Left ventricular speckle tracking-derived cardiac strain and cardiac twist mechanics in athletes: a systematic review and meta-analysis of controlled studies

Background: The athlete’s heart is associated with physiological remodeling as a consequence of repetitive cardiac loading. The effect of exercise training on left ventricular (LV) cardiac strain and twist mechanics are equivocal, and no meta-analysis has been conducted to date. Objective: The objective of this systematic review and meta-analysis was to review the literature pertaining to the effect of different forms of athletic training on cardiac strain and twist mechanics and determine the influence of traditional and contemporary sporting classifications on cardiac strain and twist mechanics. Methods: We searched PubMed/MEDLINE, Web of Science, and ScienceDirect for controlled studies of aged-matched male participants aged 18–45 years that used two-dimensional (2D) speckle tracking with a defined athlete sporting discipline and a control group not engaged in training programs. Data were extracted independently by two reviewers. Random-effects meta-analyses, subgroup analyses, and meta-regressions were conducted. Results: Our review included 13 studies with 945 participants (controls n = 355; athletes n = 590). Meta-analyses showed no athlete–control differences in LV strain or twist mechanics. However, moderator analyses showed greater LV twist in high-static low-dynamic athletes (d = –0.76, 95% confidence interval [CI] –1.32 to –0.20; p < 0.01) than in controls. Peak untwisting velocity (PUV) was greater in high-static low-dynamic athletes (d = –0.43, 95% CI –0.84 to –0.03; p < 0.05) but less than controls in high-static high-dynamic athletes (d = 0.79, 95% CI 0.002–1.58; p = 0.05). Elite endurance athletes had significantly less twist and apical rotation than controls (d = 0.68, 95% CI 0.19–1.16, p < 0.01; d = 0.64, 95% CI 0.27–1.00, p = 0.001, respectively) but no differences in basal rotation. Meta-regressions showed LV mass index was positively associated with global longitudinal (b = 0.01, 95% CI 0.002–0.02; p < 0.05), whereas systolic blood pressure was negatively associated with PUV (b = –0.06, 95% CI –0.13 to –0.001; p = 0.05). Conclusion: Echocardiographic 2D speckle tracking can identify subtle physiological differences in adaptations to cardiac strain and twist mechanics between athletes and healthy controls. Differences in speckle tracking echocardiography-derived parameters can be identified using suitable sporting categorizations

Mitochondrial function as a determinant of life span

Average human life expectancy has progressively increased over many decades largely due to improvements in nutrition, vaccination, antimicrobial agents, and effective treatment/prevention of cardiovascular disease, cancer, etc. Maximal life span, in contrast, has changed very little. Caloric restriction (CR) increases maximal life span in many species, in concert with improvements in mitochondrial function. These effects have yet to be demonstrated in humans, and the duration and level of CR required to extend life span in animals is not realistic in humans. Physical activity (voluntary exercise) continues to hold much promise for increasing healthy life expectancy in humans, but remains to show any impact to increase maximal life span. However, longevity in Caenorhabditis elegans is related to activity levels, possibly through maintenance of mitochondrial function throughout the life span. In humans, we reported a progressive decline in muscle mitochondrial DNA abundance and protein synthesis with age. Other investigators also noted age-related declines in muscle mitochondrial function, which are related to peak oxygen uptake. Long-term aerobic exercise largely prevented age-related declines in mitochondrial DNA abundance and function in humans and may increase spontaneous activity levels in mice. Notwithstanding, the impact of aerobic exercise and activity levels on maximal life span is uncertain. It is proposed that age-related declines in mitochondrial content and function not only affect physical function, but also play a major role in regulation of life span. Regular aerobic exercise and prevention of adiposity by healthy diet may increase healthy life expectancy and prolong life span through beneficial effects at the level of the mitochondrion

Dehydroepiandrosterone replacement therapy in older adults improves indices of arterial stiffness

