Yeon-pyo Hong

Reliability and validity of a self-reported measure of medication adherence in patients with type 2 diabetes mellitus in Korea

Objective This study examined the psychometric properties of the Korean version of the eight-item Morisky Medication Adherence Scale (MMAS-8) to measure adherence to diabetes medication in patients with type 2 diabetes mellitus. Methods The English version of the MMAS-8 was translated into Korean and administered to patient with type 2 diabetes mellitus via face-to-face interviews, conducted by an independent interviewer. Patient characteristics and glycosylated haemoglobin (HbA1c) levels were assessed at the same clinic visit. A proportion of patients was randomly selected for 2-week test-retest reliability via telephone interviews. Convergent validity of the MMAS-8 against a four-item MMAS, correlations with HbA1c levels and construct validity of the MMAS-8 were evaluated. Results In total, 317 patients were included; 70 completed the 2-week test–retest interview. Internal consistency reliability was moderate and test–retest reliability of the MMAS-8 was excellent, although a ceiling effect was detected. Good convergent validity was shown by the high correlation of the new scale scores with the original MMAS-4. A significant association was found between MMAS-8 scores and HbA1c levels. Using glycaemic control as a gold standard, sensitivity was 74.1% and specificity was 38.3%. Explanatory factor analysis identified three dimensions of the scale. Conclusions In light of acceptable reliability and validity, the MMAS-8 is a simple and quick method for the assessment of medication adherence among patient with type 2 diabetes mellitus, in a busy clinic setting.

Trends in Educational Differentials in Suicide Mortality between 1993 - 2006 in Korea.

Purpose This study aims to examine how inequalities in suicide by education changed during and after macroeconomic restructuring following the economic crisis of 1997 in South Korea. Materials and Methods Using Koreas 1995, 2000, and 2005 census data aggregately linked to mortality data (1993 - 2006), relative and absolute differentials in suicide mortality by education were calculated by gender and age among Korean population aged 35 and over. Results Average annual suicide mortality rates have steadily increased from 1993 - 1997 to 2003 - 2006 in almost all sociodemographic groups stratified by gender, age, and education. Based on the relative index of inequality (RII) and slope index of inequality (SII), educational differentials in suicide mortality generally increased over time in men and women aged 45 years +. Although RII did not increase with year among men and women aged 35 - 44 years, SII showed a significantly increasing trend in this age group. Conclusion These worsening absolute inequalities in suicide mortality indicate that the governmental suicide prevention policy should be directed toward socially disadvantaged groups of the Korean population.

Acute Testis Toxicity of Bisphenol A Diglycidyl Ether in Sprague-Dawley Rats

OBJECTIVES Bisphenol A diglycidyl ether (BADGE) is a liquid compound obtained by condensation of two molecules of epichlorohydrin with one molecule of bisphenol A. General and reproductive toxicity with BADGE has been reported higher than 1000 mg/kg/day. This study was performed to show the effects of acute exposure to BADGE below 1000 mg/kg/day on the testis in adult male rats. METHODS BADGE was administered by gastric lavage in a single dose of 500, 750, 1000, and 2000 mg/kg/day in 8-week old male SPF Sprague-Dawley rats. The right testis was processed for light microscopic analysis. The left testis was homogenized and spermatids were counted to determine the daily sperm production and daily abnormal sperm production. The sperm count, sperm motility, and incidence of abnormal sperm were estimated in the epididymis. In testicular sections, the seminiferous tubules were observed for qualitative changes. The progression of spermatogenesis was arbitrarily classified as full-matured, maturing, and immature. The specimen slide was observed at 3 points and 10 seminiferous tubules were evaluated at each point. RESULTS The male rats exposed to single oral dose of BADGE at 750, 1000, and 2000 mg/kg/day were significantly increased the number of immature and maturing sperm on the testis. There were no significant differences with respect to sperm head count, sperm motility, and sperm abnormality in the BADGE treatment groups. CONCLUSIONS These results suggest that single oral exposure of BADGE 750 mg/kg/day can affect adult male testis development.

