Longitudinal Changes in Arterial Stiffness Associated with Physical Activity Intensity: The Toon Health Study.

AIMS: Several studies have revealed an association between moderate-to-vigorous physical activity (MVPA) and arterial stiffness, which is a known risk factor for cardiovascular disease. However, a few studies have considered the difference in the longitudinal effect of its intensity in a large general population. Therefore, we examined the effect of MVPA intensity on longitudinal changes in arterial stiffness. METHODS: We conducted a prospective cohort study involving 1,982 Japanese men and women. Arterial stiffness was measured using the cardio-ankle vascular index (CAVI) at baseline and 5-year follow-up. Physical activity was quantified using the Japan Arteriosclerosis Longitudinal Study Physical Activity Questionnaire and categorized into quartiles as MVPA levels. Linear mixed models were used to examine the differences at baseline and the rate of changes in CAVI associated with MVPA levels for over 5 years. RESULTS: The multivariable-adjusted mean differences in CAVI at baseline were significantly lower in the third (ß=-0.019 [95% confidence interval {CI}=-0.033 to -0.005]) and fourth (ß=-0.018 [95% CI=-0.035 to -0.001]) quartiles of the MVPA group compared with those in the lowest quartile of MVPA, and the significant effect persisted 5 years later. CONCLUSIONS: In summary, this study provides evidence to support the existence of a threshold for beneficial levels of MVPA in the prevention of arterial stiffness. Furthermore, this study suggests that exceeding this threshold may exert similar effects on arterial stiffness. These findings suggest that an optimal level of MVPA exists for preventing arterial stiffness, and exceeding this threshold may not engender additional benefits.

A Cross-Sectional Study of the Relationship of Timed Up & Go Test with Physical Characteristics and Physical Activity in Healthy Japanese: The Toon Health Study.

This study evaluated the Timed Up & Go test (TUG) among healthy Japanese individuals without walking problems to clarify the relationship of TUG performance with physical characteristics and physical activity according to sex and age groups. In total, 797 men and women (30-84 years old) in Toon City, Ehime Prefecture, were assessed from 2016 to 2017. The survey data for physical characteristics, TUG performance, and physical activity measures were used. After adjusting for age according to TUG time and categorization into sex and age groups (30-64 and 65-84 years), the relationship of TUG performance with physical characteristics and physical activities was confirmed using multiple regression analysis. In men, TUG performance was associated with work and household chores in the 30-64-year age group, whereas it was only associated with skeletal muscle mass among those older than 65 years. In women, TUG performance was associated with height and amount of exercise, regardless of age. In conclusion, TUG performance may be maintained by increasing the amount of physical activity for men through work and housework, and increasing the amount of exercise for women, which may prevent the need for long-term care in the future.

The Relationship between Locomotive Syndrome Risk, Gait Pattern, and Standing Posture in Young Japanese Women: A Cross-Sectional Study.

Young people are also at risk of developing locomotive syndrome for unclear reasons. Therefore, we sought to evaluate the locomotive syndrome risk in young Japanese women and the relationship between standing posture and gait patterns. We used survey materials for physical measurements, locomotive syndrome risk tests, normal and maximum walking test, a standing posture test, and physical activity measures. A questionnaire-based cross-sectional survey was conducted with 100 Japanese female university students. The participants were divided into two groups (high-risk and low-risk groups) based on locomotive syndrome risk tests. The high-risk group accounted for 65.0% of the total participants. The high-risk group had a significantly slower walking speed and lower walking stride length than the low-risk group during maximum walking. Additionally, this high-risk group had a more prone posture than the low-risk group. Furthermore, the low-risk group included more individuals who belonged to middle and high school athletic clubs than the high-risk group. The locomotive syndrome risk was related to the walking pattern, standing posture, and past exercise habits. Therefore, long stride length, correct standing posture, and exercise habits acquired from a young age are important measures for preventing locomotive syndrome in young adults.

Influence of Insulin Resistance on the Association Between Physical Activity and Heart Rate Variability: The Toon Health Study.

BACKGROUND: Autonomic activity is possibly influenced by physical activity (PA). However, it remains unclear whether this association is modified by insulin resistance. METHODS: This population-based study between 2009 and 2012 included 2016 men and women aged 30-79 years. The PA was assessed using a validated questionnaire based on sleep, occupation, transportation, household characteristics, and leisure-time PA. Heart rate (HR) and heart rate variability (HRV) in the sitting position were determined from 5-minute recordings of pulse waves detected by a fingertip sensor. The HRV was calculated as frequency (standard deviation of normal-to-normal [NN] intervals [SDNN]), root mean square of successive differences (RMSSD), and percentage differences between normal NN intervals >50 milliseconds [pNN50]) and time domains. Insulin resistance was evaluated using the homeostasis model assessment index (HOMA-IR). RESULTS: HR, RMSSD, and pNN50 were related to the total and moderate/vigorous PA tertiles in models that included HOMA-IR. The partial regression coefficient of total PA per 1-SD increase was .05 (P = .019) for log-transformed RMSSD and 1.86 (P = .001) for pNN50. No interactive associations were observed between PA and HOMA-IR. CONCLUSIONS: Low total PA was associated with increased HR and low levels of RMSSD and pNN50, reflecting parasympathetic modulation that was not modified by insulin resistance.