The Effect of Domain-Specific Sitting Time and Exercise Habits on Metabolic Syndrome in Japanese Workers: A Cross-Sectional Study

Relationship between exercise habits and physical function in children aged 9-12 years

Exercise improves physical health and positively impacts physical functions in children. Additionally, the habitual exercise established during childhood often continues into adulthood. Therefore, childhood is an important period for establishing healthy habits. Investigating the relationship between the presence or absence of daily exercise and physical functions may provide important information to confirm poor physical function in children with poor exercise habits. Therefore, this study examined the relationship between exercise habits as defined by the Japanese Ministry of Health, Labor, and Welfare and physical function in children aged 9-12 years. Approximately 239 children were included in this study. Participants answered a questionnaire about their exercise habits. We evaluated the skeletal muscle mass index, grip strength, standing broad jump, one-leg standing time, and gait deviation index. Logistic regression analyses were performed to assess exercise habit association with skeletal muscle mass index, physical function, and gait deviation index after adjusting for sex. Of the 239 children, 75.5% (n = 178) had exercise habits. A significant association was noted between exercise habits and skeletal muscle mass index and standing broad jump (skeletal muscle mass index: OR, 1.84; 95% CI, 1.01-3.36 and p<0.05; standing long jump: OR, 1.02; 95% CI, 1.00-1.04 and p<0.05). In conclusion, exercise regardless of exercise level for at least 30 min per day, 2 days per week, for at least 1 year is important for skeletal muscle mass and instantaneous lower limb muscular strength development in school-aged children.

Effects of a smartphone app-based diet and physical activity program for men living with HIV who have dyslipidemia: A pilot randomized controlled trial

AIMS

People living with HIV are at a high risk for cardiovascular disease owing to antiretroviral therapy use and chronic inflammation. There is limited evidence on the evaluation of serum lipid levels through lifestyle modification. This study aims to evaluate the effect of a smartphone application-based diet and exercise improvement program on men living with HIV and dyslipidemia.

METHODS

This was a randomized controlled trial recruiting Japanese men living with HIV who have dyslipidemia: intervention group (n = 19) and control group (n = 19). The intervention group received a third individual guidance session during the 6-month intervention and was encouraged to record their diet on a smartphone application. An intention-to-treat analysis of the results was conducted.

RESULTS

The intervention group showed significantly reduced change in low-density lipoprotein levels compared to the control group (-4.00 ± 20.2 mg/dL vs. 10.11 ± 21.1 mg/dL) (p = .042) from baseline to 6 months post-intervention. No significant differences were found in other serum lipid levels. Abdominal circumference decreased significantly in the intervention group (p = .048) from baseline to 6 months post-intervention. Total energy, protein, carbohydrate, fat, and salt intake, dietary and physical activity behavior change stages and social support, dietary self-efficacy, and loneliness significantly improved in the intervention group (p < .05) from baseline to 6 months post-intervention.

CONCLUSIONS

A diet and physical activity improvement program using a smartphone application based on Japanese-specific health guidance may reduce low-density lipoprotein cholesterol levels in this population. Further sample expansion and examination of long-term effects are needed.

Association between Metabolic Syndrome Status and Daily Physical Activity Measured by a Wearable Device in Japanese Office Workers

(1) Background: This study examined the cross-sectional association between metabolic syndrome (MetS) status classified into three groups and daily physical activity (PA; step count and active minutes) using a wearable device in Japanese office workers. (2) Methods: This secondary analysis used data from 179 participants in the intervention group of a randomized controlled trial for 3 months. Individuals who had received an annual health check-up and had MetS or were at a high risk of MetS based on Japanese guidelines were asked to use a wearable device and answer questionnaires regarding their daily life for the entire study period. Multilevel mixed-effects logistic regression models adjusted for covariates associated with MetS and PA were used to estimate associations. A sensitivity analysis investigated the associations between MetS status and PA level according to the day of the week. (3) Results: Compared to those with no MetS, those with MetS were not significantly associated with PA, while those with pre-MetS were inversely associated with PA [step count Model 3: OR = 0.60; 95% CI: 0.36, 0.99; active minutes Model 3: OR = 0.62; 95% CI: 0.40, 0.96]. In the sensitivity analysis, day of the week was an effect modifier for both PA (p < 0.001). (4) Conclusions: Compared to those with no MetS, those with pre-MetS, but not MetS, showed significantly lower odds of reaching their daily recommended PA level. Our findings suggest that the day of the week could be a modifier for the association between MetS and PA. Further research with longer study periods and larger sample sizes are needed to confirm our results.

