Single and combined associations of accelerometer-assessed physical activity and muscle-strengthening activities on plasma homocysteine in a national sample

Prevalence and risk factors for hyperhomocysteinemia: a population-based cross-sectional study from Hunan, China

OBJECTIVES

Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases. We aimed to investigate the prevalence and risk factors for hyperhomocysteinemia, especially modifiable lifestyle factors, such as smoking behaviour and dietary factors.

DESIGN

Population-based cross-sectional study.

SETTING

Hunan Province, China PARTICIPANTS: A total of 4012 participants completed the study, between July 2013 and March 2014. The median age is 55 (interquartile range: 45-63) years, with 1644 males (41%) and 2368 females (59%).

MAIN OUTCOME MEASURES

Homocysteine level were measured by the microplate enzyme immunoassay method. Hyperthomocysteinemia was defined as ≥15 µmol/L. Questionnaire was used to investigate potential risk factors of hyperhomocysteinemia. Crude odd ratio (OR) or adjusted OR with 95% CI were determined by using univariable or multivariable logistic regression models.

RESULTS

The prevalence of hyperhomocysteinemia is 35.4% (45.4% vs 28.5% for men, women, respectively). One-year increase in age is significantly associated with 2% higher risk of hyperhomocysteinemia (OR=1.02, 95% CI: 1.01 to 1.03). One unit increase of BMI is associated with 5% higher risk of hyperhomocysteinemia (OR=1.05, 95% CI: 1.03 to 1.07). Compared with the non-smoker, smoking participants have a 24% higher risk of hyperhomocysteinemia (OR=1.24, 95% CI: 1.006 to 1.53), while the risk for those quitting smoking are not significantly different (OR=1.14, 95% CI: 0.85 to 1.54). compared with those consuming fruit and vegetable at least once every day, those consuming less than once every day had a significantly higher risk of hyperhomocysteinemia (OR=1.29, 95% CI:1.11 to 1.50). In addition, we found there were significant sex interaction with education level or alcohol drinking on the risk of hyperhomocysteinemia (p_interaction <0.05).

CONCLUSIONS

Higher BMI and older age are potential risk factors for hyperhomocysteinemia. Current smoking but not quitting smoking is associated with higher risk of hyperhomocysteinemia. Fruit and vegetable consumption may have protective effect against hyperhomocysteinemia. Alcohol consumption or education level might interact to influence the risk of hyperhomocysteinemia.

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.

Assessment of muscle-strengthening exercise in public health surveillance for adults: A systematic review

There is strong scientific evidence that muscle-strengthening exercise (i.e. use of weight machines, push-ups, sit-ups) is independently associated with a reduced risk of multiple chronic diseases (e.g. diabetes, hypertension, cardiovascular disease). However, prevalence rates for meeting the muscle-strengthening exercise guideline (≥2 times/week) are significantly lower (~20%) than those reported to meet the aerobic physical activity guideline (e.g. walking, jogging, cycling) (~50%). It is therefore important to understand public health surveillance approaches to assess muscle-strengthening exercise. The aim of this review was to describe muscle-strengthening exercise assessment in public health surveillance. Informed by the PRISMA guidelines, an extensive keyword search was undertaken across 7 electronic data bases. We identified 86,672 possible articles and following screening (n = 1140 in full-text) against specific inclusion criteria (adults aged ≥18 years, English, studies containing <1000 participants), extracted data from 156 manuscripts. Fifty-eight different survey systems were identified across 17 countries. Muscle-strengthening exercise frequency (85.3%), duration (23.7%) and intensity (1.3%) were recorded. Muscle-strengthening exercise questions varied significantly, with some (11.5%) requiring a singular 'yes' vs 'no' response, while others (7.7%) sought specific details (e.g. muscle groups targeted). Assessments of duration and intensity were inconsistent. Very few studies measured the validity (0.6%) and reliability (1.3%) of muscle-strengthening exercise questions. Discrepancy exists within the current assessment systems/surveys used to assess muscle-strengthening exercise in public health surveillance. This is likely to impede efforts to identify at risk groups and trends within physical activity surveillance, and to accurately assess associations between muscle-strengthening exercise and health-related outcomes.

