Publications by authors named "I Mark Olfert"

74 Publications

Metabolic physiology and skeletal muscle phenotypes in male and female myoglobin knockout mice.

Am J Physiol Endocrinol Metab 2021 May 10. Epub 2021 May 10.

Arkansas Children's Nutrition Center, Little Rock, AR, USA.

Myoglobin (Mb) is a regulator of O bioavailability in type I muscle and heart, at least when tissue O levels drop. Mb also plays a role in regulating cellular NO pools. Robust binding of long-chain fatty acids and long-chain acylcarnitines to Mb, and enhanced glucose metabolism in hearts of Mb knockout (KO) mice, suggests additional roles in muscle intermediary metabolism and fuel selection. To evaluate this hypothesis, we measured energy expenditure (EE), respiratory exchange ratio (RER), body weight gain and adiposity, glucose tolerance and insulin sensitivity in Mb knockout (Mb) and wildtype (WT) mice challenged with a high fat diet (HFD, 45% of calories). In males (n=10/genotype) and females (n=9/genotype) aged 5-6, 11-12, and 17-18 wk, there were no genotype effects on RER, EE, or food intake. RER and EE during cold (10˚C, 72 h), and glucose and insulin tolerance, were not different compared to within-sex WT controls. At ~18 and ~19 wk of age, female Mb adiposity was ~42-48% higher vs. WT females (p=0.1). Transcriptomics analyses (whole gastrocnemius, soleus) revealed few consistent changes, with the notable exception of a 20% drop in soleus transferrin receptor (Tfrc) mRNA. Capillarity indices were significantly increased in Mb, specifically in Mb-rich soleus and deep gastrocnemius. The results indicate that Mb loss does not have a major impact on whole-body glucose homeostasis, EE, RER, or response to a cold challenge in mice. However, the greater adiposity in female Mb mice indicates a sex-specific effect of Mb KO on fat storage and feed efficiency.
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http://dx.doi.org/10.1152/ajpendo.00624.2020DOI Listing
May 2021

Psychosocial Factors Associated with E-Cigarette Use among Young Adults in a 4-Year University in Appalachia.

Subst Use Misuse 2021 3;56(8):1182-1189. Epub 2021 May 3.

Davis College of Agriculture, Natural Resources, and Design, Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, West Virginia, USA.

Objectives: In order to determine methods to reduce vaping prevalence, motivations for use and co-occurring health behaviors and disorders need to be determined. This study investigated vaping characteristics and associated health behaviors in a young adult Appalachian college population.

Methods: Students attending an Appalachian university were invited to participate in an online survey measuring their use of e-cigarettes, motivations for use, mental health, and Adverse Childhood Experiences (ACEs). Analysis included prevalence of e-cigarette use and associations between e-cigarette use and Appalachian identity, mental health, and ACEs.

Results: Participants ( = 3398) stated that the most common motivator for using e-cigarettes was to decrease stress, followed by the good taste, friends' usage, and wanting to quit cigarettes. E-cigarette use was associated with alcohol use, anxiety, depression, stress, and Adverse Childhood Experiences (ACEs) and these variables were placed into a full logistic regression model, in which anxiety and stress were no longer significant, and alcohol use was the strongest association (OR 1.36 95% CI 1.35-1.42, <.0001). Findings demonstrate a need for efforts to reduce e-cigarette use to focus on the co-use of alcohol, co-occurring mental health disorders, and the social and enjoyment motivations for use.
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http://dx.doi.org/10.1080/10826084.2021.1914102DOI Listing
May 2021

Chronic stress induced perivascular adipose tissue impairment of aortic function and the therapeutic effect of exercise.

Exp Physiol 2021 Jun 14;106(6):1343-1358. Epub 2021 May 14.

Department of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV, USA.

New Findings: What is the central question of this study? Thoracic perivascular adipose tissue (tPVAT) is known to, in part, regulate aortic function: what are the effects of unpredictable chronic mild stress (UCMS) on the tPVAT regulation of aortic function and what is the role of exercise training in alleviating the potential negative actions of UCMS on tPVAT? What is the main finding and its importance? UCMS causes tPVAT to disrupt endothelium-dependent dilatation, increases inflammatory cytokine production and diminishes tPVAT-adiponectin. Exercise training proved efficacious in preventing tPVAT-mediated disruption of aortic function. The data support a tPVAT mechanism through which chronic stress negatively impacts vascular health, which adds to our knowledge of how psychological disorders might increase the risk of cardiovascular disease.

