Sex differences in the association between sleep duration and frailty in older adults: evidence from the KNHANES study.

BACKGROUND: Frailty is a pervasive clinical syndrome among the older population. It is associated with an increased risk of diverse adverse health outcomes including death. The association between sleep duration and frailty remains unclear. Therefore, the aim of this study was to investigate the relationship between sleep duration and frailty in community-dwelling Korean older adults and to determine whether this relationship is sex-dependent. METHODS: Data on 3,953 older adults aged ≥ 65 years were obtained from the 7th (2016-2018) Korea National Health and Nutrition Examination Survey (KNHANES). Frailty was defined using the Fried phenotype with criteria customized for the KNHANES dataset. Self-reported sleep duration was classified as short sleep duration (≤ 6 h), middle sleep duration (6.1-8.9 h), and long sleep duration (≥ 9 h). Complex samples multivariate logistic regression analysis was conducted to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The percentage of male participants with short, middle, and long sleep durations was 34.9%, 62.1%, and 16.8%, respectively, while that of female participants was 26.1%, 59.2%, and 14.7%. The prevalence of frailty in the middle sleep duration group was lower than that in the short and long sleep duration groups in both men (short, 14.7%; middle, 14.2%; long, 24.5%; p < 0.001) and women (short, 42.9%; middle, 27.6%; long, 48.6%; p < 0.001). Both short (OR = 2.61, 95% CI = 1.91 - 4.83) and long (OR = 2.57, 95% CI = 1.36 - 3.88) sleep duration groups had a significantly higher OR for frailty than the middle sleep duration group even after adjusting for confounding variables among women, but not among men. CONCLUSION: Short and long sleep durations were independently associated with frailty in community-dwelling Korean older adult women. Managing sleep problems among women should be prioritized, and effective interventions to prevent frailty should be developed accordingly.

Successful Aging of Korean Older Adults Engaging in Sports Regularly: Health Beliefs, Exercise Adherence Intention, and Health Promotion Behavior.

The population of older adults is increasing more rapidly in Korea than in any other country, making successful aging a salient need in Korean society. For successful aging, older adults must engage in sports activities regularly. This study determined the relationships among health beliefs, exercise adherence intention, health promotion behavior, and successful aging among older adults who engage in sports activities regularly. The participants were 287 adults aged 65 years or older who live in Korea and exercise regularly. Data were collected through a survey and analyzed using descriptive statistics, correlation analysis, and structural equation modeling. The integrated model lacked explanatory power in terms of goodness of fit, but the alternative model had sufficient explanatory power. The alternative model showed that health beliefs, exercise adherence intention, and health promotion behavior are significantly related and that health promotion behavior positively predicts successful aging. It also showed that health beliefs affect successful aging through the mediation of exercise adherence intention and health promotion behavior. This study is meaningful because it verifies the structural and theoretical relationships among health beliefs, exercise adherence intention, health promotion behavior, and successful aging. As a result, it provides information that can improve the welfare of older adults in Korean society.

Differences in Effort, Reward, Grit, Burnout, and Continuous Exercise Intention: Assessing the Effort-Reward Imbalance among Korean Athletes.

Although studies have shown that an imbalance between effort and reward in the workplace negatively affects an individual's physiological and mental health, few have looked at how this imbalance may affect the mental state of athletes. Therefore, this study aimed to evaluate the importance of the effort-reward imbalance (ERI) in athletes by examining whether psychological variables would differ depending on the ERI. To accomplish this, 795 registered collegiate athletes were recruited. Of them, 227 and 230 responses with the ERI in the bottom and in the top 30% of the ERI scale were selected to compare groups with a high and a low ERI. Athletes completed a self-reported 64-item questionnaire (general characteristics: 5; effort: 14; rewards: 14; grit: 12; burnout: 15; and continuous exercise intention: 4 items). Data analysis included reliability and validity using the Jamovi and SPSS/AMOS software. The results showed no significant differences in effort, reward, grit, burnout, and intention to continue to exercise based on gender, weekly training frequency, and hours of training per day. There were differences in effort, reward, grit, burnout, and intention to continue exercising based on the presence of a professional league. Additionally, differences were found in effort, reward, grit, burnout, and intention to continue exercising between the low and high ERI groups. There was a clear difference between the mental state of those who were satisfied with their effort and reward, and those who were not. However, given that the two groups spent approximately the same amount of time exercising each week, the difference may have been more a function of the psychology of athletes than an actual difference in effort and reward. As our findings confirmed that the level of the ERI in athletes is related to their mental state, further research is necessary to identify and control factors that affect the ERI in athletes.