Validity of Domain-Specific Sedentary Time Using Accelerometer and Questionnaire with activPAL Criterion

Accelerometers based on the cut-point method are generally the most used in sedentary time (ST) research. However, mixed cut-points are an issue, so an accelerometer based on metabolic equivalents (METs) could be used as an alternative. This study aimed to validate a METs-based accelerometer (HJA-750C, OMRON) and a questionnaire that estimates domain-specific sedentary time measures using activPAL as a criterion value. We also examined whether measurement validity differed according to gender and occupation. We used data from 242 workers in the validation study. Participants wore activPAL on the thigh and OMRON on the waist for seven consecutive days with daily recording logs. The Workers Living Activity-time Questionnaire (WLAQ) was administered once. The domain-specific ST assessed quantities of ST during commuting, working time, non-working time on a workday, and non-workday. Intraclass correlation coefficients (ICC) and Spearman's rho coefficients were then used to conduct analyses. The OMRON accelerometer showed acceptable values (r = 0.67-0.86 and ICC of 0.63-0.87) in the overall domain-specific ST. Additionally, each measurement result suggested that working time is the most accurate domain to measure ST (ICC of 0.87 for OMRON and 0.68 for WLAQ). Moreover, there were no differences in the overall validity of the results according to gender and occupation. The METs-based accelerometer has acceptable validity for ST measurements to be used among workers. Additionally, working time may be the preferred domain for the accurate assessment of ST in both objective and subjective measurements. These results can advance the quality of the sedentary research field.

[Examining the association between work-life factors and health disorders/excessive fatigue among Japanese truck drivers]

OBJECTIVES

Karoshi problems (overwork-related deaths and disorders caused by cerebrovascular and cardiovascular diseases) still occur in Japan. Truck drivers, who are in one of the riskiest occupations, are reported to show an increased prevalence of hypertension, obesity, hyperlipidemia, and diabetes, which are characteristic of Karoshi. Their health problems also include excessive fatigue. This cross-sectional study aimed to examine the association between work-life factors and health disorders/excessive fatigue among Japanese truck drivers.

METHODS

We distributed a questionnaire regarding work hours, health status, lifestyle, burden of driving, and excessive fatigue to 5,410 truck drivers and collected a total of 1,947 responses, all from males. The association between work-life factors and health outcomes was evaluated by multivariable logistic regression analysis adjusted for age, drinking, and smoking status.

RESULTS

The prevalence rates of obesity, hypertension, hyperlipidemia, diabetes, cardiovascular disease, cerebrovascular disease, and excessive fatigue were 22.2%, 19.3%, 8.5%, 5.6%, 2.5%, 0.7%, and 6.0%, respectively. Significant associations were observed for long-haul trips (two days or more) with obesity (adjusted odds ratio 1.5 [95% Confidence Interval 1.1-2.1]), local and night trips with hypertension (1.5 [1.0-2.2]), early morning awakening on workdays with obesity (1.5 [1.1-2.1]), being indoor-oriented on weekends with hypertension (1.5 [1.1-2.0]); and heavy burden of driving at night with hyperlipidemia (2.0 [1.3-3.0]). The adjusted odds ratios were significant for waking after sleep onset (2.6 [1.2-5.3]) and lack of sleep satisfaction (2.7 [1.4-5.1]) on workdays, less than six hours of sleep (2.8 [1.0-7.8]) and lack of sleep satisfaction (2.8 [1.5-5.2]) on weekends, 0-3 days off per month (3.6 [1.3-10.2]), and heavy burden of driving at night (2.2 [1.0-4.8]) with excessive fatigue.

CONCLUSIONS

The present findings highlight that night and early morning work, heavy burden of night driving, and the resultant decreases in the quality and quantity of sleep may represent shared risk factors for health disorders and excessive fatigue among truck drivers. Adequate measures should be taken to limit the amount of night and early morning work, reduce the burden of night driving, and ensure days off for sleep opportunities and leisure activities, with the goal of preventing Karoshi.