Objective: The diagnostic criteria for the metabolic syndrome (MetS) were published in Japan in April 2005. However, there have been no large-scale studies in rural areas to confirm these criteria. We examined the prevalence of MetS in subjects who had undergone a routine medical health checkup at our hospital, located in a rural area. This data was used to investigate the appropriateness of the diagnostic criteria for MetS.Subjects and Methods: The MetS status was examined retrospectively in 2340 subjects (1408 men, 932 women ; mean age 49.6 ± 9.7 years) who underwent a routine medical health checkup at our hospital between April 2004 and March 2005.Results: Of the 1408 men and 932 women, 209 men (14.8%) and 23 women (2.5%) were diagnosed with MetS. Forty-four men (3.1%) and 4 women (0.4%) met all three diagnostic criteria for metabolic disorders. In the female group, only 8.7% of the 932 women met the waist circumference criterion of ≥90 cm. Because this waist circumference criterion was used during the first screening but was not met by most of the women, they were eliminated from our study. Using receiver operating characteristic (ROC) analysis, the cutoff values for waist circumference were 85.0 cm (sensitivity 0.750, specificity 0.564) in men and 79.5 cm (sensitivity 0.787, specificity 0.709) in women. If the women's waist circumference criterion had been set at the value of ≥79.5 cm, this would have resulted in 48 (5.2%) women meeting the criterion.Conclusion: From the viewpoint of preventive medicine, the Japanese male MetS diagnostic criteria are fairly appropriate. However, for the women, the waist circumference criterion of ≥90 cm has been set too high and was not met by most of the female subjects. Therefore, the Japanese MetS criteria for women, particularly the cutoff value for waist circumference, requires further verification.
Human Females ; Male population group ; diagnostic criteria ; Japanese language ; Health

The aim of this study was to investigate the relationship between heart rate variability (HRV) during exercise and ventilatory threshold (VT), using the MemCalc system which is superior in spectral analysis. Nine healthy male subjects with no cardiopulmonary disease performed an exercise test to exhaustion to determine VT on a bicycle ergometer. Low frequency (LF : 0.04-0.15 Hz), high frequency (HF : 0.15-0.40Hz) and LF/HF ratio power spectra were calculated by maximum entropy method (MEM) spectral analysis, using the MemCalc system. In each case, when the subject started exercise, the HF component declined rapidly during the first 30 seconds ; and compared to the resting value, it declined to approximately 5 % at VT. The possibility of using this phenomenon as a criterion for setting intensity of exercise is tinder consideration. The LF/HF ratio showed different patterns of variation among the subjects. A significant linear relationship was seen between the declining rate of the HF component and VT (r=0.93, p<0.001), suggesting a corres pondence between the heart's capability of adjusting to maintained exercise and high endurance capacity.