mg/dL cutoff should be considered. In contrast, the 30 mg/dL cutoff remains suitable in black individuals. Further research is necessary to develop the most clinically useful Lp(a) cutoff values in individual races/ethnicities.

New automated assay of small dense low-density lipoprotein cholesterol identifies risk of coronary heart disease: the Multi-ethnic Study of Atherosclerosis.

OBJECTIVE: Coronary heart disease (CHD) is the leading cause of death in the United States, yet assessing risk of its development remains challenging. The present study evaluates a new automated assay of small dense low-density lipoprotein cholesterol content (sdLDL-C) and whether sdLDL-C is a risk factor for CHD compared with LDL-C or small LDL particle concentrations derived from nuclear magnetic resonance spectroscopy. APPROACH AND RESULTS: sdLDL-C was measured using a new automated enzymatic method, and small LDL concentrations were obtained by nuclear magnetic resonance in 4387 Multi-Ethnic Study of Atherosclerosis participants. Cox regression analysis estimated hazard ratios for developing CHD for 8.5 years after adjustments for age, race, sex, systolic blood pressure, hypertension medication use, high-density lipoprotein cholesterol, and triglycerides. Elevated sdLDL-C was a risk factor for CHD in normoglycemic individuals. Those in the top sdLDL-C quartile showed higher risk of incident CHD (hazard ratio, 2.41; P=0.0037) compared with those in the bottom quartile and indicated greater CHD risk than the corresponding quartile of LDL-C (hazard ratio, 1.75; P=0.019). The association of sdLDL-C with CHD risk remained significant when LDL-C (<2.57 mmol/L) was included in a multivariate model (hazard ratio, 2.37; P=0.012). Nuclear magnetic resonance-derived small LDL concentrations did not convey a significant risk of CHD. Those with impaired fasting glucose or diabetes mellitus showed higher sdLDL-C and small LDL concentrations but neither was associated with higher CHD risk in these individuals. CONCLUSIONS: This new automated method for sdLDL-C identifies risk for CHD that would remain undetected using standard lipid measures, but only in normoglycemic, nondiabetic individuals.

Diet quality is associated with adipose tissue and muscle mass: the Coronary Artery Risk Development in Young Adults (CARDIA) study.

BACKGROUND: Aging is associated with changes in body composition, and preventing loss of muscle mass and accumulation of excess adipose tissue in middle-aged adults may reduce age-related conditions at older ages. Dietary intake is one lifestyle factor shown to improve or maintain body composition. However, few studies have examined the Healthy Eating Index2015 (HEI2015), a measure of diet quality, and the association with body composition in adult men and women. METHODS: Participant data (n = 3017) from the Coronary Artery Risk Development in Young Adults (CARDIA) study were used to examine the associations of the HEI2015 with body composition measures at Year 25 (Y25), including (1) 25 year-change in weight, body mass index (BMI), and waist circumference and (2) a computed tomography (CT) scan at Y25 measured muscle mass, muscle quality (better quality = less lipid within the muscle), and adipose tissue depots visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and adipose within skeletal muscle (intermuscular adipose tissue; IMAT). Dietary intake was assessed by a diet history three times over 20 years, at years 0, 7, and 20. HEI2015, averaged over three exams, was created and categorized into quintiles. Multiple regression analysis evaluated the associations of body composition stratified across quintiles of HEI2015 adjusted for demographic characteristics, energy intake, lifestyle factors, and baseline anthropometric measures as appropriate. Race-sex interaction was tested (Pinteraction  > 0.30). RESULTS: Over 25 years of follow-up, averaged HEI2015 was significantly and inversely associated with weight gain (Quintile 1 (Q1) 37.3 lb vs. 32.9 in Q5; Ptrend  = 0.01), change in BMI (Q1 5.8 kg/m2 vs. 5.0 in Q5; Ptrend  = 0.005), and change in waist circumference (Q1 17.5 cm vs. 15.2 cm in Q5; Ptrend  < 0.001). By Y25, HEI2015 was inversely associated with VAT Q1 136.8 cm3 vs. 116.6 in Q5; Ptrend  < 0.001) and IMAT volumes (Q1 9.52 vs. 8.12 cm3 in Q5; Ptrend  < 0.001). Although total muscle volume declined (Ptrend  = 0.03), lean muscle mass volume was similar across quintiles (Ptrend  = 0.55). The IMAT/total muscle mass ratio declined across HEI2015 quintiles (Ptrend  < 0.001). Finally, higher HEI2015 was associated with better muscle quality at Y25 (higher value = less lipid within the muscle; Q1 41.1 vs. 42.2 HU in Q5; Ptrend  = 0.002). HEI2015 was nonlinearly, but inversely, associated with SAT (nonlinear P = 0.011). CONCLUSIONS: Improving diet quality in young to middle-aged adults is a recommended strategy to promote better measures of body composition. Our study findings suggest that healthier food choices may influence body composition.

