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Brian A. Irving
Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA

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Journal article
Published: 03 August 2021 in Viruses
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Circulating immune cell numbers and phenotypes are impacted by high-intensity acute bouts of exercise and infection history with the latent herpesviruses cytomegalovirus (CMV). In particular, CMV infection history impairs the exercise-induced mobilization of cytotoxic innate lymphoid cells 1 (ILC1) cells, also known as NK cells, in the blood. However, it remains unknown whether exercise and CMV infection modulate the mobilization of traditionally tissue-resident non-cytotoxic ILCs into the peripheral blood compartment. To address this question, 22 healthy individuals with or without CMV (20–35 years—45% CMVpos) completed 30 min of cycling at 70% VO2 max, and detailed phenotypic analysis of circulating ILCs was performed at rest and immediately post-exercise. We show for the first time that a bout of high-intensity exercise is associated with an influx of ILCs that are traditionally regarded as tissue-resident. In addition, this is the first study to highlight that latent CMV infection blunts the exercise-response of total ILCs and progenitor ILCs (ILCPs). These promising data suggest that acute exercise facilitates the circulation of certain ILC subsets, further advocating for the improvements in health seen with exercise by enhancing cellular mobilization and immunosurveillance, while also highlighting the indirect deleterious effects of CMV infection in healthy adults.

ACS Style

Eunhan Cho; Bailey Theall; James Stampley; Joshua Granger; Neil Johannsen; Brian Irving; Guillaume Spielmann. Cytomegalovirus Infection Impairs the Mobilization of Tissue-Resident Innate Lymphoid Cells into the Peripheral Blood Compartment in Response to Acute Exercise. Viruses 2021, 13, 1535 .

AMA Style

Eunhan Cho, Bailey Theall, James Stampley, Joshua Granger, Neil Johannsen, Brian Irving, Guillaume Spielmann. Cytomegalovirus Infection Impairs the Mobilization of Tissue-Resident Innate Lymphoid Cells into the Peripheral Blood Compartment in Response to Acute Exercise. Viruses. 2021; 13 (8):1535.

Chicago/Turabian Style

Eunhan Cho; Bailey Theall; James Stampley; Joshua Granger; Neil Johannsen; Brian Irving; Guillaume Spielmann. 2021. "Cytomegalovirus Infection Impairs the Mobilization of Tissue-Resident Innate Lymphoid Cells into the Peripheral Blood Compartment in Response to Acute Exercise." Viruses 13, no. 8: 1535.

Journal article
Published: 15 April 2021 in Geriatrics
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More perceived physical fatigability and poor diet quality are associated with impairments in physical function in older adults. However, the degree to which more perceived fatigability explains the association between poor diet quality and low physical function is unknown. We examined this relationship in 122 (66F, 56M) of the oldest-old participants from the Geisinger Rural Aging Study (GRAS). We used 24-h dietary recalls to assess the Healthy Eating Index (HEI), the Pittsburgh Fatigability Scale (PFS, 0–50) to assess perceived physical fatigability, and the PROMIS Physical Function 20a* to assess physical function. We grouped participants into three age categories: 80–84 (n = 51), 85–89 (n = 51), and 90+ (n = 20) years. Multiple linear regression revealed that a lower HEI was associated with higher PFS Physical score after adjusting for age group, sex, body mass index, and the number of medical conditions (p = 0.001). Several macro- and micro-nutrient intakes were also lower in those reporting more (≥15) compared to less (<15) perceived physical fatigability. Mediation analysis revealed that PFS Physical scores explained ~65% (p = 0.001) of the association between HEI total score and PROMIS19 Physical Function score. Poor diet quality may contribute to more perceived physical fatigability, which could exacerbate impairments in the oldest-old’s physical function.

ACS Style

Brett Davis; Yi-Hsuan Liu; James Stampley; G. Wood; Diane Mitchell; Gordon Jensen; Xiang Gao; Nancy Glynn; Christopher Still; Brian Irving. The Association between Poor Diet Quality, Physical Fatigability and Physical Function in the Oldest-Old from the Geisinger Rural Aging Study. Geriatrics 2021, 6, 41 .

AMA Style

Brett Davis, Yi-Hsuan Liu, James Stampley, G. Wood, Diane Mitchell, Gordon Jensen, Xiang Gao, Nancy Glynn, Christopher Still, Brian Irving. The Association between Poor Diet Quality, Physical Fatigability and Physical Function in the Oldest-Old from the Geisinger Rural Aging Study. Geriatrics. 2021; 6 (2):41.

Chicago/Turabian Style

Brett Davis; Yi-Hsuan Liu; James Stampley; G. Wood; Diane Mitchell; Gordon Jensen; Xiang Gao; Nancy Glynn; Christopher Still; Brian Irving. 2021. "The Association between Poor Diet Quality, Physical Fatigability and Physical Function in the Oldest-Old from the Geisinger Rural Aging Study." Geriatrics 6, no. 2: 41.

Original article
Published: 01 April 2021 in Physiological Reports
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Background Non‐invasive determination of mitochondrial capacity via near infrared spectroscopy (NIRS) typically involves voluntary exercise of a single muscle group followed by as many as 26 brief ischemic cuff occlusions to determine a single recovery rate constant (k). Purpose To determine the within‐ and between‐visit repeatability of a shortened bilateral NIRS protocol, and to establish the feasibility of hamstring k measurements. Methods Sixteen young (eight women, eight men; 22 ± 3 years) active adults underwent a bilateral electrical stimulation protocol in which multiple (n = 4) measurements of k for the vastus lateralis (VL) and medial hamstring (MH) muscles were determined on two visits. Repeatability (CV% and intraclass correlations, ICC) and equivalency across visits were assessed for both muscles. Results Mean k values in the VL were consistent with published values and within‐visit ICCs were moderately high for both muscles in both sexes. In men, average k values on visit 2 were within 1% (VL muscle) and 5% (MH muscle) of the values on visit 1 (all p > 0.78). In women, average k values were 10%–15% lower on visit 2 (p = 0.01 and p = 0.15 for MH and VL) with the largest between‐visit differences in a subset of participants with the most days between visits. Conclusions This bilateral NIRS protocol is time efficient and provides valid estimates of k in both sexes and muscle groups with acceptable within‐visit repeatability. Lower than expected between‐visit repeatability in some participants reinforces the need for further investigation of this newly developed protocol to identify and control for experimental and behavioral sources of variation.

