Sport-related hyperhomocysteinaemia: a putative marker of muscular demand to be noted for cardiovascular risk

Homocysteine-Potential Novel Diagnostic Indicator of Health and Disease in Horses

Homocysteine is an endogenous, non-protein sulfuric amino acid, an intermediate metabolite formed by the methionine transmethylation reaction. Its elevated serum concentration in humans, hyperhomocysteinemia, is a sensitive indicator and a risk factor for coagulation disorders, cardiovascular diseases and dementia. However, the role of homocysteine in veterinary species has not been unequivocally established. Although some research has been conducted in dogs, cats, cattle and pigs, relatively few studies on homocysteine have been conducted in horses. So far, it has been established in this species that homocysteine has an atherogenic effect, plays a role in early embryo mortality and is responsible for the induction of oxidative stress. These preliminary findings support establishing a reference range in a normal population of horses, including horses in training and merit further investigations into the role of this amino acid in health and disease in this species.

Molecular Deficits Relevant to Concussion Are Prevalent in Top-Ranked Football Players Entering the National Football League Draft

ABSTRACT

Kunces, LJ, Keenan, J, Schmidt, CM, and Schmidt, MA. Molecular deficits relevant to concussion are prevalent in top-ranked football players entering the National Football League draft. J Strength Cond Res XX(X): 000-000, 2021-Characterization of blood variants in athletes entering the highly competitive contact environment of professional football can help us understand the risk for brain injury. When coupled with longitudinal follow-up of future concussion incidence and trajectory, it may provide additional insight into factors that influence brain injury. We observed the metabolic phenotype of collegiate football players entering the 2016 National Football League (NFL) draft. The principal aims were to characterize the molecular status of individual athletes and quantify the prevalence of athletes with multiple concurrent molecular deficits. Blood was taken from 30 elite American collegiate football players 7 weeks before the NFL scouting combine and 15 weeks before entering the NFL draft. Average results revealed suboptimal values in Omega-3 Index (avg ± std, 4.66 ± 1.16%), arachidonic acid:eicosapentaenoic acid fatty acid ratio (29.13 ± 10.78), homocysteine (11.4 ± 3.4 µmol·L-1), vitamin D (30 ± 11.4 ng·ml-1), and red blood cell magnesium (4.1 ± 0.8 mg·dl-1). Using sport-optimized reference ranges from previously published research, 10% presented with 3, 40% presented with 4, and 50% of athletes presented with 5 suboptimal values at once. We conclude molecular deficits in this cohort entering the NFL draft were common, with a significant number of athletes presenting with multiple suboptimal levels. The significant commonality of the suboptimal biomarkers is relevance to brain health and function. This data warrant extensive metabolic phenotyping and consideration of prophylactic precision nutrition countermeasures by the multidisciplinary staff for athletes entering contact environments.

Exercise-Induced Hyperhomocysteinemia Is Not Related to Oxidative Damage or Impaired Vascular Function in Amateur Middle-Aged Runners under Controlled Nutritional Intake

To determine the influence of different doses of maximal acute exercise on the kinetics of plasma homocysteine (tHcy) and its relationship with oxidative status and vascular function, nine recreational runners completed a 10 km race (10K) and a marathon (M). Blood samples were collected before (Basal), immediately post-exercise (Post0), and after 24 h (Post24). Nutritional intake was controlled at each sample point. A significant increase in tHcy was observed after both races, higher after M. Basal levels were recovered at Post24 after 10K, but remained elevated at Post 24 for M. A significant decrease in GSH/GSSG ratio was observed in Post0, especially marked after M. Furthermore, this increase in pro-oxidant status remained at Post24 only after M. Other oxidative status markers failed to confirm this exercise-induced pro-oxidant status except glutathione peroxidase activity that was lower in Post24 compared to Basal in 10K and in Post0 and Post24 in M. No statistical correlation was found between oxidative markers and tHcy. No significant changes were observed in the concentration of endothelial cell adhesion molecules (VCAM-1 and E-Selectin) and VEGF. In conclusion, tHcy increases in an exercise–dose–response fashion but is not related to endothelial dysfunction mediated by oxidative stress mechanisms.