Maintained Seroprevalence of Toxoplasmosis among the Residents of Jeju Island, Korea

Seroepidemiological status of toxoplasmosis among the residents of Jeju island was surveyed and evaluated by ELISA with crude extract of Toxoplasma gondii. The sera of 2,348 residents (male 1,157 and female 1,191) were collected and checked for the IgG antibody titers, which showed 13.2% positive rate (309 sera). The positive rates were increasing gradually according to the age from 4.3% in teenage to 20.6% in seventies. The positive rates were significantly different between the sex by 16.2% for male and 10.2% for female (P<0.05). This positive rate of toxoplasmosis in Jeju island residents is regarded relatively higher than any other regions of Korea. And the high positive rate may be maintained continuously among Jeju island residents without any clear reasons until now but due to some parts peculiar socio-cultural tradition of Jeju island. Therefore, it is necessary to study further the epidemiology of toxoplasmosis of Jeju island.

Assessment of Di (2-ethylhexyl) Phthalate Exposure by Urinary Metabolites as a Function of Sampling Time

OBJECTIVES In most DEHP exposure assessment studies, single spot urine sample was used. It could not compare the exposure level among studies. Therefore, we are going to represent the necessity of selection of proper sampling time of spot urine for assessing the environmental DEHP exposure, and the association urinary DEHP metabolites with steroid hormones. METHODS We collected urine and plasma from 25 men. The urine sampling times were at the end of the shift (post-shift) and the next morning before the beginning of the shift (pre-shift). Three metabolites of DEHP {mono(2-ethylhexyl) phthalate [MEHP], mono-(2-ethyl-5-hydroxyhexyl)phthalate [MEHHP], and mono(2-ethyl-5-oxohexyl)phthalate [MEOHP]} in urine were analyzed by HPLC/MS/MS. Plasma luteinzing hormone, follicle stimulating hormone, testosterone, and 17ß-estradiol were measured at pre-shift using a ELISA kit. A log-transformed creatinine-adjusted urinary MEHP, MEHHP, and MEOHP concentration were compared between the post- and pre-shift. The Pearsons correlation was calculated to assess the relationships between log-transformed urinary MEHP concentrations in pre-shift urine and hormone levels. RESULTS The three urinary metabolite concentrations at post-shift were significantly higher than the concentrations in the pre-shift (p<0.0001). The plasma hormones were not significantly correlated with log-transformed creatinine - adjusted DEHP metabolites. CONCLUSIONS To assess the environmental DEHP exposure, it is necessary to select the urine sampling time according to the study object. There were no correlation between the concentration of urinary DEHP metabolites and serum hormone levels.

Changes in brain FDG metabolism induced by acupuncture in healthy volunteers

Background: With the aid of newly developed functional brain imaging studies, studies are ongoing to see if acupuncture first acts on specific brain areas to induce effects on the human body. Purpose: To examine if stimulation at specific acupuncture points changes brain glucose metabolism patterns, including the limbic system and specific brain areas related to the acupuncture effect in healthy volunteers using fluorodeoxyglucose positron emission tomography combined computed tomography (FDG-PET/CT). Material and Methods: Twenty healthy volunteers (11 men and 9 women; mean age 49.1±7.3 years, age range 35–62 years) were included. Two sets of PET/CT scans were obtained from each volunteer, with and without stimulation by acupuncture. Two classic acupoints, LR3 (liver meridian) and ST44 (stomach meridian) were tested at the same time, using disposable sterile stainless steel needles. After initial acupuncture, the needle was kept in place without further stimulation. FDG-PET/CT scan of the brain began 45 min after FDG injection (185–222 MBq). Results: After stimulation of LR3 and ST44 by acupuncture, glucose metabolism in the brain was increased in the left insula (BA 13), bilateral thalami, superior frontal region of the right frontal lobe, and the inferior frontal region of left frontal lobe compared with baseline. On the other hand, glucose metabolism was decreased after acupuncture in the cingulate and parahippocampal (BA 36) regions of the left limbic lobe. Conclusion: Changes of glucose metabolism in specific brain areas following stimulation by acupuncture on LR3 and ST44 were documented using FDG-PET/CT.