Plasma Neuronal Growth Regulator 1 May Link Physical Activity to Reduced Risk of Type 2 Diabetes: A Proteome-Wide Study of ARIC Participants.

Habitual physical activity (PA) impacts the plasma proteome and reduces the risk of developing type 2 diabetes (T2D). Using a large-scale proteome-wide approach in Atherosclerosis Risk in Communities study participants, we aimed to identify plasma proteins associated with PA and determine which of these may be causally related to lower T2D risk. PA was associated with 92 plasma proteins in discovery (P < 1.01 × 10-5), and 40 remained significant in replication (P < 5.43 × 10-4). Eighteen of these proteins were independently associated with incident T2D (P < 1.25 × 10-3), including neuronal growth regulator 1 (NeGR1; hazard ratio per SD 0.85; P = 7.5 × 10-11). Two-sample Mendelian randomization (MR) inverse variance weighted analysis indicated that higher NeGR1 reduces T2D risk (odds ratio [OR] per SD 0.92; P = 0.03) and was consistent with MR-Egger, weighted median, and weighted mode sensitivity analyses. A stronger association was observed for the single cis-acting NeGR1 genetic variant (OR per SD 0.80; P = 6.3 × 10-5). Coupled with previous evidence that low circulating NeGR1 levels promote adiposity, its association with PA and potential causal role in T2D shown here suggest that NeGR1 may link PA exposure with metabolic outcomes. Further research is warranted to confirm our findings and examine the interplay of PA, NeGR1, adiposity, and metabolic health.

n-3 and n-6 Fatty acids are independently associated with lipoprotein-associated phospholipase A2 in the Multi-Ethnic Study of Atherosclerosis.

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an independent risk factor for CVD and has been proposed as a marker of vascular inflammation. Polyunsaturated n-3 fatty acids (FA) and several n-6 FA are known to suppress inflammation and may influence Lp-PLA2 mass and activity. The associations of n-3 and n-6 plasma FA with Lp-PLA2 mass and activity were analysed using linear regression analysis in 2246 participants of the Multi-Ethnic Study of Atherosclerosis; statistical adjustments were made to control for body mass, inflammation, lipids, diabetes, and additional clinical and demographic factors. Lp-PLA2 mass and activity were significantly lower in participants with the higher n-3 FA EPA (ß = - 4·72, P< 0·001; ß = - 1·53; P= 0·023) and DHA levels (ß = - 4·47, ß = - 1·87; both P< 0·001). Those in the highest quintiles of plasma EPA and DHA showed 12·71 and 19·15 ng/ml lower Lp-PLA2 mass and 5·7 and 8·90 nmol/min per ml lower Lp-PLA2 activity than those in the first quintiles, respectively. In addition, lower Lp-PLA2 mass and activity were associated with higher levels of n-6 arachidonic acid (ß = - 1·63, ß = - 1·30; both P< 0·001), while γ-linolenic acid was negatively associated with activity (ß = - 27·7, P= 0·027). Lp-PLA2 mass was significantly higher in participants with greater plasma levels of n-6 linoleic (ß = 0·828, P= 0·011) and dihomo-γ-linolenic acids (ß = 4·17, P= 0·002). Based on their independent associations with Lp-PLA2 mass and activity, certain n-3 and n-6 FA may have additional influences on CVD risk. Intervention studies are warranted to assess whether these macronutrients may directly influence Lp-PLA2 expression or activity.