Influence of MTHFR polymorphisms on cardiovascular risk markers in elite athletes

OBJECTIVES

To investigate the distribution of MTHFR C677T and A1298C as well as PON1 Q192R gene polymorphisms, known to be involved in hyperhomocysteinemia-related cardiovascular risk, in elite athletes.

DESIGN AND METHODS

Genetic background at MTHFR and PON1 loci and plasma levels of homocysteine, folate, vitamin B12 and advanced oxidation protein product (AOPP) levels were assessed in thirty-seven 400m male hurdlers and thirty-four sedentary subjects.

RESULTS

Homocysteine plasma levels and AOPPs were significantly higher in hurdlers bearing the TT677/AA1298 diplotype than in both hurdlers and sedentary subjects with other diplotypes. A positive dependence between either homocysteine or AOPP plasma levels and MTHFR, but not PON1 genotype, was observed in hurdlers.

CONCLUSIONS

Elite hurdlers, having an unfavorable MTHFR genotype are exposed to increased cardiovascular risk, dependent on alterations of homocysteine and AOPP plasma levels.

Impact of physical activity and cardiovascular fitness on total homocysteine concentrations in European adolescents: The HELENA study

We examined the association of physical activity (PA), cardiovascular fitness (CVF) and fatness with total homocysteine (tHcy) concentrations in European adolescents. The present study comprised 713 European adolescents aged 14.8 ± 1.2 y (females 55.3%) from the multicenter HELENA cross-sectional study. PA was assessed through accelerometry, CVF by the 20-m shuttle run test, and body fat by skinfold thicknesses with the Slaughter equation. Plasma folate, cobalamin, and tHcy concentrations were measured. To examine the association of tHcy with PA, CVF, and fatness after controlling for a set of confounders including age, maturity, folate, cobalamin, creatinine, smoking, supplement use, and methylenetetrahydrofolate reductase 677 genotype (CC 47%, CT 43%, TT 10%), bivariate correlations followed by multiple regression models were performed. In the bivariate correlation analysis, tHcy concentrations were slightly negatively correlated (p<0.05) with CVF in females (measured both by stages: r=-0.118 and by VO2max: r=-0.102) and positively with body mass index (r=0.100). However, daily time spent with moderate and vigorous PA showed a weak positive association with tHcy in females (p<0.05). tHcy concentrations showed a tendency to decrease with increasing CVF and increase with increasing BMI in female European adolescents. However, tHcy concentrations were positively associated with moderate and vigorous PA in female European adolescents.

Effect of the MTHFR 677C/T polymorphism on homocysteinemia in response to creatine supplementation: a case study

Creatine (Cr) is recommended as a dietary supplement especially for athletes but its therapeutic potential is also discussed. It is assumed that human body uses Cr for the formation of phosphocreatine, which is necessary for muscular work as a source of energy. Production of Cr in a body is closely connected to methionine cycle where guanidinoacetate (GAA) is in a final step methylated from S-adenosylmethionine (SAM). Increased availability of SAM for phosphatidylcholine (PC) and sarcosine synthesis can potentially stimulate endogenous production of betaine a thus methylation of homocysteine (HCy) to form methionine. Our subject who was methylenetetrahydrofolate reductase (MTHFR) 677TT homozygote lowered plasma HCy from 33.3 micromol/l to 17.1 micromol/l following one-month Cr supplementation (5 g/day) opposite to 677CC and CT genotypes whose HCy levels tended to increase (but still in normal ranges). We suppose that Cr supplementation stimulates pathways leading to production of sarcosine which can serve to regenerate tetrahydrofolate (THF) to form 5,10-methylene-THF. This could potentially increase MTHFR enzyme activity which may later result in increased HCy methylation. Cr supplementation significantly effects metabolism of one carbon unit and potentially lower body´s demands for methyl groups. This could be beneficial as in the case of reduced enzyme activity such as MTHFR 677C/T polymorphism.