The association of physical activity on homocysteine in pregnant women

INTRODUCTION

Women with high levels of physical activity have improved pregnancy, labor, and delivery outcomes related to cardiovascular health. Hyperhomocysteinemia, which predicts cardiovascular disease risk, is associated with maternal vascular complications during pregnancy, such as placental abruption and preeclampsia. However, studies are lacking on whether physical activity impacts homocysteine in pregnant women, pointing to a potential mechanism behind the improved cardiovascular health in women who exercise during pregnancy. The purpose of this study was to examine if women with high levels of physical activity have lower levels of homocysteine compared to women with low levels of physical activity.

METHODS

This study was a secondary analysis using data from the 2003 to 2006 National Health and Nutrition Examination Survey. A total of 257 pregnant women were included. Physical activity was assessed objectively over seven days with accelerometers. High and low groups based on moderate-to-vigorous physical activity (MVPA) and steps/day were defined. Homocysteine and related laboratory biomarkers (vitamin B12, folate, pyridoxal 5'-phosphate) were assessed through blood draws. Data assembly was performed using SAS and analysis via SPSS Complex Samples.

RESULTS

Only an estimated 17.7 ± 4.7% of women met guidelines to achieve at least 150 min per week of MVPA. Plasma homocysteine was not different between pregnant women with high and low levels of moderate-to-vigorous physical activity (4.39 ± 0.21 and 4.44 ± 0.17 µmol/L; p > .05) or between those with high and low levels of steps (3.95 ± 0.26 and 4.62 ± 0.27 µmol/L; p > .05) when the data was split into two quantiles by the median. These results were similar when using log-transformed values for homocysteine to normalize the distribution of data. Pregnant women in the group of the high steps tended to have higher vitamin B12, folate, and pyridoxal 5'-phosphate than those in the group of the low steps. Sensitivity analyses revealed that homocysteine was not different between the upper 25% (4.04 ± 0.22 µmol/L) and lower 25% (4.17 ± 0.26 µmol/L) MVPA (p = .716) but that it was statistically higher in the low (<5000 steps/day) (4.99 ± 0.20 µmol/L) steps/day group compared to high (>7500 steps/day) steps/day (3.99 ± 0.23 µmol/L) (p = .003) after excluding individuals with hypertension and thyroid/kidney issues.

CONCLUSION

Maternal steps/day, but not MVPA, appear to be associated with homocysteine (albeit weakly) in the present study after excluding potential factors which impact homocysteine. The volume of physical activity appears to be an important indicator as this difference was not revealed until the physical activity was more distinctly separated.

The effect of physical activity on total homocysteine concentrations and cardiovascular risk in older Brazilian adults with type 2 diabetes

A low level of physical activity has a potential association with high levels of homocysteine, which implies an increased chance of older adults with type 2 diabetes mellitus developing cardiovascular disease (CVD). However, the effects of physical activity on homocysteine levels have been poorly explored in the literature. Therefore, this study compared homocysteine levels and cardiovascular risk among physically active and inactive older women with type 2 diabetes mellitus. Fifty-nine women with type 2 diabetes mellitus, between 60 and 91 years old, were evaluated. The level of physical activity was assessed using the International Physical Activity Questionnaire (IPAQ) long version to identify active and inactive older women. Blood samples were collected and anthropometric, body composition, and blood pressure measurements were performed to determine homocysteine levels and cardiovascular risk. The results demonstrated that active older women with type 2 diabetes mellitus have lower homocysteine values (F = 17.79, p < 0.001, ηp² = 0.238), cardiovascular risk scores (F = 15.84, p = p < 0.001, ηp² = 0.217), and waist circumferences (F = 2.95, p = 0.013, ηp² = 0.049) when compared with inactive older women. It was concluded that there was a difference in the levels of homocysteine, cardiovascular risk, and waist circumference between active and inactive older women with type 2 diabetes. Active older women are less likely to have cardiovascular risk than inactive older women.

Does Aerobic and Resistance Exercise Influence Episodic Memory through Unique Mechanisms?

