The Role of Physical Activity Level and B-Vitamin Status on Blood Homocysteine Levels

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.

Dietary Intake and Status of Vitamin B12 in Slovenian Population

Vitamin B12 deficiency poses a health concern, especially in vulnerable populations. Dietary vitamin B12 intake was obtained by two 24 h dietary recalls and food propensity questionnaires in a representative Slovenian cross-sectional food consumption survey, SI.Menu (n = 1248 subjects; 10-74 years). For a subgroup of 280 participants, data on serum vitamin B12 were available through the Nutrihealth study. The estimated usual population-weighted mean daily vitamin B12 intakes were 6.2 µg (adults), 5.4 µg (adolescents), and 5.0 µg (elderly). Lower intakes were observed in females. Inadequate daily vitamin B12 intake (<4 µg) was detected in 37.3% of adolescents, 31.7% of adults, and 58.3% elderlies. The significant predictors for inadequate daily vitamin B12 intake were physical activity score in all age groups, sex in adolescents and adults, financial status and smoking in elderly, and employment in adults. Meat (products), followed by milk (products), made the highest vitamin B12 contribution in all age groups. In adolescents, another important vitamin B12 contributor was cereals. The mean population-weighted serum vitamin B12 levels were 322.1 pmol/L (adults) and 287.3 pmol/L (elderly). Low serum vitamin B12 concentration (<148 nmol/L) and high serum homocysteine (>15 µmol/L) were used as criteria for vitamin B12 deficiency. The highest deficiency prevalence was found in elderlies (7.0%), particularly in males (7.9%). Factors associated with high serum homocysteine were also investigated. In conclusion, although vitamin B12 status was generally not critical, additional attention should be focused particularly to the elderly.

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.

Relationship between intake and plasma concentrations of vitamin B12 and folate in 873 adults with a physically active lifestyle: a cross-sectional study

BACKGROUND

Vitamin B12 and folate function as co-factors in pathways used during physical activity. Physical activity may therefore increase vitamin requirements, leading to a risk of deficient plasma concentrations. We aimed to investigate the relationship between intake and plasma concentrations of vitamin B12 and folate in physically active adults, as well as identify other determinants of vitamin B12 and folate plasma concentrations.

METHODS

The study population consisted of 873 adults (528 men and 345 women), aged 19-78 years, who participated in a 4-day walking event. The relationship between intake and plasma concentrations of vitamin B12 and folate was assessed using correlation and linear regression analyses. In addition, potential other determinants (sex, age, body mass index, energy intake and physical activity) of vitamin plasma concentrations were investigated.

RESULTS

Significant positive correlations were observed between intake and plasma concentrations of vitamin B12 [Pearson's correlation coefficient = 0.15; 95% confidence interval (CI) = 0.08-0.21] and folate (Pearson's correlation coefficient = 0.18; 95% CI = 0.12-0.25). In addition to vitamin intake, sex, age and energy intake were also determinants of both vitamin B12 and folate plasma concentrations in multivariable regression models.

CONCLUSIONS

The results suggest a positive association between intake and plasma concentrations for both vitamin B12 and folate in physically active people. By contrast to our hypothesis, physical activity was not a determinant of vitamin B12 and folate plasma concentrations. However, sex, age and energy intake were found to be determinants. Thus, when studying the relationship between intake and plasma concentrations of vitamin B12 or folate, these factors should be taken into account.

Association between regular aerobic exercise and hyperhomocysteine in hypertensive patients

OBJECTIVE

The relationship between total plasma homocysteine (tHcy) and exercise remains controversial. This study aimed to investigate the association between regular aerobic exercise and hyperhomocysteine (hHcy) in patients with hypertension.

METHODS

A total of 497 hypertensive patients from 7 communities of Nanjing were enrolled in this cross-sectional study. All participants were asked to complete standard questionnaires by themselves. Physical and laboratory examination were performed within 1 week after enrollment. The association between regular aerobic exercise and hHcy in hypertensive patients was estimated by a multiple logistic regression analysis.

