Learning associations between clinical information and motion-based descriptors using a large scale MR-derived cardiac motion atlas

The availability of large scale databases containing imaging and non-imaging data, such as the UK Biobank, represents an opportunity to improve our understanding of healthy and diseased bodily function. Cardiac motion atlases provide a space of reference in which the motion fields of a cohort of subjects can be directly compared. In this work, a cardiac motion atlas is built from cine MR data from the UK Biobank (~ 6000 subjects). Two automated quality control strategies are proposed to reject subjects with insufficient image quality. Based on the atlas, three dimensionality reduction algorithms are evaluated to learn data-driven cardiac motion descriptors, and statistical methods used to study the association between these descriptors and non-imaging data. Results show a positive correlation between the atlas motion descriptors and body fat percentage, basal metabolic rate, hypertension, smoking status and alcohol intake frequency. The proposed method outperforms the ability to identify changes in cardiac function due to these known cardiovascular risk factors compared to ejection fraction, the most commonly used descriptor of cardiac function. In conclusion, this work represents a framework for further investigation of the factors influencing cardiac health.Comment: 2018 International Workshop on Statistical Atlases and Computational Modeling of the Hear

Heavy Drinking Is Associated with Poor Blood Pressure Control in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Alcohol intake has been shown to have a J-shaped association with blood pressure (BP). However, this association has not been examined in mixed race populations or in people with diabetes where tighter blood pressure control is recommended. Participants in the REGARDS study who were 45 years or older (n = 30,239) were included. Medical history (including self-reported alcohol intake) was collected by telephone while blood collection and clinical measurements were done during an in-home visit. We defined diabetes as use of medications and/or fasting glucose ≥ 126 mg/dL and hypertension as use of blood pressure lowering medications and/or BP ≥ 140/90 mmHg or BP ≥ 130/80 mmHg in people with diabetes. After adjustment for confounders, heavy drinking was associated with an increased odds of hypertension (OR = 1.59; 95% CI = 1.37, 1.87). Diabetes and gender significantly modified (interaction P < 0.05 for both) the association between alcohol use and hypertension, although heavy drinking remained associated with increased odds of hypertension in sub-group analyses. We did not observe the previously described J-shaped relationship in any sub-group except white females. These data suggest heavy alcohol consumption is associated with poor BP control and that heavy drinkers may want to consider limiting alcohol intake in order to manage hypertension

Fibroblast Growth Factor–23 and Cardiac Structure and Function

Background: Fibroblast growth factor–23 (FGF‐23) is a phosphaturic factor previously associated with left ventricular hypertrophy and systolic dysfunction among individuals with chronic kidney disease. Whether FGF‐23 acts directly to induce left ventricular hypertrophy, potentially independent of its klotho coreceptor, remains uncertain. We investigated associations of FGF‐23 with cardiac structural abnormalities among individuals with a broad range of kidney function and explored potential biological mechanisms using cardiac magnetic resonance imaging and histology in klotho‐null mice, an established model of constitutively elevated FGF‐23. Methods and Results: Among 887 participants with coronary artery disease in the Heart and Soul Study, FGF‐23 was modestly associated with worse left ventricular ejection fraction (−1.0% per standard deviation increase in lnFGF‐23; standard error, 0.4%), but was not associated with the overall prevalence of concentric hypertrophy (odds ratio, 1.5; CI, 0.9 to 2.4) or eccentric hypertrophy (odds ratio, 1.1; CI, 0.9 to 1.3). FGF‐23 was only associated with concentric hypertrophy among individuals with diminished kidney function (eGFR <60 mL/min per 1.73 m2; odds ratio, 2.3; CI, 1.0 to 5.3; P‐interaction=0.28). Comparing klotho‐null with wild‐type mice, null mice did not have greater left ventricular mass (P=0.37) or a lower ejection fraction (P=0.94). Conclusions: Together, our results suggest that FGF‐23 is unlikely to have major effects on cardiovascular structure and function among patients free of substantial chronic kidney disease, and these effects may not be independent of the klotho coreceptor