Effect of folic acid supplementation on homocysteine concentration and association with training in handball players

Background

Strenuous physical activity can alter the status of folic acid, a vitamin directly associated with homocysteine (Hcy); alterations in this nutrient are a risk factor for cardiovascular disease. Handball players are a population at risk for nutrient deficiency because of poor dietary habits.

Objective

The aims of this study were to evaluate nutritional status for macronutrients and folic acid in members of a high-performance handball team, and determine the effect of a nutritional intervention with folic acid supplementation and education.

Design

A total of 14 high-performance handball players were monitored by recording training time, training intensity (according to three levels of residual heart rate (RHR): <60%, 60%–80% and >80%), and subjective perceived exertion (RPE) during a 4-month training period. Nutritional, laboratory and physical activity variables were recorded at baseline (Week 0), after 2 months of dietary supplementation with 200 μg folic acid (50% of the recommended daily allowance) (Week 8) and after 2 months without supplementation (Week 16). We compared training load and analyzed changes in plasma concentrations of Hcy before and after the intervention.

Results

Bivariate analysis showed a significant negative correlation (P < 0.01) between Hcy and folic acid concentrations (r = −0.84) at Week 8, reflecting a significant change in Hcy concentration (P < 0.05) as a result of hyperhomocysteinemia following the accumulation of high training loads. At Week 16 we observed a significant negative correlation (P < 0.01) between Hcy concentration and training time with an RHR <60%, indicating that aerobic exercise avoided abrupt changes in Hcy and may thus reduce the risk of cardiovascular accidents in high-performance athletes.

Conclusion

Integral monitoring and education are needed for practitioners of handball sports to record their folic acid status, a factor that directly affects Hcy metabolism. Folic acid supplementation may protect athletes against alterations that can lead to cardiovascular events related to exertion during competition.

Administration of tomato juice ameliorates lactate dehydrogenase and creatinine kinase responses to anaerobic training

Creatinine phosphokinase (CPK) and lactate dehydrogenase (LDH) are important biological markers of various myocardial disorders and exercise-induced muscle damage. Lycopene, on the other side, is a natural anti-oxidant with protective action against cardiovascular risk. Fifteen anaerobically trained athletes with elevated LDH and CPK baseline levels were enrolled in this study after undergoing thorough biochemical and cardiovascular evaluation with echocardiocraphy. In nine athletes tomato juice, a lycopene plain juice, was administered during and after exercise, replacing the carbohydrate supplementation beverages commonly used during training for over a 2-month period. Tomato juice administration significantly reduced LDH and CPK levels, which returned back to almost normal levels. At the same time homocysteine and C-reactive protein were also attenuated. No changes were observed in the control group, where the usual carbohydrate supplementation had been followed.

Transient increase in homocysteine but not hyperhomocysteinemia during acute exercise at different intensities in sedentary individuals

Considering that hyperhomocysteinemia is an independent risk factor for cardiovascular disease, the purpose of this study was to determine the kinetics of serum homocysteine (tHcy) and the vitamins involved in its metabolism (folates, B₁₂, and B₆) in response to acute exercise at different intensities. Eight sedentary males (18–27 yr) took part in the study. Subjects were required to complete two isocaloric (400 kcal) acute exercise trials on separate occasions at 40% (low intensity, LI) and 80% VO_2peak (high intensity, HI). Blood samples were drawn at different points before (pre4 and pre0 h), during (exer10, exer20, exer30, exer45, and exer60 min), and after exercise (post0, post3, and post19 h). Dietary, genetic, and lifestyle factors were controlled. Maximum tHcy occurred during exercise, both at LI (8.6 (8.0–10.1) µmol/L, 9.3% increase from pre0) and HI (9.4 (8.2–10.6) µmol/L, 25.7% increase from pre0), coinciding with an accumulated energy expenditure independent of the exercise intensity. From this point onwards tHcy declined until the cessation of exercise and continued descending. At post19, tHcy was not different from pre-exercise values. No values of hyperhomocysteinemia were observed at any sampling point and intensity. In conclusion, acute exercise in sedentary individuals, even at HI, shows no negative effect on tHcy when at least 400 kcal are spent during exercise and the nutritional status for folate, B₁₂, and B₆ is adequate, since no hyperhomocysteinemia has been observed and basal concentrations were recovered in less than 24 h. This could be relevant for further informing healthy exercise recommendations.