Developing A Baseline Metabolomic Signature Associated with COVID-19 Severity: Insights from Prospective Trials Encompassing 13 U.S. Centers.

Metabolic disease is a significant risk factor for severe COVID-19 infection, but the contributing pathways are not yet fully elucidated. Using data from two randomized controlled trials across 13 U.S. academic centers, our goal was to characterize metabolic features that predict severe COVID-19 and define a novel baseline metabolomic signature. Individuals (n = 133) were dichotomized as having mild or moderate/severe COVID-19 disease based on the WHO ordinal scale. Blood samples were analyzed using the Biocrates platform, providing 630 targeted metabolites for analysis. Resampling techniques and machine learning models were used to determine metabolomic features associated with severe disease. Ingenuity Pathway Analysis (IPA) was used for functional enrichment analysis. To aid in clinical decision making, we created baseline metabolomics signatures of low-correlated molecules. Multivariable logistic regression models were fit to associate these signatures with severe disease on training data. A three-metabolite signature, lysophosphatidylcholine a C17:0, dihydroceramide (d18:0/24:1), and triacylglyceride (20:4_36:4), resulted in the best discrimination performance with an average test AUROC of 0.978 and F1 score of 0.942. Pathways related to amino acids were significantly enriched from the IPA analyses, and the mitogen-activated protein kinase kinase 5 (MAP2K5) was differentially activated between groups. In conclusion, metabolites related to lipid metabolism efficiently discriminated between mild vs. moderate/severe disease. SDMA and GABA demonstrated the potential to discriminate between these two groups as well. The mitogen-activated protein kinase kinase 5 (MAP2K5) regulator is differentially activated between groups, suggesting further investigation as a potential therapeutic pathway.

Development of a proteomic signature associated with severe disease for patients with COVID-19 using data from 5 multicenter, randomized, controlled, and prospective studies.

Significant progress has been made in preventing severe COVID-19 disease through the development of vaccines. However, we still lack a validated baseline predictive biologic signature for the development of more severe disease in both outpatients and inpatients infected with SARS-CoV-2. The objective of this study was to develop and externally validate, via 5 international outpatient and inpatient trials and/or prospective cohort studies, a novel baseline proteomic signature, which predicts the development of moderate or severe (vs mild) disease in patients with COVID-19 from a proteomic analysis of 7000 + proteins. The secondary objective was exploratory, to identify (1) individual baseline protein levels and/or (2) protein level changes within the first 2 weeks of acute infection that are associated with the development of moderate/severe (vs mild) disease. For model development, samples collected from 2 randomized controlled trials were used. Plasma was isolated and the SomaLogic SomaScan platform was used to characterize protein levels for 7301 proteins of interest for all studies. We dichotomized 113 patients as having mild or moderate/severe COVID-19 disease. An elastic net approach was used to develop a predictive proteomic signature. For validation, we applied our signature to data from three independent prospective biomarker studies. We found 4110 proteins measured at baseline that significantly differed between patients with mild COVID-19 and those with moderate/severe COVID-19 after adjusting for multiple hypothesis testing. Baseline protein expression was associated with predicted disease severity with an error rate of 4.7% (AUC = 0.964). We also found that five proteins (Afamin, I-309, NKG2A, PRS57, LIPK) and patient age serve as a signature that separates patients with mild COVID-19 and patients with moderate/severe COVID-19 with an error rate of 1.77% (AUC = 0.9804). This panel was validated using data from 3 external studies with AUCs of 0.764 (Harvard University), 0.696 (University of Colorado), and 0.893 (Karolinska Institutet). In this study we developed and externally validated a baseline COVID-19 proteomic signature associated with disease severity for potential use in both outpatients and inpatients with COVID-19.