ACS Style

Rewais Hanna; Jigar Gosalia; Alaina Demalis; Zachary Hobson; Kevin K. McCully; Brian A. Irving; Swapan Mookerjee; Giampietro L. Vairo; David N. Proctor. Bilateral NIRS measurements of muscle mitochondrial capacity: Feasibility and repeatability. Physiological Reports 2021, 9, e14826 .

AMA Style

Rewais Hanna, Jigar Gosalia, Alaina Demalis, Zachary Hobson, Kevin K. McCully, Brian A. Irving, Swapan Mookerjee, Giampietro L. Vairo, David N. Proctor. Bilateral NIRS measurements of muscle mitochondrial capacity: Feasibility and repeatability. Physiological Reports. 2021; 9 (8):e14826.

Chicago/Turabian Style

Rewais Hanna; Jigar Gosalia; Alaina Demalis; Zachary Hobson; Kevin K. McCully; Brian A. Irving; Swapan Mookerjee; Giampietro L. Vairo; David N. Proctor. 2021. "Bilateral NIRS measurements of muscle mitochondrial capacity: Feasibility and repeatability." Physiological Reports 9, no. 8: e14826.

Journal article
Published: 01 January 2020 in Journal of Applied Physiology
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Collegiate athletes are exposed to varying levels of academic and physical stressors, placing them at increased risk for stress-activated latent viral infections. However, the impact of allostatic stress load on the immune response to maximal exercise in athletes remains largely unknown. This study examined the effects of a 7-mo training period and cytomegalovirus (CMV) serostatus on immune cell response to high-intensity swim tests within a group of collegiate swimmers. Samples were collected from 15 National Collegiate Athletic Association Division I swimmers (9 men, 6 women: 19.87 ± 0.64 yr) before and after exhaustive in-pool swims at 2 time points (V1: immediately post-season 1 and V3: beginning of season 2). An additional off-season (V2) time point was collected in a subset of 9 swimmers. Natural killer (NK) cell, B cell, and T cells were quantified by flow cytometry. Linear mixed models were used to determine the effects of exercise, time point, and CMV serostatus (α = 0.05). Resting senescent CD8+ T cells were higher in CMV-seropositive participants at V3 ( P = 0.005). CMV-seronegative participants had a decrease in resting senescent CD8+ T cells from V1 to V3 ( P = 0.021). After acute exercise, CMV-seropositive participants had lower naïve CD8+ T cells ( P < 0.001) and higher senescent CD8+ T cells ( P < 0.001). Increased cumulative stress levels did not appear to affect B-cell and NK-cell compartments. Immune response to exercise was impacted by CMV serostatus and allostatic stress load. Young CMV-seropositive athletes exposed to elevated stressors should be monitored to determine long-term effects of training and academic stressors. NEW & NOTEWORTHY Allostatic stress load is associated with impaired immune response to maximal exercise in cytomegalovirus (CMV)-seropositive subjects but not in CMV-seronegative young healthy adults.

ACS Style

Bailey Theall; Haoyan Wang; Connor A. Kuremsky; Eunhan Cho; Katelyn Hardin; Lyle Robelot; Jack Marucci; Shelly Mullenix; Nathan Lemoine Jr.; Neil M. Johannsen; Brian A. Irving; Guillaume Spielmann. Allostatic stress load and CMV serostatus impact immune response to maximal exercise in collegiate swimmers. Journal of Applied Physiology 2020, 128, 178 -188.

AMA Style

Bailey Theall, Haoyan Wang, Connor A. Kuremsky, Eunhan Cho, Katelyn Hardin, Lyle Robelot, Jack Marucci, Shelly Mullenix, Nathan Lemoine Jr., Neil M. Johannsen, Brian A. Irving, Guillaume Spielmann. Allostatic stress load and CMV serostatus impact immune response to maximal exercise in collegiate swimmers. Journal of Applied Physiology. 2020; 128 (1):178-188.

Chicago/Turabian Style

Bailey Theall; Haoyan Wang; Connor A. Kuremsky; Eunhan Cho; Katelyn Hardin; Lyle Robelot; Jack Marucci; Shelly Mullenix; Nathan Lemoine Jr.; Neil M. Johannsen; Brian A. Irving; Guillaume Spielmann. 2020. "Allostatic stress load and CMV serostatus impact immune response to maximal exercise in collegiate swimmers." Journal of Applied Physiology 128, no. 1: 178-188.

Journal article
Published: 09 October 2018 in IEEE Transactions on Biomedical Engineering
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Advances in several engineering fields have led to a trend towards miniaturization and portability of wearable biosensing devices, which used to be confined to large tools and clinical settings. Various systems to continuously measure electrophysiological activity through electrical and optical methods are one category of such devices. Being wearable and intended for prolonged use, the amount of noise introduced on sensors by movement remains a challenge and requires further optimization. User movement causes motion artifacts that alter the overall quality of the signals obtained, hence corrupting the resulting measurements. This paper introduces a fully wearable optical biosensing system to continuously measure pulse oximetry and heart rate, utilizing a reflectance-based probe. Furthermore, a novel data-dependent motion artifact tailoring algorithm is implemented to eliminate noisy data due to the motion artifact and measure oxygenation level with high accuracy in real-time. By taking advantages of current wireless transmission and signal processing technologies, the developed wearable photoplethysmography device successfully captures the measured signals and sends them wirelessly to a mobile device for signal processing in real-time. After applying motion artifact tailoring, evaluating accuracy with a continuous clinical device, the blood oxygenation measurements obtained from our system yielded an accuracy of at least 98%, when compared to a range of 93.6-96.7% observed before from the same initial data. Additionally, heart rate accuracy above 97% was achieved. Motion artifact tailoring and removal in real-time, continuous systems will allow wearable devices to be truly wearable and a reliable electrophysiological monitoring and diagnostics tool for everyday use.

