The Association between Serum Lipid Levels and Tinnitus Prevalence and Severity in Korean Elderly: A Nationwide Population-Based Cross-Sectional Study

PURPOSE

We aimed to investigate the association between serum lipid level and tinnitus risk in Korean older adults.

MATERIALS AND METHODS

This study used data from the 2016-2018 Korea National Health and Nutrition Examination Survey. Overall, 6021 subjects aged ≥60 years were included. Hypertriglyceridemia was defined as a serum triglyceride level of ≥200 mg/dL. The high-risk threshold of the total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-C) ratio was defined as above 5.0. The presence of tinnitus was assessed via health interviews. Tinnitus severity was classified as "not annoying," "irritating," and "severely annoying and causing sleep problems." Multivariate logistic regression analysis was performed to examine the association between serum lipid level and tinnitus risk.

RESULTS

The odds ratio (OR) of tinnitus was 1.27-times higher in the group with hypertriglyceridemia than in the group without hypertriglyceridemia after adjusting for age, sex, hypertension, diabetes, dyslipidemia, anemia, current smoking, obesity, noise exposure, stress cognition, and depressive mood or anxiety [95% confidence interval (CI) 1.04-1.56, p=0.022]. The OR of tinnitus was 1.21-times higher in the group with a high TC/HDL-C ratio than in the group without a high TC/HDL-C ratio after adjusting for the same variables as above (95% CI 1.02-1.44, p=0.025).

CONCLUSION

This study revealed that hypertriglyceridemia and high TC/HDL-C ratio were significantly associated with an increased OR of tinnitus in Korean older adults.

Assessment of Pharmacokinetic Effects of Herbal Medicines on Escitalopram

Purpose

Herbal medicines are occasionally used in combination with conventional antidepressants to mitigate various depression-associated symptoms. However, there is limited information on herb-antidepressant interactions. In this study, we investigated the pharmacokinetic (PK) effects of four herbal medicines (Gami-soyosan, Banhasasim-tang, Ojeok-san, and Bojungikgi-tang) on escitalopram, a commonly used antidepressant.

Patients and Methods

In this open-label, fixed-sequence, three-period, crossover study, 18 participants were enrolled and divided into two groups. Each group received a 10 mg oral dose of escitalopram in period 1. Participants took escitalopram once daily and their assigned herbal medicines thrice a day for 7 d in periods 2 (group 1: Gami-soyosan, group 2: Ojeok-san) and 3 (group 1: Banhasasim-tang; group 2: Bojungikgi-tang). The primary endpoints were Cmax,ss and AUCtau,ss of escitalopram. Cmax,ss and AUCtau,ss in period 1 were obtained using nonparametric superposition from single-dose data. The PK endpoints were classified according to the CYP2C19 phenotype.

Results

Of 18 participants, 16 completed the study. Systemic exposure to escitalopram resulted in a minor increase in the presence of each herbal medicine. The geometric mean ratios (GMRs, combination with herbal medicines/escitalopram monotherapy) and their 90% confidence intervals (CIs) for Cmax,ss and AUCtau,ss were as follows: Gamisoyosan- 1.1454 (0.9201, 1.4258) and 1.0749 (0.8084, 1.4291), Banhasasim-tang-1.0470 (0.7779, 1.4092) and 1.0465 (0.7035, 1.5568), Ojeok-san-1.1204 (0.8744, 1.4357) and 1.1267 (0.8466, 1.4996), and Bojungikgi-tang-1.1264 (0.8594, 1.4762) and 1.1400 (0.8515, 1.5261), respectively. Furthermore, no significant differences in the GMRs of Cmax,ss and AUCtau,ss were observed across different CYP2C19 phenotypes in any of the groups.

Conclusion

The co-administration of escitalopram with Gami-soyosan, Banhasasim-tang, Ojeok-san, or Bojungikgi-tang did not exert significant PK effects on escitalopram. These findings provide valuable insights into the safe use of herbal medicines along with escitalopram.