Serum dehydroepiandrosterone (DHEA) concentrations decrease approximately 80% between ages 25 and 75 year. Aging also results in an increase in arterial stiffness, which is an independent predictor of cardiovascular disease (CVD) risk and mortality. Therefore, it is conceivable that DHEA replacement in older adults could reduce arterial stiffness. We sought to determine whether DHEA replacement therapy in older adults reduces carotid augmentation index (AI) and carotid-femoral pulse wave velocity (PWV) as indices of arterial stiffness. A randomized, double-blind trial was conducted to study the effects of 50 mg day(-1) DHEA replacement on AI (n = 92) and PWV (n = 51) in women and men aged 65-75 year. Inflammatory cytokines and sex hormones were measured in fasting serum. AI decreased in the DHEA group, but not in the placebo group (difference between groups, -6 ± 2 AI units, P = 0.002). Pulse wave velocity also decreased (difference between groups, -3.5 ± 1.0 m s(-1) , P = 0.001); however, after adjusting for baseline values, the between-group comparison became nonsignificant (P = 0.20). The reductions in AI and PWV were accompanied by decreases in inflammatory cytokines (tumor necrosis factor α and IL-6, P < 0.05) and correlated with increases in serum DHEAS (r = -0.31 and -0.37, respectively, P < 0.05). The reductions in AI also correlated with free testosterone index (r = -0.23, P = 0.03). In conclusion, DHEA replacement in elderly men and women improves indices of arterial stiffness. Arterial stiffness increases with age and is an independent risk factor for CVD. Therefore, the improvements observed in this study suggest that DHEA replacement might partly reverse arterial aging and reduce CVD risk

Dehydroepiandrosterone replacement therapy in older adults improves indices of arterial stiffness

Serum dehydroepiandrosterone (DHEA) concentrations decrease approximately 80% between ages 25 and 75 year. Aging also results in an increase in arterial stiffness, which is an independent predictor of cardiovascular disease (CVD) risk and mortality. Therefore, it is conceivable that DHEA replacement in older adults could reduce arterial stiffness. We sought to determine whether DHEA replacement therapy in older adults reduces carotid augmentation index (AI) and carotid-femoral pulse wave velocity (PWV) as indices of arterial stiffness. A randomized, double-blind trial was conducted to study the effects of 50 mg day(-1) DHEA replacement on AI (n = 92) and PWV (n = 51) in women and men aged 65-75 year. Inflammatory cytokines and sex hormones were measured in fasting serum. AI decreased in the DHEA group, but not in the placebo group (difference between groups, -6 ± 2 AI units, P = 0.002). Pulse wave velocity also decreased (difference between groups, -3.5 ± 1.0 m s(-1) , P = 0.001); however, after adjusting for baseline values, the between-group comparison became nonsignificant (P = 0.20). The reductions in AI and PWV were accompanied by decreases in inflammatory cytokines (tumor necrosis factor α and IL-6, P < 0.05) and correlated with increases in serum DHEAS (r = -0.31 and -0.37, respectively, P < 0.05). The reductions in AI also correlated with free testosterone index (r = -0.23, P = 0.03). In conclusion, DHEA replacement in elderly men and women improves indices of arterial stiffness. Arterial stiffness increases with age and is an independent risk factor for CVD. Therefore, the improvements observed in this study suggest that DHEA replacement might partly reverse arterial aging and reduce CVD risk

Phytochemical Properties of Mentha longifolia L. Essential Oil and its Antimicrobial Effects on Staphylococcus Aureus

Background & Aim: Due to the side effects of chemical and synthetic preservatives, consumers have recently become more eager to use foods containing natural preservatives from plants, animals and microbial sources. In the present study, biochemical composition and antibacterial effects (MIC) of Mentha longifolia L. essential oil against Staphylococcus aureus have been evaluated. Methods: In this experimental study, the biochemical composition and antibacterial prosperities of this essential oil was determined by the Gas chromatography/ mass spectrophotometer (GC/MS) and micro dilution method respectively. The morphological and membrane changes of the bacterial cell under the effect of this essential oil were evaluated by transmission electron microscopy. The collected data was analyzed by the SPSS software using ANOVA. Results: The chemical analysis of the essential oil by Gas chromatography/ mass spectrophotometer (GC/MS) revealed the presence of 22 substances (95.30%), mainly including Pulegon (31.54%), 1,8 Cineol (15.89%), Menthoforan (11.8%) and Cis- Isopulegon (9.74%). Minimum inhibitory concentration of the essential oil determined under different temperature and pH values showed to be in the range of 75-1200 µg/ ml. Conclusion: The MIC results and membrane cell damage observed in the electron microscopy evaluation indicated that this essential oil have a high antibacterial activity. Therefore, this essential oil can be combined with other agents for the preservation of foods against pathogenic and toxigenic microorganisms