Health Behaviors of Cancer Survivors According to the Employment Status and Occupation: A Cross-Sectional Study.

This study aimed to identify differences in health behaviors according to the employment status and occupation of cancer survivors, as well as to identify risk factors. Using data from the Korea National and Health Nutrition Examination Survey (2008-2018), 1023 cancer survivors aged 19-60 years were classified based on their employment status and occupation, and their health behaviors were comparatively assessed. To investigate the impact of occupational status on the health behaviors of cancer survivors, we performed multivariate adjusted logistic regression analysis. Five hundred fifty-six (54.3%) cancer survivors were engaged in economic activities. After adjusting for various factors, white- and blue-collar workers exhibited an increased risk of obesity. The blue-collar group had a 1.45 times higher risk of non-practice with cancer screening, while the white-collar group had a 0.50 times lower risk of non-practice with health screening. The results provide evidence of the need to support cancer survivors in practicing healthy behaviors according to their employment status and occupation. As cancer survivors' economic activities increase, it is necessary to help them manage their health by predicting any possible health-behavior failures.

Association between Perceived Psychological Stress and Exercise Behaviors: A Cross-Sectional Study Using the Survey of National Physical Fitness.

BACKGROUND: Perceived psychological stress and exercise are bidirectionally related, and the effects of exercise on stress relief are well documented. However, research on the influence of stress on exercise remains scarce. This study examined the association between perceived psychological stress and exercise participation among Korean adults and older adults as well as the relationship between exercise frequency and perceived stress. METHODS: Data on 3440 participants (2813 adults aged 19-64 and 627 older adults aged 65 or more) were collected from the Survey of National Physical Fitness conducted by the Korea Institute of Sport Science and the Korean Ministry of Culture, Sports and Tourism in 2015. We compared the participants' health-related behaviors, including exercise, regular breakfast consumption, and smoking, according to their perceived psychological stress levels. RESULTS: Those who perceived a higher level of psychological stress reported lower levels of exercise participation, regular breakfast consumption, and smoking, with the exception of older male participants. The study also found that a higher frequency of exercise participation corresponded with a lower perceived level of psychological stress (ß = -0.080, p < 0.001) and that engaging in physical activity even once a week yields a substantial reduction in stress levels. CONCLUSIONS: In a large sample of Koreans, high levels of perceived psychological stress were significantly associated with less physical activity and infrequent weekly exercise. This study found a dose-response relationship between exercise frequency and reduced stress and suggested that psychological stress should be considered crucial in promoting physical activity.

Relationship between Perceived Stress, Obesity, and Hypertension in Korean Adults and Older Adults.

BACKGROUND: Perceived stress has a significant effect on metabolic diseases, including obesity and hypertension. However, the association between stress levels, obesity, and hypertension according to age and sex is not fully understood. Therefore, this study investigated the relationship between stress levels and obesity and hypertension in Korean adults and older adults. METHODS: We analyzed data from the 2015 survey of the Korea National Physical Fitness Project conducted by the Korea Institute of Sports Science and the Korea Ministry of Culture, Sports, and Tourism. Of the 3457 participants, 2829 were adults (20-64 years old) and 628 were older adults (≥65 years old). The correlation between obesity and hypertension according to the degree of perceived stress (low, medium, and high) was analyzed using the chi-square test. Binary logistic regression analysis was used to investigate the influence of perceived stress levels on obesity and hypertension. Age, body mass index (BMI), blood pressure, exercise frequency, smoking, breakfast, and sleeping hours were included as covariates. RESULTS: In adult males, perceived stress levels, age, and diastolic blood pressure were found to have a significant impact on obesity rates, whereas age and breakfast had a significant effect on hypertension rates. In adult females, age and systolic blood pressure were found to significantly influence obesity rates, whereas age, BMI, and exercise frequency had a significant impact on hypertension rates. In older adult females, perceived stress levels and systolic blood pressure were found to significantly impact obesity rates, and sleep duration influenced the rates of hypertension. The effect of perceived stress level on obesity and hypertension rates was less pronounced in the elderly population than in the adult population. CONCLUSIONS: This study revealed age and sex differences in the relationship between perceived stress, obesity, and hypertension among Koreans. These findings contribute to a better understanding of the complex relationship between perceived stress and metabolic disorders and emphasize the need for a deeper understanding of the specific factors involved in the prevention and management of metabolic diseases.

