Jeong-Soo Im

Prevalence of osteoporosis and reference data for lumbar spine and hip bone mineral density in a Korean population

The aims of this study were to establish reference data for bone mineral density (BMD) at central skeletal sites using Lunar dual-energy X-ray absorptiometry (DXA), and to estimate the age-and sex-specific prevalence of osteoporosis in a Korean population. We performed a population-based, cross-sectional study. The subjects were 4148 (1810 men and 2338 women) Korean adults, aged 20–79 years. The BMD for central sites (lumbar spine, femoral neck, trochanter, and Ward’s triangle) were measured by DXA. The standardized prevalence of osteoporosis among individual aged 50–79 years in lumbar spine, femoral neck, Ward’s triangle, and trochanter was 40.1%, 12.4%, 28.4%, and 4.4% in women and 6.5%, 5.9%, 3.7%, and 1.6% in men, respectively. In women, peak BMD occurred in the age range 40–49 years for the femoral neck and trochanter, 30–39 years for the lumbar spine, and 20–29 years for Ward’s triangle. In men, peak BMD values were observed at 20–29 years for all measured sites. This study establishes a normative database for BMD at central skeletal sites using dualenergy X-ray absorptiometry and provides more reliable information on the prevalence of osteoporosis in Korea.

Pharmacokinetics of hydroxychloroquine and its clinical implications in chemoprophylaxis against malaria caused by Plasmodium vivax.

ABSTRACT Hydroxychloroquine (HCQ) is an antimalarial drug used as chemoprophylaxis against malaria caused by Plasmodium vivax in the Republic of Korea Army (ROKA). In this study, we evaluated the pharmacokinetics (PK) of HCQ and its metabolites and the relationship between the PK of HCQ and the effect of treatment of HCQ on vivax malaria in South Koreans. Three PK studies of HCQ were conducted with 91 healthy subjects and patients with vivax malaria. Plasma concentrations were analyzed by noncompartmental and mixed-effect modeling approaches. A two-compartment model with first-order absorption best described the data. The clearance and the central and peripheral volumes of distribution were 15.5 liters/h, 733 liters, and 1,630 liters, respectively. We measured the plasma concentrations of HCQ in patients with prophylactic failure of HCQ and compared them with the prediction intervals of the simulated concentrations for HCQ from the final PK model built in this study. In 71% of the patients with prophylactic failure, the plasma concentrations of HCQ were below the lower bounds of the 95% prediction interval, while only 8% of them showed higher levels than the upper bounds of the 95% prediction interval. We report that a significant cause of prophylactic failure among the individuals in ROKA was ascribed to plasma concentrations of HCQ lower than those predicted by the PK model. However, prophylactic failure despite sufficient plasma concentrations of HCQ was confirmed in several individuals, warranting continued surveillance to monitor changes in the HCQ susceptibility of Plasmodium vivax in the Republic of Korea.

Geographical and temporal variations in the prevalence of mental disorders in suicide: Systematic review and meta-analysis

BACKGROUND In contrast to the previous studies reporting that most suicides occur among people with mental disorders, recent studies have reported various rates of mental disorders in suicide in different geographical regions. We aimed to comprehensively investigate the factors influencing the variation in the prevalence of mental disorders reported among suicide victims. METHOD The authors searched Embase, Medline, Web of Science, and the Cochrane Library to identify psychological autopsy studies reporting the prevalence of any mental disorders among suicide victims. A meta-regression analysis was conducted to identify the potential effects of geographical regions, the year of publication, measurements of personality disorder, measurements of comorbidity, and the ratio of females on the prevalence of mental disorders in addition to examining the heterogeneity across studies. RESULTS From 4475 potentially relevant studies, 48 studies met eligibility criteria, with 6626 suicide victims. The studies from East Asia had a significantly lower mean prevalence (69.6% [95% CI=56.8 to 80.0]) than those in North America (88.2% [95% CI=79.7-93.5]) and South Asia (90.4% [95% CI=71.8-97.2]). The prevalence of any mental disorder decreased according to the year of publication (coefficients=-0.0715, p<0.001). LIMITATIONS Substantial heterogeneities were identified within all subgroup analyses. CONCLUSIONS The prevalence of mental disorders among suicide cases seemed relatively low in the East Asia region, and recently published studies tended to report a lower prevalence of mental disorders. The link between the risk factors and suicide in the absence of a mental disorder should be examined in different geographical and sociocultural contexts.