RESULTS

Of the 497 patients, 210 had a regular aerobic exercise habit and 274 of them were detected with hHcy. Multivariate analysis revealed that exercisers have less risk of hHcy (adjusted odds ratio [OR] 0.42, 95% confidence interval [CI] 0.26-0.66) as compared to non-exercisers controlling for the established and potential confounders. Intensity, frequency, and total energy expenditure of aerobic exercise were found to be independently associated with lower hHcy risk in hypertensive patients. Gender subgroup analyses showed that this inverse relationship between regular aerobic exercise and hHcy exists in both male and female groups (adjusted OR 0.41 95%CI 0.21-0.80, and adjusted OR 0.40 95%CI 0.20-0.80, respectively).

CONCLUSIONS

Regular aerobic exercise has a negative association with hHcy in this cross-sectional study. That suggests a hypothesis that doing aerobic exercise might decrease the risk of hHcy in hypertensive patients.

Association between blood marker analyses regarding physical fitness levels in Spanish older adults: A cross-sectional study from the PHYSMED project

Biomarkers have been postulated as essential variables to measure the effects of exercise on the human body. To investigate the relationship between physical fitness (PF) and blood biomarkers that are associated with disease risk in Spanish older adults, four hundred and twenty-nine adults (57% females) aged older than 55 years from a cross-sectional study were included. A battery of PF test was performed, and participants were divided into 3 groups: low, medium and high fitness. Blood samples were collected, and subjects were also grouped based on a particular biomarker being within its reference range. Furthermore, drug intake and dietary intake were considered for each participant. Higher concentrations out of the reference range were observed for vitamin 25(OH)D (67.9%) and total cholesterol (TC) (58.6%). Participants from the low PF group presented lower significant concentrations out of the reference range for vitamin B₁₂ and triglycerides; however, participants in the low PF group showed higher significant concentrations out of the reference range for total homocysteine, creatinine, TC, HDL-cholesterol and LDL-cholesterol (LDL-c) than those in the high PF group (all p<0.05). Considering drugs related to blood lipid modifications, subjects who regularly consumed lipid reducers presented higher significant concentrations out of the reference range for TC and LDL-c than participants who did not take these drugs (p<0.01). Participants from the high PF group presented better blood marker profiles, namely, lower blood markers related to disease risk out of the reference range. These blood markers could be used as a routine method for considering PF groups in older adults.

Muscular contraction frequency does not affect plasma homocysteine concentration in response to energy expenditure- and intensity-matched acute exercise in sedentary males

Acute exercise seems to increase total plasma homocysteine (tHcy); since this variable associated with cardiovascular risk, it is important to understand the determinants of its response to all types of exercise. The aim of this study was to examine the impact of cycling at 2 different rates of muscle contraction on the complete tHcy kinetics. Eight young sedentary males were required to complete 2 isocaloric (400 kcal) acute exercise trials at 50% peak oxygen uptake on separate occasions at 50 or 80 rpm. Blood samples were drawn at different points before (4 h before exercise and immediately before exercise), during (10, 20, 30, 45, and 60 min during exercise), and after exercise (immediately and 19 h after exercise). Dietary and lifestyle factors were controlled during the research. Maximum tHcy occurred during exercise for both conditions (50 rpm: 11.4 ± 2.7 μmol·L^-1; 80 rpm: 10.8 ± 3.2 μmol·L^-1). From this point onwards tHcy declined until the cessation of exercise and continued descending below pre-exercise values at 19 h postexercise (p < 0.05). No hyperhomocysteinemia were observed at any sampling point in both trials. In conclusion, the different muscular contraction frequency during exercise has no impact on tHcy during an acute bout of exercise in sedentary individuals, when at least 400 kcal are spent during exercise and the nutritional status for folate, B₁₂, and B₆ is adequate. This information is relevant to further inform healthy exercise prescription, not only in terms of duration and intensity of exercise, but also taking into account frequency of contraction.