Mediating Effect of Sports Safety Awareness between Sports Activity Habits and the Intention to Complete Safety Education among Korean Adolescents.

BACKGROUND: As the importance of safety during sports activities continues to gain emphasis socially, the interest in creating a culture of safety and safety education to support this is also increasing. However, no study has examined the willingness of adolescents to complete safety education voluntarily. To identify methods of building a culture of sports safety among adolescents, this study investigated the structural relationship among three related variables: sports activity habits, intention to complete safety education, and sports safety awareness of Korean adolescents. METHODS: Data on 3928 adolescents aged 13-18 years old from the 2019 Sports Safety Accident Survey conducted by the Korea Sports Safety Foundation were analyzed. This encompassed frequency analysis, scale reliability, validity verification, descriptive statistics analysis, path analysis, and mediating effect verification. RESULTS: The results indicated that sports activity habits among these adolescents had a positive effect on their sports safety awareness and on their intention to complete safety education; further, their sports safety awareness had a positive effect on their intention to complete safety education. The results also showed that sports safety awareness had a partial mediating effect between sports activity habits and intention to complete safety education. The willingness of adolescents to voluntarily complete safety education is particularly important, as adolescence is a critical period when lifelong safety habits can be formed. CONCLUSIONS: Based on the results, discussions on creating safe sports activity habits for adolescents and continuous education on sports safety awareness are needed. Ultimately, we need to improve sports safety awareness by paying attention to the development and implementation of sports safety education programs for adolescents as a national policy and, through this, increase their willingness to complete safety education.

Effects of Taekwondo Training on Growth Factors in Normal Korean Children and Adolescents: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

The growth of children and adolescents is both an important health indicator and a major public health issue. Many recent studies have investigated the effects of taekwondo on growth factors, but no consensus has yet been reached. This meta-analysis aimed to determine the effects of taekwondo on the growth factors in children and adolescents (aged 8 to 16 years). Randomized controlled trials from PubMed, Web of Science, Cochrane Library, the Research Information Sharing Service, the Korea Citation Index, and the Korean-studies Information Service System were analyzed. The effect sizes (standardized mean differences, SMD) were calculated, the risk of bias and publication bias were assessed, and the effect size and subgroup analyses were pooled. We found that the taekwondo group had significantly higher levels of growth hormones (SMD 1.78, 95% confidence interval [CI] 0.98-2.58, and p < 0.001) and insulin-like growth factors (SMD 1.76, 95% CI 0.60-2.92, and p < 0.001) than the control group. For height, a medium effect size was observed (SMD 0.62, 95% CI -0.56-1.80, and p = 0.300), but the between-group difference was not significant. Thus, taekwondo had significant positive effects on the secretion of growth hormones and insulin-like growth factors in Korean children and adolescents. A longitudinal follow-up is necessary to determine the effect on height. This suggests that taekwondo can be recommended as an appropriate physical exercise for maintaining normal growth in children and adolescents.

Using the Health Belief Model to Assess the Physical Exercise Behaviors of International Students in South Korea during the Pandemic.

International students have the special status of being isolated in a foreign country during a pandemic. As Korea is a worldwide leader in education, it is important to understand the physical exercise behaviors of international students during this pandemic to assess the need for additional policies and support. The health belief model was used to score the physical exercise motivation and behaviors of international students in South Korea during the COVID-19 pandemic. In total, 315 valid questionnaires were obtained and analyzed for this study. The reliability and validity of the data were also assessed. For all variables, the values for combined reliability and the Cronbach's α were higher than 0.70. The following conclusions were drawn by comparing the differences between the measures. The results of the Kaiser-Meyer-Olkin and Bartlett tests were also higher than 0.70, confirming high reliability and validity. This study found a correlation between the health beliefs of international students and age, education, and accommodation. Consequently, international students with lower health belief scores should be encouraged to pay more attention to their personal health, participate in more physical exercise, strengthen their motivation to participate in physical exercise, and increase the frequency of their participation.

Effects of Nonpharmacological Interventions on Sleep Quality and Insomnia in Perimenopausal and Postmenopausal Women: A Meta-Analysis.