Physical Activity in Adolescence Has a Positive Effect on Bone Mineral Density in Young Men

Objectives Little is yet known about the determinants of bone mineral density (BMD) in young adults. Thus, in this study, we aimed to determine the factors that have an impact on BMD in young men. Methods Questionnaires were sent out to 111 male medical students. Information on age, socio-economic status, medical history, lifestyle, physical activity during adolescence, school club participation, current physical activity, and dietary intake were collected by the survey. Height, weight, percent body fat and muscle mass were estimated by bioelectrical impedance, and BMD was obtained using calcaneal quantitative ultrasound. Using the Poisson regression model, prevalence ratios (PRs) were used to estimate the degree of association between risk factors and osteopenia. Results The height and current physical activity showed a correlation to the Osteoporosis Index. Among the categorized variables, past physical activity during adolescence (p=0.002) showed a positive effect on the bone mineral content. In the multivariate model, past physical activity (≥1 time/wk) had a protective effect on osteopenia (PR, 0.37; 95% confidence interval [CI], 0.18 to 0.75) and present physical activity (1000 metabolic equivalent of task-min/wk) decreased the risk of osteopenia (PR, 0.64; 95% CI, 0.44 to 0.91). Conclusions Past physical activity during adolescence is as important as physical activity in the present for BMD in young men.

Environmentally relevant levels of Bisphenol A may accelerate the development of type II diabetes mellitus in adolescent Otsuka Long Evans Tokushima Fatty rats

Environmental chemicals may contribute to the development of obesity and metabolic disorders such as diabetes. Bisphenol A (BPA) is one of the environmental chemicals that are widely used in daily life. This study was performed to investigate whether low dose BPA exposure can influence the occurrence of type II diabetes mellitus. Four weeks old Otsuka Long Evans Tokushima Fatty (OLETF) rats were randomly assigned to three groups of five animals and each group was given different concentrations of corn oil with BPA (0, 0.001, and 0.1 mg/kg/day). BPA 0.1 mg/kg/ day produced impairment of glucose tolerance, and induced higher insulin (p=0.028) and malondialdehyde levels (p=0.009) in serum than control group. Serum insulin levels in BPA 0.001 mg/kg/day treated group showed significantly higher than the control group (p=0.016). BPA tended to induce down-regulation of PPARγ mRNA and protein expression in white adipose tissue than control. In conclusion, low dose BPA exposed OLETF rats in adolescent period could accelerate the development of diabetes mellitus in younger adult period.

Reduction in semen quality after mixed exposure to bisphenol A and isobutylparaben in utero and during lactation periods.

This study was performed to determine the effect of low-level exposure to a mixture of bisphenol A (BPA) and isobutylparaben (IBP) on male reproduction. Corn oil, BPA (0.05 mg/kg/day), IBP (2.5 mg/kg/day), and a BPA/IBP mixture (BPA 0.05 mg/kg/day and IBP 2.5 mg/kg/day) were administered once daily by oral gavage to female rats for 5 weeks from gestation day 6 to lactation day 21. Male pups were killed at postnatal day 70 and examined for developmental characteristics, body weight, testis and epididymis weight, steroid hormones, epididymal sperm count and motility, and histological changes in testis and epididymis. The BPA/IBP mixture produced a significant downregulation of epididymal sperm count and motility. BPA or IBP alone also reduced epididymal sperm count and motility compared to control. These results indicate that exposure to low-level BPA/IBP mixture, which showed no notable physiological response in early life stages, can decrease semen quality in adulthood.

Combination effects of bisphenol A and isobutylparaben on the green macroalga Ulva pertusa

Endocrine related disorders have increased in human and wildlife due to the exposure of the endocrine disruptors (EDs). Estrogenic EDs can generate combination effects when they are present in a mixture at a concentration that does not individually induce observable effects. Therefore, this study was performed to characterize the reproductive toxicity of bisphenol A (BPA) and isobutylparaben (IBP) exposed to Ulva pertusa (U. pertusa), and also to determine the combined effects of BPA and IBP in U. pertusa. The median sporulation inhibition concentrations (EC50) of individual BPA and IBP exposure in U. pertusa showed 23.84 mg/L and 15.65 mg/L, respectively. The inhibition on sporulation of U. pertusa to a mixture of BPA and IBP at EC50 level was observed to be higher when compared to individual exposure. In conclusion, reproduction inhibition to a mixture of BPA and IBP exposure at EC50 levels was relatively greater than individual exposure to U. pertusa.