Objectively measured sedentary behavior and moderate-to-vigorous physical activity on the health-related quality of life in US adults: The National Health and Nutrition Examination Survey 2003–2006

BackgroundHealth-related quality of life (HRQOL) represents an individual’s perception of physical, mental, and social well-being and is a strong predictor of health status. Few studies have examined associations of sedentary behavior (SB) and moderate-to-vigorous physical activity (MVPA) with HRQOL in the general population.PurposeThis study aimed to determine combined associations of objectively measured SB and MVPA on the risk of poor HRQOL in the general US population, after controlling for potential confounding factors.MethodsWe analyzed data from 5359 adults from the National Health and Nutrition Examination Survey 2003–2006. HRQOL was measured using a HRQOL-4 consisting of four questions focused on the self-perception of general health, physical health, mental health, and activity limitation. We dichotomized each HRQOL-4 component as good versus poor and defined poor overall HRQOL when participants had any poor HRQOL components. SB and MVPA were measured using an accelerometer. Survey logistic models were examined to estimate the odds ratio (OR) and 95% confidence interval (CI) for poor HRQOL by SB and MVPA as tertiles.ResultsWhen examined as a combination of SB and MVPA, a substantial decrease in the risk of poor overall HRQOL was found in individuals with low SB/high MVPA [OR 0.69 (95% CI 0.51–0.94) and moderate SB/high MVPA (OR 0.56 (95% CI 0.40–0.78)], but no significant decrease was found in individuals with high SB/high MVPA (vs. high SB/low MVPA).ConclusionOur findings suggest that both increasing MVPA and reducing time spent in SB may be useful strategies to improve HRQOL.

Effects of Chronic Disease Management Based on Clinics for Blood Pressure or Glycemic Control in Patients with Hypertension or Type 2 Diabetes Mellitus

Objective: This study aimed to examine the effects of chronic disease management program based on clinics for blood pressure control or glycemic control in patients with hypertension or type 2 diabetes mellitus in Incheon. Methods: An observational follow up study was done on 11,501 patients registrated at clinics from January 1st to December 31st, 2010 in Incheon. Experience of education and mandatory laboratory tests were assessed with the registration data and income status was identified by National Health Insurance data. The odds ratio and 95% confidence intervals were derived from logistic regression models. Results: The experience of education has a positive effect for blood pressure control in the non-control group with hypertension at the time of registration (Odds ratio 1.357, confidence intervals: 1.112~1.655). The experience of mandatory laboratory tests has a positive effect for blood pressure control in the control group with hypertension at the time of registration (Odds ratio 1.738, confidence intervals: 1.387~2.178). But the effects of the experience of education and mandatory laboratory test in patients with type 2 diabetes mellitus were not identified. Conclusions: This study revealed the relationship between the experience of education or mandatory laboratory testing and blood pressure control in patients with hypertension.

The Effects of Adherence on Hypertension Control among Newly Diagnosed Hypertension Patients

Background: This study is to research on how hypertension control is associated with adherence in newly diagnosed hypertension patients. Methods: The study is based on 255,916 patients who were diagnosed with hypertension in 2009 and didn`t have any previous medical history of hypertension or associated complication for the past year using data collected by National Health Insurance Corporation. Newly diagnosed hypertension patients are divided into two group by visiting medical center numbers (more than 300 days was adherence group, if not non-adherence group). Patients are considered to have successfully controlled their hypertension based on blood pressure measured by health examination. Chi-square test and logistic regression, repeated measured analysis of variance was used to analyze. Results: The relations between adherence and hypertension control show that 1.12 times of patients in adherence group was able to control their hypertension. The additional analysis proves that adherence group are more decreased level of blood pressure than non-adherence group except for patients who are over 70. Comparison of the average of systolic blood pressure and diastolic blood pressure between adherence and non-adherence groups shows that the blood pressure has been significantly among the adherence group. Conclusion: The study proves that constant treatment for hypertension could control the blood pressure and encourages patients to put more effort for persistent treatment. It also shows that hypertension treatment are more effective in younger patients than the elderly and strategies of approaching are different depending on age.

Association of Cigarette Prices with the Prevalence of Smoking in Korean University Students: Analysis of Effects of the Tobacco Control Policy.

BACKGROUND Increased pricing of cigarettes might be one of the most effective approaches for reducing the prevalence of smoking. This study aimed to investigate the effects of increasing cigarette prices through taxation by a tobacco intervention policy on the changes in smoking prevalence in Korean university students. MATERIALS AND METHODS The participants in this study were 23,047 healthy university students aged 18-29 years from a health examination in 2011-2015. We investigated the adjusted prevalence of daily and occasional smoking before and after increasing cigarette prices through taxation. RESULTS The prevalence of occasional smoking was significantly decreased in 2015 from 2014 in both male (from 10.7% in 2014 to 5.4%) and female (from 3.6% to 1.1%) students, but the prevalence of daily smoking did not decrease significantly. The frequency of individuals who had attempted smoking cessation during the past year was significantly higher among occasional smokers in male students (90.2%) compared with daily smokers (64.9%). For female students, there were no differences in experience of smoking cessation, willingness for smoking cessation, or E-cigarette experience between daily and occasional smokers. CONCLUSIONS We found that a policy of increasing cigarette prices through taxation is associated with decreases in the prevalence of occasional smokers, who have relatively lower nicotine dependence compared with individuals who smoke daily. The results of our study suggest that social support and direct intervention for smoking cessation at the community level are needed for university students alongside the pricing policy.

