Susceptibility of hypertensive individuals to acute blood pressure increases in response to personal-level environmental temperature decrease.

BACKGROUND: Environmental temperature is negatively associated with blood pressure (BP), and hypertension may exacerbate this association. The aim of this study is to investigate whether hypertensive individuals are more susceptible to acute BP increases following temperature decrease than non-hypertensive individuals. METHODS: The study panel consisted of 126 hypertensive and 125 non-hypertensive (n = 251) elderly participants who completed 940 clinical visits during the winter of 2016 and summer of 2017 in Beijing, China. Personal-level environmental temperature (PET) was continuously monitored for each participant with a portable sensor platform. We associated systolic BP (SBP) and diastolic BP (DBP) with the average PET over 24 h before clinical visits using linear mixed-effects models and explored hourly lag patterns for the associations using distributed lag models. RESULTS: We found that per 1 °C decrease in PET, hypertensive individuals showed an average (95 % confidence interval) increase of 0.96 (0.72, 1.19) and 0.28 (0.13, 0.42) mmHg for SBP and DBP, respectively; and non-hypertensive participants showed significantly smaller increases of 0.28 (0.03, 0.53) mmHg SBP and 0.14 (-0.01, 0.30) mmHg DBP. A lag pattern analysis showed that for hypertensive individuals, the increases in SBP and DBP were greatest following lag 1 h PET decrease and gradually attenuated up to lag 10 h exposure. No significant BP change was observed in non-hypertensive individuals associated with lag 1-24 h PET exposure. The enhanced increase in PET-associated BP in hypertensive participants (i.e., susceptibility) was more significant in winter than in summer. CONCLUSIONS: We found that a decrease in environmental temperature was associated with acute BP increases and these associations diminished over time, disappearing after approximately 10 hours. This implies that any intervention measures to prevent BP increases due to temperature drop should be implemented as soon as possible. Such timely interventions are particularly needed for hypertensive individuals especially during the cold season due to their increased susceptibility.

Relationship of calcium and magnesium intakes with the dietary approaches to stop hypertension score and blood pressure: the International Study of Macro/micronutrients and Blood Pressure.

OBJECTIVE: Research investigating calcium and magnesium intakes from the Dietary Approaches to Stop Hypertension (DASH) pattern and other sources in association with blood pressure is limited. We aimed to characterize sources/intake levels of calcium and magnesium in relation to overall diet quality (DASH-score) and determine modification effects with DASH score and blood pressure. METHODS: Cross-sectional United States data (average dietary and supplement intake from four 24 h recalls and eight blood pressure measurements) from two separate visits, 2195 men and women (40-59 years) in the International Study of Macro/Micronutrients and Blood Pressure were analysed. Food-based adherence to the DASH diet was estimated. Linear models tested associations between each 1-point DASH score with blood pressure. Participants were stratified by adherence to sex-specific recommended allowance for magnesium and calcium intakes. Effect-modification was tested across DASH-score quintiles and median of urinary sodium. RESULTS: DASH-score was inversely associated with SBP in fully adjusted models (-0.27; 95%CI: -0.38 to -0.15 mmHg). SBP was inversely associated with dietary calcium intake from DASH food groups: -1.54 (95% CI: -2.65 to -0.43) mmHg; calcium intake from other non-DASH food groups: -1.62 (95% CI: -2.94 to -0.29) mmHg. Dietary magnesium intake from DASH food groups (-1.59; 95% CI: -2.79, -0.40 mmHg) and from other non-DASH foods (-1.92; 95% CI: -3.31, -0.53 mmHg) was inversely associated with SBP. CONCLUSION: A higher DASH score showed a consistent association with lower BP suggesting a relationship between intakes of calcium and Mg with BP regardless of whether the source is part of the DASH diet or not, even when adjusted for supplement intakes.The INTERMAP is registered as NCT00005271 at www.clinicaltrials.gov .

