Combined effects of sleep and objectively-measured daily physical activity on arterial stiffness in middle-aged and older adults.

Although sleep quality and physical activity (PA) may influence on arterial stiffness, the combined effects of these two factors on arterial stiffness remain unknown. A total of 103 healthy middle-aged and older men and women (aged 50-83 years) with no history of cardiovascular disease and depression were included in this study. Arterial stiffness was measured using carotid-femoral pulse wave velocity (cfPWV), brachial-ankle PWV (baPWV), and femoral-ankle PWV (faPWV). Poor sleepers were defined as those with a Pittsburgh Sleep Quality Index score of >5.5. Using an accelerometer for seven consecutive days, low levels of PA were defined as low moderate-to-vigorous-intensity PA (MVPA) <19.0 min/day and low step counts <7100 steps/day, respectively. Poor sleepers with low PA levels, as determined by MVPA and daily steps, showed higher cfPWV, but not faPWV or baPWV, in middle-aged and older adults. Furthermore, in the analysis of covariance (ANCOVA) analyses adjusted for age, obesity, dyslipidemia, and sedentary behavior, the cfPWV result remained significant. Our study revealed that the coexistence of poor sleep quality and decreased PA (low MVPA or daily steps) might increase central arterial stiffness in middle-aged and older adults. Therefore, adequate sleep (good and sufficient sleep quality) and regular PA, especially at appropriate levels of MVPA (i.e., at least of 7100 steps/day), should be encouraged to decrease central arterial stiffness in middle-aged and older adults.

Effects of plant- and animal-based-protein meals for a day on serum nitric oxide and peroxynitrite levels in healthy young men.

Plant-based diets that replace animal-based proteins with plant-based proteins have received increased attention for cardiovascular protection. Nitric oxide (NO) plays an essential role in the maintenance of endothelial function. However, under higher oxidative stress, NO generation produces peroxynitrite, a powerful oxidant and vasoconstrictor. Diet-replaced protein sources has been reported to decrease oxidative stress. However, the effects of plant-based protein on NO and peroxynitrite have not yet been clarified. Therefore, this study aimed to compare the effects of plant- and animal-based-protein meals for a day on NO, peroxynitrite, and NO/peroxynitrite balance. A crossover trial of two meal conditions involving nine healthy men was performed. Participants ate standard meals during day 1. On day 2, baseline measurements were performed and the participants were provided with plant-based-protein meals or animal-based-protein meals. The standard and test meals consisted of breakfast, lunch, and dinner and were designed to be isocaloric. Plant-based-protein meals contained no animal protein. Blood samples were collected in the morning after overnight fasting before and after the test meals consumption. In the plant-based-protein meal condition, serum NOx levels (the sum of serum nitrite and nitrate) significantly increased, while serum peroxynitrite levels did not change significantly. Animal-based-protein meals significantly increased serum peroxynitrite levels but showed a trend of reduction in the serum NOx levels. Furthermore, serum NO/peroxynitrite balance significantly increased after plant-based-protein meals consumption, but significantly decreased after animal-based-protein meals consumption. These results suggest that, compared with animal-based-protein meals, plant-based-protein meals increase NO levels and NO/peroxynitrite balance, which reflects increased endothelial function.

Ascending aortic impedance in young endurance athletes: a time-resolved phase-contrast MRI study.