This study aimed to analyze the effects of nonpharmacological interventions on perimenopausal and postmenopausal women with sleep problems. Eight databases (MEDLINE/PubMed, Cochrane Library, EMBASE, CINAHL, and four Korean databases) were searched, from their inception through to 30 November 2021, for randomized controlled trials (RCTs) evaluating the effects of nonpharmacological interventions versus control conditions on sleep quality and insomnia in perimenopausal and postmenopausal women. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), and the severity of insomnia was assessed using the Insomnia Severity Index (ISI). In the meta-analysis, corrected standardized mean differences (SMDs; Hedges' g) and 95% confidence intervals (CIs) were calculated as effect measures by applying the random effects model and inverse variant method. Fifteen trials met our inclusion criteria. Nonpharmacological interventions were found to have positive effects on sleep quality, measured with the PSQI (SMD = -1.32; 95% CI = -1.78 to -0.86; p < 0.001), and on the severity of insomnia, measured using the ISI (SMD = -1.11; 95% CI = -1.82 to -0.41; p = 0.002), compared with the control groups. Among perimenopausal and postmenopausal women with sleep problems, nonpharmacological interventions improved sleep quality and reduced the severity of insomnia.

Effects of a Post-Traumatic Growth Program on Young Korean Breast Cancer Survivors.

Background: This study aimed to enhance post-traumatic growth in young breast cancer patients by providing them with self-disclosure and social support resources, to reduce intrusive rumination and increase deliberate rumination. This study was conducted at a university-based cancer center in Seoul, South Korea. The study included a four-week group-based psychoeducational program, which supported the post-traumatic personal growth of breast cancer patients. The primary outcome was increased post-traumatic growth, and the secondary outcomes were rumination, distress, and traumatic perception. Methods: The study included 38 young breast cancer patients, with a mean age of 42.21 years and mean time since diagnosis of 13.84 months. Results: Results of the study revealed statistically significant improvements in total post-traumatic growth and all subdomains, after the intervention (p < 0.001) and one month later (p < 0.001), as compared to the baseline. A significant improvement was also observed in deliberate rumination after the intervention (p = 0.038). Furthermore, the patients had a statistically significant decrease in anxiety, after the intervention (p = 0.035) and one month later (p = 0.005), as compared to the baseline. Conclusions: Overall, the program encourages activities that promote post-traumatic growth, enabling young breast cancer patients to return to their normal lives. Specifically, the growth allows patients to return to work and maintain a healthy body and mind. The results of this study indicate that this program can be used as an effective psychological intervention for young breast cancer patients.

Analysis of Fall Events, Physical Fitness, and Gait Speed According to Fall Risk in Older Korean Women.

The present study aimed to investigate the associations between fall risk and previous fall events, physical fitness, and gait speeds on flat ground and during obstacle avoidance in older adult women in Korea. Data were analyzed for 148 women over 65 years of age, divided into low (n = 52) and high Berg Balance Scale (BBS) score groups (n = 96). Physical fitness was assessed using arm curl, chair stand, 2 min step, chair sit-and-reach, timed up-and-go, and single-leg stance tests. Gait speed was measured on flat ground and during obstacle avoidance (5 cm, 10% of height, 30 cm). The incidence of falls was 18.2% lower among participants with BBS scores above the mean than in those with scores below the mean (p < 0.05). Furthermore, the two groups exhibited significant differences in the chair stand, chair sit-and-reach, timed up-and-go, and single-leg stance test results. The upper BBS group appeared faster at all four gait speeds, and participants in the upper BBS group were less likely to exhibit lower physical fitness in each test, with odds ratios (ORs) ranging from 0.227 to 0.447. The upper BBS group was also less likely to exhibit lower gait speed in most conditions, with ORs ranging from 0.327 to 0.516. Further studies should consider exercise programs that promote balance, muscular strength, and proprioception to lower the risk of falling in older adults.

The Effects of 24 Weeks of Non-Face-to-Face Home Exercise on Body Composition, Physical Fitness, Cardiovascular Function, and Blood Profiles in Pre-Metabolic Syndrome Korean Adults: A Pilot Study.

Background: This study assessed Korean residents' health improvements by reducing chronic disease morbidity through customized health management. After identifying each participant's strength and health through physical examinations and blood pressure tests, the effects of 24 weeks of online, non-face-to-face home workouts on body composition, physical fitness, cardiovascular function, and blood profiles in Korean adults with pre-metabolic syndrome were determined. Methods: Adults living in Chungcheongbuk-do, aged 19−65, and at the pre-metabolic syndrome stage were recruited at the Jeungpyeong-gun Public Health Center, Chungcheongbuk-do, Korea. For 24 weeks, from February 2022 to July 2022, they exercised for 60−70 min, three times a week, on average, at a maximum heart rate of 60−70%. The "Mobile Healthcare" application was used to record exercise time, number of exercises, number of sets, and Rating of Perceived Exertion at the end of each exercise. Body composition, physical fitness, cardiovascular function, and blood profiles were measured before and after participation. Results: There were no significant differences in weight, body mass index, body fat, waist-to-hip ratio, waist circumference, systolic blood pressure, diastolic blood pressure, resting heart rate levels, or glucose levels after participation in the workout (p > 0.05). However, muscle strength/handgrip strength, sitting-rising test results, single-leg balance, triglycerides, high-density lipoprotein, low-density lipoprotein, and total cholesterol showed a statistically significant difference (p < 0.05). Conclusions: Although the 24 weeks of non-face-to-face home workouts did not positively affect body composition or cardiovascular function, it improved physical fitness and dyslipidemia.