ACS Style

Pedro J. Chacon; Limeng Pu; Tallis H. Da Costa; Young-Ho Shin; Taher Ghomian; Hamed Shamkhalichenar; Hsiao-Chun Wu; Brian Irving; Jin-Woo Choi. A Wearable Pulse Oximeter With Wireless Communication and Motion Artifact Tailoring for Continuous Use. IEEE Transactions on Biomedical Engineering 2018, 66, 1505 -1513.

AMA Style

Pedro J. Chacon, Limeng Pu, Tallis H. Da Costa, Young-Ho Shin, Taher Ghomian, Hamed Shamkhalichenar, Hsiao-Chun Wu, Brian Irving, Jin-Woo Choi. A Wearable Pulse Oximeter With Wireless Communication and Motion Artifact Tailoring for Continuous Use. IEEE Transactions on Biomedical Engineering. 2018; 66 (6):1505-1513.

Chicago/Turabian Style

Pedro J. Chacon; Limeng Pu; Tallis H. Da Costa; Young-Ho Shin; Taher Ghomian; Hamed Shamkhalichenar; Hsiao-Chun Wu; Brian Irving; Jin-Woo Choi. 2018. "A Wearable Pulse Oximeter With Wireless Communication and Motion Artifact Tailoring for Continuous Use." IEEE Transactions on Biomedical Engineering 66, no. 6: 1505-1513.

Review
Published: 19 July 2018 in Nutrients
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Diminished bioavailability of nitric oxide (NO), the gaseous signaling molecule involved in the regulation of numerous vital biological functions, contributes to the development and progression of multiple age- and lifestyle-related diseases. While l-arginine is the precursor for the synthesis of NO by endothelial-nitric oxide synthase (eNOS), oral l-arginine supplementation is largely ineffective at increasing NO synthesis and/or bioavailability for a variety of reasons. l-citrulline, found in high concentrations in watermelon, is a neutral alpha-amino acid formed by enzymes in the mitochondria that also serves as a substrate for recycling l-arginine. Unlike l-arginine, l-citrulline is not quantitatively extracted from the gastrointestinal tract (i.e., enterocytes) or liver and its supplementation is therefore more effective at increasing l-arginine levels and NO synthesis. Supplementation with l-citrulline has shown promise as a blood pressure lowering intervention (both resting and stress-induced) in adults with pre-/hypertension, with pre-clinical (animal) evidence for atherogenic-endothelial protection. Preliminary evidence is also available for l-citrulline-induced benefits to muscle and metabolic health (via vascular and non-vascular pathways) in susceptible/older populations. In this review, we examine the impact of supplementing this important urea cycle intermediate on cardiovascular and metabolic health outcomes and identify future directions for investigating its therapeutic impact on cardiometabolic health.

ACS Style

Timothy D. Allerton; David N. Proctor; Jacqueline M. Stephens; Tammy R. Dugas; Guillaume Spielmann; Brian A. Irving. l-Citrulline Supplementation: Impact on Cardiometabolic Health. Nutrients 2018, 10, 921 .

AMA Style

Timothy D. Allerton, David N. Proctor, Jacqueline M. Stephens, Tammy R. Dugas, Guillaume Spielmann, Brian A. Irving. l-Citrulline Supplementation: Impact on Cardiometabolic Health. Nutrients. 2018; 10 (7):921.

Chicago/Turabian Style

Timothy D. Allerton; David N. Proctor; Jacqueline M. Stephens; Tammy R. Dugas; Guillaume Spielmann; Brian A. Irving. 2018. "l-Citrulline Supplementation: Impact on Cardiometabolic Health." Nutrients 10, no. 7: 921.

Clinical trial
Published: 01 June 2018 in Contemporary Clinical Trials
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Total Knee Arthroplasty (TKA, also known as total knee replacement) is a highly effective surgical intervention for the restoration of physical function and improving quality of life in patients with disabling knee osteoarthritis. Recent data suggest that obesity is a major risk factor in the pathogenesis and progression of knee osteoarthritis, with increases in body mass index (BMI, kg/m) directly correlating with the prevalence of knee osteoarthritis. However, recent data also suggest that there are increased risks associated with TKAs when performed in patients with morbid obesity (BMI > 40 kg/m). Patients with morbid obesity are routinely referred for weight management prior to surgery. Many of these patients fail to meet the recommended weight loss goals prior to TKA, potentially making them ineligible for surgery or placing them at increased risk for sub-optimal outcomes. Thus, the purpose of this study is to examine the potential therapeutic impact and long-term outcomes of surgically induced weight loss on TKA outcomes. Specifically, these outcomes will include measures of physical function, mobility, and indices of joint function at 1 and 2 years post-TKA compared between extremely obese patients who undergo TKA (Control group, n = 150) and those with TKA performed ~1 year after bariatric surgery (Test group, n = 150). An additional primary endpoint will be the percent of bariatric patients that negate or delay the need for TKA. Secondary endpoints include perioperative outcomes after TKA.

ACS Style

Peter N. Benotti; Christopher D. Still; G. Craig Wood; Jamie L. Seiler; Christopher J. Seiler; Shane P. Thomas; Anthony T. Petrick; Michael Suk; Brian Irving; Jonathan Samuels; James Browne; Jonathan Morton; Alexander McLawhorn. Surgical weight-loss to improve functional status trajectories following total knee arthroplasty: SWIFT trial: Rationale, design, and methods. Contemporary Clinical Trials 2018, 69, 1 -9.