Population pharmacokinetic-pharmacodynamic modeling of clopidogrel for dose regimen optimization based on CYP2C19 phenotypes: A proof of concept study

Clopidogrel is an antiplatelet drug used to reduce the risk of acute coronary syndrome and stroke. It is converted by CYP2C19 to its active metabolite; therefore, poor metabolizers (PMs) of CYP2C19 exhibit diminished antiplatelet effects. Herein, we conducted a proof-of-concept study for using population pharmacokinetic-pharmacodynamic (PK-PD) modeling to recommend a personalized clopidogrel dosing regimen for individuals with varying CYP2C19 phenotypes and baseline P2Y12 reaction unit (PRU) levels. Data from a prospective phase I clinical trial involving 36 healthy male participants were used to develop the population PK-PD model predicting the concentrations of clopidogrel, clopidogrel H4, and clopidogrel carboxylic acid, and linking clopidogrel H4 concentrations to changes in PRU levels. A two-compartment model effectively described the PKs of both clopidogrel and clopidogrel carboxylic acid, and a one-compartment model of those of clopidogrel H4. The CYP2C19 phenotype was identified as a significant covariate influencing the metabolic conversion of the parent drug to its metabolites. A PD submodel of clopidogrel H4 that stimulated the fractional turnover rate of PRU levels showed the best performance. Monte Carlo simulations suggested that PMs require three to four times higher doses than extensive metabolizers to reach the target PRU level. Individuals within the top 20th percentile of baseline PRU levels were shown to require 2.5-3 times higher doses than those in the bottom 20th percentile. We successfully developed a population PK-PD model for clopidogrel considering the impact of CYP2C19 phenotypes and baseline PRU levels. Further studies are necessary to confirm actual dosing recommendations for clopidogrel.

Pharmacokinetic and pharmacodynamic drug-drug interactions between evogliptin and empagliflozin or dapagliflozin in healthy male volunteers

Evogliptin (EV) is a novel dipeptidyl peptidase-4 inhibitor (DPP4i) for glycemic control in patients with type 2 diabetes mellitus (T2DM). This study evaluated the pharmacokinetic (PK) and pharmacodynamic (PD) interactions between EV and sodium glucose cotransporter-2 inhibitors (SGLT2i) in healthy volunteers since combination therapy of DPP4i and SGLT2i has been considered as an effective option for T2DM treatment. A randomized, open-label, multiple-dose, two-arm, three-period, three treatments, two-sequence crossover study was conducted in healthy Korean volunteers. In arm 1, subjects were administered 5 mg of EV once daily for 7 days, 25 mg of empagliflozin (EP) once daily for 5 days, and the combination once daily for 5 days (EV + EP). In arm 2, subjects were administered 5 mg of EV once daily for 7 days, 10 mg of dapagliflozin (DP) once daily for 5 days, and the combination once daily for 5 days (EV + DP). Serial blood samples were collected for PK analysis, and oral glucose tolerance tests were conducted for PD analysis. In each arm, a total of 18 subjects completed the study. All adverse events (AEs) were mild with no serious AEs. The geometric mean ratio and confidence interval of the main PK parameters (maximum concentration of the drug in plasma at steady state and area under the plasma drug concentration-time curve within a dosing interval at a steady state) between EV and either EP or DP alone were not significantly altered by co-administration. Administration of EV + EP or EV + DP did not result in significant PD changes, as determined by the glucose-lowering effect. Administration of EV + EP or EV + DP had no significant effects on the PK profiles of each drug. All treatments were well-tolerated.

Pharmacokinetic and pharmacodynamic interaction of DWP16001, a sodium-glucose cotransporter-2 inhibitor, with phentermine in healthy subjects

BACKGROUND

DWP16001, a sodium-glucose cotransporter-2 inhibitor, has shown promise for improving blood glucose control and facilitating weight loss. Co-administration with phentermine could enhance these effects. So, we aimed to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) interactions of DWP16001 and phentermine.

METHODS

We conducted a randomized, open-label, 3-treatment, 6-sequence, 3-period crossover study involving 24 healthy adults. Participants received either DWP16001 (2 mg), phentermine (37.5 mg), or a combination of both once daily for 7 days. Blood samples, urine samples, and body weights were collected to evaluate the PK and PD.

