Hyunrim Choi

Association between Bone Mineral Density and Sleep Duration in the Korean Elderly Population.

Background An association between sleep duration and a wide spectrum of diseases has been reported, but little is known about its relationship with bone mineral density (BMD). Previously conducted studies in Korea and abroad have reported results that are controversial. The present study sought to assess whether sleep duration can be considered an independent risk factor of osteoporosis. Methods We included participants over the age of 60 years with data on self-reported habitual sleep duration and BMD measured with dual X-ray absorptiometry. Comprehensive data on the study sample was obtained from the Korea National Health and Nutritional Survey performed from 2008 to 2010. Sex-stratified multiple regression analyses were conducted with adjustments for possible confounding factors. Results There was a significant inverse dose-dependent association between sleep duration and BMD measured at total hip, femur neck, and lumbar spine for women and total hip and femur neck for men. Sex-stratified regression analyses adjusted for age and body mass index revealed that sleep duration had a negative correlation with BMD at total hip and femoral neck for both women (β = -0.0048; P = 0.0172 for total hip, β = -0.0037; P = 0.0303 for femur neck) and men (β = -0.0057; P = 0.0218 for total hip, β = -0.0057; P = 0.0143 for femur neck). For women, the significance remained after further adjustment of confounding variables. Conclusion Prolonged sleep duration appears to have a significant association with lower total hip and femur neck BMD in elderly women but not in elderly men.

The Relationship between Prevalence of Osteoporosis and Proportion of Daily Protein Intake

Background The association between daily protein intake and osteoporosis is still controversial and only a few studies have explored the issue in Korea. This study investigated the relationship between daily protein intake and the prevalence of osteoporosis in Korean adults. Methods This study analyzed data extracted from the Korean National Health and Nutrition Examination Survey 4. Participants were aged 19 years or older and had never been treated for osteoporosis. The percentage of calories coming from protein intake was assessed by 24-hour recall method, and participants were divided into three groups according to recommended daily dietary protein intake as a proportion of total daily calories (i.e., <10%, 10%-20%, and >20%). A lumbar or femur neck bone mineral density T-score less than -2.5 was indicative of the presence osteoporosis. The influence of daily protein intake on the prevalence of osteoporosis was analyzed. Results In both sexes, the group with the highest protein intake had significantly lower odds of developing lumber osteoporosis when compared to the group with the lowest protein intake, after adjusting for associated factors (females: odds ratio [OR], 0.618; 95% confidence interval [CI], 0.610 to 0.626; P for trend <0.001; males: OR, 0.695; 95% CI, 0.685 to 0.705; P for trend <0.001). Conclusion Sufficient daily protein intake lowered the prevalence of osteoporosis in Korean adults. Further prospective studies are necessary to verify the preventive effect of adequate protein intake on osteoporosis.

Optimal Cutoff Points of Anthropometric Parameters to Identify High Coronary Heart Disease Risk in Korean Adults

Several published studies have reported the need to change the cutoff points of anthropometric indices for obesity. We therefore conducted a cross-sectional study to estimate anthropometric cutoff points predicting high coronary heart disease (CHD) risk in Korean adults. We analyzed the Korean National Health and Nutrition Examination Survey data from 2007 to 2010. A total of 21,399 subjects aged 20 to 79 yr were included in this study (9,204 men and 12,195 women). We calculated the 10-yr Framingham coronary heart disease risk score for all individuals. We then estimated receiver-operating characteristic (ROC) curves for body mass index (BMI), waist circumference, and waist-to-height ratio to predict a 10-yr CHD risk of 20% or more. For sensitivity analysis, we conducted the same analysis for a 10-yr CHD risk of 10% or more. For a CHD risk of 20% or more, the area under the curve of waist-to-height ratio was the highest, followed by waist circumference and BMI. The optimal cutoff points in men and women were 22.7 kg/m2 and 23.3 kg/m2 for BMI, 83.2 cm and 79.7 cm for waist circumference, and 0.50 and 0.52 for waist-to-height ratio, respectively. In sensitivity analysis, the results were the same as those reported above except for BMI in women. Our results support the re-classification of anthropometric indices and suggest the clinical use of waist-to-height ratio as a marker for obesity in Korean adults.

Health-related Quality of Life and Related Factors in Full-time and Part-time Workers.