Ventricular-vascular coupling in endurance athletes remains incompletely understood. The purpose of this study was to determine the ascending aortic impedance in endurance athletes and explore its associations with traditional cardiovascular measurements. In 15 young male endurance runners and 19 young healthy men, time-resolved (CINE) two-dimensional (2-D) phase-contrast MRI quantified the ascending aortic flow while the pressure waveform was simultaneously collected via a generalized transfer function. The aortic impedance modulus and phase were calculated in the frequency domain while characteristic impedance (ZcF) was calculated by averaging moduli between the 4th and 8th heart rate (HR) harmonics. Stroke volume (SV), left ventricular (LV) morphometry, double product, aortic compliance, and total peripheral resistance (TPR) were also measured. Endurance athletes had higher SV, slower HR, greater LV end-diastolic volume and mass, and lower double product than sedentary participants (all P < 0.05). ZcF was significantly lower in athletes than in sedentary participants (73.3 ± 19.2 vs. 93.4 ± 19.0 dyn·s/cm5, P = 0.005). Furthermore, ZcF was negatively correlated with SV (r = -0.691) and aortic compliance (r = -0.601) but was positively correlated with double product (r = 0.445) and TPR (r = 0.458; all P < 0.05). Multivariate analysis revealed that ZcF was the strongest predictor of SV followed by TPR and HR (adjusted R2 = 0.788, P < 0.001). Therefore, our findings collectively suggest that LV afterload quantified by aortic ZcF is significantly lower in endurance athletes than in sedentary adults. The lower pulsatile LV afterload may contribute to greater SV in endurance athletes.NEW & NOTEWORTHY This is the first study to investigate aortic impedance with the noninvasive, simultaneous recordings of aortic pressure using SphygmoCor XCEL and flow using phase-contrast MRI. We found that the characteristic impedance (Zc) is significantly lower in endurance athletes than sedentary adults, is the strongest predictor of stroke volume (SV), and is inversely associated with aortic compliance. These findings suggest that aortic impedance is a key determinant of the ventricular-vascular coupling adapted to long-term training in endurance athletes.

Association of Lower Extremity Muscle Strength and Function with Renal Resistive Index in Individuals with and without Chronic Kidney Disease.

Age-related loss of lower extremity muscle strength is pronounced in individuals with chronic kidney disease (CKD). In contrast, an increase in intrarenal flow pulsatility results in initial age-related changes in renal hemodynamics, leading to the development of CKD. To date, it remains unclear whether lower extremity muscle strength determines elevated renal flow pulsatility. This study aimed to determine the association of lower extremity muscle strength and function with intrarenal hemodynamics in individuals with and without CKD. One hundred seventy-six individuals without CKD (aged 63 ± 9 years) and 101 individuals with CKD (aged 66 ± 8 years) were included in this study. Using Doppler ultrasound, the renal resistive index (RI) was measured as a parameter of renal hemodynamics. Knee extensor muscle strength (KES), gait speed (GS), and the 30 s chair stand test (30s-CST) were used to measure lower extremity muscle strength and function. Multivariate analyses showed that GS and 30s-CST scores were independent determinants of renal RI, whereas the KES score was not associated with renal RI in individuals with and without CKD. In the two-way analysis of covariance, renal RI was the highest in individuals with CKD who had lower KES, GS, and 30s-CST scores. Reduced lower extremity muscle strength and function are independent determinants of elevated renal flow pulsatility in individuals with and without CKD.

Sugar-Rich Food Intake Is Negatively Associated with Plasma Pentraxin 3 Levels.

Background: Levels of pentraxin 3 (PTX3), an anti-inflammatory cardioprotective protein, increase after weight loss in obese men and aerobic exercise in non-obese adults. However, the effect of nutritional characteristics on PTX3 levels remains unclear. This population-based, cross-sectional study investigated the association between circulating PTX3 levels and food intake in Japanese adults. Methods: We hypothesized that the consumption of high amounts of high-sugar foods would lead to low plasma PTX3 levels, resulting in obesity. This study included 327 participants categorized depending on the consumption of the recommended amount of confectionary and sugar-sweetened beverages (CSSB) into high and low groups. Results: PTX3 levels were significantly lower in the high CSSB group than in the low CSSB group. Biological sex was the strongest effector of PTX3 levels. Moreover, the intake of Tsukudani and CSSB, as well as some metabolic syndrome factors, also affect PTX3 levels. In the groups categorized by sex and age, the determinants of PTX3 levels differed. Body mass index, waist circumference (WC), and high-density lipoprotein cholesterol (HDL-C) were significantly associated with PTX3 levels in women. Tsukudani, HDL-C, heart rate, saturated fatty acids, systolic blood pressure, and CSSB were associated with PTX3 levels in individuals aged >65 years. Conclusion: Our results show that circulating PTX3 levels are affected by sex, sugar-rich foods, and metabolic syndrome characteristics (WC, HDL-C).

Effects of lactotripeptide ingestion and physical activity intervention on the fatigue status of middle-aged and older adults: a randomized controlled trial.