The Role of Diet in the Prevention of Hypertension and Management of Blood Pressure: An Umbrella Review of Meta-Analyses of Interventional and Observational Studies.

High blood pressure (BP) is a major pathological risk factor for the development of several cardiovascular diseases. Diet is a key modifier of BP, but the underlying relationships are not clearly demonstrated. This is an umbrella review of published meta-analyses to critically evaluate the wide range of dietary evidence from bioactive compounds to dietary patterns on BP and risk of hypertension. PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception until October 31, 2021, for relevant meta-analyses of randomized controlled trials or meta-analyses of observational studies. A total of 175 publications reporting 341 meta-analyses of randomized controlled trials (145 publications) and 70 meta-analyses of observational studies (30 publications) were included in the review. The methodological quality of the included publications was assessed using Assessment of Multiple Systematic Reviews 2 and the evidence quality of each selected meta-analysis was assessed using NutriGrade. This umbrella review supports recommended public health guidelines for prevention and control of hypertension. Dietary patterns including the Dietary Approaches to Stop Hypertension and the Mediterranean-type diets that further restrict sodium, and moderate alcohol intake are advised. To produce high-quality evidence and substantiate strong recommendations, future research should address areas where the low quality of evidence was observed (for example, intake of dietary fiber, fish, egg, meat, dairy products, fruit juice, and nuts) and emphasize focus on dietary factors not yet conclusively investigated.

Uncertainty-weighted Multi-tasking for T1ρ and T2 Mapping in the Liver with Self-supervised Learning.

Multi-parametric mapping of MRI relaxations in liver has the potential of revealing pathological information of the liver. A self-supervised learning based multi-parametric mapping method is proposed to map T1ρ and T2 simultaneously, by utilising the relaxation constraint in the learning process. Data noise of different mapping tasks is utilised to make the model uncertainty-aware, which adaptively weight different mapping tasks during learning. The method was examined on a dataset of 51 patients with non-alcoholic fatter liver disease. Results showed that the proposed method can produce comparable parametric maps to the traditional multi-contrast pixel wise fitting method, with a reduced number of images and less computation time. The uncertainty weighting also improves the model performance. It has the potential of accelerating MRI quantitative imaging.

An uncertainty aided framework for learning based liverT1ρmapping and analysis.

Objective. QuantitativeT1ρimaging has potential for assessment of biochemical alterations of liver pathologies. Deep learning methods have been employed to accelerate quantitativeT1ρimaging. To employ artificial intelligence-based quantitative imaging methods in complicated clinical environment, it is valuable to estimate the uncertainty of the predicatedT1ρvalues to provide the confidence level of the quantification results. The uncertainty should also be utilized to aid the post-hoc quantitative analysis and model learning tasks.Approach. To address this need, we propose a parametric map refinement approach for learning-basedT1ρmapping and train the model in a probabilistic way to model the uncertainty. We also propose to utilize the uncertainty map to spatially weight the training of an improvedT1ρmapping network to further improve the mapping performance and to remove pixels with unreliableT1ρvalues in the region of interest. The framework was tested on a dataset of 51 patients with different liver fibrosis stages.Main results. Our results indicate that the learning-based map refinement method leads to a relative mapping error of less than 3% and provides uncertainty estimation simultaneously. The estimated uncertainty reflects the actual error level, and it can be used to further reduce relativeT1ρmapping error to 2.60% as well as removing unreliable pixels in the region of interest effectively.Significance. Our studies demonstrate the proposed approach has potential to provide a learning-based quantitative MRI system for trustworthyT1ρmapping of the liver.

Divergent Survival Outcomes Associated with Elevated Branched-Chain Amino Acid Levels among Older Adults with or without Hypertension and Diabetes: A Validated, Prospective, Longitudinal Follow-Up Study.

