Although it is common to assess visceral adipose tissue (VAT) by CT and MRI with a single slice at the umbilicus or the fourth and fifth lumbar vertebrae (L4-L5), recent studies reported that this single-slice method for determining an individual’s VAT may be inaccurate. Therefore, VAT accumulation should be based on total volume and determined with multiple slices rather than by cross-sectional area. However, obtaining multiple slices is burdensome for both subjects and analysts and lacks versatility despite its accuracy. The purpose of this study was to develop a new equation model for predicting VAT volume while maintaining the measurement accuracy of the multiple-slice method. We analyzed data from 214 Japanese male adults (48.5±9.3 years) and developed multiple, stepwise, linear regressions with VAT volume as a dependent variable and age, BMI, waist circumference and VAT areas (the standard L4-L5 measurement site 0 cm, +5 cm, +10 cm) as independent variables. From these results, we determined the best prediction equation for VAT volume as follows: VAT volume = (30.4×BMI) + (17.9×VAT area at L4-L5+10 cm) – 501.5. The model explained 93.1% of VAT variance and the predicted VAT volume significantly correlated with the measured VAT volume (r=0.97). This study developed a new VAT assessment method with a high level of accuracy. The method is significantly less burdensome in measurement and analysis than the multiple-slice method. Researchers can use this equation when they require an accurate evaluation of VAT accumulation. However, they should bear in mind that this equation was derived from data acquired from middle-aged, overweight and obese male subjects.

Our previous study revealed that a 14-week indirect lifestyle intervention (LSI) implemented through wives had significant effects on weight loss among obese men. The purpose of the current study was to compare long-term maintenance of body weight after LSI between direct (DI) and indirect (II) intervention groups. Of participants in the previous intervention study, 15 men in the DI group and 24 married couples in the II group consented to a 2-year follow-up measurement session. Body weight, metabolic syndrome (MS) components, daily energy intake, and activity energy expenditure were measured pre- and post-LSI and at the follow-up. Participation rate in the 2-year follow-up tended to be higher in the II group (66.7%) than in the DI group (44.1%). Changes in body weight during the 2-year period in the DI and II groups were 1.4 ± 2.9 kg (P = 0.09) and 1.0 ± 3.4 kg (P = 0.15), respectively. There were no differences in the measurements or their changes between the two groups at the 2-year follow-up; however, we did find a significant correlation in the change in energy intake (r = 0.68, P < 0.01) between wives and husbands. While we found no significant difference in body weight maintenance between the DI and II groups, our study showed that many husbands in the II group succeeded in long-term maintenance of their weight loss, indicating that an indirect LSI through wives can affect the long-term maintenance of body weight among obese men.

The aim of this study was to examine a weight reduction program and residual effects, through confirming the relationship between changes in the morphological and psychological indices including personality and self-efficacy (SE) of the participants. Twenty-five middle-aged women were divided into two groups based on type of weight reduction program intervention. Thirteen women participated in a 3-month diet-only weight reduction program (DO group, 53.3±7.4 yr), and 12 women took part in a 3-month diet and aerobic exercise program (DE group, 48.3±9.6 yr). After the programs, the compatibility score of personality in the DO group was negatively correlated to SE that is indicated as confidence in ability to maintain decreased body weight at 2, 3, and 4 years after the program (r=-0.69, -0.58, and -0.60). It can be seen that personality has an effect on the results of the DO group weight reduction program. Additionally, despite a significant decrease in body-weight and %fat in both groups, only the change of %fat significantly correlated with SE. On the basis of these correlations, the changes of %fat that related to the movability perception of body movements has a greater effect on SE after the program than the information only of weight loss. The results of this study suggest that personality and SE accounted for weight maintenance, and were associated with the results of the weight reduction program.

The purpose of this study was to examine the association between the hierarchy of higher-level functional capacity (instrumental self-competence, intellectual activity, social role) and the quantity of physical activity in older women (n = 175, 72.1 ± 5.8 years). Physical activity was estimated with a uniaxial accelerometer that calculated light-intensity physical activity (LPA), and moderate-to vigorous-intensity physical activity (MVPA). Higher-level functional capacity was assessed with the Tokyo Metropolitan Institute of Gerontology (TMIG) index of competence. According to the three subscales (instrumental self-competence, intellectual activity, and social role) of the TMIG index, participants who reported a score of 1 or more below the respective full marks were categorized as a group with reduced status. Logistic regression analysis was conducted to examine association between the hierarchy of higher-level functional capacity and the quantity of physical activity divided by intensity of activity, adjusted by covariance. Only low MVPA showed a significantly lower odds ratio than high MVPA in reduced status of instrumental self-competence. Since instrumental self-competence was significantly related with only the quantity of MVPA, it may be more important to focus on “quantity” of physical activity to prevent reductions in higher-level functional capacity in advanced stages of declining functional capacity.

Fall-related factors (FRFs) are classified into intrinsic factors and extrinsic factors. Intervention programs, which focused on modifiable factors (MFs) among FRFs have been designed to prevent falls. The purpose of this study was to identify easily-measurable intrinsic MFs for falls and recurrent falls. Cross-sectional analysis was carried out on the data from 483 community-dwelling older adults, aged 65-92 years (73.7 ± 5.9 yr, 138 men, 345 women). We measured history of falls in the past year and 7 domains of FRFs. Of these, 20 items were selected as MFs. Analyses of FRFs and MFs were conducted by comparing (separated by sex) those who did not report a fall with those who reported any number of falls, and those who reported no falls or one fall with those who reported recurrent falls. Using the significant items as independent variables, multiple logistic regression analysis with forward selection method was performed. The prevalence of falls and recurrent falls was: in men, 24.6% and 14.5%; in women, 26.7% and 12.5%. There were no significant differences in prevalence of falls or recurrent falls between genders. The following items were selected as the MFs most strongly associated with falls: climbing 10 steps with difficulty and tandem walk; and associated with recurrent falls: climbing 10 steps with difficulty, sit and reach, and tandem walk. These results are useful in determining the focus of fall prevention programs to be used in future community-based interventions.