Aerobic and resistance exercise (acute and chronic) independently and collectively induce beneficial responses in the brain that may influence memory function, including an increase in cerebral blood flow, neurogenesis, neuroelectrical alterations, and protein production. However, whether aerobic and resistance exercise improve memory via similar or distinct mechanisms has yet to be fully explained. Here, we review the unique influence of aerobic and resistance exercise on neural modulation, proteins, receptors, and ultimately, episodic memory. Resistance training may optimize neural communication, information processing and memory encoding by affecting the allocation of attentional resources. Moreover, resistance exercise can reduce inflammatory markers associated with neural communication while increasing peripheral and central BDNF (brain-derived neurotrophic factor) production. Aerobic training increases hippocampal levels of BDNF and TrkB (Tropomyosin receptor kinase B), protein kinases and glutamatergic proteins. Likewise, both aerobic and anaerobic exercise can increase CREB (cAMP response element-binding protein) phosphorylation. Thus, we suggest that aerobic and resistance exercise may influence episodic memory via similar and, potentially, distinct mechanisms.

Association between plasma total homocysteine level within normal range and bone mineral density in adults

BACKGROUND

Growing evidence indicates that homocysteine is a noteworthy marker for general health status. However, research regarding plasma total homocysteine (tHcy) levels and bone mineral density (BMD) is sparse and controversial. Hence, we aimed to investigate the association between plasma tHcy level within normal range and lumbar BMD in adults.

METHODS

In this cross-sectional study, using the National Health and Nutrition Examination Survey database, data on 10748 adults aged between 30 and 85 years were analyzed. The weighted multiple logistic regression analyses were conducted to evaluate the association between plasma tHcy level and lumbar BMD. The fitted smoothing curves were performed to explore potential non-linear relationships. When non-linearity was detected, we further calculated the inflection point using a recursive algorithm and constructed a weighted two-piecewise linear regression model.

RESULTS

After adjusting for all the covariates, the association between plasma tHcy and lumbar BMD was different in various age groups (adults aged 30-49 years: β = -0.0004, 95% CI -0.0025, 0.0018; adults aged 50-69 years: β = 0.0001, 95% CI -0.0025, 0.0026; adults aged 70-85 years: β = 0.0050, 95% CI 0.0008, 0.0092). In the subgroup analysis stratified by gender, this association also differed based on gender. There was a negative trend in females (aged 30-49 years: β = -0.0022, 95% CI -0.0054, 0.0011; aged 50-69 years: β = -0.0028, 95% CI -0.0062, 0.0007), and a positive trend in males (aged 30-49 years: β = 0.0018, 95% CI -0.0012, 0.0048; aged 50-69 years: β = 0.0027, 95% CI -0.0009, 0.0063) in both 30-49 years group and 50-69 years group. In the 70-85 years group, this association was significantly positive in males (β = 0.0136, 95% CI 0.0068, 0.0204), but was not significantly different in females (β = 0.0007, 95% CI -0.0046, 0.0060).

CONCLUSION

The correlation between plasma tHcy level within the normal range and lumbar BMD differs by age and gender.

Activity Tracker-Based Metrics as Digital Markers of Cardiometabolic Health in Working Adults: Cross-Sectional Study

Background

Greater adoption of wearable devices with multiple sensors may enhance personalized health monitoring, facilitate early detection of some diseases, and further scale up population health screening. However, few studies have explored the utility of data from wearable fitness trackers in cardiovascular and metabolic disease risk prediction.

Objective

This study aimed to investigate the associations between a range of activity metrics derived from a wearable consumer-grade fitness tracker and major modifiable biomarkers of cardiometabolic disease in a working-age population.

Methods

This was a cross-sectional study of 83 working adults. Participants wore Fitbit Charge 2 for 21 consecutive days and went through a health assessment, including fasting blood tests. The following clinical biomarkers were collected: BMI, waist circumference, waist-to-hip ratio, blood pressure, triglycerides (TGs), high-density lipoprotein (HDL) and low-density lipoprotein cholesterol, and blood glucose. We used a range of wearable-derived metrics based on steps, heart rate (HR), and energy expenditure, including measures of stability of circadian activity rhythms, sedentary time, and time spent at various intensities of physical activity. Spearman rank correlation was used for preliminary analysis. Multiple linear regression adjusted for potential confounders was used to determine the extent to which each metric of activity was associated with continuous clinical biomarkers. In addition, pairwise multiple regression was used to investigate the significance and mutual dependence of activity metrics when two or more of them had significant association with the same outcome from the previous step of the analysis.