Branched-chain amino acids are critical metabolic intermediates that can indicate increased risk of cardiometabolic disease when levels are elevated or, alternatively, suggest sufficient mitochondrial energy metabolism and reserve in old age. The interpretation of BCAA levels can be context-dependent, and it remains unclear whether abnormal levels can inform prognosis. This prospective longitudinal study aimed to determine the interrelationship between mortality hazard and fasting serum BCAA levels among older men and women aged ≥65 years with or without hypertension and diabetes mellitus. At baseline (0Y), fasting serum BCAA concentration in 2997 community-living older men and women were measured. Approximately 14 years later (14Y), 860 study participants returned for repeat measurements. Deaths were analysed and classified into cardiovascular and non-cardiovascular causes using International Classification of Diseases codes. Survival analysis and multivariable Cox regression were performed. During a median follow-up of 17Y, 971 (78.6%) non-cardiovascular and 263 (21.4%) cardiovascular deaths occurred among 1235 (41.2%) deceased (median age, 85.8 years [IQR 81.7-89.7]). From 0Y to 14Y, BCAA levels declined in both sexes, whereas serum creatinine concentration increased (both p < 0.0001). In older adults without hypertension or diabetes mellitus, the relationship between mortality hazard and BCAA level was linear and above-median BCAA levels were associated with improved survival, whereas in the presence of cardiometabolic disease the relationship was U-shaped. Overall, adjusted Cox regression determined that each 10% increment in BCAA concentration was associated with a 7% (p = 0.0002) and 16% (p = 0.0057) reduction in mortality hazard estimated at 0Y and 14Y, respectively. Our findings suggested that abnormally high or low (dyshomeostatic) BCAA levels among older adults with hypertension and/or diabetes mellitus were associated with increased mortality, whereas in those with neither disease, increased BCAA levels was associated with improved survival, particularly in the oldest-old.

Discovering Protein-Protein Interactions using Co-Fractionation-Mass Spectrometry with Label-Free Quantitation.

Proteins generally achieve their functions through interactions with other proteins, so being able to determine which proteins interact with which other proteins underlies much of molecular biology. Co-fractionation (CF) is a mass spectrometry-based method for detecting proteome-wide protein-protein interactions. An attractive feature of CF is that it is not necessary to label or otherwise alter samples. Although we have previously published a widely used protocol for a label-incorporated CF methodology, no published protocols currently exist for the label-free variation. In this chapter, we describe a label-free CF-MS protocol. This protocol takes a minimum of a week, excluding the time for cell/tissue culture. It begins with cell/tissue lysis under non-denaturing conditions, after which intact protein complexes are isolated using size exclusion chromatography (SEC) where they are fractionated according to size. The proteins in each fraction are then prepared for mass spectrometry analysis where the constituent proteins are identified and quantified. Finally, we describe an in-house bioinformatics pipeline, PrInCE, to accurately predict protein complexes. Taken together, co-fractionation methodologies combined with mass spectrometry can identify and quantify thousands of protein-protein interactions in biological systems.

Metabolomic Signatures of Sedentary Behavior and Cardiometabolic Traits in US Hispanics/Latinos: Results from HCHS/SOL.

PURPOSE: The aim of this study was to understand the serum metabolomic signatures of moderate-to-vigorous physical activity (MVPA) and sedentary behavior, and further associate their metabolomic signatures with incident cardiometabolic diseases. METHODS: This analysis included 2711 US Hispanics/Latinos from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) aged 18-74 yr (2008-2011). An untargeted, liquid chromatography-mass spectrometry was used to profile the serum metabolome. The associations of metabolites with accelerometer-measured MVPA and sedentary time were examined using survey linear regressions adjusting for covariates. The weighted correlation network analysis identified modules of correlated metabolites in relation to sedentary time, and the modules were associated with incident diabetes, dyslipidemia, and hypertension over the 6-yr follow-up. RESULTS: Of 624 metabolites, 5 and 102 were associated with MVPA and sedentary behavior at false discovery rate (FDR) <0.05, respectively, after adjusting for socioeconomic and lifestyle factors. The weighted correlation network analysis identified 8 modules from 102 metabolites associated with sedentary time. Four modules (branched-chain amino acids, erythritol, polyunsaturated fatty acid, creatine) were positively, and the other four (acyl choline, plasmalogen glycerol phosphatidyl choline, plasmalogen glycerol phosphatidyl ethanolamine, urea cycle) were negatively correlated with sedentary time. Among these modules, a higher branched-chain amino acid score and a lower plasmalogen glycerol phosphatidyl choline score were associated with increased risks of diabetes and dyslipidemia. A higher erythritol score was associated with an increased risk of diabetes, and a lower acyl choline score was linked to an increased risk of hypertension. CONCLUSIONS: In this study of US Hispanics/Latinos, we identified multiple serum metabolomic signatures of sedentary behavior and their associations with risk of incident diabetes, hypertension, and dyslipidemia. These findings suggest a potential role of circulating metabolites in the links between sedentary behavior and cardiometabolic diseases.

