Noriaki Tsunawake

The effect of frequency and mode of sports activity on the psychological status in tetraplegics and paraplegics.

Objective: To examine whether the psychological benefits of sports activity differ between tetraplegics and paraplegics with spinal cord injury, and investigate the effect of frequency and modes of sports activity on the psychological benefits. Methods: The Self-rating Depression Scale (SDS), State-Trait Anxiety Inventory (STAI) and Profiles of Mood States (POMS) were administered to 169 male individuals with spinal cord injury (mean age=42.7 years) including 53 tetraplegics and 116 paraplegics. The subjects were divided into four groups according to their frequencies of sports activity; High-active (more than three times a week; n=32), Middle-active (once or twice a week, n=41), Low-active (once to three times a month, n=32), and Inactive (no sports participation, n=64). Results: Analysis of variance revealed significant differences in depression for SDS, trait anxiety for STAI and depression and vigor for POMS among the groups. High-active group showed the lowest scores of depression and trait anxiety and the highest score of vigor among the four groups. In contrast, no significant difference was found for any psychological measurements between tetraplegics and paraplegics. In addition, there was no significant difference for any psychological measurements among modes (wheelchair basketball, wheelchair racing, wheelchair tennis and minor modes). Conclusions: These findings demonstrated that sports activity can improve the psychological status, irrespective of tetraplegics and paraplegics, and that the psychological benefits are emphasized by sports activity at high frequency. Spinal Cord (2000) 38, 309–314.

Limitation of muscle deoxygenation in the triceps during incremental arm cranking in women

The present study investigated the difference in oxygen kinetics in the exercising muscle between arm cranking and leg cycling in women. Twenty-seven females completed incremental arm cranking and leg cycling tests on separate days. During each exercise, spatially resolved near-infrared spectroscopy was used to measure changes in the tissue oxygen saturation (SO2), oxygenated (oxy-) hemoglobin and/or myoglobin (Hb/Mb), deoxygenated (deoxy-) Hb/Mb, and total Hb/Mb in the triceps during arm cranking and in the vastus lateralis during leg cycling. During arm cranking, there was a rapid increase in the respiratory exchange ratio and a lower ventilatory threshold compared to leg cycling, which confirmed accelerated anaerobic glycolysis in this mode of exercise. During leg cycling, SO2 remained decreased near to or until approaching peak oxygen uptake (V̇O2peak). During arm cranking, however, the decrease in oxy-Hb/Mb and increase in deoxy-Hb/Mb stopped at the middle of V̇O2peak (mean 51.4%), consequently resulting in a leveling off in the SO2 decrease, although total Hb/Mb continued to increase. These results might suggest that the oxygen demand in the triceps attained the maximum at that intensity, despite an adequate oxygen supply during arm cranking.

Multivariate analysis of factors influencing physical work capacity in wheelchair-dependent paraplegics with spinal cord injury

Abstract The purpose of this study was to determine the main factors that influence physical work capacity (PWC) in wheelchair-dependent paraplegics with spinal cord injury (SCI) using multivariate analysis. Thirty-two male paraplegics with SCI (PSCI) performed a submaximal arm exercise test on an arm-cranking ergometer to determine their PWC (oxygen uptake: ml ·  kg−1 · min−1) at a heart rate of 150 beats · min−1 (PWC150). Hayashis Quantification first type was applied to analyze the effects on PWC150 of six factors: age, smoking, level of physical activity, occupation, level of SCI and period since SCI. This analysis revealed high partial correlation coefficients between PWC150 and the level of SCI (0.651) and physical activity level (0.583) compared to other factors. In addition, the multiple correlation coefficient for six factors in predicting PWC150 was 0.726. These results indicate that the level of SCI and physical activity are the most important factors in determining PWC in wheelchair-dependent male PSCI.

Relationship between physical characteristics and physiological responses during maximal arm cranking in paraplegics.