RESULTS

The PK of the combination was found to be similar to that of the monotherapy. The geometric mean ratio (GMR) of Cmax,ss, and AUCtau,ss were 0.98 and 1.00, respectively, for DWP16001, and 1.01 and 0.94, respectively, for phentermine. Co-administration did not significantly affect the 24-hour urinary glucose excretion compared to DWP16001 monotherapy, and the GMR was 0.90. Participants tended to experience greater weight loss in the combination therapy group, and all demonstrated good tolerance.

CONCLUSIONS

Our findings indicate that there were no significant interactions during co-administration. These results suggest that the combination of DWP16001 and phentermine may be safe and effective for the treatment of obesity and diabetes.

CLINICAL TRIAL REGISTRATION

NCT05321732.

The effects of long-term cumulative HbA1c exposure on the development and onset time of dementia in the patients with type 2 diabetes mellitus: hospital based retrospective study (2005-2021)

AIMS

We examine cumulative effect of long-term glycemic exposure in patients with type 2 diabetes mellitus (T2DM) on the development of dementia.

METHODS

The study involved 20,487 records of patients with T2DM identified in the electronic medical record at Severance Hospital, Korea. Cumulative HbA1c (AUC_HbA1c) and mean HbA1c over time (HbA1c_avg) as measures of long-term glycemic exposure were compared for the development of dementia and the time to dementia.

RESULTS

AUC_HbA1c and HbA1c_avg were significantly higher in patients who later developed dementia than in those who did not dementia (AUC_HbA1c: 56.2 ± 26.4 vs. 52.1 ± 26.1 %*Year; HbA1c_avg: 7.0 ± 1.0 vs. 7.3 ± 1.0 %). Odds ratio of dementia increased when HbA1c_avg was 7.2% (55 mmol/mol) or above, and when AUC_HbA1c was 42 %*Year (e.g., HbA1c 7.0% maintained for 6 years) or above. Among those who developed dementia, as HbA1c_avg increased, the time to dementia onset decreased (β = -380.6 days, 95% confidence interval [CI]: -416.2 to -345.0).

CONCLUSIONS

Our results indicate poorly controlled T2DM was associated with an increased risk of developing dementia, as measured by AUC_HbA1c and HbA1c_avg. Higher cumulative glycemic exposure may lead to developing dementia in a shorter time.

Evaluation of pharmacokinetic interactions between lobeglitazone, empagliflozin, and metformin in healthy subjects

Concomitant administration of lobeglitazone, empagliflozin, and metformin is expected to enhance blood glucose-lowering effects and improve medication compliance in patients with diabetes mellitus. In this study, we investigated the pharmacokinetic (PK) interactions and safety of lobeglitazone and co-administered empagliflozin and metformin, which are approved agents used in clinical settings. Two randomized, open-label, multiple-dose, 2-treatment, 2-period, 2-sequence crossover clinical trials (parts 1 and 2) were conducted independently. In part 1, lobeglitazone monotherapy or lobeglitazone, empagliflozin, and metformin triple therapy was administered for 5 days. In part 2, empagliflozin and metformin dual therapy or the abovementioned triple therapy were administered for 5 days. Serial blood samples were collected up to 24 hours after the last dose in each period for PK evaluation. The primary PK parameters (AUC_tau,ss, C_max,ss) of treatment regimens in each study part were calculated and compared. For lobeglitazone, the geometric mean ratios (GMRs) with 90% confidence intervals (CI) for triple therapy over monotherapy were 1.08 (1.03-1.14) for C_max,ss and 0.98 (0.90-1.07) for AUC_tau,ss. For empagliflozin, the GMRs and 90% CIs for triple therapy over dual therapy were 0.87 (0.78-0.97) for C_max,ss and 0.97 (0.93-1.00) for AUC_tau,ss. For metformin, the GMRs and 90% CIs for triple therapy over dual therapy were 1.06 (0.95-1.17) for C_max,ss and 1.04 (0.97-1.12) for AUC_tau,ss. All reported adverse events were mild. The triple therapy consisting of lobeglitazone, empagliflozin, and metformin did not show any clinically relevant drug interactions in relation to the PKs and safety of each drug substance.

