Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

PROLONGED STANDING INCREASES LOWER PERIPHERAL ARTERIAL STIFFNESS INDEPENDENT OF WALKING BREAKS

Aaron R. CaldwellƗ1, Benjamin T. Harris*1, Megan E. Rosa-CaldwellƗ1, Marcus PayneƗ1, Bryce DanielsƗ1, Kaitlin M. Gallagherǂ1, Matthew S. Ganioǂ1, FACSM. 1University of Arkansas, Fayetteville, AR. Prolonged sitting creates an atherogenic environment that causes reductions in arterial function. Standing desks have been promoted as a healthy alternative to sitting, but the cardiovascular benefits of standing desks have not been thoroughly investigated. Physical activity, such as taking walking breaks, increases shear stress, and thereby prevents sitting-induced reductions in arterial function. Therefore, walking breaks, even when compared to standing may provide cardiovascular benefits. Purpose: First, to observe changes in arterial stiffness, as assessed by pulse wave velocity (PWV), with a 2 hour bout of standing. Second, to determine if short, intermittent walking bouts provide a comparative advantage to standing alone. Methods: 20 apparently healthy adults (BMI = 22.9 ± 3.2 kg/m2; Age = 21 ± 5 years old) stood for 2 consecutive hours while being assessed for heart rate (HR), mean arterial pressure (MAP), and central (CPWV), upper peripheral (UPWV), and lower peripheral (LPWV) PWV before, during, and after the standing bout. Subjects participated in two trials in a randomized order. In one trial, the subjects stood at a standing desk immobile for 2 hours. In the other trial, subjects performed 5-minute walking breaks after every 25 minutes of standing for a total of two hours of standing with 4 walking breaks. A repeated measures ANOVA utilized for statistical analyses. Results: There was no time by trial interaction for any measure of arterial stiffness (p = 0.82, p = 0.21, and p = 0.15; for CPWV, UPWV, and LPWV respectively). However, from beginning to end of each trial LPWV increased 85 ± 126 cm/s independent of trial (i.e., main effect of time; p \u3c 0.001). There was a non-significant tendency for greater increases in LPWV during the standing (120 ± 142 cm/s) versus the walking trial (50 ± 127 cm/s; p = 0.15). There were no differences regarding HR or MAP (p \u3e 0.05) CONCLUSION: Standing for 2 hours leads to increases in peripheral arterial stiffness. Walking breaks during 2 hours of standing did not significantly attenuate these changes. However, the suggestive evidence (p=0.15) for walking breaks to improve LPWV suggests that future studies should investigate longer duration trials and/or longer walking breaks that are applicable to occupational settings, such as assembly-line work. Supported by funding from Southwest Center for Occupational and Environmental Health NIOSH Pilot Project Research Training Progra

