Individual mean-variance relation and stock-level investor sentiment

This research studies the effect of stock-level investor sentiment on individual stock returns’ mean-variance relation. Using unique buy and sell volume data of retail investors in Korean stock market, we find that a positive mean-variance relation is undermined among high-sentiment stocks, but holds among low-sentiment stocks. We adopt buy-sell imbalances of retail investors for individual stocks as a measure of stock-level investor sentiment. Further, our findings provide empirical evidence of a strong riskreturn trade-off among stocks with low retail concentration (e.g., large capitalization, high-priced, and growth stocks). Existing research only analyzes market-wide investor sentiment. However, we study the effect of stock-level investor sentiment on individual stock returns. Therefore, our findings suggest novel implications about the investment strategy that the stock-level investor sentiment is important when constructing portfolios based on variance

Familial Correlation and Heritability of Hand Grip Strength in Korean Adults (Korea National Health and Nutrition Examination Survey 2014 to 2019)

Background The onset and progression of sarcopenia are highly variable among individuals owing to genetic and environmental factors. However, there are a limited number of studies measuring the heritability of muscle strength in large numbers of parent-adult offspring pairs. We aimed to investigate the familial correlation and heritability of hand grip strength (HGS) among Korean adults. Methods This family-based cohort study on data from the Korea National Health and Nutrition Examination Survey (2014 to 2019) included 5,004 Koreans aged ≥19 years from 1,527 families. HGS was measured using a digital grip strength dynamometer. Familial correlations of HGS were calculated in different pairs of relatives. Variance component methods were used to estimate heritability. Results The heritability estimate of HGS among Korean adults was 0.154 (standard error, 0.066). Correlation coefficient estimates for HGS between parent-offspring, sibling, and spouse pairs were significant at 0.07, 0.10, and 0.23 (p<0.001, p=0.041, and p<0.001, respectively). The total variance in the HGS phenotype was explained by additive genetic (15.4%), shared environmental (11.0%), and unique environmental (73.6%) influences. The odds of weak HGS significantly increased in the offspring of parents with weak HGS (odds ratio [OR], 1.69–3.10; p=0.027–0.038), especially in daughters (OR, 2.04–4.64; p=0.029–0.034). Conclusion HGS exhibits a familial correlation and significant heritable tendency in Korean adults. Therefore, Asian adults, especially women, who have parents with weak HGS, need to pay special attention to their muscle health with the help of healthy environmental stimuli

Non-Alcoholic Fatty Liver Disease with Sarcopenia and Carotid Plaque Progression Risk in Patients with Type 2 Diabetes Mellitus

Background We aimed to evaluate whether non-alcoholic fatty liver disease (NAFLD) with or without sarcopenia is associated with progression of carotid atherosclerosis in patients with type 2 diabetes mellitus (T2DM). Methods We investigated 852 T2DM patients who underwent abdominal ultrasonography, bioelectrical impedance analysis, and carotid artery ultrasonography at baseline and repeated carotid ultrasonography after 6 to 8 years. NAFLD was confirmed by abdominal ultrasonography, and sarcopenia was defined as a sex-specific skeletal muscle mass index (SMI) value <2 standard deviations below the mean for healthy young adults. SMI was calculated by dividing the sum of appendicular skeletal mass by body weight. We investigated the association between NAFLD with or without sarcopenia and the progression of carotid atherosclerosis. Results Of the 852 patients, 333 (39.1%) were classified as NAFLD without sarcopenia, 66 (7.7%) were classified as sarcopenia without NAFLD, and 123 (14.4%) had NAFLD with sarcopenia at baseline. After 6 to 8 years, patients with both NAFLD and sarcopenia had a higher risk of atherosclerosis progression (adjusted odds ratio, 2.20; P<0.009) than controls without NAFLD and sarcopenia. When a subgroup analysis was performed on only patients with NAFLD, female sex, absence of central obesity, and non-obesity were significant factors related to increased risk of plaque progression risk in sarcopenic patients. Conclusion NAFLD with sarcopenia was significantly associated with the progression of carotid atherosclerosis in T2DM patients

Socioeconomic inequalities in obesity among Korean women aged 19-79 years: the 2016 Korean Study of Women’s Health-Related Issues

OBJECTIVES While the prevalence of obesity in Asian women has remained stagnant, studies of socioeconomic inequalities in obesity among Asian women are scarce. This study aimed to examine the recent prevalence of obesity in Korean women aged between 19 years and 79 years and to analyze socioeconomic inequalities in obesity. METHODS Data were derived from the 2016 Korean Study of Women’s Health-Related Issues. The chi-square test and logistic regression analysis were used to analyze the associations between socioeconomic factors and obesity using Asian standard body mass index (BMI) categories: low (<18.5 kg/m2 ), normal (18.5-22.9 kg/m2 ), overweight (23.0-24.9 kg/m2 ), and obese (≥25.0 kg/ m2 ). As inequality-specific indicators, the slope index of inequality (SII) and relative index of inequality (RII) were calculated, with adjustment for age and self-reported health status. RESULTS Korean women were classified into the following BMI categories: underweight (5.3%), normal weight (59.1%), overweight (21.2%), and obese (14.4%). The SII and RII revealed substantial inequalities in obesity in favor of more urbanized women (SII, 4.5; RII, 1.4) and against of women who were highly educated (SII, -16.7; RII, 0.3). Subgroup analysis revealed inequalities in obesity according to household income among younger women and according to urbanization among women aged 65-79 years. CONCLUSIONS Clear educational inequalities in obesity existed in Korean women. Reverse inequalities in urbanization were also apparent in older women. Developing strategies to address the multiple observed inequalities in obesity among Korean women may prove essential for effectively reducing the burden of this disease