The Effect of a Clinic Based Incentive Program on Medication Adherence among Patients with Hypertension or Diabetes Mellitus in Incheon

Background: This study was conducted to evaluate the factors affecting adherence in patients with hypertension and type 2 diabetes mellitus before and after a clinic based patient incentive program in Incheon. Methods: An observational follow-up study was done for 28,355 patients in one registered group and 245,598 patients in a non-registered group from March 16th 2009 to December 31th 2010 in Incheon. The registration, mandatory laboratory tests and number of clinic visits were collected by merging the Incheon Chronic Disease Management System data and the National Health Insurance Corporation (NHIC) data. As a measure of patient adherence, we used a variable of prescription days from the NHIC and defined above 80% of average prescription days as an appropriate patient adherence. Repeated measures analysis of variance and logistic regression were used to analyze the differences in patient adherence and factors affecting adherence. Results: The changes in prescription days for the registered group are larger than for the non-registered group. In the logistic regression model, including the variables with sex, age, income status and number of clinic visits, the registered group exhibited a higher Odds ratio in the patient adherence. Conclusion: This study revealed the association between registration and appropriate patient adherence in patients with hypertension or type 2 diabetes mellitus.

Factors Affecting Reticulocyte Enrichment by Density Gradient Ultracentrifugation

cause cell volume changes, after clearly defining a criterion for fair comparison of the experimental conditions. After basal reticulocyte levels (BRLs) of 6 normal subjects were compared, the one with the highest BRL was selected as the blood donor (donor 1) during the initial phase of this study. However, we had to switch to another blood donor (donor 2) with the next high BRL because donor 1 had infections and received antibiotic therapy. This study was performed after written informed consents were obtained and the study protocol approved by the Institutional Review Board of Gil Medical Center, Gachon University of Medicine and Science. Since a control experiment revealed no difference between citrate/ dextrose anticoagulant (pH 7.4) and EDTA, Vacutainer TM tubes (BD, Franklin Lakes, N.J., USA) were used for blood collection. The BRL of donor 2 who provided blood samples for all the data presented here varied between 2.18 and 3.26% over the course of this study. Both donor 1 and donor 2 showed unusually high BRLs of 1 3% after they spent a stressful week with much less sleep than usual due to personal reasons. Presently, this is the only possible cause we can conjecture for the increased erythropoietic activity. Although repeated blood drawings can also induce erythropoiesis, this cause seems unlikely for our cases because the BRLs of both donors dropped to normal levels when they recovered from the severe tiredness despite regular blood donation. Reticulocytes constitute only 0.6–2.7% of the red blood cells (RBCs) in normal subjects [1] . Because of the low content, an efficient enrichment method is a prerequisite for studying the biology of reticulocytes. Several different types of enrichment methods have thus far been developed including density gradient centrifugation [2–7] , preparative electrophoresis [8] , affinity chromatography on transferrin-liganded sepharose [9] , as well as immunomagnetic separation using a monoclonal antibody to transferrin receptor [10] . Although almost pure reticulocytes can be obtained by the immunomagnetic method, density gradient ultracentrifugation still remains the method of choice when a large quantity of cells is required and a relatively low enrichment of 30–60% is acceptable. A strategy to maximize enrichment by density gradient ultracentrifugation can be developed based on the knowledge of cell volume control mechanisms such as regulatory cell volume decrease and regulatory cell volume increase [11–13] . A previous study utilized a high K +

The Effects of Adherence and Hypertension Control on Complication among Newly Diagnosed Hypertension Patients

Background: This study aimed to research on how adherence and blood control could make a difference when it comes to develop complications. Methods: The study’s subjects were 255,916 patients who were newly diagnosed with hypertension in 2009 using data collected by National Health Insurance Cooperation. Patients are considered as a group under adherence if visit days and prescription days are more than 300 days. Patients are considered to have successfully controled their hypertension based on actual value measured by National Health Insurance Cooperation and the study takes a look at whether they were diagnosed with complications of cerebrocardiovascular disease in 2012. Chi-square test and logistic regression was used to analyze. Results: Patients who were able to control their hypertension show 0.80 times chance of developing cerebrovascular disease, and 0.89 times chance of developing cardiocerebrovascular disease. The group of adherence shows lower chance of developing complication in general than the group of non-adherence. Conclusion: The study revealed that hypertension’s constant treatment could control the blood pressure and prevent complications. It is important that encourages patients to effort for persistent treatment for reducing complication.