INHIBITION OF miR-16 IN VITRO DECREASES GLUCOSE UPTAKE AND INSULIN SIGNALING

Seongkyun Lim, David E. Lee, Megan E. Rosa-Caldwell, Jacob L. Brown, Tyrone A. Washington, Nicholas P. Greene. University of Arkansas, Fayetteville, AR Type 2 Diabetes Mellitus (T2DM) is a fast-growing epidemic and skeletal muscle insulin resistance may be the onset point in the development of T2DM. Recent data have suggested that microRNAs (miR) may play an important role in T2DM glucose intolerance. Specifically, reduced miR-16 content in muscle has been noted in human and murine models of T2DM. However, regulation of miR-16 and its relation to skeletal muscle insulin resistance is largely unexplored. PURPOSE: To investigate how miR-16 content affects insulin resistance and glucose regulation in myotubes during normal and insulin resistant states. METHODS: This study was performed in two experiments. Experiment 1: To test if miR-16 is necessary for muscle insulin sensitivity C2C12 myoblasts were plated in six well plates and differentiated upon confluence. Cells were transfected with a plasmid to inhibit function of miR-16. Experiment 2: To test if miR-16 is sufficient to ameliorate insulin resistance C2C12 were similarly differentiated and transfected with plasmid to overexpress functional miR-16, cells were then treated with a 1-oleoyl-2-acetyl-sn-glycerol (OAG), a diacylglycerol/DAG analog to stimulate lipid overload-induced insulin resistance. For both experiments cells were stimulated with insulin and measures of glucose uptake and insulin signaling were measured via uptake of 2-NBDG (a fluorescent analog of glucose), and immunoblotting of the insulin signaling cascade. Data were analyzed by ANOVA or t-test as appropriate, significance was denoted at p\u3c0.05. RESULTS: Experiment 1: Insulin-stimulated glucose uptake was ~25% lower in myotubes following miR16 inhibition compared to control (p=0.01). Furthermore, insulin signaling was lower in myotubes with miR16 inhibition compared to control (31%, p=0.002). Experiment 2: OAG-induced insulin resistant myotubes in vitro exhibited significantly lower glucose uptake (p=0.01) compared to control (12%). However, overexpression of miR16 did not improve OAG-induced impaired glucose uptake (p\u3e0.05). CONCLUSION: miR-16 may be necessary for appropriate glucose handling, however miR-16 is not sufficient to rescue glucose regulation during pathological insulin resistance. ACKNOWLEDGEMENTS: This study was funded by the Arkansas Bioscience Institute and American College of Sports Medicine Research Endowment Grant

MIR-16 KNOCKOUT REVEALS IMPAIRED INSULIN SENSITIVITY: A PILOT STUDY

Seongkyun Lim, Megan E. Rosa-Caldwell, Wesley S. Haynie, David E. Lee, Tyrone A. Washington, Nicholas P. Greene, FACSM; University of Arkansas, Fayetteville, AR Type 2 diabetes mellitus (T2DM) has become the most common metabolic disease in western society, leading to serious health problems and financial burdens. Numerous investigations have approached different therapeutics to target T2DM, but the underlying molecular mechanisms are still not completely understood. Our laboratory and others have recently demonstrated consistent downregulation of the microRNA-16 (miR-16) in skeletal muscle across human, rodent and tissue culture models of T2DM. PURPOSE: To investigate how deletion of miR-16 gene affects glucose handling and insulin sensitivity during insulin resistance. METHODS:7 wildtype (WT) and 9 skeletal muscle specific miR-16 knockout (KO) male mice were used for this study. At 9 wks of age, glucose tolerance test (GTT) and insulin tolerance test (ITT) were performed. At 10 wks of age, half of the mice were given high-fat diet (HFD; 45% calories from fat) to induce insulin resistance, while the remainder were fed with normal chow (NC) as control. At 13 wks of age, GTT and ITT were repeated to examine the effect of HFD in miR-16 KO mice. RESULTS: Body weight was increased by 22.7% in WT mice with HFD and 16.7% in miR-16 KO mice with HFD compared to WT mice with NC.GTT area under curve (AUC) was increased by 30% in miR-16 KO mice with HFD compared to WT mice with NC. ITT data revealed a blunted response to insulin in miR-16 KO mice group with NC and HFD compared to WT mice with NC and HFD. CONCLUSION: Previous data from our group and others that downregulated miR-16 in skeletal muscle across human and animal models of T2DM may be in part due to impaired response to insulin in miR-16 KO condition. Further research is warranted to elucidate molecular mechanisms of miR-16 and its potential role in insulin resistance. ACKNOWLEDGEMENTS: This study was funded by the Arkansas Bioscience Institute and American College of Sports Medicine Research Endowment Grant