AMA Style

Peter N. Benotti, Christopher D. Still, G. Craig Wood, Jamie L. Seiler, Christopher J. Seiler, Shane P. Thomas, Anthony T. Petrick, Michael Suk, Brian Irving, Jonathan Samuels, James Browne, Jonathan Morton, Alexander McLawhorn. Surgical weight-loss to improve functional status trajectories following total knee arthroplasty: SWIFT trial: Rationale, design, and methods. Contemporary Clinical Trials. 2018; 69 ():1-9.

Chicago/Turabian Style

Peter N. Benotti; Christopher D. Still; G. Craig Wood; Jamie L. Seiler; Christopher J. Seiler; Shane P. Thomas; Anthony T. Petrick; Michael Suk; Brian Irving; Jonathan Samuels; James Browne; Jonathan Morton; Alexander McLawhorn. 2018. "Surgical weight-loss to improve functional status trajectories following total knee arthroplasty: SWIFT trial: Rationale, design, and methods." Contemporary Clinical Trials 69, no. : 1-9.

Journal article
Published: 01 May 2018 in Medicine & Science in Sports & Exercise
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Brian A. Irving; Timothy D. Allerton; Guillaume Spielmann; Stefany Primeaux; Arnold Nelson; Dennis Landin; Neil M. Johannsen. Offspring of Mothers with Diabetes have Reduced Muscle Oxidative Capacity Measured by Near Infrared Spectroscopy. Medicine & Science in Sports & Exercise 2018, 50, 149 -150.

AMA Style

Brian A. Irving, Timothy D. Allerton, Guillaume Spielmann, Stefany Primeaux, Arnold Nelson, Dennis Landin, Neil M. Johannsen. Offspring of Mothers with Diabetes have Reduced Muscle Oxidative Capacity Measured by Near Infrared Spectroscopy. Medicine & Science in Sports & Exercise. 2018; 50 (5S):149-150.

Chicago/Turabian Style

Brian A. Irving; Timothy D. Allerton; Guillaume Spielmann; Stefany Primeaux; Arnold Nelson; Dennis Landin; Neil M. Johannsen. 2018. "Offspring of Mothers with Diabetes have Reduced Muscle Oxidative Capacity Measured by Near Infrared Spectroscopy." Medicine & Science in Sports & Exercise 50, no. 5S: 149-150.

Journal article
Published: 01 May 2018 in Medicine & Science in Sports & Exercise
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Connor A. Kuremsky; Wang Haoyan; Neil M. Johannsen; Jack Marucci; Shelly Mullenix; Brian A. Irving; Rick L. Sharp; Brian Harrell; Guillaume Spielmann. Correlations Between Serum Biomarkers Of Stress And Subjective Measures Of Well-being In Collegiate Swimmers. Medicine & Science in Sports & Exercise 2018, 50, 111 .

AMA Style

Connor A. Kuremsky, Wang Haoyan, Neil M. Johannsen, Jack Marucci, Shelly Mullenix, Brian A. Irving, Rick L. Sharp, Brian Harrell, Guillaume Spielmann. Correlations Between Serum Biomarkers Of Stress And Subjective Measures Of Well-being In Collegiate Swimmers. Medicine & Science in Sports & Exercise. 2018; 50 (5S):111.

Chicago/Turabian Style

Connor A. Kuremsky; Wang Haoyan; Neil M. Johannsen; Jack Marucci; Shelly Mullenix; Brian A. Irving; Rick L. Sharp; Brian Harrell; Guillaume Spielmann. 2018. "Correlations Between Serum Biomarkers Of Stress And Subjective Measures Of Well-being In Collegiate Swimmers." Medicine & Science in Sports & Exercise 50, no. 5S: 111.

Journal article
Published: 01 May 2018 in Medicine & Science in Sports & Exercise
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Michael E. Owens; Haoyan Wang; Nathan P. Lemoine; Jack Marucci; Shelly Mullenix; Arnold G. Nelson; Ralph R. Castle; Brian A. Irving; Guillaume Spielmann; Jennifer Rood; Timothy S. Church; Brian Harrell; Neil M. Johannsen. Effects of Training Camp on Hematological Variables in Athletes with Sickle Cell Trait. Medicine & Science in Sports & Exercise 2018, 50, 741 .

AMA Style

Michael E. Owens, Haoyan Wang, Nathan P. Lemoine, Jack Marucci, Shelly Mullenix, Arnold G. Nelson, Ralph R. Castle, Brian A. Irving, Guillaume Spielmann, Jennifer Rood, Timothy S. Church, Brian Harrell, Neil M. Johannsen. Effects of Training Camp on Hematological Variables in Athletes with Sickle Cell Trait. Medicine & Science in Sports & Exercise. 2018; 50 (5S):741.

Chicago/Turabian Style

Michael E. Owens; Haoyan Wang; Nathan P. Lemoine; Jack Marucci; Shelly Mullenix; Arnold G. Nelson; Ralph R. Castle; Brian A. Irving; Guillaume Spielmann; Jennifer Rood; Timothy S. Church; Brian Harrell; Neil M. Johannsen. 2018. "Effects of Training Camp on Hematological Variables in Athletes with Sickle Cell Trait." Medicine & Science in Sports & Exercise 50, no. 5S: 741.