The purpose of this study was to elucidate the main physical factor(s) affecting cardiorespiratory responses during maximal arm cranking exercise in patients with paraplegia. Peak oxygen uptake (peak VO2), peak pulmonary ventilation (peak VE) and peak heart rate (peak HR) were measured during maximal arm cranking exercise in 28 Japanese male patients. A cluster analysis was applied to the data for peak VO2, peak HR and peak VE, and then the subjects were classified into four groups (A, B, C and D). Group A showed high peak VE and peak HR and low peak VO2, Group B low peak VO2 and high values for other parameters, Group C the greatest physiological values for all measurements among the groups and, in contrast, Group D showed low peak VO2 and the lowest peak VE and peak HR among the groups. The subjects in Group C had low level of spinal cord injury and were sports participants. On the other hand, duration since injury was not related to the cardiorespiratory responses during maximal arm cranking. These findings indicate that the effects on these responses of years since injury are subordinate to those of the level of spinal cord injury and training.

Physical activity cut‐offs and risk factors for preventing child obesity in Japan

There is no official recommendations for physical activity level or steps for preventing and improving child obesity in Japan.

Effect of exercise on bone status and body composition in Japanese students

PURPOSE We evaluated the effect of exercise on stiffness and fat-free mass (FFM), which consists of bone and muscle, in Japanese students. It is uncertain whether exercise or sports activities will help to accumulate overall peak bone mass in Japanese adolescents. METHODS A total of 710 Japanese students (age = 15-20 yr) were enrolled. Students who regularly engage in physical exercise were assigned to an exercise group; other students were assigned to a nonexercise group. Body composition, including height, weight, waist circumference, hip circumference, body mass index, and waist-to-hip ratio, were measured and calculated. Lung volume, body volume, and body fat percentage were evaluated by air displacement plethysmography. Fat mass and FFM were derived from body fat percentage and body weight. Bone status, such as speed of sounds, broadband ultrasound attenuation, and stiffness, which is defined as bone density, was assessed by quantitative ultrasound. RESULTS In both sexes, height, weight, body mass index, circumferences, waist-to-hip ratio, lung volume, and body volume between the exercise and nonexercise groups did not show any significant differences. FFM, speed of sounds, broadband ultrasound attenuation, and stiffness in the exercise group were statistically higher than those in the nonexercise group (P < 0.05). Although stiffness positively correlated with age with the exception of the nonexercise group in females (P < 0.01), stiffness correlated with FFM in the exercise and nonexercise groups in both sexes (P < 0.01). CONCLUSIONS Ours is the first analysis of a trend in peak bone mass, including the effect of exercise in Japanese students. For Japanese pubertal females who did not have a history of regular exercise, stiffness slowly decreased with age. Exercise habits in early childhood are important in the relationship between stiffness and FFM.

A proposed method for the evaluation of body fat in Japanese adults that predicts obesity

The present study was designed to develop a simple predictive equation for the percent body fat (%BF) in Japanese adults based on variables collected during health examinations. We hypothesized that a benchmark for defining metabolic syndrome and obesity could be based on %BF, which was measured by underwater weighing (UW) as a gold standard for body composition assessment. Thus, we developed a predictive equation for %BF derived from UW that may contribute to the assessment of obesity status, characterized by an excess accumulation of visceral or subcutaneous fat. The subjects were 810 Japanese participants (283 men, 527 women, ages 18-59 years). Anthropometric variables, including height, weight, 7 circumferences, and 8 skinfold thicknesses, were measured. The developed predictive equation was as follows: %BF = 10.558 × sex (1 for men; 2 for women) + 0.069 × age + 0.667 × body mass index + 0.314 × abdominal circumference - 35.881.The coefficient of determination (r(2)) was 0.69. The predicted %BF derived from this equation was highly correlated with UW-measured values and did not show underestimation or overestimation in either sex. These data suggested that this predictive equation for %BF can be used for all Japanese adults and does not require the use of medical equipment and special measurement techniques. By combining the equation for %BF developed in this study with a %BF cutoff value of metabolic syndrome and obesity (>25.0% in men and >30.0% in women), all Japanese adults can easily and conveniently assess obesity status.