Trial Registration

ClinicalTrials.gov Identifier: NCT04334213.

Effect of Rifampicin on the Pharmacokinetics of Evogliptin in Healthy Volunteers

Purpose

Evogliptin (DA-1229) is a novel, potent, and selective dipeptidyl peptidase 4 (DPP-4) inhibitor for treating type 2 diabetes mellitus. This study investigates the effect of rifampicin on evogliptin pharmacokinetics.

Patients and Methods

An open-label, crossover, one-sequence study was conducted on 12 healthy subjects. Reference baseline pharmacokinetic samples were collected on day 1 after the subjects were administered a single dose of 5 mg evogliptin. After a washout period, the subjects were administered 600 mg rifampicin once daily for 10 days, from days 8 to 17, for full induction of hepatic enzyme activity. On day 17, single doses of evogliptin (5 mg) were administered along with rifampicin (600 mg). The test pharmacokinetic samples were collected with a sampling schedule identical to that used for the reference.

Results

Maximum concentration (C_max) and area under the plasma drug concentration-time curve (AUC_0-96h) of evogliptin with and without co-administration of rifampicin were compared. Reference and test C_max and AUC_0-96h values of evogliptin were 4.70 ng/mL vs 4.86 ng/mL and 153.97 ng∙h/mL vs 58.83 ng∙h/mL, respectively. All adverse events were mild in intensity and considered unrelated to evogliptin administration.

Conclusion

Rifampicin decreased the AUC_0-96h of evogliptin by 61.8% without significantly affecting C_max. The mechanism underlying the decrease in AUC_0-96h is thought to be the induction of cytochrome P450 (CYP), especially 3A, by rifampicin. The adverse events, none of which were serious, were not significantly altered by the concomitant administration of evogliptin and rifampicin. Nevertheless, it would be prudent that evogliptin dosing should be carefully considered when co-administered with CYP3A inducers.

Effects of Hepatic Impairment on the Pharmacokinetic Profile and Safety of Lobeglitazone

In this open-label, single-dose, parallel-group study, we compared the pharmacokinetic profile and safety of lobeglitazone, a thiazolidinedione acting as an agonist for peroxisome proliferator-activated receptors, in patients with hepatic impairment (HI) and healthy matched controls for age, sex, and body weight. After a single oral dose of lobeglitazone (0.5 mg), the lobeglitazone (parent drug) and M7 (major metabolite) plasma concentrations and pharmacokinetic parameters were analyzed and compared between the HI patient groups and healthy matched control groups. The geometric mean ratio (GMR; 90% confidence interval [CI]) for maximum concentration (C_max ) and area under the plasma concentration-time curve from time 0 extrapolated to infinity (AUC_inf ) of lobeglitazone was 1.06 (0.90-1.24) and 1.07 (0.82-1.40), respectively, for mild HI vs control A. The GMR (90%CI) of C_max and AUC_inf was 0.70 (0.56-0.88) and 1.00 (0.72-1.37), respectively, for moderate HI vs control B. For M7, the GMR (90%CI) of C_max and AUC_inf was 1.09 (0.75-1.57) and 1.18 (0.71-1.97), respectively, for mild HI vs control A and 1.50 (0.95-2.38) and 1.79 (1.06-3.04), respectively, for moderate HI vs control B. Notable adverse events or tolerability issues were not observed. Lobeglitazone may be safely used in patients with mild or moderate HI without dose adjustment.