Site-Specific Difference of Bone Geometry Indices in Hypoparathyroid Patients

BackgroundHypoparathyroid patients often have a higher bone mineral density (BMD) than the general population. However, an increase in BMD does not necessarily correlate with a solid bone microstructure. This study aimed to evaluate the bone microstructure of hypoparathyroid patients by using hip structure analysis (HSA).MethodsNinety-five hypoparathyroid patients >20 years old were enrolled and 31 of them had eligible data for analyzing bone geometry parameters using HSA. And among the control data, we extracted sex-, age-, and body mass index-matched three control subjects to each patient. The BMD data were reviewed retrospectively and the bone geometry parameters of the patients were analyzed by HSA.ResultsThe mean Z-scores of hypoparathyroid patients at the lumbar spine, femoral neck, and total hip were above zero (0.63±1.17, 0.48±1.13, and 0.62±1.10, respectively). The differences in bone geometric parameters were site specific. At the femoral neck and intertrochanter, the cross-sectional area (CSA) and cortical thickness (C.th) were higher, whereas the buckling ratio (BR) was lower than in controls. However, those trends were opposite at the femoral shaft; that is, the CSA and C.th were low and the BR was high.ConclusionOur study shows the site-specific effects of hypoparathyroidism on the bone. Differences in bone components, marrow composition, or modeling based bone formation may explain these findings. However, further studies are warranted to investigate the mechanism, and its relation to fracture risk

Efficacy and safety of vitamin D3 B.O.N intramuscular injection in Korean adults with vitamin D deficiency

Objective: There has been no prospective study that examined intramuscular injection of high-dose vitamin D in Korean adults. The aim of this study was to assess the efficacy and safety of high-dose vitamin D3 after intramuscular injection in Korean adults with vitamin D deficiency. Method: This study was a 24-week, prospective, multicenter, randomized, double-blind, placebo-controlled trial. A total of 84 subjects ≥19 and <65 years of age were randomly allocated to either the vitamin D3 or placebo group in a 2:1 ratio. After randomization, a single injection of plain vitamin D3 200,000 IU or placebo was intramuscularly administered. If serum 25-hydroxyvitamin D (25[OH]D) concentrations were <30 ng/mL on week 12 or thereafter, a repeat injection was administered. Results: After a single intramuscular injection of vitamin D3 to adults with vitamin D deficiency, the proportion of subjects with serum 25(OH)D concentrations ≥30 ng/mL within 12 weeks was 46.4% in the vitamin D3 group and 3.6% in the placebo group (p < 0.0001). The proportion of subjects with serum 25(OH)D concentrations ≥30 ng/mL within 24 weeks was 73.2% in the vitamin D3 group and 3.6% in the placebo group (p < 0.0001). Mean change in serum 25(OH)D concentrations at weeks 12 and 24 after vitamin D3 injection was 12.8 ± 8.1 and 21.5 ± 8.1 ng/mL, respectively, in the vitamin D3 group, with no significant changes in the placebo group. Serum parathyroid hormone concentrations showed a significant decrease in the vitamin D3 group but no change in the placebo group. Conclusion: Intramuscular injection of vitamin D3 200,000 IU was superior to placebo in terms of its impact on serum 25(OH)D concentrations, and is considered to be safe and effective in Korean adults with vitamin D deficiency

Effects of Single Vitamin D Injection (200,000 Units) on Serum Fibroblast Growth Factor 23 and Sclerostin Levels in Subjects with Vitamin D Deficiency

