Publications by authors named "Steven D Buchthal"

Background And Aims: Body fat distribution, i.e., visceral (VAT), subcutaneous adipose tissue (SAT) and intramuscular fat, is important for disease prevention, but sex and ethnic differences are not well understood.

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Objective: Given the importance of body fat distribution in chronic disease development, feasible methods to assess body fat are essential. This study compared dual-energy x-ray absorptiometry (DXA) in measuring visceral and subcutaneous adipose tissue (VAT and SAT) with magnetic resonance imaging (MRI).

Methods: VAT and SAT were assessed using similar DXA and MRI protocols among 1,795 elderly participants of the Adiposity Phenotype Study (APS) and 309 children/adolescents in Shape Up! Kids (SKids).

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Purpose: Visceral adipose tissue (VAT) may be more important than subcutaneous fat in type 2 diabetes (T2D) etiology. We examined a VAT score developed in reference to MRI measurement of VAT in the Multiethnic Cohort (MEC) as a risk factor for incident T2D.

Methods: Two nested case-control studies of cancer allowed calculation of the VAT score based on anthropometric measures and 8 biomarkers among 2,556 participants without T2D.

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Objectives: As rates of obesity around the world have increased, so has the detection of high level of liver fat in children and adolescents. This may put them at risk for cardiovascular disease later in life. This analysis of a cross-sectional population-based study of children and adolescents evaluated demographic and lifestyle determinants of percent liver fat.

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Background: As the proportion of visceral (VAT) to subcutaneous adipose tissue (SAT) may contribute to type 2 diabetes (T2D) development, we examined this relation in a cross-sectional design within the Multiethnic Cohort that includes Japanese Americans known to have high VAT. The aim was to understand how ectopic fat accumulation differs by glycemic status across ethnic groups with disparate rates of obesity, T2D, and propensity to accumulate VAT.

Methods: In 2013-2016, 1,746 participants aged 69.

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Background/objective: As dietary intake and endocrine metabolism are vastly different by sex, we evaluated differences in the association of diet quality with body composition between men and women.

Subjects/methods: Close to 2000 participants from the Multiethnic Cohort completed calibrated quantitative food frequency questionnaires at cohort entry (1993-96) and clinic visit (2013-16), from which the Healthy Eating Index (HEI-2010) was computed. Adiposity measures were obtained through DXA and MRI at clinic visit.

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Objective: The relationship of diet quality assessed by established indices (HEI-2010, AHEI-2010, aMED, DASH) with adiposity measures was examined, especially visceral adipose tissue (VAT) and nonalcoholic fatty liver (NAFL).

Methods: Close to 2,000 participants of the Multiethnic Cohort completed validated food frequency questionnaires at cohort entry (1993-1996) and clinic visit (2013-2016) when they underwent whole-body dual-energy x-ray absorptiometry and abdominal magnetic resonance imaging scans. Linear regression was used to estimate mean values of adiposity measures by dietary index tertiles at baseline and standardized regression coefficients (β ) after adjusting for total adiposity and other covariates.

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Importance: The very early postnatal period witnesses extraordinary rates of growth, but structural brain development in this period has largely not been explored longitudinally. Such assessment may be key in detecting and treating the earliest signs of neurodevelopmental disorders.

Objective: To assess structural growth trajectories and rates of change in the whole brain and regions of interest in infants during the first 3 months after birth.

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Background: We hypothesized that the degree of preserved functional connectivity within the DMN during the first week after cardiopulmonary arrest (CPA) would be associated with functional outcome at hospital discharge.

Methods: Initially comatose CPA survivors with indeterminate prognosis at 72 h were enrolled. Seventeen CPA subjects between 4 and 7 days after CPA and 17 matched controls were studied with task-free fMRI.

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Genome-wide association studies have identified common genetic variants that can contribute specifically to the risk of abdominal adiposity, as measured by waist circumference or waist-to-hip ratio. However, it is unknown whether these genetic risk factors affect relative body fat distribution in the abdominal visceral and subcutaneous compartments. The association between imaging-based abdominal fat mass and waist-size risk variants in the FTO, LEPR, LYPLAL1, MSRA, NRXN3, and TFAP2B genes was investigated.

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The prevalence of type 2 diabetes is greater among African Americans (AA) vs. European Americans (EA), independent of obesity and lifestyle. We tested the hypothesis that intramyocellular lipid (IMCL) or extramycellular lipid (EMCL) would be associated with insulin sensitivity among healthy young women, and that the associations would differ with ethnic background.

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Intramyocellular lipid (IMCL) has been inversely associated with insulin sensitivity in some, but not all, studies. This study utilized fast, high-resolution, magnetic resonance spectroscopic imaging (MRSI) to: investigate relationships between muscle lipids (IMCL and extramyocellular lipid (EMCL)) and insulin sensitivity in muscles of varying oxidative capacity, explore ethnic differences in these relationships, and determine whether a eucaloric, low-fat dietary intervention would reduce IMCL and increase insulin sensitivity. Subjects were 30 healthy, African-American (AA; n=14) and European-American (EA; n=16) males, BMI 26.

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in vivo (1)H MRS reveals reduced N-acetylaspartate (NAA) and elevated myo-inositol (mI) in patients with mild Alzheimer's disease (AD) and patients with amnestic mild cognitive impairment (MCI). We are unaware of studies that have documented abnormal scyllo-inositol (sI) levels in patients with AD or patients with MCI, although a previous MRS study in older adults has indicated that sI is a peak of interest to measure in AD. Fifteen patients with mild AD, 26 patients with amnestic MCI, and 19 healthy older adults were recruited to this study.

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To determine whether vitreous lactate concentrations are correlated with intraocular pressure (IOP) rise, retinal ganglion cell (RGC) damage, and nerve fiber layer (NFL) thickness decrease in a rabbit model of ocular hypertension. Also, to learn whether proton nuclear magnetic resonance ((1)H-NMR) spectroscopy can provide sequential, non-invasive in vivo measurements of vitreous lactate. Intra-anterior chamber injections of 20-mum latex beads were used to impede aqueous drainage in New Zealand White rabbits, causing an elevation of IOP.

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Background: We previously reported that 20% of women with chest pain but without obstructive coronary artery disease (CAD) had stress-induced reduction in myocardial phosphocreatine-adenosine triphosphate ratio by phosphorus-31 nuclear magnetic resonance spectroscopy (abnormal MRS), consistent with myocardial ischemia. The prognostic implications of these findings are unknown.

Methods And Results: Women referred for coronary angiography for suspected myocardial ischemia underwent MRS handgrip stress testing and follow-up evaluation.

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Background: Previous studies showed low resting phosphocreatine/adenosine triphosphate (PCr/ATP) ratios within this patient population compared with controls; however, these low PCr/ATP did not correlate with endomyocardial biopsy rejection. One possible explanation is the presence of cardiac allograft vasculopathy (CAV), which might be manifested as a transient ischemic event in the mildly stressed transplanted heart. If transient ischemia is invoked through the (31)P magnetic resonance spectroscopy (MRS) stress test, monitoring of such an event should be achievable and thus implicating possible ischemic involvement.

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The phosphocreatine (PCr) overshoot is a well-documented phenomenon and is readily observable by 31P MRS. In addition, a second 31P MRS observation during ischemia with reperfusion is a diminution in ATP levels. Combining these two as the 'PCr Overshoot' the PCr/ATP ratio may provide an index of viability.

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