Results

The participants were predominantly middle aged (mean age 44.3 years, SD 12), Chinese (62/83, 75%), and male (64/83, 77%). Blood biomarkers of cardiometabolic disease (HDL cholesterol and TGs) were significantly associated with steps-based activity metrics independent of age, gender, ethnicity, education, and shift work, whereas body composition biomarkers (BMI, waist circumference, and waist-to-hip ratio) were significantly associated with energy expenditure–based and HR-based metrics when adjusted for the same confounders. Steps-based interdaily stability of circadian activity rhythm was strongly associated with HDL (beta=5.4 per 10% change; 95% CI 1.8 to 9.0; P=.005) and TG (beta=−27.7 per 10% change; 95% CI −48.4 to −7.0; P=.01). Average daily steps were negatively associated with TG (beta=−6.8 per 1000 steps; 95% CI −13.0 to −0.6; P=.04). The difference between average HR and resting HR was significantly associated with BMI (beta=−.5; 95% CI −1.0 to −0.1; P=.01) and waist circumference (beta=−1.3; 95% CI −2.4 to −0.2; P=.03).

Conclusions

Wearable consumer-grade fitness trackers can provide acceptably accurate and meaningful information, which might be used in the risk prediction of cardiometabolic disease. Our results showed the beneficial effects of stable daily patterns of locomotor activity for cardiometabolic health. Study findings should be further replicated with larger population studies.

Physical Activity, Muscle-Strengthening Activities, and Systemic Inflammation Among Retinopathy Patients

OBJECTIVE

We evaluated the specific association between muscle-strengthening activity (MSA) and accelerometer-assessed physical activity on systemic inflammation among retinopathy patients in the United States.

METHODS

Data from the 2005-2006 National Health and Nutrition Examination Survey (NHANES) were used to identify 157 retinopathy patients between 40 and 85 years of age with complete data on select study variables. MSA was assessed via self-report. Participation in moderate-to-vigorous physical activity (MVPA) was determined from objective accelerometer data. Systemic inflammation was assessed using C-reactive protein (CRP), which was quantified using latex-enhanced nephelometry. Nonproliferative retinopathy was determined using Early Treatment Diabetic Retinopathy Study grading criteria, as well as objective retinal imaging assessments using the Canon Non-Mydriatic Retinal Camera CR6-45NM. Individuals were excluded if they had been diagnosed with coronary artery disease, congestive heart failure, heart attack, or stroke.

RESULTS

MVPA (β = -0.004, 95% CI -0.007 to -0.001, P = 0.006) but not MSA (β = -0.0001, 95% CI -0.002 to 0.001, P = 0.86) was associated with lower CRP levels. Additionally, for a more substantive 30 minutes/day increase in MVPA, there was a corresponding 0.12 mg/dL decrease in CRP.

CONCLUSION

In this nationally representative sample of adults, only individuals who engaged in higher levels of MVPA had lower CRP levels, which is indicative of reduced systemic inflammation. MSA was not associated with systemic inflammation among this cohort. Our findings suggest that MVPA is inversely associated with systemic inflammation among retinopathy patients, which is noteworthy because increased systemic inflammation may facilitate retinopathic severity.

The affective and behavioral responses to repeated "strength snacks"

Background A training program consisting of only one-repetition maximum (1RM) training results in similar strength adaptations as traditional resistance exercise. However, little is known regarding the affective or behavioral responses to this type of training. Aim To examine the affective and behavioral response to either a traditional resistance exercise program or a biweekly 1RM-training program. Methods Participants were trained for 8 weeks (2× per week). The HYPER group completed four sets of 8-12 repetitions; the 1RM group (TEST) worked up to a single maximal repetition. Results The TEST group felt more revitalized and had an increase in positive engagement during their first visit, whereas the HYPER group showed an increase in feelings of physical exhaustion during their first and last visits. There were no pre to post differences for the change in behavior or self-efficacy between groups. Conclusion 1RM training appears to elicit a more favorable affective response, compared with HYPER training, which may ultimately improve adherence to resistance-type exercise.