Randomized controlled trial
Published: 22 January 2018 in Physiological Reports
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The purpose of this study was to test the hypothesis that high-intensity interval exercise (HIE) significantly increases growth hormone (GH) secretion to a greater extent than moderate-intensity continuous exercise (MOD) in young women. Five young, sedentary women (mean ± SD; age: 22.6±1.3 years; BMI: 27.4±3.1 kg/m2) were tested during the early follicular phase of their menstrual cycle on three occasions. For each visit, participants reported to the laboratory at 1700 h, exercised from 1730–1800 h, and remained in the laboratory until 0700 h the following morning. The exercise component consisted of either 30-min of moderate-intensity continuous cycling at 50% of measured peak power (MOD), four 30-s “all-out” sprints with 4.5 min of active recovery (HIE), or a time-matched sedentary control using a randomized, cross-over design. The overnight GH secretory profile of each trial was determined from 10-min sampling of venous blood from 1730–0600 h, using deconvolution analysis. Deconvolution GH parameters were log transformed prior to statistical analyses. Calculated GH AUC (0–120 min) was significantly greater in HIE than CON (P = 0.04), but HIE was not different from MOD. Total GH secretory rate (ng/mL/12.5 h) was significantly greater in the HIE than the CON (P = 0.05), but MOD was not different from CON or HIE. Nocturnal GH secretion (ng/mL/7.5 h) was not different between the three trials. For these women, in this pilot study, a single bout of HIE was sufficient to increase 12.5 h pulsatile GH secretion. It remains to be determined if regular HIE may contribute to increased daily GH secretion.

ACS Style

Sarah E. Deemer; Todd J. Castleberry; Chris Irvine; Daniel E. Newmire; Michael Oldham; George A. King; Vic Ben-Ezra; Brian A. Irving; Kyle D. Biggerstaff. Pilot study: an acute bout of high intensity interval exercise increases 12.5 h GH secretion. Physiological Reports 2018, 6, e13563 .

AMA Style

Sarah E. Deemer, Todd J. Castleberry, Chris Irvine, Daniel E. Newmire, Michael Oldham, George A. King, Vic Ben-Ezra, Brian A. Irving, Kyle D. Biggerstaff. Pilot study: an acute bout of high intensity interval exercise increases 12.5 h GH secretion. Physiological Reports. 2018; 6 (2):e13563.

Chicago/Turabian Style

Sarah E. Deemer; Todd J. Castleberry; Chris Irvine; Daniel E. Newmire; Michael Oldham; George A. King; Vic Ben-Ezra; Brian A. Irving; Kyle D. Biggerstaff. 2018. "Pilot study: an acute bout of high intensity interval exercise increases 12.5 h GH secretion." Physiological Reports 6, no. 2: e13563.

Comment
Published: 22 November 2016 in Diabetes
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Brian A. Irving; Guillaume Spielmann. Does Citrulline Sit at the Nexus of Metformin's Pleotropic Effects on Metabolism and Mediate Its Salutatory Effects in Individuals With Type 2 Diabetes? Diabetes 2016, 65, 3537 -3540.

AMA Style

Brian A. Irving, Guillaume Spielmann. Does Citrulline Sit at the Nexus of Metformin's Pleotropic Effects on Metabolism and Mediate Its Salutatory Effects in Individuals With Type 2 Diabetes? Diabetes. 2016; 65 (12):3537-3540.

Chicago/Turabian Style

Brian A. Irving; Guillaume Spielmann. 2016. "Does Citrulline Sit at the Nexus of Metformin's Pleotropic Effects on Metabolism and Mediate Its Salutatory Effects in Individuals With Type 2 Diabetes?" Diabetes 65, no. 12: 3537-3540.

Journal article
Published: 29 October 2016 in Nutrients
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Nutrient tranters (NT) facilitate nutrient absorption and contribute to the regulation of circulating nutrients. In this cross-sectional study, we determined the associations between the level of obesity; mRNA abundance for NTs; and serum concentrations of amino acids, short-chain fatty acids, and glucose in patients with morbid obesity undergoing a Roux-en-Y gastric bypass. Proximal jejunal samples were obtained at the time of surgery from 42 patients (90% female, age = 42.6 ± 11.9 years, pre-operative body mass index (BMI) = 55.5 ± 11.3 kg/m2) undergoing a Roux-en-Y gastric bypass. RNA was extracted from the jejunal mucosa and quantitative real-time–PCR was performed for the NTs studied. BMI negatively correlated with jejunal mRNA abundance of the amino acid NTs TauT (r = −0.625, p < 0.0001), ASCT2 (r = −0.320, p = 0.039), LAT1 (r = −0.304, p = 0.05). BMI positively correlated with jejunal mRNA abundance of the lactate/short-chain fatty acid NT SMCT1 (r = 0.543, p = 0.0002). Serum concentrations of the short-chain fatty acids, butyric, valeric, and isocaproic acid correlated positively with BMI (n = 30) (r = 0.45, r = 0.44, r = 0.36, p ≤ 0.05; respectively). Lower jejunal mRNA abundance for the amino acid NTs TauT, ASCT2, and LAT1 could protect against further obesity-related elevations in circulating amino acids. The positive correlation between BMI and the jejunal mRNA abundance of the high-affinity short-chain fatty acid/monocarboxylate transporter SMCT1 is intriguing and requires further investigation.

ACS Style

Brian A. Irving; G. Craig Wood; Peter N. Bennotti; Ellappan Babu; Abhishek Deshpande; Michelle R. Lent; Anthony Petrick; Jon Gabrielsen; William Strodel; Glenn S. Gerhard; Christopher D. Still; Vadivel Ganapathy; David D. K. Rolston. Nutrient Transporter Expression in the Jejunum in Relation to Body Mass Index in Patients Undergoing Bariatric Surgery. Nutrients 2016, 8, 683 .

AMA Style

Brian A. Irving, G. Craig Wood, Peter N. Bennotti, Ellappan Babu, Abhishek Deshpande, Michelle R. Lent, Anthony Petrick, Jon Gabrielsen, William Strodel, Glenn S. Gerhard, Christopher D. Still, Vadivel Ganapathy, David D. K. Rolston. Nutrient Transporter Expression in the Jejunum in Relation to Body Mass Index in Patients Undergoing Bariatric Surgery. Nutrients. 2016; 8 (11):683.