CANCER CACHEXIA: METABOLIC CHANGES IN CARBOHYDRATE METABOLISM OF THE LIVER

Sarah M. Ramey*1, Megan E. Rosa-CaldwellƗ1, Jacob L. BrownƗ1, David E. LeeƗ1, Richard A. PerryƗ1, Wesley A. HaynieƗ1, Aaron R. CaldwellƗ1, Tyrone A. Washingtonǂ1, Michael P. Wiggsǂ2, Nicholas P. Greeneǂ1 1University of Arkansas, Fayetteville, Arkansas; 2Univeristy of Texas at Tyler, Tyler, Texas One negative side effect of cancer that dramatically affects cancer prognosis and progression is the development of cancer cachexia. Cancer cachexia is defined as cancer-associated muscle wasting. This is thought to be at least partially mediated by increased energy expenditure and is responsible for the death of 20-40% of all cancer patients. Although the liver is known to be the predominant regulator of whole body metabolism, there is little known about its relationship to the development of cancer cachexia. PURPOSE: The purpose of this exploratory study was to investigate alterations in liver metabolism by examining measures of glycogen storage throughout the progression of Lewis Lung Carcinoma (LLC) induced cancer cachexia. METHODS: C57BL/6J mice were injected with 1X106 LLC Cells in the left posterior leg, and the control group with phosphate buffered saline (PBS). The experimental groups included PBS, 1wk, 2wk, 3wk, and 4wk of cancer progression with 10-16 in each group. Sections of liver (n=~8/group) were cut and periodic acid-Schiff (PAS) stain for glycogen was completed. Images were analyzed for total area of stain as well as intensity of stain using NIS-Elements imaging software. A Welch’s one-way analysis of variance was used to determine differences between groups, a Tukey post hoc was used to determine differences between means. Significance was denoted at p\u3c0.05. RESULTS: 4wk animals had ~30% larger livers compared to all other groups with no other differences detected (~1000mg compared to ~1300mg, p\u3c0.05). However, there was no statistical differences detected between groups on either PAS area stained (~50% across groups, p\u3e0.05) or intensity of stain (Arbitrary Intensity Unit ~30 across groups, p\u3e0.05). Furthermore, neither glycogen area nor intensity correlated with liver size (r = 0.12 and r = 0.16 respectively). CONCLUSION: Differences in liver sizes are not attributable to glycogen storage. Though there were no differences in glycogen content, the increase in liver size suggests disruption of other processes in the liver. For future projects, we will further investigate mechanisms for liver hypertrophy in order to determine the relationship between the liver and cancer cachexia progression. This study was supported by The Arkansas Bioscience Institute and National Institutes of Health R15AR069913

EXTRACELLULAR MATRIX REMODELING AND FIBROSIS DURING THE DEVELOPMENT OF CANCER CACHEXIA

Wesley S. Haynie1, Jacob L. Brown1, David E. Lee1, Megan E. Rosa-Caldwell1, Richard, A. Perry1, Lemuel A. Brown1, Nicholas P. Greene1, Tyrone A. Washington1. 1University of Arkansas, Fayetteville, Arkansas. Cancer-cachexia is the largely irreversible wasting of lean body mass as a result of cancer progression, affecting ~80% of all cancer patients with as much as ~40% of cancer-related deaths being attributed directly to cachexia. Cachexia has been associated with increased fibrosis and reduced physiological function in cardiac muscle, but the possible role and development of fibrosis and associated extracellular matrix (ECM) remodeling in skeletal muscle has lacked evaluation. PURPOSE: To examine the effects of cancer cachexia on ECM remodeling and the development of fibrosis in skeletal muscle. METHODS: 40 C57BL6/J mice were injected with either Lewis Lung Carcinoma cells or a PBS control into their hind-flank at 8 wks of age. The tumor was allowed to develop for 1, 2, 3, or 4 wks (n=8 per group). Tibialis anterior (TA) muscle was extracted and immediately frozen for morphology and mRNA abundance analysis using RT-qPCR. RESULTS: There were no changes in TA muscle weight until 4 wks post-tumor implantation which resulted in a ~22% lower muscle wet weight compared to PBS control (p\u3c0.05). PicroSirius Red staining of TA muscle sections resulted in no change in collagen abundance in all groups with the exception of a 2-3-fold increase at 4 wks relative to all other groups (p\u3c0.05). Collagen 1 mRNA abundance was ~50 % and ~60 % lower than control at 3 and 4 wks post tumor injection, respectively (p\u3c0.05). Collagen 1 mRNA abundance was ~2-fold higher at 1 and 2 wks but there was no difference at 3 or 4wks, all relative to control (p\u3c0.05). The ratio of Collagen 3:1 mRNA abundance decreased ~30-50% from 1-3wks compared to control (p\u3c0.05), but there was no difference at 4-wks. MMP-2 mRNA abundance was ~50% higher at 1-wk compared to control (p\u3c0.05), but was not different 2-4wks from control (p\u3c0.05). MMP-9 mRNA abundance was 3 and 6-fold greater than control at 3 and 4-wks post-injection, respectively (p\u3c0.05). There was a main effect of tumor implantation to reduce TIMP-1 mRNA abundance ~20-70% (p\u3c0.05). CONCLUSION: The development of cancer cachexia results in dysregulation of ECM remodeling and increased collagen deposition within skeletal muscle. This dysregulation could negatively affect skeletal muscle’s ability to maintain muscle mass and respond to other environmental stressors. ACKNOWLEDGEMENTS: This study was funded by the National Institutes of Health, Award number: R15 AR069913/AR/NIAMS