Comparison of the pharmacokinetics and pharmacodynamics of YH4808 in healthy subjects for defining an appropriate dosing regimen

YH4808 is a novel potassium-competitive acid blocker developed for gastric acid-related disorders. Previous studies indicate its potential to improve symptoms of gastric acid-related disorders. The current study was aimed to find the optimal regimen of YH4808 for night time pH control. This study was performed in two parts. Each was a randomized, open-label, active-controlled, multiple-doses, two-treatment, two-period crossover study conducted in 20 healthy Korean volunteers. Subjects were randomly assigned to one of the four groups. The three groups received different dosage regimens of YH4808 (100 mg twice a day, 200 mg once a day, or 200 mg twice a day), and the fourth group received esomeprazole 40 mg twice a day. The pharmacokinetic parameters demonstrated that the systemic exposure of YH4808 increased in a dose-proportional manner. The difference in the proportion of time above pH 4 over 24 h from the baseline was the greatest in the group receiving YH4808 200 mg twice a day. The values of the area under the effect curve at night time (12 A.M.–7 A.M.) were higher in all YH4808 groups than in the esomeprazole group. However, the differences among the YH4808 groups were not statistically significant (p > 0.05). YH4808 exhibited potential for better pH control during the night in comparison to esomeprazole. The optimal regimen for night time pH control among all the YH4808 regimens was 200 mg twice a day.

Association between Daily Sunlight Exposure and Fractures in Older Korean Adults with Osteoporosis: A Nationwide Population-Based Cross-Sectional Study

PURPOSE

We aimed to investigate the association between daily sunlight exposure duration and fractures in older Korean adults with osteoporosis.

MATERIALS AND METHODS

We utilized data from the 2008-2011 Korea National Health and Nutrition Examination Survey. Osteoporosis was diagnosed based on a T-score of ≤-2.5 using dual energy X-ray absorptiometry. The duration of daily sunlight exposure and fracture were assessed via intensive health interviews by trained staff using standardized health questionnaires. Fracture was defined as one or more fractures of the femur, wrist, and spine.

RESULTS

A total of 638 patients with osteoporosis aged ≥65 years were included. The odds ratio (OR) of total fractures was 0.55 times lower in the group with ≥5 h of daily sunlight exposure than in the group with <5 h of exposure after adjusting for age, sex, family history of osteoporosis or fracture, body mass index, bone mineral density of the femoral neck, serum 25-hydroxyvitamin D, current smoking, alcohol intake, daily calcium intake, and physical activity [95% confidence interval (CI) 0.31-0.97, p=0.040]. In patients with vitamin D insufficiency, the OR of total fracture was 0.52 times lower in the group with ≥5 h of daily sunlight exposure than in the group with less exposure after adjusting the above variables (95% CI 0.28-0.97, p=0.041).

CONCLUSION

Sunlight exposure for ≥5 h a day was significantly associated with a decreased OR of fracture in older Korean adults with osteoporosis. This association was also significant in patients with vitamin D insufficiency.

The diagnostic value of phase angle, an integrative bioelectrical marker, for identifying individuals with dysmobility syndrome: the Korean Urban-Rural Elderly study

Low phase angle, a non-invasive bioimpedance marker, is associated with elevated odds of dysmobility syndrome and its components. Phase angle (estimated cutoffs: < 4.8° in men; < 4.5° in women) can be used to detect dysmobility syndrome in community-dwelling older adults as a simple, integrative screening tool.

INTRODUCTION

Dysmobility syndrome uses a score-based approach to predict fracture risk that incorporates the concepts of osteoporosis, sarcopenia, and obesity. Low phase angle (PhA), a simple, non-invasive bioelectrical impedance marker, was associated with low lean mass, high fat mass, and poor muscle function. We aimed to investigate the association between PhA and dysmobility syndrome, with the exploration of the diagnostic cutoffs.

METHODS

In a community-dwelling Korean older adult cohort, dysmobility syndrome was defined as the presence of ≥ 3 of the following components: osteoporosis, low lean mass, falls in the preceding year, low grip strength, high fat mass, and poor timed up and go performance.

RESULTS

Among the 1825 participants (mean age 71.6, women 66.7%), subjects were classified into sex-stratified PhA tertiles. The prevalence of dysmobility syndrome increased from the highest PhA tertile group to the lowest (15.50 to 2.45% in men; 33.41 to 12.25% in women, P for trend < 0.001). The mean PhA values decreased as the dysmobility score increased (5.33° to 4.65° in men; 4.76° to 4.39° in women, P for trend < 0.001). Low PhA (cutoff: < 4.8° in men; < 4.5° in women) was associated with twofold elevated odds of dysmobility syndrome after adjusting for age, sex, and conventional risk factors. Low PhA improved the identification of individuals with dysmobility syndrome when added to the conventional risk model (area under the curve, 0.73 to 0.75, P = 0.002).