Chicago/Turabian Style

Brian A. Irving; G. Craig Wood; Peter N. Bennotti; Ellappan Babu; Abhishek Deshpande; Michelle R. Lent; Anthony Petrick; Jon Gabrielsen; William Strodel; Glenn S. Gerhard; Christopher D. Still; Vadivel Ganapathy; David D. K. Rolston. 2016. "Nutrient Transporter Expression in the Jejunum in Relation to Body Mass Index in Patients Undergoing Bariatric Surgery." Nutrients 8, no. 11: 683.

Original article
Published: 07 September 2016 in Obesity Science & Practice
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Objectives Impaired physical function (i.e., inability to walk 200 feet, climb a flight of stairs or perform activities of daily living) predicts poor clinical outcomes and adversely impacts medical and surgical weight management. However, routine assessment physical function is seldom performed clinically. The PROMIS Physical Function Short Form 20a (SF‐20a) is a validated questionnaire for assessing patient reported physical function, which includes published T‐score percentiles adjusted for gender, age and education. However, the effect that increasing levels of obesity has on these percentiles is unclear. We hypothesized that physical function would decline with increasing level of obesity independent of gender, age, education and comorbidity. Materials and Methods This study included 1,627 consecutive weight management patients [(mean ± SEM), 44.7 ± 0.3 years and 45.1 ± 0.2 kg/m2] that completed the PROMIS SF‐20a during their initial consultation. We evaluated the association between obesity level and PROMIS T‐score percentiles using multiple linear regression adjusting for gender, age, education and Charlson Comorbidity Index (CCI). Results Multiple linear regression T‐score percentiles were lower in obesity class 2 (−12.4%tile, p < 0.0001), class 3 (−17.0%tile, p < 0.0001) and super obesity (−25.1%tile, p < 0.0001) compared to class 1 obesity. Conclusion In patients referred for weight management, patient reported physical function was progressively lower in a dose‐dependent fashion with increasing levels of obesity, independent of gender, age, education and CCI.

ACS Style

J. Fleming; G. C. Wood; C. Seiler; A. Cook; M. R. Lent; C. D. Still; P. N. Benotti; B. A. Irving. Electronically captured, patient‐reported physical function: an important vital sign in obesity medicine. Obesity Science & Practice 2016, 2, 399 -406.

AMA Style

J. Fleming, G. C. Wood, C. Seiler, A. Cook, M. R. Lent, C. D. Still, P. N. Benotti, B. A. Irving. Electronically captured, patient‐reported physical function: an important vital sign in obesity medicine. Obesity Science & Practice. 2016; 2 (4):399-406.

Chicago/Turabian Style

J. Fleming; G. C. Wood; C. Seiler; A. Cook; M. R. Lent; C. D. Still; P. N. Benotti; B. A. Irving. 2016. "Electronically captured, patient‐reported physical function: an important vital sign in obesity medicine." Obesity Science & Practice 2, no. 4: 399-406.

Observational study
Published: 12 May 2016 in Obesity Surgery
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This study evaluated the social environment of bariatric surgery patients in the preoperative period. Forty bariatric surgery patients (mean = 46.2 ± 11.2 years), 35 adult cohabitating family members (mean = 45.2 ± 12.7 years), and 15 cohabitating children (mean = 11.5 ± 3.6 years) were recruited from a large rural medical center. Adult participants (patients and family members) completed height, weight, body composition, blood draws, and physical activity assessments (accelerometry), as well as eating behavior and social support inventories before the patient underwent bariatric surgery. Child participants completed demographic, height, and weight assessment only. Over 90 % of adult family members were overweight or obese (body mass index (BMI) ≥ 25 kg/m2, as were 50 % of children (BMI percentile ≥ 85 %). More than one third (37.1 %) of family members met the criteria for moderate to severe insulin resistance. Physical activity measured by accelerometry was moderately correlated between the patient and adult family members (r = 0.46, p = 0.023). Bariatric surgery patients reported high levels of social support from their family members on multiple social support measures. Many family members of bariatric surgery patients also lived with obesity and related comorbidities, and demonstrate high sedentary behavior. However, patients reported high levels of support from family members, including support in following a healthy diet and engaging in physical activity. Engaging families in behavior change may help bariatric surgery patients and their families to become healthier.

ACS Style

Michelle R. Lent; Lisa Bailey-Davis; Brian A. Irving; G. Craig Wood; Adam M. Cook; Annemarie G. Hirsch; Christopher D. Still; Peter N. Benotti; Jennifer Franceschelli-Hosterman. Bariatric Surgery Patients and Their Families: Health, Physical Activity, and Social Support. Obesity Surgery 2016, 26, 2981 -2988.

AMA Style

Michelle R. Lent, Lisa Bailey-Davis, Brian A. Irving, G. Craig Wood, Adam M. Cook, Annemarie G. Hirsch, Christopher D. Still, Peter N. Benotti, Jennifer Franceschelli-Hosterman. Bariatric Surgery Patients and Their Families: Health, Physical Activity, and Social Support. Obesity Surgery. 2016; 26 (12):2981-2988.

Chicago/Turabian Style

Michelle R. Lent; Lisa Bailey-Davis; Brian A. Irving; G. Craig Wood; Adam M. Cook; Annemarie G. Hirsch; Christopher D. Still; Peter N. Benotti; Jennifer Franceschelli-Hosterman. 2016. "Bariatric Surgery Patients and Their Families: Health, Physical Activity, and Social Support." Obesity Surgery 26, no. 12: 2981-2988.