Abstract: Chronic stress is a major risk for cardiovascular disease. Perivascular adipose tissue (PVAT) has been shown to regulate vascular function; however, the impact of chronic stress and the comorbidity of metabolic syndrome (MetS) on thoracic (t)PVAT is unknown. Additionally, aerobic exercise training (AET) is known to combat the pathology of MetS and chronic stress, but the role of tPVAT in these actions is also unknown. Therefore, the purpose of this study was to examine the effects of unpredictable chronic mild stress (UCMS) on the tPVAT regulation of aortic function and the preventative effect of AET. Lean (LZR) and obese (OZR) Zucker rats (16-17 weeks old) were exposed to 8 weeks of UCMS with and without treadmill exercise (AET). In LZR, UCMS impaired aortic endothelium-dependent dilatation (EDD) (assessed ex vivo by wire myography) and aortic stiffness (assessed by elastic modulus) with no change in OZR subject to UCMS. However, both LZR and OZR UCMS tPVAT impaired EDD compared to respective controls. LZR and OZR subject to UCMS had higher oxidative stress production, diminished adiponectin and impaired aortic nitric oxide levels. Divergently, UCMS induced greater inflammatory cytokine production in LZR UCMS tPVAT, but not in OZR UCMS tPVAT. AET prevented the tPVAT impairment of aortic relaxation with UCMS in LZR and OZR. Additionally, AET reduced aortic stiffness in both LZR and OZR. These beneficial effects on tPVAT regulation of the aorta are likely due to AET preservation of adiponectin, reduced oxidative stress and inflammation, and enhanced nitric oxide. UCMS impaired tPVAT-regulated aortic function in LZR, and augmented MetS-induced EDD in OZR. Conversely, AET in combination with UCMS largely preserved aortic function and the tPVAT environment, in both groups.
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http://dx.doi.org/10.1113/EP089449DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8169624PMC
June 2021

Role of Perivascular Adipose Tissue and Exercise on Arterial Function with Obesity.

Exerc Sport Sci Rev 2021 Jul;49(3):188-196

Biological Sciences, School of Biological Sciences, University of Reading, Reading, UK.

Adipose tissue and arterial dysfunction are common in the obese state. Perivascular adipose tissue (PVAT) plays an important role in mediating arterial health, and with obesity, the PVAT dysfunction negatively affects arterial health. Exercise training exerts direct and beneficial effects on PVAT, providing an additional and novel pathway by which exercise can improve arterial health in diseased populations.
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http://dx.doi.org/10.1249/JES.0000000000000251DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8195847PMC
July 2021

Electronic Cigarettes and Vaping-Associated Lung Injury (EVALI): A Rural Appalachian Experience.

Hosp Pract (1995) 2021 Apr 21;49(2):79-87. Epub 2021 Jan 21.

Section of Pulmonary, Critical Care and Sleep Medicine, West Virginia University School of Medicine, Morgantown, WV, USA.

Electronic cigarette use has increased dramatically since their introduction in 2007. Respiratory complications, particularly lipoid pneumonia, have been reported as early as 2012. An outbreak of pulmonary injury in 2019 has been reported in patients using vaping products. To describe a rural Appalachian tertiary center's experience of EVALI and to identify novel mechanisms of pulmonary injury patterns. We present a consecutive case series of 17 patients admitted to our rural, academic, tertiary care institution with EVALI from August 2019 to March 2020. Demographics, baseline characteristics, co-morbidities, vaping behavior, and hospital course were recorded. Broncho-alveolar lavage specimens were assessed for lipid-laden macrophages and hemosiderin-laden macrophages with stains for Oil-Red-O (n = 15) and Prussian Blue (n = 14) respectively.The patient volunteered e-liquid materials (n = 6), and vapors were analyzed using a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) to describe the chemical profile. Post-discharge interviews were conducted. The most common CT finding was bilateral ground-glass opacities with a predilection for lower lung zones. The most frequent pulmonary injury pattern was lipoid pneumonia. The majority of EVALI patients were critically ill requiring ventilation or ECMO. The most severely ill patients were noted to be positive for iron stains in macrophages and showed higher volatile organic compound (VOC) levels in chemical analysis.: Based on our experience, EVALI in rural Appalachia presented with relatively severe respiratory failure. Worse outcomes appear to be correlated to high levels of VOCs, iron deposition in lungs, and concomitant infection.
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http://dx.doi.org/10.1080/21548331.2020.1843282DOI Listing
April 2021