Demographic, Health and Lifestyle Factors Associated with the Metabolome in Older Women.

Demographic and clinical factors influence the metabolome. The discovery and validation of disease biomarkers are often challenged by potential confounding effects from such factors. To address this challenge, we investigated the magnitude of the correlation between serum and urine metabolites and demographic and clinical parameters in a well-characterized observational cohort of 444 post-menopausal women participating in the Women's Health Initiative (WHI). Using LC-MS and lipidomics, we measured 157 aqueous metabolites and 756 lipid species across 13 lipid classes in serum, along with 195 metabolites detected by GC-MS and NMR in urine and evaluated their correlations with 29 potential disease risk factors, including demographic, dietary and lifestyle factors, and medication use. After controlling for multiple testing (FDR < 0.01), we found that log-transformed metabolites were mainly associated with age, BMI, alcohol intake, race, sample storage time (urine only), and dietary supplement use. Statistically significant correlations were in the absolute range of 0.2-0.6, with the majority falling below 0.4. Incorporation of important potential confounding factors in metabolite and disease association analyses may lead to improved statistical power as well as reduced false discovery rates in a variety of data analysis settings.

Lifestyle Score and Risk of Hypertension in the Airwave Health Monitoring Study of British Police Force Employees.

BACKGROUND: Evidence suggest that promoting a combination of healthy lifestyle behaviors instead of exclusively focusing on a single behavior may have a greater impact on blood pressure (BP). We aimed to evaluate lifestyle factors and their impact on the risk of hypertension and BP. METHODS: We analyzed cross-sectional health-screening data from the Airwave Health Monitoring Study of 40,462 British police force staff. A basic lifestyle-score including waist-circumference, smoking and serum total cholesterol was calculated, with a greater value indicating a better lifestyle. Individual/combined scores of other lifestyle factors (sleep duration, physical activity, alcohol intake, and diet quality) were also developed. RESULTS: A 1-point higher basic lifestyle-score was associated with a lower systolic BP (SBP; -2.05 mmHg, 95%CI: -2.15, -1.95); diastolic BP (DBP; -1.98 mmHg, 95%CI: -2.05, -1.91) and was inversely associated with risk of hypertension. Combined scores of other factors showed attenuated but significant associations with the addition of sleep, physical activity, and diet quality to the basic lifestyle-score; however, alcohol intake did not further attenuate results. CONCLUSIONS: Modifiable intermediary factors have a stronger contribution to BP, namely, waist-circumference and cholesterol levels and factors that may directly influence them, such as diet, physical activity and sleep. Observed findings suggest that alcohol is a confounder in the BP-lifestyle score relation.

Cross-sectional study of household solid fuel use and renal function in older adults in China.

