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Pulmonary diseases, including chronic obstructive pulmonary disease (COPD), are major chronic diseases that result in decreased pulmonary function. Relationships between body composition and pulmonary function have been reported. However, few epidemiological studies have used the visceral fat area (VFA) to measure body composition. This study aimed to examine the relationship between body composition and pulmonary function. A cross-sectional study was conducted between 2015 and 2016, using data obtained from 1,287 residents aged between 19 and 91 years living in the Iwaki area of Hirosaki City, a rural region in Aomori Prefecture, Japan. Pulmonary function was evaluated using the forced vital capacity (FVC) as a percentage of the predicted value (predicted FVC%) and the ratio of forced expiratory volume in one second (FEV1) to FVC. The measurements for evaluating body composition included the body fat percentage (BFP) of the whole body and trunk, skeletal muscle index (SMI), body mass index (BMI), VFA, waist circumference (WC) at the navel level, and waist-to-hip ratio (WHR). To adjust for potential confounders, Spearman’s partial correlation analysis was used to examine the relationship between the measurements of body composition and pulmonary function. There were significant correlations between the predicted FVC% and the following parameters: BFP (whole body and trunk) in younger males; SMI in older males; WC, VFA, BMI, and SMI in younger females; and BFP (whole body and trunk) and VFA in older females. Contrastingly, WC and VFA in younger males and WC in younger females were correlated with the FEV1/FVC ratio. VFA was correlated with the FEV1/FVC ratio in younger males and predicted FVC% in older females. These findings suggest that visceral fat accumulation may increase the development of obstructive pulmonary disease in young males and accelerate the decline of pulmonary function (predicted FVC%) in older females.

This study aimed to compare the COP (center of foot pressure) control ability of junior soccer players between the kicking foot and the supporting foot using the COP control test. The participants were 40 junior soccer players (133.6±5.4 cm, 28.8±3.4 kg, 9.1±0.6 years old, soccer history: 3.8±1.3 years) belonging to a local soccer team. The COP control test was carried out using the COP trajectory measuring instrument T.K.K5810 and COP adjustment software 1.1.0 (Takei Scientific Instruments Co., Ltd.) to examine the lower right and left lower limb differences in the COP control ability. Of the 40 participants, 35 who kicked the ball with their right foot according to the questionnaire took part in the COP control test. The target-tracking COP control test tracks the target that moves regularly on the monitor with the COP and measures the total error over time. Each participant randomly practiced one standing position on both feet and one standing position (kicking foot and supporting foot), took a 30-second break between trials, and then performed two trials. The evaluation variable was total COP errors made in 30 s with the moving target. Of the two trials, for each player, the data with the best record were included for analysis. The mean COP control test scores when standing on one leg were 602.8±163.2 cm for the kicking leg and 561.6±159.1 cm for the supporting leg. The COP control test score with both feet standing was 487.0±146.2 cm. The scores of one-foot standing (kicking foot and supporting foot) were significantly higher than those for participants standing on both feet (p < 0.05), and many participants had better scores for their supporting foot than their kicking foot. However, there was no significant difference in the mean value of the kicking foot and the supporting foot and of the symmetry index, the effect size was also small. The results indicate that the COP control ability of junior soccer players does not differ between their kicking foot and their supporting foot.