Journal article
Published: 01 May 2016 in Medicine & Science in Sports & Exercise
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Brian A. Irving; Matthew L. Johnson; Ian R. Lanza; Matthew R. Robinson; Adam R. Konopka; Katherine A. Klaus; K.Sreekumaran Nair. Sedentary Behavior Inversely Relates to Insulin Sensitivity and Mitochondrial Oxidative Capacity in Inactive Obese Adults. Medicine & Science in Sports & Exercise 2016, 48, 750 .

AMA Style

Brian A. Irving, Matthew L. Johnson, Ian R. Lanza, Matthew R. Robinson, Adam R. Konopka, Katherine A. Klaus, K.Sreekumaran Nair. Sedentary Behavior Inversely Relates to Insulin Sensitivity and Mitochondrial Oxidative Capacity in Inactive Obese Adults. Medicine & Science in Sports & Exercise. 2016; 48 ():750.

Chicago/Turabian Style

Brian A. Irving; Matthew L. Johnson; Ian R. Lanza; Matthew R. Robinson; Adam R. Konopka; Katherine A. Klaus; K.Sreekumaran Nair. 2016. "Sedentary Behavior Inversely Relates to Insulin Sensitivity and Mitochondrial Oxidative Capacity in Inactive Obese Adults." Medicine & Science in Sports & Exercise 48, no. : 750.

Randomized controlled trial
Published: 31 August 2015 in Diabetes
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Caloric restriction (CR) improves insulin sensitivity and reduces the incidence of diabetes in obese individuals. The underlying mechanisms whereby CR improves insulin sensitivity are not clear. We evaluated the effect of 16-weeks of CR on whole-body insulin sensitivity by pancreatic clamp before and after CR in 11 obese participants (BMI=35 kg/m2) in comparison with a matched control period (CON, N=9, BMI=34 kg/m2). Compared to CON, CR increased the glucose infusion rate needed to maintain euglycemia during hyperinsulinemia indicating enhancement of peripheral insulin sensitivity. This improvement in insulin sensitivity was not accompanied by changes in skeletal muscle mitochondrial oxidative capacity or oxidant emissions, nor was there changes in skeletal muscle ceramide, diacylglycerol, or amino acid metabolite levels. However, CR lowered insulin-stimulated thioredoxin-interacting protein (TXNIP) levels and enhanced non-oxidative glucose disposal. These results support a role for TXNIP in mediating the improvement in peripheral insulin sensitivity after CR.

ACS Style

Matthew L. Johnson; Klaus Distelmaier; Ian Lanza; Brian Irving; Matthew M. Robinson; Adam R. Konopka; Gerald Shulman; K. Sreekumaran Nair. Mechanism by which caloric restriction improves insulin sensitivity in sedentary obese adults. Diabetes 2015, 65, db150675 -84.

AMA Style

Matthew L. Johnson, Klaus Distelmaier, Ian Lanza, Brian Irving, Matthew M. Robinson, Adam R. Konopka, Gerald Shulman, K. Sreekumaran Nair. Mechanism by which caloric restriction improves insulin sensitivity in sedentary obese adults. Diabetes. 2015; 65 (1):db150675-84.

Chicago/Turabian Style

Matthew L. Johnson; Klaus Distelmaier; Ian Lanza; Brian Irving; Matthew M. Robinson; Adam R. Konopka; Gerald Shulman; K. Sreekumaran Nair. 2015. "Mechanism by which caloric restriction improves insulin sensitivity in sedentary obese adults." Diabetes 65, no. 1: db150675-84.

Journal article
Published: 02 April 2015 in Analytical and Bioanalytical Chemistry
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Stable isotope-labeled amino acids have long been used to measure the fractional synthesis rate of proteins, although the mass spectrometry platforms used for such analyses have changed throughout the years. More recently, tandem mass spectrometers such as triple quadrupoles have been accepted as the standard platform for enrichment measurement due to their sensitivity and the enhanced specificity offered by multiple reaction monitoring (MRM) experiments. The limit in the utility of such platforms for enrichment analysis occurs when measuring very low levels of enrichment from small amounts of sample, particularly proteins isolated from two-dimensional gel electrophoresis (2D-GE), where interference from contaminant ions impacts the sensitivity of the measurement. We therefore applied a high-resolution orbitrap mass spectrometer to the analysis of [ring-(13)C6]-phenylalanine enrichment in individual muscle proteins isolated with 2D-GE. Comparison of samples analyzed on both platforms revealed that the high-resolution MS has significantly improved sensitivity relative to the triple quadrupole MS at very low-level enrichments due to its ability to resolve interferences in the m/z dimension. At higher enrichment levels, enrichment measurements from the orbitrap platform showed significant correlation (R (2) > 0.5) with those of the triple quadrupole platform. Together, these results indicate that high-resolution MS platforms such as the orbitrap are not only as capable of performing isotope enrichment measurements as the more commonly preferred triple quadrupole instruments, but offer unparalleled advantages in terms of mass accuracy and sensitivity in the presence of similar-mass contaminants.

ACS Style

Kelly M. Hines; G. Charles Ford; Katherine A. Klaus; Brian A. Irving; Beverly L. Ford; Kenneth L. Johnson; Ian Lanza; K. Sreekumaran Nair. Application of high-resolution mass spectrometry to measure low abundance isotope enrichment in individual muscle proteins. Analytical and Bioanalytical Chemistry 2015, 407, 4045 -52.

AMA Style

Kelly M. Hines, G. Charles Ford, Katherine A. Klaus, Brian A. Irving, Beverly L. Ford, Kenneth L. Johnson, Ian Lanza, K. Sreekumaran Nair. Application of high-resolution mass spectrometry to measure low abundance isotope enrichment in individual muscle proteins. Analytical and Bioanalytical Chemistry. 2015; 407 (14):4045-52.