BACKGROUND: Emerging evidence links outdoor air pollution and declined renal function but the relationship between household air pollution and renal function is not well understood. METHODS: Using cross-sectional data from the multi-provincial INTERMAP-China Prospective Study, we collected blood samples and questionnaire information on stove use and socio-demographic factors. We calculated estimated glomerular filtration rate (eGFR) from serum creatinine to assess renal function. Participants with eGFR <60 mL/min per 1.73 m2 were defined as having chronic kidney disease (CKD) in this analysis. Generalized estimating equations were used to estimate the association of household fuel with renal function and prevalent CKD in models adjusting for confounders. RESULTS: Among the 646 enrolled adults (40-79y; 56% female), one-third exclusively used clean fuel (gas and electric) cookstoves and 11% of northern China participants (n = 49 of 434) used only clean fuel heaters, whereas the rest used solid fuel. In multivariable models, use of solid fuel cookstoves was associated with 0.17 ml/min/1.73 m2 (95% CI: -0.30, 0.64) higher eGFR and 19% (0.86, 1.64) higher prevalence of CKD than exclusive clean fuel use. Greater intensity of solid fuel use was associated with 0.25 ml/min/1.73 m2 (-0.71, 0.21) lower eGFR per 5 stove-use years, though the confidence intervals included the null, while greater current intensity of indoor solid fuel use was associated with 1.02 (1.00, 1.04) higher prevalent CKD per 100 stove-use days per year. Larger associations between current solid fuel use and intensity of use with lower eGFR and prevalent CKD were observed among participants in southern China, those with hypertension or diabetes (eGFR only), and females (CKD only), through these groups had small sample sizes and some confidence intervals included the null. CONCLUSION: We found inconsistent evidence associating household solid fuel use and renal function in this cross-sectional study of peri-urban Chinese adults.

Small High-Density Lipoprotein and Omega-3 Fatty Acid Intake Differentiates Japanese and Japanese-Americans: The INTERLIPID Study.

AIM: To identify the most differentiated serum lipids, especially concerning particle size and fractions, between Japanese living in Japan and Japanese-Americans in Hawaii, in the absence of possible genetic confounders, and cross-sectionally examine the associated modifiable lifestyle factors. METHODS: Overall, 1,241 (aged 40-59 years) Japanese living in Japan and Japanese-Americans in Hawaii were included. We quantified 130 serum lipid profiles (VLDL 1-5, IDL, LDL 1-6, high-density lipoprotein [HDL] 1-4, and their subfractions) using Bruker's 1H-nuclear magnetic resonance spectrometer for the primary outcome. Modifiable lifestyle factors included body mass index (BMI), physical activity, alcohol and smoking habits, and 70 nutrient parameters. We evaluated the different lipids between the groups using partial least squares-discriminant analysis and association between extracted lipids and lifestyle factors using multivariable linear regression analysis. RESULTS: Concentrations of HDL4, HDL with the smallest particle size, were lower in Japanese than in Japanese-Americans of both sexes. Higher fish-derived omega-3 fatty acid intake and lower alcohol intake were associated with lower HDL4 concentrations. A 1% higher kcal intake of total omega-3 fatty acids was associated with a 9.8-mg/dL lower HDL4. Fish-derived docosapentaenoic acid, eicosapentaenoic acid, and docosahexaenoic acid intake were inversely associated with HDL4 concentration. There was no relationship between country, sex, age, or BMI. CONCLUSIONS: Japanese and Japanese-Americans can be differentiated based on HDL4 concentration. High fish intake among the Japanese may contribute to their lower HDL4 concentration. Thus, HDL particle size may be an important clinical marker for coronary artery diseases or a fish consumption biomarker.

Circulating plasma phospholipid fatty acid levels as a biomarker of habitual dietary fat intake: The INTERMAP/INTERLIPID Study.

