CARDIAC DAMAGE BIOMARKERS ARE AFFECTED BY TRAINING STATUS BUT NOT EXERCISE MODE OR ACE GENE

Akram Falahati 1,2, Yair Pincu1, & Hamid Arazi 2 1Department of Health and Exercise Sciences, University of Oklahoma, Norman, Oklahoma, 2Department of Exercise Physiology, University of Guilan, Rasht, Iran PURPOSE: This study aimed to investigate the effects of exercise mode on cardiac damage in young men and to test the contribution of training status and Angiotensin-Converting Enzyme insertion/deletion (ACE-I/D) polymorphism to exercise-associated cardiac damage. METHODS: We measured circulating levels of cardiac Troponin I (cTnI) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) in 29 trained and 27 untrained soccer players before and after moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) running tests. ACE-I/D polymorphism was evaluated from circulating leukocyte-derived DNA. RESULTS: Compared to untrained, trained soccer players had higher cTnI levels – independently of exercise mode (pre-exercise: 0.014±0.007 vs. 0.010±0.005 ng/mL; post HIIE: 0.031±0.008 vs. 0.0179±0.007 ng/mL and post MICE: 0.030±0.007 vs. 0.018±0.007 ng/mL in trained vs. untrained, respectively). No group differences were found in the NT-proBNP response to exercise. No within training-status group differences were found in cTnI levels across the three ACE-I/D polymorphism categories for trained (DD: 0.015±0.008 ng/mL; ID: 0.015±0.007 ng/mL; II: 0.014±0.008 ng/mL) and their untrained counterparts (DD: 0.010±0.004 ng/mL; ID: 0.011±0.004 ng/mL; II: 0.010±0.006 ng/mL). CONCLUSION: Training status but not exercise mode nor ACE-I/D polymorphism affected circulating markers of cardiac damage in young healthy men. Additionally, ACE genotype did not impacted biomarkers of cardiac damage in response to HIIE and MICE, suggesting that the ACE gene does not play a significant role in exercise-induced cardiac damage in young healthy men. Keywords: ACE gene; exercise; hs-cTnI; NT-proBNP; soccer; traine

ASSOCIATIONS BETWEEN WALKING PARAMETERS AND HEALTH OUTCOMES IN OLDER ADULTS WITH METABOLIC SYNDROME

Shabnam Samaei1, & Yair Pincu1 1University of Oklahoma, Norman, Oklahoma PURPOSE: To investigate the relationships between walking parameters and health and well-being outcomes in older adults with and without Type 2 Diabetes (T2D) and Metabolic Syndrome (MetSyn). METHODS: A total of 70 subjects, (age≥65 years), were recruited from diabetes outpatient and community clinics. Daily step count and walking distance were assessed using a pedometer. Comfortable walking speed and average step length were measured. Health parameters and well-being measures were collected. RESULTS: Subjects with MetSyn walked less and slower than subjects with no MetSyn (2.56±0.27 vs. 3.46±0.32 km/day and 3.48±0.18 vs. 4.29±0.16 km/hr, respectively, p\u3c0.05). While no significant differences were found in walking parameters between individuals with and without diabetes, individuals with abdominal obesity walked less and at a slower pace compared to individuals with no abdominal obesity – independently of diabetes (2.73±0.25 vs. 3.69±0.43 km/day, 3.64±0.13 vs. 4.58±0.23 km/hr, respectively; P\u3c0.05). Daily number of steps and daily walking distance did not correlate with health outcomes, however, individuals with comfortable walking speed ≥4km/hr had smaller waist circumference, lower BMI, and improved emotional well-being (p\u3c0.05). CONCLUSION: This study underscores the significance of walking speed in conjunction with daily step count in predicting health outcomes in older adults with T2D and MetSyn. Routine walking parameter assessments, including comfortable walking speed, can be valuable in clinical care and in designing effective intervention programs. KEYWORDS: Central obesity, Chronic metabolic conditions, Comfortable walking speed, Pedometer, Daily step coun

The impact of mechanically stimulated muscle-derived stromal cells on aged skeletal muscle

Perivascular stromal cells, including mesenchymal stem/stromal cells (MSCs), secrete paracrine factor in response to exercise training that can facilitate improvements in muscle remodeling. This study was designed to test the capacity for muscle-resident MSCs (mMSCs) isolated from young mice to release regenerative proteins in response to mechanical strain in vitro, and subsequently determine the extent to which strain-stimulated mMSCs can enhance skeletal muscle and cognitive performance in a mouse model of uncomplicated aging. Protein arrays confirmed a robust increase in protein release at 24 h following an acute bout of mechanical strain in vitro (10%, 1 Hz, 5 h) compared to non-strain controls. Aged (24 month old), C57BL/6 mice were provided bilateral intramuscular injection of saline, non strain control mMSCs, or mMSCs subjected to a single bout of mechanical strain in vitro (4 ×104). No significant changes were observed in muscle weight, myofiber size, maximal force, or satellite cell quantity at 1 or 4 wks between groups. Peripheral perfusion was significantly increased in muscle at 4 wks post-mMSC injection (p < 0.05), yet no difference was noted between control and preconditioned mMSCs. Intramuscular injection of preconditioned mMSCs increased the number of new neurons and astrocytes in the dentate gyrus of the hippocampus compared to both control groups (p < 0.05), with a trend toward an increase in water maze performance noted (p=0.07). Results from this study demonstrate that acute injection of exogenously stimulated muscle-resident stromal cells do not robustly impact aged muscle structure and function, yet increase the survival of new neurons in the hippocampus

In Vitro Cytogenetic Assays: Chromosomal Aberrations and Micronucleus Tests

Chromosome damage is a very important indicator of genetic damage relevant to environmental and clinical studies. Detailed descriptions of the protocols used for detection of chromosomal aberrations induced by genotoxic agents in vitro both in the presence or absence of rat liver-derived metabolizing systems are given in this chapter. Structural chromosomal aberrations that can be observed and quantified at metaphases are described here. For the detection of chromosomal damage (fragments or whole chromosome) in interphase, the micronucleus test can be used, and a description of this test is also presented. Criteria for determining a positive result using appropriate statistical methods are described