Assessment of Salivary Nitric Oxide Levels in Elite University Athletes in Japan: Findings From a Cross Sectional Study Design.

BACKGROUND: High-intensity exercise affects the level of salivary nitric oxide (NO) with an impact on oxidative stress such as a reactive nitrogen-oxide species. However, in athletes with high-intensity training, the relationship between salivary NO levels and oxidative stress is yet to be clear. Additionally, the association of salivary NO levels and the common health disorders of athletes is unknown. Thus, the aim of this cross-sectional study was to clarify the relationship between salivary NO levels and oxidative stress, and the health/medical disorders existing in elite class university athletes. METHODS: In 250 athletes (males, 151 and females, 99) from undergraduate levels of Japanese University, we investigated the relationship between levels of salivary NO and oxidative stress markers: derived reactive oxygen species (d-ROMs) and biological antioxidant potential (BAP), and also examined that whether salivary NO levels are associated with diseases. RESULTS: There were no significant association between the levels of salivary NO and oxidative stress markers (such as d-ROM and BAP). From the questionnaire, asthma was the most prevalent as evident from medical history of the athletes. Additionally, the salivary NO levels were higher (520 ± 43 µmol/L vs. 375 ± 13 µmol/L, P < 0.05) in the asthma group (n = 9) than in the non-asthma group (n = 241). We determined the optimal cut-off value (P = 0.019) of the salivary NO levels for asthma was 425 µmol/L, with a sensitivity of 88.9% and specificity of 61.8% (area under the curve (AUC), 0.73). CONCLUSIONS: Our results suggest that the high levels of salivary NO in trained university athletes in Japan may potentially predict asthma. And this salivary NO level is not associated with markers of oxidative stress and existing diseases in athletes studied here.

Individual differences in cardiac and vascular components of the pressor response to isometric handgrip exercise in humans.

We tested the hypotheses that, in humans, changes in cardiac output (CO) and total peripheral vascular resistance (TPR) occurring in response to isometric handgrip exercise vary considerably among individuals and that those individual differences are related to differences in muscle metaboreflex and arterial baroreflex function. Thirty-nine healthy subjects performed a 1-min isometric handgrip exercise at 50% of maximal voluntary contraction. This was followed by a 4-min postexercise muscle ischemia (PEMI) period to selectively maintain activation of the muscle metaboreflex. All subjects showed increases in arterial pressure during exercise. Interindividual coefficients of variation (CVs) for the changes in CO and TPR between rest and exercise periods (CO: 95.1% and TPR: 87.8%) were more than twofold greater than CVs for changes in mean arterial pressure (39.7%). There was a negative correlation between CO and TPR responses during exercise (r = -0.751, P < 0.01), but these CO and TPR responses correlated positively with the corresponding responses during PEMI (r = 0.568 and 0.512, respectively, P < 0.01). The CO response during exercise did not correlate with PEMI-induced changes in an index of cardiac parasympathetic tone and cardiac baroreflex sensitivity. These findings demonstrate that the changes in CO and TPR that occur in response to isometric handgrip exercise vary considerably among individuals and that the two responses have an inverse relationship. They also suggest that individual differences in components of the pressor response are attributable in part to variations in muscle metaboreflex-mediated cardioaccelerator and vasoconstrictor responses.

Curvature of cervical vertebra in 8020 achievers observed by lateral cephalogram.

The hypothesis of this research was that elderly people with many remaining teeth and good occlusion (8020 achievers) would be able to maintain proper head and body posture, despite aging. The purpose of this study, as a first stage, was to clarify the aging phenomenon of cervical curvature in 8020 achievers in comparison with that in young adults. Subjects consisted of twenty-eight 8020 achievers, with a mean age of 82.96+/-3.3 years and 26.5+/-4.0 teeth. For comparison, forty adults in their 20's with a mean age of 22.9+/-0.7 years and 28.2+/-0.6 teeth were also enrolled. The cervical vertebra was assessed based on the distance from the CV line (tangential line of the 2nd and 6th cervical vertebra) to each cervical vertebra and the angles formed by the cervical and reference lines in the cranial bone. Every distance from the CV line to each cervical vertebra in the 8020 group was bigger than that in the 20's group (p<0.01-0.001). The distance from the CV line to CV-3 and CV-5 in 8020 women was larger than that in 8020 men (p<0.05). Every distance from the CV line to each cervical vertebra in 8020 women was larger than that in 20's women (p<0.01-0.001). There was no significant difference between 8020 men and 20's men. The difference between the women's group was more marked than that between age groups for men. The cervical curvature in 8020 achievers showed a greater tendency toward cervical lordosis than that in young adults. In the 8020 achievers, the curvature in women was greater than that in men. The curvature in 8020 women seemed was marked, showing strong cervical lordosis, despite the presence of many remaining teeth and good occlusion. It remains to be determined by comparing 8020 achievers with ordinary elderly whether the condition of the teeth influences spinal curvature with aging.