This randomized controlled trial aimed to investigate the effects of eight weeks of lactotripeptide (LTP) ingestion, physical activity (PA) intervention, and combined intervention on the fatigue status of middle-aged and older adults. A total of 78 middle-aged and older adults (63 ± 8 years of age) were randomly assigned to four groups: placebo, LTP, placebo with PA intervention (placebo + PA), and LTP with PA intervention (LTP + PA). All participants ingested the placebo or LTP tablets daily (three tablets/day). The placebo + PA and LTP + PA groups participated in a weekly supervised exercise class and were instructed to increase their moderate- to vigorous-intensity PA at home. The visual analog scale, Brief Fatigue Inventory, Profile of Mood States second edition (POMS2), and Beck Depression Inventory second edition (BDI-II) were administered before and after the intervention. No significant interactions or main effects were observed between LTP ingestion and PA intervention on any of the fatigue scales. The main-effect analyses revealed that the PA intervention improved the total mood disturbance score of the POMS2 (F = 5.22, P = 0.03) and BDI-II score (F = 4.81, P = 0.03). After the post hoc paired comparisons, the total mood disturbance and BDI-II scores improved more with the combined intervention than with the PA intervention alone (percentage difference between the effect of combined intervention and PA intervention alone was 3.7% for total mood disturbance score and 13.7% for BDI-II score). The present study suggests that eight weeks of LTP ingestion and PA intervention did not have a significant effect on fatigue status. However, the PA intervention improved mood status and depressive symptoms, and these effects were enhanced by LTP ingestion.

Effect of curcumin supplementation on inflammatory status and muscle damage in competitive female soccer players: a placebo-controlled, singleblind, nonrandomized, crossover pilot study.

PURPOSE: Curcumin, a major component of turmeric, has anti-inflammatory and antioxidative properties, which are associated with protective effects against muscle damage. This study examined the effects of dietary curcumin on inflammation and muscle damage in female competitive soccer players. METHODS: A single-blinded, placebo-controlled, nonrandomized, crossover pilot study was conducted. Six competitive female soccer players (20.0 ± 2.0 yearsold) who participated in a 2-week preseason training program were assigned to two conditions: placebo and curcumin. The participants ingested a placebo or curcumin dosage (270 mg/day) during 2 weeks of preseason training, with 1 week of washout. Fasting blood samples were collected under resting conditions before (day 0) and after (day 15) the training period to examine changes in the concentration of interleukin 6 (IL-6), an inflammatory marker, and indices reflective of muscle damage. RESULTS: Curcumin decreased the concentration of IL-6 released (mean decrease, -30.2 ± 28.1%), whereas no decrease was observed in the placebo condition (13.4 ± 17.4%). Changes in plasma IL-6 concentrations were significantly greater in the curcumin condition than in the placebo condition (p < 0.05). However, curcumin supplementation had no significant effects on muscle damage indices. CONCLUSION: The present study shows that curcumin supplementation could attenuate inflammation, as indicated by IL-6 concentrations, in competitive female soccer players during the training period.

Elevated urinary angiotensinogen excretion links central and renal hemodynamic alterations.

Inappropriate activation of intrarenal renin-angiotensin system (RAS) may contribute to the pathogenesis of cardio-renal syndrome (CRS). We aimed to examine the cross-sectional associations of urinary angiotensinogen (AGT) excretion, a biomarker of intrarenal RAS activity, with central (aortic) and renal hemodynamic parameters in middle-aged and older adults, including patients with chronic kidney disease. Aortic and renal hemodynamic parameters were measured using applanation tonometry and duplex ultrasonography in 282 participants. Urinary AGT, liver-type fatty acid-binding protein (L-FABP), and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured for each participant. Multiple linear regression analyses demonstrated that urinary AGT levels were associated with aortic blood pressures, pulsatile measures of renal blood flow, plasma NT-proBNP and urinary L-FABP levels after adjusting for potential covariates, including age, sex, body mass index, estimated glomerular filtration rate (GFR), and medication use. Additionally, when classified based on GFR stages and urinary AGT levels, plasma NT-proBNP and urinary L-FABP levels increased in participants with lower GFR and higher AGT groups. Our findings suggest that urinary AGT excretion is a shared determinant of central (aortic) and renal hemodynamics in middle-aged and older adults, providing clinical evidence for the potential role of intrarenal RAS activity in the development of CRS.