An association analysis between mitochondrial DNA A10398G polymorphism and temperament in Japanese young adults.

The mitochondrial (mt) DNA C5178A and A10398G polymorphisms have been reported to be associated with mental disorders such as bipolar disorder. However, the effects of these polymorphisms on temperament in healthy people are poorly understood. Evaluating healthy subjects can have the advantage of providing new strategies for maintaining psychological health and preventing mental illness. We examined the association between mtDNA polymorphisms and temperament in Japanese students. There was no significant difference in examined temperament when analysed by genotypes, 5178–10398 haplotypes, or sex. The subgroup analysis based on sex indicated that there was an interactive effect of the mtDNA A10398G polymorphism and sex on anxiety and obsession. This finding is preliminary and cannot exclude the possibility of false-positive due to small sample size (144 subjects) and multiple statistical testing. Further studies involving a larger sample size or other ethnic groups are necessary to confirm that mtDNA A10398G polymorphism can be a genetic factor for temperament.

Factors Influencing Cumulative Fatigue Symptoms in Female Nurses Working in Two Shifts Rotation System in Japan

Background: This study aimed to clarify factors affecting cumulative fatigue in nurses working two-shift rotations system with 16-hour night time shifts. Methods: A cross sectional design was employed; subjects were 96 nurses. The Cumulative Fatigue Symptoms Index (CFSI) was used to assess cumulative fatigue, and number of steps was counted as an objective measure/ index of physical activity. Data were collected over four days, which included a day shift, night shift, and day off a series of nursing shift. Participant characteristics such as their CFSI scores and years of experience were analyzed using a Mann-Whitney U or a Kruskal–Wallis test. In addition, logistic regression analysis was performed to examine the association between cumulative fatigue and potential contributing factors. Results: Valid data were obtained from 96 female nurses. Cumulative fatigue was found to be related to having less than 5 years of clinical experience (OR = .22, 95% CI=.05-.92), subjective busyness of nightime shifts (OR = 3.12-3.69, 95% CI= 1.06-12.11), and the number of steps taken on one’s day off (OR =.03, 95% CI= .10-.92). The subjective busyness in night shift work was an increasing risk factor of CFSI, and less than 5 years clinical experience and the numbers of steps of day off were lowering risk factors of CFSI. Conclusion: Clinical experience less than 5 years, subjective busyness in night shift work, and the number of steps on a day off as a measure of physical activity were identified as factors associated with CFSI in nurses working in two-shift rotation system.

Factors Influencing Recovery from Fatigue after a 16-hour Night Shift among Female Japanese Nurses

Background: The present study aimed to evaluate self-reported fatigue recovery among Japanese nurses who perform shift work and to evaluate how their fatigue was affected by a day off after a night shift. Methods: We recruited 66 healthy female Japanese nurses at three regional private hospitals. The nurses were divided into a recovery group and a non-recovery group, based on their self-reported experience of fatigue during the interval from the time before their night shift to after a following day off. Unpaired t-test and logistic regression analyses were used to find associations of self-reported fatigue with demographic and lifestyle factors. Results: The recovery group included 45 nurses, and the non-recovering group included 21 nurses. The recovery group exhibited a high degree of fatigue at five assessment points, while the non-recovery group only exhibited a high degree of fatigue at the post–day off assessment. The adjusted odds ratios (95% confidence intervals) for self-reported fatigue during the night shift were 1.27 (1.00–1.61) for the age of the nurse’s youngest child and 1.04 (1.00–1.08) for the nurse’s time spent napping (P < 0.05). Conclusion: Sleeping before a night shift may facilitate recovery after the shift, although fatigue was also influenced by the age of the nurse’s youngest child and the nurse’s napping time.