Metabolic markers in sports medicine

Physical exercise induces adaptations in metabolism considered beneficial for health. Athletic performance is linked to adaptations, training, and correct nutrition in individuals with genetic traits that can facilitate such adaptations. Intense and continuous exercise, training, and competitions, however, can induce changes in the serum concentrations of numerous laboratory parameters. When these modifications, especially elevated laboratory levels, result outside the reference range, further examinations are ordered or participation in training and competition is discontinued or sports practice loses its appeal. In order to correctly interpret commonly used laboratory data, laboratory professionals and sport physicians need to know the behavior of laboratory parameters during and after practice and competition. We reviewed the literature on liver, kidney, muscle, heart, energy, and bone parameters in athletes with a view to increase the knowledge about clinical chemistry applied to sport and to stimulate studies in this field. In liver metabolism, the interpretation of serum aminotransferases concentration in athletes should consider the release of aspartate aminotransferase (AST) from muscle and of alanine aminotransferase (ALT) mainly from the liver, when bilirubin can be elevated because of continuous hemolysis, which is typical of exercise. Muscle metabolism parameters such as creatine kinase (CK) are typically increased after exercise. This parameter can be used to interpret the physiological release of CK from muscle, its altered release due to rhabdomyolysis, or incomplete recovery due to overreaching or trauma. Cardiac markers are released during exercise, and especially endurance training. Increases in these markers should not simply be interpreted as a signal of cardiac damage or wall stress but rather as a sign of regulation of myocardial adaptation. Renal function can be followed in athletes by measuring serum creatinine concentration, but it should be interpreted considering the athlete's body-mass index (BMI) and phase of the competitive season; use of cystatin C could be a reliable alternative to creatinine. Exercise and training induce adaptations in glucose metabolism which improve glucose utilization in athletes and are beneficial for reducing insulin insensitivity in nonathletes. Glucose metabolism differs slightly for different sports disciplines, as revealed in laboratory levels. Sport activities induce a blood lipid profile superior to that of sedentary subjects. There are few reports for a definitive conclusion, however. The differences between athletes and sedentary subjects are mainly due to high-density lipoprotein cholesterol (HDLC) concentrations in physically active individuals, although some differences among sport disciplines exist. The effect of sports on serum and urinary markers for bone metabolism is not univocal; further studies are needed to establish the real and effective influence of sport on bone turnover and especially to establish its beneficial effect.

Creatine kinase MM TaqI and methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms influence exercise-induced C-reactive protein levels

Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. Results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.

Association of recreational physical activity with homocysteine, folate and lipid markers in young women

We assessed the influence of recreational physical activity in young healthy women on homocysteine, a potential risk factor for cardiovascular disease (CVD). Participants were 124 23-year-old normal-weight Italian recreational athletes (performing 8.7 +/- 2.46 h week(-1) exercise) and 116 controls. Median blood homocysteine, folate and lipid markers did not differ between athletes and controls. Elevated homocysteine levels at CVD risk > or =12.0 and > or =15.0 micromol l(-1) were not different between groups. Continuous homocysteine was inversely related to folate (P < 0.001), positively associated with age (P = 0.009) and creatinine (P = 0.033), but not associated with hours of exercise, body mass index, and lipid markers. Women with folate depletion (<3.0 microg l(-1)) were 4.5-fold more likely to have homocysteine > or =15.0 micromol l(-1). Recreational physical exercise does not adversely impact homocysteine levels among young women. Only low folate significantly increases the risk for hyperhomocysteinemia in young women.