BackgroundVitamin D deficiency remains common in all age groups and affects skeletal and non-skeletal health. Fibroblast growth factor 23 is a bone-derived hormone that regulates phosphate and 1,25-dihydroxyvitamin D homeostasis as a counter regulatory factor. 1,25-Dihydroxyvitamin D stimulates fibroblast growth factor 23 synthesis in bone, while fibroblast growth factor 23 suppresses 1,25-dihydroxyvitamin D production in the kidney. The aim of this study was to evaluate the effects of vitamin D3 intramuscular injection therapy on serum fibroblast growth factor 23 concentrations, and several other parameters associated with bone metabolism such as sclerostin, dickkopf-1, and parathyroid hormone.MethodsA total of 34 subjects with vitamin D deficiency (defined by serum 25-hydroxyvitamin D levels below 20 ng/mL) were randomly assigned to either the vitamin D injection group (200,000 units) or placebo treatment group. Serum calcium, phosphate, urine calcium/creatinine, serum 25-hydroxyvitamin D, fibroblast growth factor 23, sclerostin, parathyroid hormone, and dickkopf-1 levels were serially measured after treatment.ResultsComparing the vitamin D injection group with the placebo group, no significant changes were observed in serum fibroblast growth factor 23, parathyroid hormone, or dickkopf-1 levels. Serum sclerostin concentrations transiently increased at week 4 in the vitamin D group. However, these elevated levels declined later and there were no statistically significant differences as compared with baseline levels.ConclusionSerum fibroblast factor 23, sclerostin, parathyroid hormone, and dickkopf-1 levels were not affected significantly by single intramuscular injection of vitamin D3

Self-perceptions of body weight status according to age-groups among Korean women: A nationwide population-based survey.

While numerous studies have investigated body image, including body weight perception, most of which have focused on adolescents or young women, few studies have attempted to evaluate body weight perceptions in adult women according to age groups. This study was conducted to investigate the accuracy of self-perceived weight and actual body mass index (BMI) values among adult Korean women according to age. We used data from the 2016 Korean Study of Women's Health Related Issues, a population-based, nationwide, cross-sectional survey. BMI was calculated from self-reported weight and height. Participants were asked to describe their body image by choosing one of the following descriptions: very underweight, underweight, about right, overweight, or obese. The proportions of women aged 20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years who underestimated their body weight relative to their actual BMI category were 12.6%, 15.1%, 22.2%, 34.0%, 45.6%, and 50.7%, respectively; those who overestimated their body weight comprised 18.7%, 17.8%, 14.3%, 10.8%, and 7.4%. In all BMI categories, the proportion of those who overestimated their weight status increased as age decreased, while those who underestimated their weight status increased as age increased. After adjusting for possible covariates, age was strongly associated with both underestimation and overestimation. The odds ratio for underestimating one's weight status among women aged 70-79 yeas was 2.96 (95% CI: 2.10-4.18), and that for overestimation was 0.52 (95% CI: 0.35-0.79), compared to women aged 20-29 years. Age is the most important factor associated with weight perceptions among Korean women, affecting both underestimation and overestimation of weight status

Contingent association between the size of the social support network and osteoporosis among Korean elderly women.

ObjectiveTo investigate the association between the number of personal ties (or the size of the social support network) and the incidence of osteoporosis among older women in Korea.MethodsData from the Korean Urban Rural Elderly Study were used. Bone density was measured by dual-energy X-ray absorptiometry at the lumbar spine (L1-L4) and femur neck. T-score, the standardized bone density compared with what is normally expected in a healthy young adult, was measured and the presence of osteoporosis was determined, if the T-score was ResultsOf the 1,846 participants, 44.9% were diagnosed with osteoporosis. The association between the social support network size and the incidence of osteoporosis was curvilinear in both bivariate and multivariate analyses. Having more people in one's social support network size was associated with lower risk of osteoporosis until it reached around four. Increasing the social support network size beyond four, in contrast, was associated with a higher risk of osteoporosis. This association was contingent on the average intimacy level of the social network. At the highest average intimacy level ("extremely close"), increasing the number of social support network members from one to six was associated with linear decrease in the predicted probability of osteoporosis from 45% to 30%. However, at the lowest average intimacy level ("not very close"), the predicted probability of osteoporosis dramatically increased from 48% to 80% as the size of the social network increased from one to six.ConclusionOur results show that maintaining a large and intimate social support network is associated with a lower risk of osteoporosis among elderly Korean women, while a large but less-intimate social relationship is associated with a higher risk

Association between Metabolically Healthy Obesity and Subclinical Atherosclerosis in the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) Cohort

We aimed to investigate the association between a new definition of metabolic health (MH) and subclinical atherosclerosis in a cohort of patients without previous cardiovascular disease (CVD). In total, 7824 community-dwelling adults were categorized as normal weight, overweight, or obese. Metabolically healthy obesity (MHO) was defined as obesity accompanied by all of the following criteria: systolic blood pressure (BP) < 130 mmHg, no use of BP-lowering medication, waist-hip ratio <0.832 (women) and <0.887 (men), and no prevalent diabetes. Carotid atherosclerosis was defined as carotid plaque or mean carotid intima-media thickness ≥ 1.1 mm. The prevalence of carotid atherosclerosis was 8.3% and 1113 (14.2%) patients were classified as having MHO. All individuals classified as metabolically unhealthy were at an increased risk of carotid atherosclerosis independent of body mass index categories. Conversely, the risk of carotid atherosclerosis in individuals with MHO was not significantly increased compared to that in metabolically healthy normal weight participants (hazard ratio 1.20, 95% confidence interval 0.87–1.67). This new definition of MH was able to identify people with MHO without an increased risk of CVD in an Asian community cohort