Systematic and random errors based on self-reported diet may bias estimates of dietary intake. The objective of this pilot study was to describe errors in self-reported dietary intake by comparing 24 h dietary recalls to provided menu items in a controlled feeding study. This feeding study was a parallel randomized block design consisting of a standard diet (STD; 15% protein, 50% carbohydrate, 35% fat) followed by either a high-fat (HF; 15% protein, 25% carbohydrate, 60% fat) or a high-carbohydrate (HC; 15% protein, 75% carbohydrate, 10% fat) diet.
View Article and Find Full Text PDFRisk of severe disease and death due to COVID-19 is increased in certain patient demographic groups, including those of advanced age, male sex, and obese body mass index. Investigations of the biological variations that contribute to this risk have been hampered by heterogeneous severity, with immunologic features of critical disease potentially obscuring differences between risk groups. To examine immune heterogeneity related to demographic risk factors, we enrolled 38 patients hospitalized with clinically homogeneous COVID-19 pneumonia - defined as oxygen saturation less than 94% on room air without respiratory failure, septic shock, or multiple organ dysfunction - and performed single-cell RNA-Seq of leukocytes collected at admission.
View Article and Find Full Text PDFBackground: In people with obesity, β-cell function may adapt to insulin resistance. We describe β-cell function in people with severe obesity and normal fasting glucose (NFG), impaired fasting glucose (IFG), and type 2 diabetes (T2DM), as assessed before, 3 to 6 months after, and 2 years after medical weight loss to describe its effects on insulin sensitivity, insulin secretion, and β-cell function.
Methods: Fifty-eight participants with body mass index (BMI) ≥ 35 kg/m2 (14 with NFG, 24 with IFG, and 20 with T2DM) and 13 normal weight participants with NFG underwent mixed meal tolerance tests to estimate insulin sensitivity (S[I]), insulin secretion (Φ), and β-cell function assessed as model-based Φ adjusted for S(I).
Local inflammation in obese adipose tissue has been shown to contribute to insulin resistance; however, the role of macrophage infiltration within skeletal muscle is still debatable. This study aimed to evaluate the association of skeletal muscle macrophage gene expression with adiposity levels and insulin sensitivity in obese patients. Twenty-two nondiabetic obese patients and 23 healthy lean controls were included.
View Article and Find Full Text PDFIn recent years, mass spectrometry-based metabolomics has increasingly been applied to large-scale epidemiological studies of human subjects. However, the successful use of metabolomics in this context is subject to the challenge of detecting biologically significant effects despite substantial intensity drift that often occurs when data are acquired over a long period or in multiple batches. Numerous computational strategies and software tools have been developed to aid in correcting for intensity drift in metabolomics data, but most of these techniques are implemented using command-line driven software and custom scripts which are not accessible to all end users of metabolomics data.
View Article and Find Full Text PDFObjective: To examine the independent contributions of objectively measured sleep duration and fragmentation on cardiometabolic risk accumulation in free-living obese adolescents.
Study Design: Characteristics of metabolic syndrome (waist circumference, mean arterial pressure, fasting high-density lipoprotein cholesterol, triglycerides, glucose) were measured in obese adolescents and standardized residuals (z-scores) were summed (inverse high-density lipoprotein cholesterol) to create a continuous cardiometabolic risk score (cMetScore), adjusted for age, sex, and race. Sleep and physical activity were objectively measured in habitual, free-living conditions for 7 days (SenseWear Pro3, BodyMedia, Pittsburgh, Pennsylvania; n = 37; 54% female, ages 11-17 years).
We assessed the influence of serum 25-hydroxyvitamin D (25[OH]D) and parathyroid hormone (PTH) concentrations on oral glucose tolerance, body composition, and muscle strength in older, nondiabetic adults who performed resistance exercise training (RT) while consuming diets with either 0.9 or 1.2 g protein kg(-1) d(-1).
View Article and Find Full Text PDFBackground: Pediatric weight management programs have substantial attrition rates, which have led to recommendations to assess readiness prior to enrollment. Both pretreatment readiness scales and behaviors, such as exercise, have been theorized to predict subsequent program completion. The purpose of this study was to explore the role of self-reported pretreatment exercise in adolescents on completion of a pediatric weight management program and to explore the predictive ability of standard readiness scales.
View Article and Find Full Text PDFJ Gerontol A Biol Sci Med Sci
September 2013
To develop a global view of muscle transcriptional differences between older men and women and sex-specific aging, we obtained muscle biopsies from the biceps brachii of young and older men and women and profiled the whole-genome gene expression using microarray. A logistic regression-based method in combination with an intensity-based Bayesian moderated t test was used to identify significant sex- and aging-related gene functional groups. Our analysis revealed extensive sex differences in the muscle transcriptome of older individuals and different patterns of transcriptional changes with aging in men and women.
View Article and Find Full Text PDFBackground: The purpose of this study was to determine the sex-specific pattern of pediatric cardiometabolic risk with principal component analysis, using several biological, behavioral and parental variables in a large cohort (n = 2866) of 6th grade students.
Methods: Cardiometabolic risk components included waist circumference, fasting glucose, blood pressure, plasma triglycerides levels and HDL-cholesterol. Principal components analysis was used to determine the pattern of risk clustering and to derive a continuous aggregate score (MetScore).
Inhibitory signaling through Tyr985 of the leptin receptor contributes to the attenuation of anorectic leptin action in obese animals. Leptin receptor (LEPR-B) Tyr985Leu homozygote mutant mice (termed l/l) were previously generated to study Tyr985's contributions to inhibition of LEPR-B signaling; young female l/l mice display a lean, leptin-sensitive phenotype, while young male l/l are not significantly different from wild-type. We report here that testosterone (but not estrogen) determines the sex-specificity of the l/l phenotype.
View Article and Find Full Text PDFObjective: To explore whether reasons for enrollment in a pediatric multidisciplinary weight management program (PMWMP) are associated with subsequent weight loss.
Method: A retrospective analysis of obese adolescents (12-18 years old, body mass index [BMI] > 95th percentile) who enrolled in a PMWMP from April 2007 to March 2009, and had BMI measurements at weeks 1 and 12. Reasons for enrollment were obtained from parents' responses to an enrollment questionnaire (which allowed selection of more than one reason).
Leptin, a protein hormone secreted by adipose tissue, plays an important role in regulating energy metabolism and the immune response. Despite similar extremes of adiposity, mutant mouse models, db/db, carrying spontaneous deletion of the active form of the leptin receptor (LEPR-B) intracellular signaling domain, and the s/s, carrying a specific point mutation leading to a dysfunctional LEPR-B-STAT3 signaling pathway, have been shown to have robust differences in glucose homeostasis. This suggests specific effects of leptin, mediated by non-STAT3 LEPR-B pathways.
View Article and Find Full Text PDFThe primary aim of this investigation was to evaluate the effect of training on the immune activation in skeletal muscle in response to an acute bout of resistance exercise (RE). Seven young healthy men and women underwent a 12-wk supervised progressive unilateral arm RE training program. One week after the last training session, subjects performed an acute bout of bilateral RE in which the trained and the untrained arm exercised at the same relative intensity.
View Article and Find Full Text PDFBackground: The molecular mechanisms underlying the sex differences in human muscle morphology and function remain to be elucidated. The sex differences in the skeletal muscle transcriptome in both the resting state and following anabolic stimuli, such as resistance exercise (RE), might provide insight to the contributors of sexual dimorphism of muscle phenotypes. We used microarrays to profile the transcriptome of the biceps brachii of young men and women who underwent an acute unilateral RE session following 12 weeks of progressive training.
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