PRELIMINARY STUDY: MUSCLE WASTING IS EXACERBATED IN APCMin/+ MICE WITH LEUCINE SUPPLEMENTATION

Katarina A. Bejarano1, Wesley S. Haynie1, Richard, A. Perry1, Lemuel A. Brown1, David E. Lee1, Jacob L. Brown1, Megan E. Rosa-Caldwell1, Nicholas P. Greene1, Tyrone A. Washington1. 1University of Arkansas, Fayetteville, Arkansas. Cancer Cachexia is a devastating syndrome that affects around 50-80% of cancer patients and is characterized by a rapid, drastic fat and muscle mass loss. The APCMin/+ mouse strain is a well-studied mouse model of human colorectal cancer and cancer cachexia. The branched-chain amino acid leucine is known to stimulate muscle growth/maintenance through activation of the protein mTOR and protein synthesis. PURPOSE: To examine the effects of chronic leucine supplementation on the development of cancer cachexia in APCMin/+ mice. METHODS: 7 APCMin/+ mice (APC) and 11 wild-type (WT) were used for this study. The animals were assigned to the following groups: WT no leucine (WTNL, n=5), WT leucine (WTL, n=5), APCMin/+ no leucine (APCNL, n=5) and APCMin/+ leucine (APCL, n=2). Mice were given ad libitum access to food and water. Mice in the leucine groups received leucine in their water at a concentration of 1.5%. Plantaris muscles and tibias were excised at 20 weeks of age. Tissue was immediately frozen for morphology and gene expression analysis using RT-qPCR. RESULTS: The number of polyps increased in APCMin/+ compared to WT (46.57 ± 2.44 vs 0.00 ± 0.00). The number of polyps \u3c 1 mm was increased (7.75 ± 2.05 vs. 14.33 ± 1.45) in APCL compared to APCNL (p\u3c.05). There was a main effect for APCMin/+ to have lower body mass in than WT mice (p\u3c.0001). There was a main effect of genotype to decrease plantaris weight/tibia length in APCMin/+ mice (p\u3c.0001) and a main effect of leucine to decrease plantaris weight/tibia length in APCMin/+ mice compared to WT mice (p\u3c.05). There was an ~8-fold increase in atrogin-1 gene expression in APCNL compared to WTNL mice (p\u3c.05). Atrogin-1 gene expression was ~7-fold lower in APCL compared to APCNL (p\u3c.05). There was a main effect of genotype to increase MuRF1 expression in APCMin/+ mice compared to WT mice (p\u3c.05). There was a main effect of leucine to decrease MuRF1 expression in APCMin/+ mice compared to WT mice (p\u3c.05). CONCLUSION: Contrary to our initial hypothesis, leucine supplementation seemed to exacerbate muscle mass loss in cachectic mice. Based on gene expression of the E3 ubiquitin ligases, this loss in muscle mass may be independent of protein degradation

