With the progress of industrialization, physical environmental factors, such as traffic and environmental noise, have been shown to increase the risk of cardiovascular and metabolic diseases. Although antioxidant vitamins and trigonelline-containing compounds are known to improve the arterial function, their relationship with noise has not yet been fully investigated. This study aimed to investigate the effects of oral antioxidant vitamins and trigonelline-containing supplements on the vascular endothelial function during transient noise exposure. A single-blind crossover comparative study evaluated the vascular endothelial function in response to noise exposure in ten healthy men. Subjects were assigned to either the P trial (taking only a placebo) or a T trial (taking only trigonelline-containing vitamin supplementation) group where they took the assigned substance for 3 consecutive days. On the final day, they received an average noise exposure of 85 dB for 15 min. The FMD of the brachial artery was measured before and after noise exposure. No significant differences SBP, DBP, or HR before and after noise exposure were observed between the two trials groups. At 0 min after noise exposure, the FMD was higher in the T trial group than in the P trial group, and a significant difference was observed between the two conditions. It has been suggested that taking a vitamin supplement containing trigonelline before transient noise exposure may suppress the decline in the vascular endothelial function.

The purpose of the present study was to examine the validity and reliability of the stages of change for sedentary behavior scale among workers. The participants were 2400 Japanese workers aged 20-59 years (male: 50.0%, mean age: 40.4±10.8 years) recruited from research company. With an internet-based survey, the stages of change for sedentary behavior, total sitting time (min/day), socio-demographic characteristics, health-related characteristics and work-related characteristics were obtained. “Too much sitting” was defined as sitting or lying down for a total of 8 hours or more per day on average. Participants were categorized into one of 5 stages based on their present status for “too much sitting” and motivational readiness for reducing sedentary behavior. For the criterion validity, a one-way analysis of variance was utilized to compare the total sitting time among the 5 stages. To assess the test-retest reliability, randomly-selected 200 workers answered the scale again two weeks later. Then, the Kappa index (k) was calculated. As results, the means of total sitting time were significantly distinguished across the stages [F (4, 2395) =111.5, p<0.001, η²=0.16]. Participants in early stages (precontemplation, contemplation, preparation) had significantly longer sitting time than those in the Maintenance (Precontemplation>Contemplation, Preparation>Action, Maintenance) (p<0.001). The scale to assess the readiness to reduce sedentary time has shown good 2-week test-retest reliability (k=0.64). These results suggest that the developed scale presented good validity and reliability to assess the motivational readiness for reducing prolonged sedentary behavior among Japanese workers.

In this study, I aimed to estimate the cardiac output (Q), stroke volume (SV), and arteriovenous oxygen difference (a-vDO₂) during submaximal and maximal exercise using oxygen uptake (VO₂), heart rate (HR), and hemoglobin concentration (Hb) during exercise. This study was based on 1) Whipp et al. (1996), who found that maximal stroke volume (SVmax) can be estimated from HR, VO₂, and arterial oxygen content (CaO₂) during submaximal exercise, and 2) Durand (1980), who found that the slope of the linear relationship between VO₂ and Q is the reciprocal of CaO₂. In the present study, we used the Q during submaximal and maximal exercise reported by Åstrand et al. (1964) as a validity criterion and investigated the validity of the Q estimated using the present method from the VO₂, HR, and Hb data they reported simultaneously. Excluding the data of the two subjects detected as outliers, the bias, precision, and percentage errors of Q were -0.01±2.10 L/min, 4.1 L/min, and 25.1%, respectively. Data where the difference between estimated Q and measured Q was within ±20% represented 88.9% of the total. These results were similar to those of previous studies that examined the validity of Q during exercise using the impedance method. Outliers can be avoided by assessing the value of ΔVO₂/ΔHR based on the SVmax presumed from the subject’s characteristics. For laboratories that routinely perform exercise stress tests, the addition of Hb measurements allows the estimation of Q, SV, and a-vDO₂ during exercise.