Background There has been a rapid increase in the number of part-time workers in Korea with little information available on associated changes in quality of life. This study was designed to compare part-time and full-time workers in terms of the quality of life and related factors. Methods Data were extracted from the 4th Korea National Health and Nutrition Examination Survey, conducted in 2008. Of the 1,284 participants selected, 942 were females (range, 20 to 64 years). Based on the information provided by self-administered questionnaire, subjects were categorized according to the working pattern (full-time and part-time) and working hours (<30 and ≥30 hours). Differences in socio-demographic characteristics, health-related behaviors, and job characteristics were assessed by t-test and chi-square test. EuroQol-five dimensions (EQ-5D) index was implemented in order to measure the quality of life. Differences in the EQ-5D index scores between the groups were compared by t-test, stepwise multivariate logistic regression analyses. Results Quality of life did not differ by work patterns. In males, the Organization for Economic Cooperation and Development part-time group was associated with poorer quality of life (odds ratio [OR], 0.49; P = 0.028). For both sexes, the non-stress group was linked with superior quality of life in comparison to the stress group (OR, 2.64; P = 0.002; OR, 2.17; P < 0.001). Female employees engaged in non-manual labor had superior quality of life than those engaged in manual labor (OR, 1.40; P = 0.027). Conclusion This study concludes that working less than 30 hours per week is related to lower quality of life in comparison to working 30 hours or more in male employees in Korea.

Body Mass Index and Mortality according to Gender in a Community-Dwelling Elderly Population: The 3-Year Follow-up Findings from the Living Profiles of Older People Surveys in Korea

Background Body mass index is widely regarded as an important predictor of mortality. The purpose of this study was to investigate the relationship between body mass index and mortality and to compare community-dwelling elderly people in South Korea according to sex. Methods Data were collected from the 2008 and 2011 Living Profiles of Older People Surveys, which comprised 10,613 community-living South Korean men and women aged 65 years or older. The participants were stratified into five groups according to body mass index as defined by the World Health Organization guidelines. The sociodemographic characteristics of participants and mortality rates were compared across the body mass index groups. Results The highest survival rates were observed in men with a body mass index of 25.0–29.9 kg/m2. A similar trend was observed in women, but it was not statistically significant. After adjusting for covariates, this association was also found in men across all BMI index groups, but not in women. Conclusion This study supports previous findings that overweight or mild obesity is associated with the lowest mortality and suggests that the current categories of obesity require revision. Furthermore, the absence of statistically significant findings in the female cohort suggests that body mass index is not a suitable predictor of mortality in women and that an alternative is required.

Health Behavior and Factors Associated with Depression in North Korean Adolescent Defectors in South Korea: The Korea Youth Risk Behavior Web-Based Survey, 2011–2014

Background The number of North Korean adolescent defectors entering South Korea has been increasing. The health behavior, including mental health-related behavior, and factors associated with depression in North Korean adolescent defectors residing in South Korea were investigated. Methods Data obtained from the Korea Youth Risk Behavior Web-Based Survey (2011–2014) dataset were utilized. In total, 206 North Korean adolescent defectors were selected, and for the control group, 618 matched South Korean adolescents were selected. Frequency analysis was used to determine the place of birth and nationality of the parents, chi-square tests were used to compare the general characteristics of the North and South Korean subjects, and multivariate logistic regressions were conducted to compare the health behavior of the two sets of subjects. To determine the factors associated with depression in the North Korean subjects, a logistic regression was performed. Results The North Korean adolescents reported higher current smoking (adjusted odds ratio [aOR], 2.54; 95% confidence interval [CI], 1.48 to 4.35), current drinking (aOR, 1.85; 95% CI, 1.15 to 2.99), and drug use rates (aOR, 10.99; 95% CI, 4.04 to 29.88) than did the South Korean adolescents. The factors associated with depression in the North Korean adolescents were current smoking (aOR, 6.99; 95% CI, 1.62 to 30.06), lifetime drinking experience (aOR, 5.32; 95% CI, 1.51 to 18.75), and perceived stress (aOR, 4.74; 95% CI, 1.74 to 12.90). Conclusion There were differences in health behavior between the North and South Korean adolescents. A specialized approach for North Korean adolescent defectors is required to promote proper health behavior and adaptation to South Korean society.