CONCLUSION

Low PhA was associated with dysmobility syndrome and its components, independent of age, sex, body mass index, nutritional status, and inflammation.

Defining an international cut-off of two-legged countermovement jump power for sarcopenia and dysmobility syndrome

We aimed to establish jump power cut-offs for the composite outcome of either sarcopenia (EWGSOP2) or dysmobility syndrome using Asian and Caucasian cohorts. Estimated cut-offs were sex specific (women: < 19.0 W/kg; men: < 23.8 W/kg) but not ethnicity specific. Jump power has potential to be used in definitions of poor musculoskeletal health.

PURPOSE

Weight-corrected jump power measured during a countermovement jump may be a useful tool to identify individuals with poor musculoskeletal health, but no cut-off values exist. We aimed to establish jump power cut-offs for detecting individuals with either sarcopenia or dysmobility syndrome.

METHODS

Age- and sex-matched community-dwelling older adults from two cohorts (University of Wisconsin-Madison [UW], Korean Urban Rural Elderly cohort [KURE], 1:2) were analyzed. Jump power cut-offs for the composite outcome of either sarcopenia defined by EWGSOP2 or dysmobility syndrome were determined.

RESULTS

The UW (n = 95) and KURE (n = 190) cohorts were similar in age (mean 75 years) and sex distribution (68% women). Jump power was similar between KURE and UW women (19.7 vs. 18.6 W/kg, p = 0.096) and slightly higher in KURE than UW in men (26.9 vs. 24.8 W/kg, p = 0.050). In UW and KURE, the prevalence of sarcopenia (7.4% in both), dysmobility syndrome (31.6% and 27.9%), or composite of either sarcopenia or dysmobility syndrome (32.6% and 28.4%) were comparable. Low jump power cut-offs for the composite outcome differed by sex but not by ethnicity (< 19.0 W/kg in women; < 23.8 W/kg in men). Low jump power was associated with elevated odds of sarcopenia (adjusted odds ratio [aOR] 4.07), dysmobility syndrome (aOR 4.32), or the composite of sarcopenia or dysmobility syndrome (aOR 4.67, p < 0.01 for all) independent of age, sex, height, and ethnicity.

CONCLUSION

Sex-specific jump power cut-offs were found to detect the presence of either sarcopenia or dysmobility syndrome in older adults independent of Asian or Caucasian ethnicity.

Association Between 10-Year Fracture Probability and Nonalcoholic Fatty Liver Disease With or Without Sarcopenia in Korean Men: A Nationwide Population-Based Cross-Sectional Study

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) and sarcopenia, which are common in elderly men, are known as risk factors of fracture. However, few studies have examined the association with fracture in these patients. Therefore, we aimed to investigate the association between NAFLD with or without sarcopenia and 10-year fracture probability in Korean men aged ≥50 years.

MATERIALS AND METHODS

Data of 2,525 individuals from the 2010-2011 Korea National Health and Nutrition Examination Survey were analyzed. NAFLD was defined using the fatty liver index (FLI) and comprehensive NAFLD score (CNS), and liver fibrosis using the fibrosis 4 calculator. Sarcopenia was defined as the lowest quintile for sex-specific sarcopenia index cutoff; values. The Fracture Risk Assessment (FRAX) tool was used to predict the 10-year probability of major osteoporotic and hip fractures.

RESULTS

Compared to the no NAFLD group, the 10-year major osteoporotic fracture probability was significantly associated with the FLI-defined (β = 0.16, P = 0.002) and CNS-defined (β = 0.20, P < 0.001) NAFLD groups with liver fibrosis. Similarly, the 10-year hip fracture probability was significantly associated with the FLI- and CNS-defined NAFLD with liver fibrosis groups compared to the group without NAFLD (FLI-defined group, β = 0.04, P = 0.046; CNS-defined group, β = 0.05, P = 0.048). Furthermore, in the group with sarcopenia, the 10-year major osteoporotic fracture probability was significantly associated with the FLI- and CNS-defined NAFLD with liver fibrosis groups compared to the group without NAFLD (FLI-defined group, β = 0.29, P = 0.003; CNS-defined group, β = 0.38, P < 0.001).