The purposes of this study were (i) to determine the characteristics of physical function for frail older adults, compared with those for the independent and the dependent, (ii) to examine validity of the “health check-up questionnaire” (Kihon Check-list: CL) for finding frail older adults. Five hundred thirty-nine older Japanese people (75.5 ± 7.0 years) were assigned to each one of the three categories: the independent, the frail and the dependent according to the classification criteria of long-term care insurance system. Physical function score (PFS) was estimated by principal components analysis. Logistic regression analysis was conducted to assess validity of the CL and to examine the screening tool for detecting frail older adults who have a higher risk for becoming the dependent. Significant differences were observed among the three groups in PFS (the independent, 0.580 ± 0.467; the frail, -0.309 ± 0.733; the dependent -1.347 ± 0.949). The Odds ratio (OR) of the dependent for older adults to whom the CL was applied was 2.4 (95% confidence interval (CI): 1.3 - 4.5), and the OR for those to whom both the CL and the hand-grip strength test were applied was 5.4 (2.6 - 11.5). These data suggest that the comprehensive status of physical function of frail older adults, which varied widely, was intermediate between the independent and the dependent. It is useful to add the hand-grip strength test to the CL as a screening tool to subdivide frail older adults.

BACKGROUND: The purpose of this study was to examine the association between habitual walking and multiple or injurious falls among community-dwelling older adults. METHODS: Cross-sectional analysis was conducted on the data from 708 community-dwelling older adults, aged 60-91 years (72.3 +/- 6.6 yr, 233 men and 475 women). Prevalence of falls between walkers and non-walkers was compared separately by the number of risk factors (Groups R0, R1, R2, R3 and R4+). Logistic regression analysis was used to assess the association between habitual walking and falls separately by lower (R<3) and higher (R3+) risk groups. An interaction between habitual walking and risk of falling was examined in logistic regression analysis among all participants. RESULTS: In Groups R0, R1 and R2, prevalence of falls was lower in walkers than non-walkers; however, in Groups R3 and R4+, prevalence of falls was higher in walkers. Logistic regression analysis showed that habitual walking was significantly associated with fewer falls (Odds ratio (OR): 0.44, 95% confidence interval (CI): 0.20-0.97) among the lower risk group, but significantly associated with greater falls (OR: 4.61, 95% CI: 1.32-16.09) among the higher risk group. The interaction between habitual walking and higher risk of falling was significant (P < 0.05). CONCLUSION: Habitual walking seems to positively affect the prevention of multiple or injurious falls but only in community-dwelling older adults who have less than three risk factors.

The purpose of this study was to determine whether hand-grip strength (HGS) can be a significant discrimination factor of mobility limitation (ML) among older adults. Cross-sectional analysis was conducted on data from 939 community-dwelling older adults, aged 65-96 years (74.4 ± 6.4 yr, 266 men, 673 women). ML was defined as self-reported difficulty in walking 400 m, climbing 10 steps, and rising from a chair. Trained testers assessed standardized measurements of HGS and lower extremity performance score (LEPS) calculated by four tests (i.e., tandem stance, 5-chair sit-to-stand, alternate step, and timed up & go). Receiver operating characteristic (ROC) analysis was conducted to identify discrimination power of HGS and LEPS for ML. The areas under the ROC curves (AUCs) of HGS and LEPS for ML were 0.82 and 0.87 in men; 0.70 and 0.85 in women, respectively. No significant difference was detected between the AUCs of HGS and LEPS (P = 0.12) in men, whereas in women, the AUC was significantly lower in HGS than LEPS (P < 0.001). The optimal HGS cut-off values for ML were 31.0 kg (sensitivity 75%, specificity 81%) for men and 19.6 kg (sensitivity 73%, specificity 57%) for women. In men, the HGS test could be as useful as LEPS for identifying ML. In women, discrimination power for ML by HGS alone was considered acceptable; however, a combination of HGS and lower extremity performance tests could be more useful for monitoring the hierarchical levels of physical frailty.

Although research on physical fitness science in Japan has developed along with occupational health issues, the role of researchers in this area has been reduced by technological advancements. Nowadays, the automation and mechanization of manual tasks have created new occupational problems. These new problems affecting workers, such as prolonged occupational sitting and a decline in cardiorespiratory fitness (CRF), have been shown to increase the risk of several diseases (i.e., diabetes, obesity, heart diseases, and mortality), and further studies are needed to clarify this issue. Furthermore, in response to changes in the social structure due to the “low birthrate, aging society, and shrinking population”, a workforce with a different form than that from the postwar period is required. Therefore, the need to consider how we can avert this national crisis with the new role of researchers in the field of physical fitness science is once again drawing attention. In this article, we introduce the research being conducted by the National Institute of Occupational Safety and Health in Japan to meet the needs of “healthy and long working” and discuss this research in the context of future issues. Specifically, we introduce the development of a tool (the Worker’s Living Activity-time Questionnaire) to assess workers’ sitting time and epidemiological research using it. Finally, we describe the efforts to develop a new index for evaluating workers’ CRF and social implementation experiments to make the workplace a base for health promotion.