Chicago/Turabian Style

Kelly M. Hines; G. Charles Ford; Katherine A. Klaus; Brian A. Irving; Beverly L. Ford; Kenneth L. Johnson; Ian Lanza; K. Sreekumaran Nair. 2015. "Application of high-resolution mass spectrometry to measure low abundance isotope enrichment in individual muscle proteins." Analytical and Bioanalytical Chemistry 407, no. 14: 4045-52.

Randomized controlled trial
Published: 01 April 2015 in The Journal of Clinical Endocrinology & Metabolism
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Context: Skeletal muscle from sedentary older adults exhibits reduced mitochondrial abundance and oxidative capacity. Objective: The primary objective was to determine whether 8 weeks of combined training (CT) has a more robust effect than endurance training (ET) or resistance training (RT) on mitochondrial physiology in healthy young (18–30 years) and older (≥65 years) adults. Intervention: Thirty-four young and 31 older adults were randomly assigned to 8 weeks of ET, RT, and control/CT. Control subjects completed 8 weeks of no exercise (control) followed by 8 weeks of CT. Body composition, skeletal muscle strength, and peak oxygen uptake were measured before and after the intervention. Vastus lateralis muscle biopsy samples were obtained before and 48 hours after the intervention. Mitochondrial physiology was evaluated by high-resolution respirometry and expression of mitochondrial proteins and transcription factors by quantitative PCR and immunoblotting. Results: ET and CT significantly increased oxidative capacity and expression of mitochondrial proteins and transcription factors. All training modalities improved body composition, cardiorespiratory fitness, and skeletal muscle strength. CT induced the most robust improvements in mitochondria-related outcomes and physical characteristics despite lower training volumes for the ET and RT components. Importantly, most of the adaptations to training occurred independent of age. Conclusion: Collectively, these results demonstrate that both ET and CT increase muscle mitochondrial abundance and capacity although CT induced the most robust improvements in the outcomes measured. In conclusion, CT provides a robust exercise regimen to improve muscle mitochondrial outcomes and physical characteristics independent of age.

ACS Style

Brian A. Irving; Ian Lanza; Gregory C. Henderson; Rajesh R. Rao; Bruce M. Spiegelman; K. Sreekumaran Nair. Combined Training Enhances Skeletal Muscle Mitochondrial Oxidative Capacity Independent of Age. The Journal of Clinical Endocrinology & Metabolism 2015, 100, 1654 -1663.

AMA Style

Brian A. Irving, Ian Lanza, Gregory C. Henderson, Rajesh R. Rao, Bruce M. Spiegelman, K. Sreekumaran Nair. Combined Training Enhances Skeletal Muscle Mitochondrial Oxidative Capacity Independent of Age. The Journal of Clinical Endocrinology & Metabolism. 2015; 100 (4):1654-1663.

Chicago/Turabian Style

Brian A. Irving; Ian Lanza; Gregory C. Henderson; Rajesh R. Rao; Bruce M. Spiegelman; K. Sreekumaran Nair. 2015. "Combined Training Enhances Skeletal Muscle Mitochondrial Oxidative Capacity Independent of Age." The Journal of Clinical Endocrinology & Metabolism 100, no. 4: 1654-1663.

Clinical science
Published: 22 January 2015 in Metabolism
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Aims Prior studies have reported that elevated concentrations of several plasma amino acids (AA), particularly branched chain (BCAA) and aromatic AA predict the onset of type 2 diabetes. We sought to test the hypothesis that circulating BCAA, aromatic AA and related AA metabolites decline in response to the use of insulin sensitizing agents in overweight/obese adults with impaired fasting glucose or untreated diabetes. Methods We performed a secondary analysis of a randomized, double-blind, placebo, controlled study conducted in twenty five overweight/obese (BMI ~30kg/m2) adults with impaired fasting glucose or untreated diabetes. Participants were randomized to three months of pioglitazone (45mg per day) plus metformin (1000mg twice per day, N=12 participants) or placebo (N=13). We measured insulin sensitivity by the euglycemic-hyperinsulinemic clamp and fasting concentrations of AA and AA metabolites using ultra-pressure liquid chromatography tandem mass spectrometry before and after the three-month intervention. Results Insulin sensitizer therapy that significantly enhanced insulin sensitivity reduced 9 out of 33 AA and AA metabolites measured compared to placebo treatment. Moreover, insulin sensitizer therapy significantly reduced three functionally clustered AA and metabolite pairs: i) phenylalanine/tyrosine, ii) citrulline/arginine, and iii) lysine/α-aminoadipic acid. Conclusions Reductions in plasma concentrations of several AA and AA metabolites in response to three months of insulin sensitizer therapy support the concept that reduced insulin sensitivity alters AA and AA metabolites.

ACS Style

Brian A. Irving; Rickey E. Carter; Mattias Soop; Audrey Weymiller; Husnain Syed; Helen Karakelides; Sumit Bhagra; Kevin Short; Laura Tatpati; Rocco Barazzoni; K. Sreekumaran Nair. Effect of Insulin Sensitizer Therapy on Amino Acids and Their Metabolites. Metabolism 2015, 64, 720 -728.

AMA Style

Brian A. Irving, Rickey E. Carter, Mattias Soop, Audrey Weymiller, Husnain Syed, Helen Karakelides, Sumit Bhagra, Kevin Short, Laura Tatpati, Rocco Barazzoni, K. Sreekumaran Nair. Effect of Insulin Sensitizer Therapy on Amino Acids and Their Metabolites. Metabolism. 2015; 64 (6):720-728.

Chicago/Turabian Style

Brian A. Irving; Rickey E. Carter; Mattias Soop; Audrey Weymiller; Husnain Syed; Helen Karakelides; Sumit Bhagra; Kevin Short; Laura Tatpati; Rocco Barazzoni; K. Sreekumaran Nair. 2015. "Effect of Insulin Sensitizer Therapy on Amino Acids and Their Metabolites." Metabolism 64, no. 6: 720-728.