Effects of maslinic acid supplementation on exercise-induced inflammation and oxidative stress in water polo athletes: A randomized, double-blind, crossover, and placebo-controlled trial.

BACKGROUND: Olive fruit is rich in bioactive pentacyclic triterpenoids, primarily maslinic acid (MA). Previous studies have demonstrated that MA exhibits anti-inflammatory and anti-oxidative effects; however, it is unclear whether MA intake during training inhibits perceptual fatigue and muscle soreness in athletes. This study analyzed the effects of MA supplementation during athletic training on perceptual fatigue and muscle soreness. METHODS: This randomized, double-blind, cross-over, and placebo-controlled trial involved 12 young, healthy male water polo athletes. After daily training for seven days, they ingested either olive fruit extract, containing 60 mg/day MA, or a placebo. We measured perceptual fatigue and muscle soreness during the intervention using a visual analog scale and inflammatory and oxidative stress-related proteins. RESULTS: Perceptual fatigue and muscle soreness and the area under the curve during the training period were significantly lower (main effect of MA; P < 0.05) following MA supplementation than those for the placebo. MA supplementation during training lowered perceptual fatigue and muscle soreness by decreasing inflammatory factors in water polo athletes. Additionally, we examined the detailed mechanism of MA, added the participant's serum to the culture medium at a 10% concentration to determine inflammation- and oxidative stress-related intracellular signals. Skeletal muscle cells (C2C12) cultured with MA-conditioned serum before and after intervention also suppressed expression of inflammation and oxidative stress-related proteins. CONCLUSION: These findings suggest that MA intake not only reduces perceptual fatigue and muscle soreness but also decreases inflammation and oxidative stress in the blood and skeletal muscle.

Effects of Changes in Body Fat Mass as a Result of Regular Exercise on Hemoglobin A1c in Patients With Type 2 Diabetes Mellitus: A Meta-Analysis.

An increase in visceral fat is associated with an increase in insulin resistance, so reducing body fat mass through exercise may help alleviate type 2 diabetes mellitus (T2DM). The current meta-analysis evaluated the effect of changes in body fat via an intervention of regular exercise on hemoglobin A1c (HbA1c) in patients with T2DM. The inclusion criteria were randomized controlled trials involving adults with T2DM, intervention involving exercise alone, an overall duration of intervention ≥12 weeks, and reporting HbA1c and body fat mass. The mean differences (MDs) were defined as the MD between the exercise group and the control group, and the MDs in HbA1c (in percentage) and body fat mass (in kilograms) were calculated. All MDs in HbA1c were pooled as overall effects. A meta-regression analysis was performed to evaluate the relationship between the MD in the body fat mass (in kilograms) and the MD in HbA1c. Twenty studies (1,134 subjects) were analyzed. The pooled MD in HbA1c (in percentage) decreased significantly (-0.4; 95% confidence interval [-0.5, -0.3]) but contained significant heterogeneity (Q = 52.7, p < .01; I2 = 41.6%). A meta-regression analysis showed that a decrease in the MD in body fat mass was significantly associated with a decrease in the MD in HbA1c (R2 = 80.0%) and heterogeneity decreased (Q = 27.3, p = .61; I2 = 11.9%), and a reduction in body fat mass of 1 kg was estimated to decrease the HbA1c (%) by approximately 0.2. The current study suggested that a decrease in HbA1c due to regular exercise depends on a reduction in body fat mass in patients with T2DM.

Summary of the clinical practice manual for late-onset hypogonadism.

Testosterone plays an important role in maintaining both physical and mental function. Age-related testosterone depletion contributes to the development of angina, arteriosclerosis, obesity, metabolic syndrome, dementia, frailty, and a range of other conditions. A condition involving age-related testosterone depletion and the associated clinical symptoms is defined as late-onset hypogonadism (LOH). LOH is treated by testosterone replacement therapy. Indications for testosterone replacement therapy are determined by evaluating symptoms and signs.

Eccentric exercise improves myocardial oxygen supply/demand balance with decelerating aortic diastolic pressure decay: The acute and chronic studies.