Proton-pump inhibitor use is associated with low serum magnesium concentrations

Although case reports link proton-pump inhibitor (PPI) use and hypomagnesemia, no large-scale studies have been conducted. Here we examined the serum magnesium concentration and the likelihood of hypomagnesemia ( < 1.6 mg/dl) with a history of PPI or histamine-2 receptor antagonist used to reduce gastric acid, or use of neither among 11,490 consecutive adult admissions to an intensive care unit of a tertiary medical center. Of these, 2632 patients reported PPI use prior to admission, while 657 patients were using a histamine-2 receptor antagon ist. PPI use was associated with 0.012 mg/dl lower adjusted serum magnesium concentration compared to users of no acid-suppressive medications, but this effect was restricted to those patients taking diuretics. Among the 3286 patients concurrently on diuretics, PPI use was associated with a significant increase of hypomagnesemia (odds ratio 1.54) and 0.028 mg/dl lower serum magnesium concentration. Among those not using diuretics, PPI use was not associated with serum magnesium levels. Histamine-2 receptor antagonist use was not significantly associated with magnesium concentration without or with diuretic use. The use of PPI was not associated with serum phosphate concentration regardless of diuretic use. Thus, we verify case reports of the association between PPI use and hypomagnesemia in those concurrently taking diuretics. Hence, serum magnesium concentrations should be followed in susceptible individuals on chronic PPI therapy.National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant 2R01 EB001659

Genetically Elevated Fetuin-A Levels, Fasting Glucose Levels, and Risk of Type 2 Diabetes: The Cardiovascular Health Study*

OBJECTIVE Fetuin-A levels are associated with higher risk of type 2 diabetes, but it is unknown if the association is causal. We investigated common (>5%) genetic variants in the fetuin-A gene (AHSG) fetuin-A levels, fasting glucose, and risk of type 2 diabetes. RESEARCH DESIGN AND METHODS Genetic variation, fetuin-A levels, and fasting glucose were assessed in 2,893 Caucasian and 542 African American community-living individuals 65 years of age or older in 1992–1993. RESULTS Common AHSG variants (rs4917 and rs2248690) were strongly associated with fetuin-A concentrations (P < 0.0001). In analyses of 259 incident cases of type 2 diabetes, the single nucleotide polymorphisms (SNPs) were not associated with diabetes risk during follow-up and similar null associations were observed when 579 prevalent cases were included. As expected, higher fetuin-A levels were associated with higher fasting glucose concentrations (1.9 mg/dL [95% CI, 1.2–2.7] higher per SD in Caucasians), but Mendelian randomization analyses using both SNPs as unbiased proxies for measured fetuin-A did not support an association between genetically predicted fetuin-A levels and fasting glucose (−0.3 mg/dL [95% CI, −1.9 to 1.3] lower per SD in Caucasians). The difference between the associations of fasting glucose with actual and genetically predicted fetuin-A level was statistically significant (P = 0.001). Results among the smaller sample of African Americans trended in similar directions but were statistically insignificant. CONCLUSIONS Common variants in the AHSG gene are strongly associated with plasma fetuin-A concentrations, but not with risk of type 2 diabetes or glucose concentrations, raising the possibility that the association between fetuin-A and type 2 diabetes may not be causal

Soluble CD14 and CD14 Variants, Other Inflammatory Markers, and Glucose Dysregulation in Older Adults: The Cardiovascular Health Study

ObjectiveExperimental studies have implicated soluble (s)CD14, an effector of lipopolysaccharide-induced inflammation, in insulin resistance, but its role in human metabolic endotoxemia has not been studied. We evaluated sCD14 in relation to dysglycemia in older adults and how this compares to other markers of inflammation.Research design and methodsWe investigated associations of sCD14, interleukin-6 (IL-6), CRP, and white blood cell (WBC) count with insulin resistance (quantitative insulin-sensitivity check index and HOMA 2 of insulin resistance) and incident type 2 diabetes in a population-based cohort of older adults. We also assessed the causal role of sCD14 in insulin resistance using an instrumental variable approach by Mendelian randomization.ResultsAfter adjustment for conventional risk factors, each of the four biomarkers showed positive cross-sectional associations with both insulin resistance measures. These associations persisted after mutual adjustment for all markers except sCD14. Over a median follow-up of 11.6 years, 466 cases of diabetes occurred. All biomarkers except sCD14 were positively associated with diabetes, although only WBC count remained associated (hazard ratio 1.43 per doubling [95% CI 1.07, 1.90]) after mutual adjustment. Instrumental variable analysis did not support a causal role for sCD14 in insulin resistance.ConclusionsAmong older adults, sCD14 was associated with insulin resistance, but this disappeared after adjustment for other biomarkers, showed no evidence of a causal basis, and was not accompanied by a similar association with diabetes. IL-6, CRP, and WBC count were each associated with insulin resistance and diabetes, WBC count most robustly. These findings do not support a central role for sCD14, but they highlight the preeminence of WBC count as an inflammatory measure of diabetes risk in this population