The Mediating Effects of Social Support on the Relationship between Uncertainty and Quality of Life among Patients with Chronic Low Back Pain: A Cross-Sectional Survey.

Background: This study aimed to investigate the mediating effects of social support on the relationship between uncertainty and quality of life (QOL) in patients with chronic low back pain (LBP). Methods: From 1 July 2019 to 25 March 2020, data were collected using a structured questionnaire from inpatients and outpatients > 20 years of age with chronic LBP lasting > 3 months. Inpatients included patients waiting for surgery and those recovering after surgery. The exclusion criteria were cancer and other serious pathological diseases. The relationships between uncertainty, social support, and QOL were analyzed using Pearson's correlation coefficients. Results: Uncertainty, the independent variable, exerted a significant effect on social support, the mediator (B = 0.33, p < 0.001). In addition, both uncertainty (B = 0.37, p < 0.001) and social support (B = 0.45, p < 0.001) exerted statistically significant effects on QOL, the dependent variable. Conclusions: Disease-related uncertainty can reduce QOL in patients with chronic LBP, and this relationship is mediated by the level of social support. To develop strategies for strengthening social support from healthcare providers, family, and friends, future studies should examine the experiences of patients with chronic LBP from various perspectives, including pain intensity and duration.

Association between Blood Vitamin D Levels and Regular Physical Activity in Korean Adolescents.

This study aimed to investigate the relationship between vitamin D levels and physical activity in adolescents using data from the Korea National Health and Nutrition Survey (KNHANES). The serum vitamin D concentrations were measured between 2008 and 2014 and analyzed. Adolescents aged 13 to 18 years comprised 4527 of the 61,370 participants surveyed. A final dataset including 2811 adolescents was obtained after those with missing data were excluded. Those who did not participate or only participated in 1−3 days of intense physical activity (p < 0.001), moderate physical activity (p = 0.002), and muscular exercise (weight training) (p < 0.001) showed a higher level of vitamin D deficiency than those who performed the same activities 4−7 days per week. Our results showed that most of the adolescents (76%) were vitamin D-deficient, and the risk was higher among high school than middle school students (odds ratio (OR) = 1.70, 95% confidence interval (CI) = 1.40−2.06; p < 0.001) and higher in girls than boys (OR = 1.43, 95% CI = 1.18−1.72; p < 0.001). Reduced participation in physical activity was correlated with vitamin D deficiency. Furthermore, vitamin D deficiency was associated with a lower frequency of participation in all forms of physical activity, and the association increased significantly with an increase in body mass index.

Factor Structure of the Korean Version of the Occupational Socialization of Beginning Physical Education Teachers Scale in the Context of the COVID-19 Pandemic and Its Relationship with Health Perception Education.

This study aimed to explore the factor structure of the Korean version of the occupational socialization of beginning physical education teachers scale, in the context of the COVID-19 pandemic, and to verify its relationship with health perception education. In October 2021, 257 Korean beginning physical education teachers were enrolled in this study. Data were analyzed using frequency analysis, exploratory factor analysis, confirmatory factor analysis, descriptive statistics, reliability analysis, and multiple regression analysis. Regarding the findings, first, the occupational socialization of beginning physical education teachers scale showed a six-factor structure: role recognition, past physical education class experience, pre-service teacher education, organizational atmosphere, fellow physical education teachers, and sports facility. Second, occupational socialization of beginning physical education teachers showed a partial positive effect on health perception education. These results suggest that the Korean Metropolitan and Provincial Offices of Education and Korean schools should develop various methods to support and ensure the occupational socialization of beginning physical education teachers. Such efforts may enable these new professionals to effectively adapt to their schools, teaching roles, and provide effective health education to students under the difficult context of the COVID-19 pandemic, wherein normal educational activities are hindered.