Both eccentric (ECC) and concentric (CON) exercises improve energy expenditure and blood lipid profile. Although ECC exercise has a more beneficial effect on these factors than CON exercise, its benefits on vital organs are still unclear. This study investigated the mode-of-action-dependent effects on myocardial perfusion index. Seventeen healthy men (age: 26 ± 5 years) were randomly enrolled in CON (n = 9) and ECC (n = 8) groups. Transient exercise and regular training (three-day a week for 4-week) included bicep curl comprising 5-set of 10-repetition, each using 75% one-repetition maximum concentric loading. The ECC group performed one-repetition of ECC for 3-s and CON for 1-s, while the CON group performed one-repetition of CON for 3-s and ECC for 1-s. All participants were assessed for subendocardial viability ratio (SEVR, myocardial perfusion index) and aortic diastolic pressure decay. Before study, these were found to be same for both groups. Transient (ΔSEVR: 20.3 ± 13.3%, p = 0.01; Δdecay: -0.07 ± 0.02 s-1, p < .001) and regular (ΔSEVR: 18.5 ± 12.8%, p = .001; Δdecay: -0.06 ± 0.05 s-1, p = .004) ECC (but not CON) exercises significantly increased SEVR and decelerated decay. Increased SEVR with ECC exercise was associated with decelerated decay (transient ECC: r2 = 0.56, 95% confidence interval [CI] = -0.95 to -0.10, p = .03; regular ECC: r2 = 0.53, 95% CI = -0.95 to -0.05, p = .04). These findings suggest that ECC exercise improves myocardial perfusion and diastolic pressure contour is involved in physiological mechanisms.

Genetic polymorphisms related to muscular strength and flexibility are associated with artistic gymnastic performance in the Japanese population.

This study aimed to examine how genetic polymorphisms related to muscular strength and flexibility influence artistic gymnastic performance in an attempt to identify a novel polymorphism associated with flexibility. In study 1, the passive straight-leg-raise (PSLR) score and aromatase gene CYP19A1 rs936306 polymorphism, a key enzyme for estrogen biosynthesis, were assessed in 278 individuals. In study 2, athletes (281 gymnasts and 1908 other athletes) were asked about their competition level, and gymnasts were assessed using the difficulty score (D-score) for each event. Muscular strength- (ACTN3 R577X rs1815739 and ACE I/D rs4341) and flexibility-related (ESR1 rs2234693 T/C and CYP19A1 rs936306 C/T) genetic polymorphisms were analyzed. In study 1, males with the CYP19A1 CT + TT genotype showed significantly higher PSLR scores than those with the CC genotype. In study 2, male gymnasts with the R allele of ACTN3 R577X showed a correlation with the floor, rings, vault, and total D-scores. In addition, male gymnasts with the C allele of ESR1 T/C and T allele of CYP19A1 C/T polymorphisms were correlated with the pommel horse, parallel bars, horizontal bar, and total D-scores. Furthermore, genotype scores of these three polymorphisms correlated with the total D-scores and competition levels in male gymnasts. In contrast, no such associations were observed in female gymnasts. Our findings suggest that muscular strength- and flexibility-related polymorphisms play important roles in achieving high performance in male artistic gymnastics by specifically influencing the performance of events that require muscular strength and flexibility, respectively.HighlightsEstrogen-related CYP19A1 polymorphism is a novel determinant of flexibility in males.Muscular strength- and flexibility-related polymorphisms play important roles in high performance in male artistic gymnastics.Genotypes of ACTN3 R577X, ESR1 rs2234693, and CYP19A1 rs936306 may contribute to training plan optimization and event selection in artistic gymnastics.

Association between the intake of plant and animal proteins and the serum fibroblast growth factor-23 level in patients with chronic kidney disease analyzed by the isocaloric substitution model.