Hemoglobin A1c and Arterial and Ventricular Stiffness in Older Adults

Objective: Arterial and ventricular stiffening are characteristics of diabetes and aging which confer significant morbidity and mortality; advanced glycation endproducts (AGE) are implicated in this stiffening pathophysiology. We examined the association between HbA1c, an AGE, with arterial and ventricular stiffness measures in older individuals without diabetes. Research Design & Methods: Baseline HbA1c was measured in 830 participants free of diabetes defined by fasting glucose or medication use in the Cardiovascular Health Study, a population-based cohort study of adults aged ≥65 years. We performed cross-sectional analyses using baseline exam data including echocardiography, ankle and brachial blood pressure measurement, and carotid ultrasonography. We examined the adjusted associations between HbA1c and multiple arterial and ventricular stiffness measures by linear regression models and compared these results to the association of fasting glucose (FG) with like measures. Results: HbA1c was correlated with fasting and 2-hour postload glucose levels (r = 0.21; p<0.001 for both) and positively associated with greater body-mass index and black race. In adjusted models, HbA1c was not associated with any measure of arterial or ventricular stiffness, including pulse pressure (PP), carotid intima-media thickness, ankle-brachial index, end-arterial elastance, or left ventricular mass (LVM). FG levels were positively associated with systolic, diastolic and PP and LVM. Conclusions: In this sample of older adults without diabetes, HbA1c was not associated with arterial or ventricular stiffness measures, whereas FG levels were. The role of AGE in arterial and ventricular stiffness in older adults may be better assessed using alternate AGE markers

Total and High-Molecular-Weight Adiponectin and Risk of Incident Diabetes in Older People

OBJECTIVE To delineate the associations of total adiponectin, high-molecular-weight (HMW) adiponectin, and the HMW-to-total adiponectin ratio with diabetes in older adults. RESEARCH DESIGN AND METHODS Total and HMW adiponectin were measured in a population-based study of older adults. The relations of total adiponectin, HMW adiponectin, and their ratio with incident diabetes (n = 309) were assessed in 3,802 individuals. RESULTS Total and HMW adiponectin were highly correlated (r = 0.94). Analysis using cubic splines revealed that the associations between total and HMW adiponectin and new-onset diabetes were not linear. Specifically, after adjustment for confounders, there were similar inverse relationships for total (hazard ratio per SD 0.49 [95% CI 0.39–0.63]) and HMW adiponectin (0.42 [0.32–0.56]) with diabetes up to values of 20 and 10 mg/L, respectively, above which the associations plateaued. These associations persisted after adjustment for potential mediators (blood pressure, lipids, C-reactive protein, and homeostasis model assessment of insulin resistance [HOMA-IR]). There was, however, evidence of interaction by HOMA-IR in the lower range of adiponectin, with stronger inverse associations among insulin-sensitive than insulin-resistant participants. HMW-to-total adiponectin ratio showed a linear adjusted association with outcome, but this was abolished by inclusion of mediating variables. CONCLUSIONS In this older cohort, increasing concentrations of total and HMW adiponectin were associated with comparably lower risks of diabetes, but these associations leveled off with further increases above concentrations of 20 and 10 mg/L, respectively. The more pronounced risk decreases at the lower range among participants without insulin resistance support a role for adiponectin that is independent of baseline hyperinsulinemia, but this will require further investigation

Kidney International advance online publication

There are few reports of associations between alcohol consumption and risk of chronic kidney disease (CKD). To investigate this further, we studied 5476 participants aged 28-75 years in the Prevention of Renal and Vascular EndStage Disease (PREVEND) study, a prospective populationbased cohort, who were free of CKD at baseline (1997/1998). Alcohol consumption was self-reported on a questionnaire validated against serum high-density lipoprotein cholesterol. The primary outcome was de novo CKD defined as a combination of a creatinine-cystatin C-based estimated glomerular filtration rate (eGFR) under 60 ml/min per 1.73 m 2 and/or the mean of two consecutive 24-h urinary albumin excretions over 30 mg. During four serial follow-up examinations (median 10.2 years until February 2012), 903 participants developed CKD. Compared with those abstaining from alcohol, the multivariable-adjusted hazard ratios (95% confidence interval) for CKD risk were 0.85 (0.69-1.04) for occasional (under 10 g/week), 0.82 (0.69-0.98) for light (10-69.9 g/week), 0.71 (0.58-0.88) for moderate (70-210 g/week), and 0.60 (0.42-0.86) for heavier (over 210 g/week) alcohol consumers (significant trend). Similar inverse associations for alcohol consumption were found when CKD was defined as eGFR o60 ml/min per 1.73 m 2 or as 24-h urinary albumin excretion over 30 mg. Thus, in this population-based cohort, alcohol consumption was inversely associated with the risk of developing CKD