Short term e-bicycle riding results in favorable cardiometabolic shifts in moderately active adults.

PURPOSE: Electric bikes (EB) are a form of active transportation with demonstrated health benefits. The purpose of this study was to determine the influence of riding an EB for one week on indices of cardiometabolic health in middle-aged adults. METHODS: Adults (n = 22; age = 57.1 ± 11.3 year; BMI = 27.7 ± 4.9) participated in a 2 week study. During Week 1, participants were instructed to continue regular activities. Starting Week 2 participants were provided an EB to ride at least 3 days for a minimum of 30 min·day-1. Physical activity (PA) and glucose were measured continuously. Body composition, blood lipids, glucose, insulin, hemoglobin A1c (HbA1c), plasma endothelin-1 (ET-1), and carotid-femoral pulse wave velocity (cf-PWV) were measured on days 1 and 14.Data and Statistical analyses or Statistics. Each participant served as their own control. Paired t-tests compared dependent variables between week 1 (without EB) and week 2 (with EB). RESULTS: When provided an EB for one week, moderate to vigorous PA increased by 6-9 min·day-1 (P < 0.05) and sedentary time decreased by ~ 77 min·day-1 (P < 0.05). Data from 24 h continuous glucose monitoring showed the percentage of time in healthy range (70-120 mg·dl-1 glucose) increased (P < 0.05) from week 1 to week 2. Compared to day 1, cf-PWV was lower at day 14 (P < 0.05) following one week of riding an EB. CONCLUSION: Moderately-active, middleaged adults showed improved continuous glucose regulation and lower central arterial stiffness following one week of riding an EB.

Climate Change, Air Pollution, and Physical Inactivity: Is Active Transportation Part of the Solution?

Active transportation is defined as self-propelled, human-powered transportation modes, such as walking and bicycling. In this article, we review the evidence that reliance on gasoline-powered transportation is contributing to global climate change, air pollution, and physical inactivity and that this is harmful to human health. Global climate change poses a major threat to human health and in the future could offset the health gains achieved over the last 100 yr. Based on hundreds of scientific studies, there is strong evidence that human-caused greenhouse gas emissions are contributing to global climate change. Climate change is associated with increased severity of storms, flooding, rising sea levels, hotter climates, and drought, all leading to increased morbidity and mortality. Along with increases in atmospheric CO2, other pollutants such as nitrogen dioxide, ozone, and particulate matter (e.g., PM2.5) are released by combustion engines and industry, which can lead to pulmonary and cardiovascular diseases. Also, as car ownership and vehicle miles traveled have increased, the shift toward motorized transport has contributed to physical inactivity. Each of these global challenges has resulted in, or is projected to result in, millions of premature deaths each year. One of the ways that nations can mitigate the health consequences of climate change, air pollution, and chronic diseases is through the use of active transportation. Research indicates that populations that rely heavily on active transportation enjoy better health and increased longevity. In summary, active transportation has tremendous potential to simultaneously address three global public health challenges of the 21st century.

Acute physical activity effects on cardiac gene expression.

Regular bouts of physical activity may cause changes in gene expression that accumulate over time and ultimately affect phenotypes, such as body weight, blood lipid profile and tumour development. Furthermore, acute activity may affect gene expression and phenotypes differently depending on whether the individual is regularly inactive or active. One-month-old male Sprague-Dawley rats (n = 72) were equally divided into SED (standard laboratory cage, n = 24), PA (large activity box, n = 24) and EX groups (exercise wheel inside standard cage, n = 24). At 3 months of age, half the animals from each group were killed at rest and the other half following 30 min of physical activity. The RNA was extracted from cardiac tissue, and microarray analysis was performed on 27,000 genes. Select gene results were validated using quantitative PCR. No gene expression differences occurred when comparing all 3-month-old groups at rest. A relatively small percentage of genes (1.9%) were differentially expressed (P < 0.05) following acute swimming activity in all groups, but only 37 unique and identifiable genes reached or exceeded twofold differences in expression. The genes Atf3, Fos, Apold1 and Pxdn were expressed differently among SED, PA and EX following acute activity, with a clear separation of the magnitude in gene expression with SED > PA > EX. Differences in gene expression levels in young physically inactive and active animals following acute activity have different regulatory roles in gene networks that affect health-related phenotypes.

Exercise-induced changes in cardiac gene expression and its relation to spatial maze performance.