Fibroblast growth factor-23 (FGF23) is a phosphaturic hormone secreted by the bone in response to dietary phosphate intake. Since the phosphate content in the diet correlates with the protein content, both plant- and animal-based protein intake can increase the serum FGF23 level. However, a higher percentage of energy from plant protein than from animal protein is associated with a lower serum FGF23 level in patients with chronic kidney disease (CKD) in the United States. Since dietary habits differ between Asian and Western populations, we performed a cross-sectional study to determine the association between the percentages of energy from plant and animal proteins and the serum FGF23 level in Japanese CKD patients. In 107 non-dialysis CKD patients (age: 66 ± 9 years; estimated glomerular filtration rate: 56 ± 21 mL/min/1.73 m2), the percentages of energy from plant and animal proteins were assessed using a food frequency questionnaire based on food groups. Venous blood samples were used to measure the serum FGF23, phosphate, 1,25-dihydroxyvitamin D, and intact parathyroid hormone levels. The percentages of energy from plant and animal proteins showed a negative and positive association, respectively, with the serum FGF23 level. Furthermore, isocaloric substitution modeling showed that replacing animal protein with plant protein was associated with a low serum FGF23 level. Our findings suggest that encouraging diets with high plant protein level may prevent an increase in the serum FGF23 level in Japanese CKD patients.

Association between trunk flexibility and renal flow pulsatility in middle-aged and older adults.

BACKGROUND: Recent clinical studies have indicated that poor trunk flexibility is associated with arterial stiffness in the aged. Arterial stiffness leads to elevated renal flow pulsatility, which accelerates age-related renal dysfunction and damages. However, data indicating the potential link between flexibility fitness and renal flow pulsatility are lacking. This study examined the cross-sectional association between trunk flexibility and renal flow pulsatility in middle-aged and older adults. METHODS: A total of 175 middle-aged and older adults (aged 63 ± 9 years) were included in this study. Sit-and-reach tests (SRT) were performed to assess their trunk flexibility. Using a Doppler ultrasound, renal pulsatility index (PI) and resistive index (RI) were measured as parameters of renal flow pulsatility. RESULTS: The study found that, in middle-aged and older adults, the SRT score was an independent determinant of renal PI (ß = -0.134, P = 0.027) and RI (ß = -0.135, P = 0.027). In the one-way analysis of covariance (ANCOVA), the renal PI and RI in the older group with a lower SRT score were found to be significantly higher than those in the middle-aged group. CONCLUSIONS: Trunk flexibility is an independent determinant of renal flow pulsatility in middle-aged and older adults.

Microstructural organization of the corpus callosum in young endurance athletes: A global tractography study.

Introduction: Aerobic exercise training has been shown to improve microstructural organization of the corpus callosum (CC); however, evidence of this topographic effect is limited. Purpose: To compare the CC microstructural organization between endurance athletes and sedentary adults using a white-matter fiber tractography approach. Materials and methods: Diffusion tensor imaging (DTI) and T1-weighted structural data were collected from 15 male young endurance athletes and 16 age- and sex-matched sedentary adults. DTI data were analyzed with a global probabilistic tractography method based on neighborhood anatomical information. Fractional anisotropy (FA) and mean, radial (RD), and axial diffusivities were measured in the eight CC tracts: rostrum, genu, splenium, and body's prefrontal, premotor, central, parietal, and temporal tracts. Cortical thickness of the CC tract endpoints and the CC tract length and volume were also measured. Physical activity level was assessed by metabolic equivalents (METs). Results: The athlete group had an average VO2max of 69.5 ± 3.1 ml/kg/min, which is above 90%ile according to the American College of Sports Medicine guideline. Compared with the sedentary group, the athlete group had higher FA in the CC body's premotor and parietal tracts and the CC splenium. These tracts showed lower RD in the athlete compared with sedentary group. The voxelwise analysis confirmed that the athlete group had higher FA in the CC and other white matter regions than the sedentary group, including the corona radiata, internal capsule, and superior longitudinal fasciculus. Cortical thickness of the CC tract endpoints and the CC tract lengths and volumes were similar between the two groups. Physical activity levels were positively correlated with FA in the CC body's parietal (r = 0.486, p = 0.006) and temporal (r = 0.425, p = 0.017) tracts and the CC splenium (r = 0.408, p = 0.023). Conclusion: Young endurance athletes have higher microstructural organization of the CC tracts connected the sensorimotor and visual cortices than the age- and sex-matched sedentary adults.

Acute influences of tennis services on cardiac output and brachial hemodynamics in young male tennis players.