Nutrition Assessment of B-Vitamins in Highly Active and Sedentary Women

Background: Female athletes and active women require adequate nutrition for optimal health and performance. Nutrition assessments are needed to identify potential nutrients of concern. Folate, vitamin B6, and vitamin B12 function in important pathways used during physical activity and female athletes may be at risk for poor status of these micronutrients. This cross-sectional study described a comprehensive nutrition assessment of the B-vitamins (folate, vitamin B6, and vitamin B12) using both dietary (food and dietary supplements) and biochemical assessments among highly active and sedentary women. Methods: Highly active (n = 29; age 20 ± 2 years; body mass index (BMI) 23.8 ± 3.5 kg/m²) and sedentary (n = 29; age 24 ± 3 years; BMI 22.6 ± 3.0 kg/m²) women were recruited for this study. Participants completed 7-day weighed food records and a fasting blood draw. Results: Although the highly active women reported higher intakes of energy (p < 0.01), folate (p < 0.01), vitamin B6 (p < 0.01), and vitamin B12 (p < 0.01), no significant differences were found between the groups for biomarkers of folate, vitamin B6, and vitamin B12. All of the highly active women had biomarkers within the desired reference ranges, suggesting good status. In general, most participants were able to meet the 1998 Recommended Daily Allowance (RDA) from food alone. For the women that reported using dietary supplements, micronutrient intakes met the 1998 RDA and in some cases, exceeded the Tolerable Upper Intake Level. Conclusion: This nutrition assessment documented good status for folate, vitamin B6, and vitamin B12 in the highly active women. Similar assessment approaches (food, dietary supplements, and biomarkers) should to completed with other nutrients of concern for the female athlete.

What do we know about homocysteine and exercise? A review from the literature

High total homocysteine (tHcy) concentrations contribute to an increased risk of cardiovascular diseases and neurodegenerative disorders. Several investigations have focused on the effect of exercise on tHcy concentrations, but results remain controversial. The differences among the methodologies in the investigations make difficult the interpretation of results. This review differentiates the effects of exercise on tHcy and establishes the relation with the implicated biomarkers on tHcy metabolism related to exercise. The electronic database MEDLINE (http://www.ncbi.nlm.nih.gov) was used for searching studies published between years 2002 and 2015. 'Homocysteine', 'Training ', 'Exercise', 'Physical Activity' as well as combinations out of these terms were entered in the database. Articles were grouped in: 1) Acute effect of exercise on tHcy, 2) chronic exercise and tHcy, 3) relationship of physical activity (PA) level and cardiorespiratory fitness with tHcy, and 4) biomarkers related to tHcy and exercise. From a total of 30 articles, most of the studies analyzing the acute effect of exercise showed an increase on tHcy concentrations. Studies analyzing the chronic effect on tHcy concentrations showed contradictory results and no consensus exists probably due to the differences in the methodology, exercise interventions and participants characteristics. Low cardiorespiratory fitness seems to be associated with high tHcy; in contrast, the relation of PA levels and tHcy needs further research. Regarding biomarkers related to tHcy and exercise, some studies showed an increase of folate, vitamin B12, and creatine after acute exercise that could to be due to requirement of protein turnover and an increased metabolic demand of vitamin-B.

Effect of physical activity on levels of homocysteine, folate, and vitamin B12 in the elderly

OBJECTIVES

Homocysteine (Hcy) has emerged as a risk factor for cardiovascular diseases (CVD). However the relationship of physical activity (PA) with Hcy levels in the elderly is controversial. Accordingly, the current study examined the effect of low and high participation in PA on serum Hcy in young (n = 77; 18-50 years) and old (n = 207; > 65 years) males (n = 141) and females (n = 142).

METHODS

Level of PA was obtained in a 1-to-1 interview and participants divided into low and high groups. Serum Hcy, folate, and vitamin B12 were obtained after 12 hour fast drawn by venipuncture.

RESULTS

Levels of Hcy correlated with folate (r = -0. 5; p = 0.000) and vitamin B12 (r = -0.3; p = 0.000). The ANOVA revealed a main effect of PA for Hcy (p = 0.04) but not for folate (p = 0.2) and vitamin B12 (p = 0.2). Main effects were found also of age for Hcy (p = 0.000) and folate (p = 0.005) as well as of gender for Hcy (p = 0.000) and vitamin B12 (p = 0.000). Subsequent ANCOVA showed lower levels of Hcy in the participants with greater versus lower PA even after controlling for B12 vitamin.