BACKGROUND: Accurate assessment of fat intake is essential to examine relationships between diet and disease risk. However, estimating individual intakes of fat quantity by dietary assessment is difficult. OBJECTIVE: We assessed the association of plasma phospholipid fatty acid levels with dietary intake of fatty acids in the INTERMAP/INTERLIPID study, conducted with a standardized protocol. METHODS: The study participants were 1339 men and women ages 40-59 years from five Japanese populations one from Hawaii; four from Japan. Fatty acid intake was estimated from four standardized 24-hour dietary recalls. Plasma phospholipid fatty acid composition was analyzed by gas chromatography. We illustrated the relationship between intake and circulating fatty acid levels using Spearman's rank-correlation coefficients, mean, and median values. RESULTS: Spearman's rank-correlation coefficients between intake (g/d) and circulating fatty acid levels (µg/ml) were -0.03 to 0.21 for saturated fatty acids and monounsaturated fatty acids and -0.04 to 0.32 for trans fatty acids. The coefficients for essential n-3 and n-6 fatty acids were moderate to high, especially for eicosapentaenoic acid (EPA), 0.60; docosahexaenoic acid (DHA), 0.41; and EPA+DHA, 0.51. The circulating levels and intake of marine-derived n-3 fatty acids showed a linear association, at least for the intake of EPA+DHA up to 2.1 g/d. CONCLUSION: We observed high correlation between intake and circulating levels of marine-derived n-3 fatty acids in participants from Japanese and Japanese-American populations with high and low fish intake. Plasma phospholipid marine-derived n-3 fatty acid measurements are a simple and reliable biomarker for assessing dietary intake.

Plasma metabolites associated with cognitive function across race/ethnicities affirming the importance of healthy nutrition.

INTRODUCTION: We studied the replication and generalization of previously identified metabolites potentially associated with global cognitive function in multiple race/ethnicities and assessed the contribution of diet to these associations. METHODS: We tested metabolite-cognitive function associations in U.S.A. Hispanic/Latino adults (n = 2222) from the Community Health Study/ Study of Latinos (HCHS/SOL) and in European (n = 1365) and African (n = 478) Americans from the Atherosclerosis Risk In Communities (ARIC) Study. We applied Mendelian Randomization (MR) analyses to assess causal associations between the metabolites and cognitive function and between Mediterranean diet and cognitive function. RESULTS: Six metabolites were consistently associated with lower global cognitive function across all studies. Of these, four were sugar-related (e.g., ribitol). MR analyses provided weak evidence for a potential causal effect of ribitol on cognitive function and bi-directional effects of cognitive performance on diet. DISCUSSION: Several diet-related metabolites were associated with global cognitive function across studies with different race/ethnicities. HIGHLIGHTS: Metabolites associated with cognitive function in Puerto Rican adults were recently identified. We demonstrate the generalizability of these associations across diverse race/ethnicities. Most identified metabolites are related to sugars. Mendelian Randomization (MR) provides weak evidence for a causal effect of ribitol on cognitive function. Beta-cryptoxanthin and other metabolites highlight the importance of a healthy diet.

The Winchcombe meteorite, a unique and pristine witness from the outer solar system.

Direct links between carbonaceous chondrites and their parent bodies in the solar system are rare. The Winchcombe meteorite is the most accurately recorded carbonaceous chondrite fall. Its pre-atmospheric orbit and cosmic-ray exposure age confirm that it arrived on Earth shortly after ejection from a primitive asteroid. Recovered only hours after falling, the composition of the Winchcombe meteorite is largely unmodified by the terrestrial environment. It contains abundant hydrated silicates formed during fluid-rock reactions, and carbon- and nitrogen-bearing organic matter including soluble protein amino acids. The near-pristine hydrogen isotopic composition of the Winchcombe meteorite is comparable to the terrestrial hydrosphere, providing further evidence that volatile-rich carbonaceous asteroids played an important role in the origin of Earth's water.

Investigation of the urinary sodium-to-potassium ratio target level based on the recommended dietary intake goals for the Japanese population: The INTERMAP Japan.