EFFECTS OF LEUCINE SUPPLEMENTATION ON MARKERS OF ATROPHY IN CANCER CACHEXIA

Kyle L. Rankin1, Wesley S. Haynie1, Megan E. Rosa-Caldwell1, Katarina A. Bejarano1, Seongkyun Lim1, Lemuel A. Brown1, Richard A. Perry1, Nicholas P. Greene1, Tyrone A. Washington1 1University of Arkansas, Fayetteville, Arkansas Nearly 80% of cancer patients are afflicted with cancer-cachexia, which is associated with wasting of lean body mass and is a prevalent cause of death among cancer patients. The amino acid leucine has been shown to promote muscle growth by augmenting protein synthesis through mTOR activation. Therefore, supplementation of leucine could prove beneficial for mitigating skeletal muscle wasting during cancer cachexia progression. PURPOSE: To determine the effect of leucine supplementation on cancer cachexia in APC Min/+ (APC) mice. METHODS:9 APC and 9 C57BL/6J Wild Type (WT)male litter mates were used in this study. Within each of these two groups, 4 were given water (APC-NL) and 5 were given 1.5% leucine-supplemented water(APC-L), with ad libitum access to food and water. Gastrocnemius(GA)muscle and tibias (TI) were extracted at ~14-21 weeks of age, or when mice became moribund. Tissue was homogenized and analyzed for genetic expression via RT-qPCR. Data were analyzed via Two-Way ANOVA, and following a significant F-test, a Fisher’s LSD post-hoc was run. RESULTS: Body weight for APC-NL mice was ~14% lower than both WT-NL and WT-L(p\u3c0.05).Bodyweight for APC-L mice was ~25% lower than both WT-NL and WT-L (p\u3c0.05).Gastrocnemius mass for APC mice was ~33% lower than both WT-NL and WT-L(p\u3c0.05). There were no differences in GA mass/TI length for either WT-NL or WT-L. APC-NL GA mass/TI length was ~25%lower than both WT-NL and WT-L, and GAmass/TI length for APC-L was ~20% lower than the APC-NL group(p\u3c0.05). There was no difference in expression of MuRF-1across all groups.IL-6expressionin the APC-NL group was~1-fold greater compared to both WT-NL and WT-L(p\u3c0.05).IL-6expression in APC-L was ~1-fold greater than the APC-NL group(p\u3c0.05).There was no statistical difference between WT-NL, WT-Land APC-NL for Atrogin-1expression, but there was a ~6-fold increase in Atrogin-1expression in APC-L compared to both WT-NL and WT-L(p\u3c0.05).CONCLUSION: Cancer cachexia has previously shown marked increases in skeletal muscle atrophy, commonly through atrophy-related genes such as Atrogin-1and MuRF-1, as well as IL-6. Our results indicate leucine supplementation may exacerbate skeletal muscle wasting and increase these atrophic genes and atrophic signaling in conjunction with an already cachectic environment during cancer cachexia. ACKNOWLEDGEMENTS: This study was funded by the Arkansas Biological Institute, the major research component of the Arkansas Tobacco Settlement Proceeds Act of 2000, and by the National Institutes of Health, Award number: R15 AR069913/AR/NIAMS