CONCLUSION

These results confirm the importance of the vitamins for regulating Hcy levels. Additionally, the data suggests that PA affects Hcy levels without affecting and independent of B vitamins in the elderly.

The effects of exercise training and acute exercise duration on plasma folate and vitamin B12

BACKGROUND/OBJECTIVES

Energy production and the rebuilding and repair of muscle tissue by physical activity require folate and vitamin B12 as a cofactor. Thus, this study investigated the effects of regular moderate exercise training and durations of acute aerobic exercise on plasma folate and vitamin B12 concentrations in moderate exercise trained rats.

MATERIALS/METHODS

Fifty rats underwent non-exercise training (NT, n = 25) and regular exercise training (ET, n = 25) for 5 weeks. The ET group performed moderate exercise on a treadmill for 30 min/day, 5 days/week. At the end of week 5, each group was subdivided into 4 groups: non-exercise and 3 exercise groups. The non-exercise group (E0) was sacrificed without exercising and the 3 exercise groups were sacrificed immediately after exercising on a treadmill for 0.5 h (E0.5), 1 h (E1), and 2 h (E2). Blood samples were collected and plasma folate and vitamin B12 were analyzed.

RESULTS

After exercise training, plasma folate level was significantly lower and vitamin B12 concentration was significantly higher in the ET group compared with the NT group (P < 0.05). No significant associations were observed between plasma folate and vitamin B12 concentrations. In both the NT and ET groups, plasma folate and vitamin B12 were not significantly changed by increasing duration of aerobic exercise. Plasma folate concentration of E0.5 was significantly lower in the ET group compared with that in the NT group. Significantly higher vitamin B12 concentrations were observed in the E0 and E0.5 groups of the ET group compared to those of the NT group.

CONCLUSION

Regular moderate exercise training decreased plasma folate and increased plasma vitamin B12 levels. However, no significant changes in plasma folate and vitamin B12 concentrations were observed by increasing duration of acute aerobic exercise.

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 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.

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.

Associations among objectively measured physical activity, fasting plasma homocysteine concentration, and MTHFR C677T genotype

Elevated fasting plasma homocysteine (Hcy) level is a vascular disease risk factor. Plasma Hcy is affected by 5,10-methylenetetrahydofolate reductase (MTHFR) genotype and dietary folate intake. This cross-sectional study in 434 Japanese adults examined the associations among objectively measured physical activity (PA), plasma Hcy adjusting for dietary folate intake, and MTHFR C677T genotype. Daily PA was measured by triaxial accelerometry and all subjects completed a questionnaire about their dietary habits. Plasma Hcy and MTHFR C677T genotype were determined. Plasma Hcy in subjects with the TT genotype was significantly higher than in those with CC or CT genotype (p < 0.001). Plasma Hcy was significantly different between ≥ 200 (7.6 ± 0.2 nmol/mL) and <200 µg/day (8.3 ± 0.3 nmol/mL) folate intake groups (p = 0.003). There were no differences in plasma Hcy adjusting for age, sex, and folate intake between groups according to PA category in all subjects. However, there were significant interactions between time spent in light PA (p = 0.003), vigorous PA (p = 0.001), or inactivity (p = 0.004), and MTHFR genotype. In only the TT genotype, shorter time spent in light PA was associated with higher plasma Hcy than a longer time spent in light PA (11.5 ± 3.3 nmol/mL vs. 8.5 ± 3.3 nmol/mL, p < 0.001), and longer time spent in vigorous PA and inactivity were associated with higher plasma Hcy (11.8 ± 3.3 nmol/mL vs. 8.4 ± 3.2 nmol/mL, 11.6 ± 3.3 nmol/mL vs. 8.4 ± 3.3 nmol/mL, respectively, p < 0.001). In conclusion, light and vigorous PA were associated with plasma Hcy only in the TT genotype, but there were no such associations in all genotypes.