CONCLUSIONS

NAFLD with liver fibrosis is significantly associated with a higher 10-year major osteoporotic and hip fracture probability in Korean men aged ≥50 years, and this positive association was more profound in patients with sarcopenia. Therefore, screening middle-aged to elderly men who have NAFLD combined with liver fibrosis and sarcopenia may help prevent fractures.

Pharmacokinetics and safety of evogliptin in hepatically impaired patients

AIMS

Evogliptin is a potent and selective dipeptidyl peptidase-4 inhibitor for glycaemic control in patients with type 2 diabetes mellitus. Since evogliptin is mainly eliminated through hepatic metabolism, we investigated the pharmacokinetics (PKs) and safety characteristics of evogliptin in Korean patients with mild or moderate hepatic impairment.

METHODS

An open-label, parallel-group study was conducted in patients with mild or moderate hepatic impairment and healthy control subjects matched to each patient for sex, age and body mass index. A single dose (5 mg) of evogliptin was administered orally, and serial blood samples were collected over 120 h to assess the PK profile of evogliptin and its main metabolites (M7 and M8).

RESULTS

Patients with mild hepatic impairment and their matched healthy controls showed similar maximum concentration (C_max ) and area under the concentration-time curve values from 0 to 120 h (AUC_last ); the geometric mean ratio (GMR) and 90% confidence interval (CI) were 1.04 (0.80, 1.35) and 1.01 (0.90, 1.14), respectively. Exposure to evogliptin (C_max and AUC_last ) was increased by about 40% in patients with moderate hepatic impairment-the GMR and 90% CI were 1.37 (1.09, 1.72) and 1.44 (1.18, 1.75), respectively. The metabolic ratios of M7 and M8 were lower in patients with moderate hepatic impairment than in matched healthy controls. Evogliptin was well tolerated by both patients and healthy subjects.

CONCLUSION

Although evogliptin exposure was increased in patients with moderate hepatic impairment, the increase is unlikely to affect safety and efficacy adversely, and no dose adjustment is warranted.

Pharmacodynamic evaluation of YH4808 for Helicobacter pylori eradication in healthy subjects

YH4808 is a novel selective potassium-competitive acid blocker demonstrated to be safe and to have inhibitory effects against gastric acid secretion in previous studies. A randomized, open-label, multiple-dose, 3-treatment, 1-period, parallel design study was conducted to compare the Helicobacter pylori eradication rates and acid suppression capacities of three regimens in 60 healthy subjects with H. pylori-positive, and the potential of YH4808 to replace proton-pump inhibitors (PPIs) in standard regimens for H. pylori eradication. Group 1 received YH4808, amoxicillin, and clarithromycin as a novel triple regimen, while Group 2 received YH4808 and amoxicillin only, and Group 3 received esomeprazole, amoxicillin, and clarithromycin, as the standard triple regimen. H. pylori eradication rates were 85.0% for Group 1, 25.0% for Group 2, and 83.3% for Group 3. Relative response rate between Group 1 and 3 was 1.02 (0.50–2.07; 95% CI, χ² test p = 0.8881). Furthermore, the novel triple regimen, YH4808, amoxicillin, and clarithromycin, stably inhibited acid secretion and maintained a gastric pH greater than 4 or 5 for 24 hours, which was comparable to the pH range in the standard triple regimen. However, the onset times of the YH4808 regimens were earlier than that for the regimens using esomeprazole. There were no differences in the incidences or severity of adverse events among the three groups. Overall, the novel triple regimen was safe and well-tolerated. YH4808 could replace PPIs in standard triple regimens used for H. pylori eradication.