Growing epidemiological evidence has shown an association of the urinary sodium (Na) to potassium (K) ratio (Na/K ratio) with blood pressure and cardiovascular diseases. However, no clear cutoff level has been defined. We investigated the cutoff level of the urinary Na/K ratio under different dietary guidelines for Japanese individuals, especially that endorsed by the 2020 revised Japanese Dietary Reference Intakes (DRIs). A population of 1145 Japanese men and women aged 40 to 59 years from the INTERMAP study was examined. Using high-quality standardized data, the averages of two 24 h urinary collections and four 24 h dietary recalls were used to calculate the 24 h urinary and dietary Na/K ratios, respectively. Associations between the urinary and dietary Na/K ratios were tested by sex- and age-adjusted partial correlation. The optimal urinary Na/K ratio cutoff level was determined by receiver operating characteristic (ROC) curves and sex-specific cross tables for recommended dietary K and salt. Overall, the average molar ratio of 24 h urinary Na/K was 4.3. We found moderate correlations (P < 0.001) of the 24 h urinary Na/K ratio with 24 h urinary Na and K excretion (r = 0.52, r = -0.49, respectively) and the dietary Na/K ratio (r = 0.53). ROC curves showed that a 24 h urinary Na/K ratio of approximately 2 predicted Na and K intake that meets the dietary goals of the Japanese DRIs. The range of urinary Na/K ratios meeting the dietary goals of the Japanese DRIs for both Na and K was 1.6‒2.2 for men and 1.7‒1.9 for women. Accomplishing a urinary Na/K ratio of 2 would be desirable to achieve the DRIs dietary goals for both Na and K simultaneously in middle-aged Japanese men and women accustomed to Japanese dietary habits. This observational study is registered at www.clinicaltrials.gov as NCT00005271.

The diagnostic value of multiparameter cardiovascular magnetic resonance for early detection of light-chain amyloidosis from hypertrophic cardiomyopathy patients.

Background: Early-stage amyloidosis of the heart is prone to be underdiagnosed or misdiagnosed, increasing the risk of early heart failure and even death of the patient. To ensure timely intervention for cardiac light-chain amyloidosis (AL CA), it is vital to develop an effective tool for early identification of the disease. Recently, multiparameter cardiovascular magnetic resonance (CMR) has been used as a comprehensive tool to assess myocardial tissue characterization. We aimed to investigate the difference in left ventricular (LV) strain, native T1, extracellular volume (ECV), and late gadolinium enhancement (LGE) between AL CA patients, hypertrophic cardiomyopathy patients (HCM), and healthy control subjects (HA). Moreover, we explored the value of multiparameter CMR for differential diagnosis of the early-stage AL CA patients from HCM patients, who shared similar imaging characteristics under LGE imaging. Methods: A total of 38 AL CA patients, 16 HCM patients, and 17 HA people were prospectively recruited. All subjects underwent LGE imaging, Cine images, and T1 mapping on a 3T scanner. The LV LGE pattern was recorded as none, patchy or global. LV strain, native T1, and ECV were measured semi-automatically using dedicated CMR software. According to clinical and biochemical markers, all patients were classified as Mayo stage I/II and Mayo stage IIIa/IIIb. Univariable and multivariable logistic regression models were utilized to identify independent predictors of early-stage AL CA from HCM patients. Receiver operator characteristic (ROC) curve analysis and Youden's test were done to determine the accuracy of multiparameter CMR in diagnosing Mayo stage I/II AL CA and establish a cut-off value. Results: For Mayo stage I/II AL CA patients, the global longitudinal strain (GLS) absolute value (11.9 ± 3.0 vs. 9.5 ± 1.8, P < 0.001) and the global circumferential strain (GCS) absolute value (19.0 ± 3.6 vs. 9.5 ± 1.8, P < 0.001) were significantly higher than in HCM patients. The native T1 (1334.9 ± 49.9 vs. 1318.2 ± 32.4 ms, P < 0.0001) and ECV values (37.8 ± 5.7 vs. 31.3 ± 2.5%, P < 0.0001) were higher than that of HCM patients. In multiparameter CMR models, GCS (2.097, 95% CI: 1.292-3.403, P = 0.003), GLS (1.468, 95% CI: 1.078-1.998, P = 0.015), and ECV (0.727, 95% CI: 0.569-0.929, P = 0.011) were the significant variables for the discrimination of the early-stage AL CA patients from HCM patients. ROC curve analysis and Youden's test were used on GCS, GLS, ECV, and pairwise parameters for differentiating between Mayo stage I/II AL CA and HCM patients, respectively. The combination of GLS, GCS, and ECV mapping could distinguish Mayo stage I/II AL amyloidosis patients from hypertrophic cardiomyopathy with excellent performance (AUC = 0.969, Youden index = 0.813). Conclusion: In early-stage AL CA patients with atypical LGE, who had similar imaging features as HCM patients, ECV mapping, GCS, and GLS were correlated with the clinical classification of the patients. The combination of GCS, GLS, and ECV could differentiate early-stage AL CA from HCM patients. Multiparameter CMR has the potential to provide an effective and quantitative tool for the early diagnosis of myocardial amyloidosis.