What are the health benefits of muscle and bone strengthening and balance activities across life stages and specific health outcomes?

Many activities of daily living require muscular strength and power as well as balance. Consequently, preserving musculoskeletal function is a prerequisite for maintaining mobility and independent living during ageing. Estimates suggest that the prevalence of physical activity guidelines for strength and balance is low. Review of reviews of: a) observation studies of the prospective association between measures of musculoskeletal fitness and health outcomes and b) randomised controlled trials of resistance, balance and skeletal impact training exercises on bone health, risk of falls, physical function, motor and cognitive function, quality of life and activities of daily living. Preserving muscular strength/power in middle and older age is associated with a reduced risk of all-cause and cardiovascular mortality. Impaired muscular strength/power and balance is associated with an increased risk of falls and lower bone mineral content. Regular supervised exercise incorporating high intensity resistance training, vertical impacts and a balance challenge are most likely to be beneficial to health and wellbeing, bone health and reduce the risks of falls. Adults in late middle and older age would benefit from a regular program of exercise that incorporates high intensity resistance training, impact exercises and balance challenges.

Cross-sectional association of exercise, strengthening activities, and cardiorespiratory fitness on generalized anxiety, panic and depressive symptoms

OBJECTIVE

Limited research has evaluated the individual and combined associations of physical activity (PA), cardiorespiratory fitness (CRF) and muscle strengthening activities (MSA) on generalized anxiety, panic and depressive symptoms. We evaluated this topic in a representative sample of young (20-39 years) adults, with considerations by sex.

METHODS

Data from the 1999-2004 National Health and Nutrition Examination Survey (N = 2088) were used. Generalized anxiety, panic and depressive symptoms were assessed via self-report as well as using the Generalized Anxiety Disorder, Panic Disorder, and Depressive Disorders modules of the automated version of the World Health Organization Composite International Diagnostic Interview (CIDI-Auto 2.1). PA and MSA were assessed via validated self-report questionnaires and CRF was determined via a submaximal treadmill-based test. An index variable was created summing the number (range = 0-3) of these parameters for each participant. For example, those meeting PA guidelines, MSA guidelines and having moderate-to-high CRF were classified as having an index score of 3.

RESULTS

MSA was not independently associated with generalized anxiety, panic and depressive symptoms, but those with higher levels of PA and CRF had a reduced odds of these symptoms (ranging from 40 to 46% reduced odds). Compared to those with an index score of 0, those with an index score of 1, 2, and 3, respectively, had a 39%, 54% and 71% reduced odds of having generalized anxiety, panic and depressive symptoms. Results were consistent across both sexes.

CONCLUSION

PA and CRF, but not MSA, were independently associated with generalized anxiety, panic and depressive symptoms. There was evidence of an additive association between PA, CRF, and MSA on these symptoms.

A higher effort-based paradigm in physical activity and exercise for public health: making the case for a greater emphasis on resistance training

It is well known that physical activity and exercise is associated with a lower risk of a range of morbidities and all-cause mortality. Further, it appears that risk reductions are greater when physical activity and/or exercise is performed at a higher intensity of effort. Why this may be the case is perhaps explained by the accumulating evidence linking physical fitness and performance outcomes (e.g. cardiorespiratory fitness, strength, and muscle mass) also to morbidity and mortality risk. Current guidelines about the performance of moderate/vigorous physical activity using aerobic exercise modes focuses upon the accumulation of a minimum volume of physical activity and/or exercise, and have thus far produced disappointing outcomes. As such there has been increased interest in the use of higher effort physical activity and exercise as being potentially more efficacious. Though there is currently debate as to the effectiveness of public health prescription based around higher effort physical activity and exercise, most discussion around this has focused upon modes considered to be traditionally 'aerobic' (e.g. running, cycling, rowing, swimming etc.). A mode customarily performed to a relatively high intensity of effort that we believe has been overlooked is resistance training. Current guidelines do include recommendations to engage in 'muscle strengthening activities' though there has been very little emphasis upon these modes in either research or public health effort. As such the purpose of this debate article is to discuss the emerging higher effort paradigm in physical activity and exercise for public health and to make a case for why there should be a greater emphasis placed upon resistance training as a mode in this paradigm shift.