CHANGES IN LIVER FIBROSIS DURING THE PROGRESSION OF CANCER-CACHEXIA IN MICE

Kyle W. Turner*1, Megan E. Rosa-CaldwellƗ1, Jacob L. BrownƗ1, David E. LeeƗ1, Richard A. PerryƗ1, Wesley A. HaynieƗ1, Tyrone A. Washingtonǂ1, Michael P. Wiggsǂ2, Nicholas P. Greeneǂ1 1University of Arkansas, Fayetteville, Arkansas; 2Univeristy of Texas at Tyler, Tyler, Texas Cancer is one of the most widespread and deadly diseases in recent history. Cancer-cachexia is a systematic, metabolic disorder that greatly disrupts the patient’s energy balance, causing uncontrollable weight and skeletal muscle loss. This cancer-induced cachexia is one of the major causes of cancer-related death. As the primary metabolic organ controlling energy balance, the liver is likely involved with the progression of cancer-cachexia. However, very little research has investigated the liver’s involvement in the progression of cancer-cachexia. PURPOSE: The purpose of this study was to observe changes in liver fibrosis during the progression of cancer-cachexia. METHODS: C57BL/6J mice were injected with 1X106 lewis lung carcinoma cells in the hind flank and cancer was allowed to progress for 1,2, 3, or 4 wks. Control animals were injected with sterile phosphate buffered saline solution (PBS) and harvested with 4 wks animals, creating five groups (CON, 1, 2, 3 or 4wks cancer progression, n=10-16/group). Livers were harvested and ~8 samples/group were analyzed for collagen deposition and measures of mitochondrial content. Results were analyzed by one-way ANOVA as well as regression analysis. When differences were found, a Tukey-Kramer post hoc was used to determine differences among means, significance was determined at p\u3c0.05. RESULTS: Liver weights normalized to tibia length were ~30% larger in 4wks animals compared to all other groups (p\u3c0.05). Sirius red staining for collagen indicated that collagen area increased over time in an exponential fashion (r2=0.78), with 4wks having statistically greater collagen deposition than all other groups. Preliminary analysis (n=4/group) of COX-IV content in the liver suggested no change in mitochondrial content. CONCLUSION: The liver is clearly affected by the progression of cancer-cachexia, becoming much larger and more fibrotic. It can be inferred that this fibrotic damage may also exacerbate the energy balance problems caused by cancer-cachexia. Therefore, further research needs to be conducted in this area to more thoroughly understand the liver’s role in this pathology. This study was supported by The Arkansas Bioscience Institute and National Institutes of Health R15AR069913

MUSCLE SPECIFIC OVEREXPRESSION OF PGC-1α1 PROMOTES FAVORABLE EXERCISE RESPONSES UNDER LIPID OVERLOAD CONDITIONS REGARDLESS OF EXERCISE VOLUME

Megan E. Rosa-Caldwell1, Jacob L. Brown1, David E. Lee1, Thomas A. Blackwell1, Richard A. Perry Jr.1, Wesley S. Haynie1, Lemuel A. Brown1, Tyrone A. Washington1, Nicholas P. Greene1 1University of Arkansas Obesity and its associated comorbidities remain the pivotal public health concern of the 21st century. One predominant interest in the development of insulin resistance is the degradation and dysfunction of skeletal mitochondria. PGC-1α1, the principle regulator of mitochondrial biogenesis has been proposed as a possible therapeutic target to alleviate lipid overload-induced mitochondrial dysfunction, yet current data remain controversial on the efficacy of artificially promoting PGC-1α1 as a therapeutic modality. PURPOSE: The purpose of this study was to investigate the efficacy of genetic overexpression of PGC-1α1 alone and in combination with physical activity as a therapeutic agent during lipid overload. METHODS: ~40 wild type (WT) mice and mice with muscle-specific overexpression of PGC-1α1 (MCK-PGC-1α) were given Western Diet (WD) at 8 wks of age and allowed to consume food ab libitum throughout the course of the study. At 12 wks of age, animals were randomly divided into sedentary (SED) and physical activity (voluntary wheel running [VWR]) interventions. At ages 7, 11, and 15 wks animals underwent glucose tolerance tests (GTT). At 16 wks of age animals were humanly euthanized and tissues collected for analysis. RESULTS: MCK-PGC-1α animals were slightly lighter and had less epididymal fat compared to WT (~6% and ~28% respectively). Food efficiency (ratio of weight gained to food consumed) was ~17% lower in MCK-PGC-1α animals. While there was no difference at 7 wks age, at 11 wks age MCK-PGC-1α had ~50% greater integrated area under the curve (IAUC) compared to WT. Yet at 15 wks, VWR had 30% lower IAUC compared to SED, regardless of genotype. MCK-PGC-1α -VWR ran ~3X more per day compared to WT-VWR. Correlations for distance per day v. IAUC, body weight, and epididymal fat were significant and moderately strong (r=-0.67--0.71) for WT-VWR, but in TG there was no correlation between these variables and distance per day (r=0.10-0.20). CONCLUSION: Taken together, these results suggest increasing PGC-1α1 may augment exercise-induced adaptations regardless of exercise volume, but overexpression of PGC-1α1 during lipid overload without physical activity does not appear to mitigate insulin resistance and may in fact exacerbate the condition