OBJECTIVES: This study aimed to examine the influences of tennis service exercise on cardiac output (CO) and bilateral brachial hemodynamics in young tennis players. DESIGN: Experimental study. METHODS: Ten young male tennis players (21 ±â€¯2 years of age) participated. Each performed 100 tennis services without a return shot for experimental tennis exercise. Cardiovascular hemodynamic variables, including bilateral brachial blood flow (BF), shear rate (SR), blood pressure, and CO, were collected under three conditions: 1) baseline, 2) immediately after the tennis services (post), and 3) 1 h after the tennis services (1-hour). The positive incremental area under the curve (iAUC) for brachial hemodynamic variables was calculated. RESULTS: Immediately after the 100 tennis services, CO, brachial BF, SR, and brachial vascular conductance (VC) in the dominant and non-dominant arms increased (p < 0.05). At the 1-hour condition, CO returned to baseline; the brachial BF, SR, and VC in the non-dominant arm returned to baseline levels, whereas the same variables in the dominant arm remained increased. The iAUC for brachial BF and VC in the dominant arm was higher than that in the non-dominant arm. Furthermore, the brachial BF/CO ratio index in the dominant arm increased at the post and 1-hour conditions, whereas that in the non-dominant arm was unchanged. CONCLUSIONS: Tennis service exercise specifically increases brachial BF, SR, and VC in the dominant arm, independent of increased CO. Our findings contribute to unveiling the underlying mechanisms of brachial artery adaptations in tennis players.

Associations of circulating xanthine oxidoreductase activity with cardiometabolic risk markers in overweight and obese Japanese men: a cross-sectional pilot study.

Circulating xanthine oxidoreductase (XOR) activity may contribute to the pathogenesis of obesity-related adverse cardiometabolic profiles. This pilot study aimed to examine the cross-sectional associations between plasma XOR activity and cardiometabolic risk (CMR) markers in overweight and obese men. In 64 overweight and obese Japanese men (aged 31-63 years), plasma XOR activity and several CMR markers, such as homeostasis model assessment of insulin resistance (HOMA-IR), and clustered CMR score were measured in each participant. Clustered CMR score was constructed based on waist circumference, triglyceride, blood pressure, fasting plasma glucose, and high-density lipoprotein cholesterol. Plasma XOR activity in overweight and obese men was positively associated with the body mass index, waist circumference, visceral fat area, body fat mass, hemoglobin A1c, serum 8-hydroxy-2'-deoxyguanosine, HOMA-IR, and clustered CMR score and was inversely associated with handgrip strength and high-density lipoprotein cholesterol. Multiple linear regression analysis further demonstrated that the associations of plasma XOR activity with HOMA-IR and the clustered CMR score remained significant after adjustment for covariates including uric acid. Our data demonstrate that circulating XOR activity was independently associated, albeit modestly, with HOMA-IR and the clustered CMR score. These preliminary findings suggest that circulating XOR activity can potentially be one of the preventive targets and biomarkers of cardiometabolic disorders in over-weight and obese men.

Effect of Aerobic Exercise Training on Circulating Fibroblast Growth Factor-21 Response to Glucose Challenge in Overweight and Obese Men: A Pilot Study.

BACKGROUND AND STUDY PURPOSE: Fibroblast growth factor-21 (FGF21) is a liver-derived hormone that lowers blood glucose. Although aerobic exercise training also lowers blood glucose, its effect on circulating FGF21levels remains obscure. This study aimed to examine the effect of aerobic exercise training on serum FGF21 levels in overweight and obese men. METHODS: A total of 14 overweight/obese men were included in the analyses. Participants attended supervised aerobic exercise training for 12 weeks (three times per week) and completed the standard oral glucose tolerance test pre- and post-exercise training. Plasma glucose, serum insulin, and serum FGF21 levels were measured at fasting and 60 and 120 min after glucose loading. RESULTS: The exercise training reduced plasma glucose and serum FGF21 levels during glucose loading (p<0.05). The change in the area under the curve of plasma glucose was positively correlated with that in the area under the curve of serum FGF21 (r s =0.569, p=0.034). CONCLUSION: Lowering postprandial circulating FGF21 levels may be associated with the improved glucose tolerance induced by habitual aerobic exercise in overweight and obese men.