Background: There is a lack of evidence of the complicated pathways of underlying determinants in the phases of physical activity. The purpose of this study was to evaluate simultaneously a set of potential determinants on the initiation and maintenance phases of leisure-time physical activity (LTPA).

Methods: The longitudinal data of 54,359 Korean adults aged 40–69 years from the Health Examinees study were used. The median follow-up duration was 4.2 years. The self-reported durations per week of LTPA was repeatedly assessed. Based on previous longitudinal studies, the potential determinants were selected, and hypothetical models were constructed that consider the complex associations between the determinants. The standardized coefficients for direct and indirect effects were estimated using path analysis to differentiate contributions of mediation from the total effects.

Results: In the total population, age, education, chronic diseases, smoking, depression symptoms, and self-rated health were significantly associated with both initiation and maintenance phases. Income (B = 0.025) and social supports (B = 0.019) were associated only with the initiation phase. Waist-to-hip ratio (B = −0.042) and stress (B = −0.035) were associated only with the maintenance phase. After stratifying by sex, the significant effects of education, chronic diseases, and smoking were found only in men. The initiation phase-specific effects of income and social supports and the maintenance phase-specific effects of stress were found only in women. It was estimated that indirect effects contributed approximately 15% of the total effect.

Conclusion: The findings suggested that there were initiation- or maintenance-specific determinants of leisure-time physical activity according to sex.

Background: The association between overweight and chronic musculoskeletal pain may vary by anatomical site and be modified by hypertension status. This study examined the associations between overweight and low back and knee pains and their effect modification by hypertension status.

Methods: We conducted a community-based cross-sectional study involving 2,845 adults (1,080 men and 1,765 women) aged 40–89 years. Chronic knee pain (CKP) and low back pain (CLBP) lasting more than 3 months were categorized into more or less severe pain. Odds ratios (ORs) and 95% confidence intervals (CIs) of the association between overweight and more or less severe CKP and CLBP were determined using logistic regression and stratified by hypertension status. Adjustment variables were age, sex, area, hypertension, smoking and drinking status, inactivity, job category, mental stress, depression, and overall CKP or CLBP.

Results: Overall, 288 (10.1%) and 631 (22.2%) adults had more and less severe CKP, respectively, and 284 (10.0%) and 830 (29.2%) had more and less severe CLBP, respectively. Overweight was associated with overall CKP and more or less severe CKP, regardless of hypertension status. Overweight was not associated with overall CLBP; its association was more pronounced for more severe CLBP. The association between overweight and more severe CLBP was evident among non-hypertensives (multivariable OR 1.72; 95% CI, 1.09–2.71); however, that between overweight and less severe CLBP was not evident (multivariable OR 1.07; 95% CI, 0.73–1.56).

Conclusions: As hypertension may attenuate the association between overweight and CLBP, we should consider hypertension status for proper management of CLBP among overweight individuals.

Background: Kawasaki disease is suspected to be triggered by previous infection. The prevention measures for coronavirus disease 2019 (COVID-19) have reportedly reduced transmission of certain infectious diseases. Under these circumstances, the prevention measures for COVID-19 may reduce the incidence of Kawasaki disease.

Methods: We conducted a retrospective study using registration datasets of patients with Kawasaki disease who were diagnosed in all 11 inpatient pediatric facilities in Yamanashi Prefecture. The eligible cases were 595 cases that were diagnosed before the COVID-19 pandemic (from January 2015 through February 2020) and 38 cases that were diagnosed during the COVID-19 pandemic (from March through November 2020). Incidence of several infectious disease were evaluated using data from the Infectious Disease Weekly Report conducted by the National Institute of Infectious Diseases.

Results: Epidemics of various infectious diseases generally remained at low levels during the first 9 months (March through November 2020) of the COVID-19 pandemic. Moreover, the incidence of COVID-19 was 50–80 times lower than the incidence in European countries and the United States. The total number of 38 cases with Kawasaki disease for the 9 months during the COVID-19 pandemic was 46.3% (−3.5 standard deviations [SDs] of the average [82.0; SD, 12.7 cases] for the corresponding 9 months of the previous 5 years. None of the 38 cases was determined to be triggered by COVID-19 based on their medical histories and negative results of severe acute respiratory syndrome coronavirus 2 testing at admission.

Conclusion: These observations provide a new epidemiological evidence for the notion that Kawasaki disease is triggered by major infectious diseases in children.