Cognitive performance is sensitive to both neural and non-neural changes induced by physical activity and inactivity. This study investigated whether access to physical activity outside a standard laboratory animal cage affected cognitive performance as measured by navigation of a spatial maze. It also examined gene expression in heart tissue for genes associated with cardiovascular function given recent reports of cognitive impairment associated with hyperlipidemia. Furthermore, we measured expression of neural-regulatory genes typically expressed in brain, but also found in cardiac tissue. Male Sprague-Dawley rats (n = 72) were separated into three groups having different access to physical activity: none outside a standard cage, twice-weekly physical activity, and every other day exercise on a running wheel. Compared with a sedentary group, spatial maze performance was enhanced in animals that had access to physical activity, either twice-weekly in a large box or every other day on a running wheel. Both the cardiovascular and neural-related genes expressed in the heart were distinguished by access to physical activity. Several genes that are associated with heart rate, cholesterol biosynthesis, blood pressure, and cell adhesion regulation, including GJA1, FDFT1, EDN1, and CD36, differed in animals based on access to physical activity. Neural-related genes expressed in cardiac tissue associated with neurite outgrowth, neuroplasticity, and neurogenesis including RTN4, HOMER2, ACTB, NCDN, KIF5B, and HMGB2, were expressed differently among the three groups. Significant shifts in ten cardiovascular and neural-related gene expressions in cardiac tissue were associated with physical activity and may have influenced learning and performance on a spatial maze.

Short-term isometric exercise reduces systolic blood pressure in hypertensive adults: possible role of reactive oxygen species.

OBJECTIVE: A short-term isometric exercise protocol was tested in ten hypertensive individuals to determine its efficacy as a high blood pressure-reducing intervention. DESIGN: The study was a prospective case study of 10 hypertensive individuals (8 men, 2 woman, mean age = 52 + 5 years) who underwent six weeks of isometric exercise training (three sessions/week). METHODS: Blood pressure, blood lipids and markers of oxidative stress were monitored before, during and following the isometric intervention. Electron spin resonance spectroscopy was used to directly measure radicals in the blood samples. RESULTS: After six weeks, systolic blood pressure decreased an average 13 mm Hg (p < 0.05) from a mean blood pressure of 146 to 133 mm Hg, a level that is below the usual 140 mm Hg hypertension threshold. Blood lipids were unchanged, but markers of oxidative stress were affected, with a dramatic decrease in exercise-induced oxygen centered radicals (-266%), (p < 0.05) and an increased resting whole blood glutathione:oxidized glutathione (+61%) in hypertensive adults following six weeks of isometric exercise. CONCLUSION: Six weeks of isometric exercise training was effective in lowering systolic but not diastolic blood pressure in pre-hypertensive and hypertensive individuals, and enhanced antioxidant protection is a likely underlying mechanism.

Access to exercise and its relation to cardiovascular health and gene expression in laboratory animals.

The interaction between genes and environment can influence cardiovascular disease (CVD). This 16 month study investigated if genes associated with cardiovascular (CV) regulation were expressed differently in animals having: 1) no access to physical activity or exercise (SED), 2) access to hour-long, twice weekly activity (PA), and 3) access every-other-day to a running wheel (EX). Out of 31,000 genes, a CV subset comprising 44 genes was investigated. Ten genes from this subset were expressed differently in EX compared with SED, and 34 genes were expressed differently in PA compared with SED (p<0.05). Total cholesterol (70+/-8 vs. 101+/-9 mg dl(-1)), triglycerides (104+/-8 vs. 127+/-4 mg dl(-1)), resting systolic blood pressure (130+/-3 vs. 141+/-3 mmHg), mean arterial pressure (110+/-2 vs. 120+/-2 mmHg) and heart rate (380+/-6 vs. 405+/-9 beats min(-1)) were lower in EX compared with SED (p<0.05), but intracellular adhesion molecule levels did not differ among groups. Mean gene expressions for Gja1, Fdft1, Edn1, Cd36, and Hmgb2 differed in animals according to access to physical activity. These genes play roles in heart rate, cholesterol biosynthesis, blood pressure, cell adhesion, and transcription and neurogenesis regulation, respectively. In conclusion, a total of 44 CV genes were expressed differently in SED compared to PA and EX; and SED showed more physiological evidence of CVD.

Exercise improves biomarkers of health and stress in animals fed ad libitum.

Voluntary and forced exercise decrease morbidity and mortality in laboratory animals. Caloric restriction has similar effects on health and unique benefits on life span. Nonetheless, in most experiments, animals do not have access to physical activity and are fed ad libitum (AL). We hypothesized that with regular access to either unlimited running wheel exercise (EX) or limited physical activity (PA), key biomarkers of health would be enhanced enough to counter some consequences of a sedentary AL lifestyle. This 16-month study compared body weight, tumor number and size, tissue lesions, oxidative stress, and reactive stress in (1) sedentary animals with no access to physical activity (SED); (2) animals with access to hour-long, twice weekly activity in a large box (PA); and (3) animals with access every other day to a running wheel (EX). At the end of the study, EX body weight was 8-9% lower than PA and SED. In addition, EX had no kidney lesions versus 50% in PA and SED, and had smaller tumor size (10+/-2 vs. 14+/-4 and 30+/-4 mm). Exhaustive exercise lowered glutathione/oxidized glutathione ratio in EX and PA, but in SED, the ratio was depressed even in resting animals. In all treatments, prolactin (PRL) levels were lower in resting animals than in acutely exercised animals. In conclusion, EX had the most favorable health biomarkers while SED had the least. PA did not confer gross health benefits different than the SED group, but was biochemically more similar to EX animals.