Uncertainty-aware self-supervised neural network for liverT1ρmapping with relaxation constraint.

Objective.T1ρmapping is a promising quantitative MRI technique for the non-invasive assessment of tissue properties. Learning-based approaches can mapT1ρfrom a reduced number ofT1ρweighted images but requires significant amounts of high-quality training data. Moreover, existing methods do not provide the confidence level of theT1ρestimation. We aim to develop a learning-based liverT1ρmapping approach that can mapT1ρwith a reduced number of images and provide uncertainty estimation.Approach. We proposed a self-supervised neural network that learns aT1ρmapping using the relaxation constraint in the learning process. Epistemic uncertainty and aleatoric uncertainty are modelled for theT1ρquantification network to provide a Bayesian confidence estimation of theT1ρmapping. The uncertainty estimation can also regularize the model to prevent it from learning imperfect data. Main results. We conducted experiments onT1ρdata collected from 52 patients with non-alcoholic fatty liver disease. The results showed that when only collecting twoT1ρ-weighted images, our method outperformed the existing methods forT1ρquantification of the liver. Our uncertainty estimation can further regularize the model to improve the performance of the model and it is consistent with the confidence level of liverT1ρvalues.Significance. Our method demonstrates the potential for accelerating theT1ρmapping of the liver by using a reduced number of images. It simultaneously provides uncertainty ofT1ρquantification which is desirable in clinical applications.

Abnormal Cerebral Blood Flow and Volumetric Brain Morphometry in Patients With Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is a serious breathing disorder, leading to myocardial infarction, high blood pressure, and stroke. Brain morphological changes have been widely reported in patients with OSA. The pathophysiological mechanisms of cerebral blood flow (CBF) changes associated with OSA are not clear. In this study, 20 patients with OSA and 36 healthy controls (HCs) were recruited, and then pseudo-continuous arterial spin labeling (pCASL) and voxel-based morphometry (VBM) methods were utilized to explore blood perfusion and morphological changes in the patients with OSA. Compared with the HC group, the OSA group showed increased CBF values in the right medial prefrontal cortex (mPFC), left precentral gyrus, and right insula and showed decreased CBF values in the right temporal pole (TP) and the right cerebellum_Crus2. Compared with the HC group, the patients with OSA showed decreased gray matter volume (GMV) in the right dorsal lateral prefrontal cortex (DLPFC), the right occipital pole, and the vermis. There were no significantly increased GMV brain regions found in patients with OSA. Pearson correlation analysis showed that the reduced GMV in the right DLPFC and the right occipital pole was both positively correlated with Mini-Mental State Examination (MMSE) (r = 0.755, p < 0.001; r = 0.686, p = 0.002) and Montreal Cognitive Assessment (MoCA) scores (r = 0.716, p = 0.001; r = 0.601, p = 0.008), and the reduced GMV in the right occipital pole was negatively correlated with duration of illness (r = -0.497, p = 0.036). Patients with OSA have abnormal blood perfusion metabolism and morphological changes in brain regions including the frontal lobe and the cerebellum and were closely related to abnormal behavior, psychology, and cognitive function, which play an important role in the pathophysiological mechanism of OSA.