Anti-angiogenic property of edible berries.

Recent studies show that edible berries may have potent chemopreventive properties. Anti-angiogenic approaches to prevent and treat cancer represent a priority area in investigative tumor biology. Vascular endothelial growth factor (VEGF) plays a crucial role for the vascularization of tumors. The vasculature in adult skin remains normally quiescent. However, skin retains the capacity for brisk initiation of angiogenesis during inflammatory skin diseases such as psoriasis and skin cancers. We sought to test the effects of multiple berry extracts on inducible VEGF expression by human HaCaT keratinocytes. Six berry extracts (wild blueberry, bilberry, cranberry, elderberry, raspberry seed, and strawberry) and a grape seed proanthocyanidin extract (GSPE) were studied. The extracts and uptake of their constituents by HaCaT were studied using a multi-channel HPLC-CoulArray approach. Antioxidant activity of the extracts was determined by ORAC. Cranberry, elderberry and raspberry seed samples were observed to possess comparable ORAC values. The antioxidant capacity of these samples was significantly lower than that of the other samples studied. The ORAC values of strawberry powder and GSPE were higher than cranberry, elderberry or raspberry seed but significantly lower than the other samples studied. Wild bilberry and blueberry extracts possessed the highest ORAC values. Each of the berry samples studied significantly inhibited both H2O2 as well as TNF alpha induced VEGF expression by the human keratinocytes. This effect was not shared by other antioxidants such as alpha-tocopherol or GSPE but was commonly shared by pure flavonoids. Matrigel assay using human dermal microvascular endothelial cells showed that edible berries impair angiogenesis.

Comparison of gene and protein expressions in rats residing in standard cages with those having access to an exercise wheel.

Lifelong physical inactivity is associated with morbidity in adulthood, possibly influenced by changes in gene and protein expressions occurring earlier in life. mRNA (Affymetrix gene array) and proteomic (2D-DIGE MALDI-TOF/MS) analyses were determined in cardiac tissue of young (3 months) and old (16 months) Sprague-Dawley rats housed with no access to physical activity (SED) versus an exercise wheel (EX). Unfavorable phenotypes for body weight, dyslipidemia, and tumorogenesis appeared more often in adult SED versus EX. No differentially expressed genes (DEGs) occurred between groups at 3 or 16 months. Within groups, SED and EX shared 215 age-associated DEGs. In SED, ten unique DEGs occurred with age; three had cell adhesion functions (fn1, lgals3, ncam2). In EX, five unique DEGs occurred with age; two involved hypothalamic, pituitary, and gonadal hormone axis (nrob2, xpnpep2). Protein expression involved in binding, sugar metabolic processes, and vascular regulation declined with age in SED (KNT1, ALBU, GPX1, PYGB, LDHB, G3P, PYGM, PGM1, ENOB). Protein expression increased with age in EX for ATP metabolic processes (MYH6, MYH7, ATP5J, ATPA) and vascular function (KNT1, ALBU, GPX1). Differences in select gene and protein expressions within sedentary and active animals occurred with age and contributed to distinct health-related phenotypes in adulthood.

Revisiting influences on tumor development focusing on laboratory housing.

Spontaneous tumors are reported to occur in 45% to 71% of Sprague-Dawley rats, yet few studies have considered the effect of the sedentary condition of standard laboratory cages on tumorigenesis. Tumor profiles and tumor promoting hormone prolactin were compared in female Sprague-Dawley rats (108) that were allocated into 3 groups: those housed without outside activity (SED group), with twice-weekly 1-h sessions of physical activity in large box (PA group), and with regular voluntary running-wheel exercise (EX). Compared with the EX group, SED rats had more and larger tumors throughout most of their lifespan; tumor profiles of PA rats were similar to those of the SED group. A larger percentage of animals in the SED group had tumors (54%), compared with EX rats (38%). At 64 wk, tumors in SED animals included thyroid carcinoma, malignancy, mammary fibroadenoma, cystadenoma, and granuloma, whereas benign mammary gland cysts were most common in EX. Prolactin levels were highest in SED animals at 24 and 52 wk. In conclusion, increased tumor number, increased tumor size, type of spontaneous tumor, and increased prolactin in rats were associated with standard laboratory housing, which limited physical activity, and were not primarily due to aging.