Evaluation of pharmacokinetic interactions between amoxicillin, clarithromycin, and the potassium-competitive acid blocker YH4808 in healthy subjects

YH4808 is a novel potassium-competitive acid blocker that was developed as a therapeutic agent for gastric acid-related diseases; it may replace proton pump inhibitors, which are widely used in combination with amoxicillin and clarithromycin for Helicobacter pylori eradication. We compared the pharmacokinetic (PK) profiles and safety of amoxicillin, clarithromycin, and YH4808 used as monotherapies or in combination for evaluating potential drug interactions. An open-label, randomized, single-dose, Latin-square (4 × 4) crossover study was conducted in 32 healthy Korean volunteers. Subjects were randomly assigned to one of the 4 treatment sequences that consisted of 4 periods separated by 21-day washout intervals. PK parameters of YH4808, amoxicillin and clarithromycin administered in combination were compared with those of the respective monotherapies. The geometric mean ratios of the maximum concentration (C_max) and the area under the time-concentration curve from time zero to time of the last quantifiable concentration (AUC_last) of YH4808 increased during the triple therapy by 48.6% and 29.1%, respectively. Similarly, the C_max and AUC_last of M3 (active metabolite of YH4808) increased by 23.3% and 16.0%, respectively. The C_max and AUC_last of clarithromycin increased by 27.4% and 30.5%, and those of 14-hydroxyclarithromycin were increased by 23.1% and 32.4%, respectively. The corresponding amoxicillin values decreased during the triple therapy by 21.5% and 15.6%, respectively. There was no clinically significant change in safety assessment related to either monotherapies or triple therapy. In conclusion, amoxicillin, clarithromycin and YH4808 administered as triple therapy did not exhibit significant PK interactions and were not associated with safety issues.

The safety, pharmacodynamics, and pharmacokinetics of immediate-release formulation containing esomeprazole 20 mg/sodium bicarbonate 800 mg in healthy adult male

Background

Esomeprazole is the most effective treatment for acid-related disorders and is widely used with enteric coating due to rapid degradation in the acidic environment. However, the enteric-coated formulation delays absorption and onset of action. To overcome this limitation, an immediate-release formulation containing esomeprazole 20 mg and sodium bicarbonate 800 mg (IR-ESO) was developed.

Purpose

To evaluate the safety, pharmacokinetics (PK), and pharmacodynamics of IR-ESO compared to those of esomeprazole 20 mg (ESO).

Methods

A randomized, open-label, multiple-dose, two-treatment, two-sequence crossover study was conducted in 40 healthy male subjects. Subjects received either IR-ESO or ESO for 7 days. After single and multiple dosing, blood samples were collected for PK analysis, and intragastric pH was assessed by 24-hr pH monitoring.

Results

Plasma esomeprazole exposure of IR-ESO was similar to that of ESO after single and multiple dosing. Time to peak concentration of IR-ESO (0.50–0.75 hr) was shorter than that of ESO (1.25–1.50 hr). Percentage changes in 24-hr integrated gastric acidity from baseline for IR-ESO were similar to those for ESO. In addition, mean time to maintain gastric pH >4 for 24 hr was similar for both drugs (IR-ESO 55.5–69.9% vs ESO 56.8–70.2%). Evaluation of time to first reach pH 4 after dosing indicated that IR-ESO showed a faster onset than ESO. All subjects found the drug tolerable, and there were no significant differences in adverse events between two drugs.

Conclusion

This study showed that IR-ESO produced a rapid, safe and sustained gastric acid suppression (ClinicalTrials.gov: NCT03211143).

Comparison of biosimilar filgrastim with a reference product: pharmacokinetics, pharmacodynamics, and safety profiles in healthy volunteers

Purpose

Filgrastim, a granulocyte-colony stimulating factor, is used to treat patients with neutropenia, including neutropenic fever. Leucostim^® is a recombinant filgrastim product tested for biosimilarity with its reference product, Neupogen^®. We conducted a comparative clinical trial of the 2 products.

Patients and methods

A randomized, open-label, 2-way crossover, single-dose Phase I study was conducted for 56 healthy subjects. After a 5 and 10 μg/kg single subcutaneous administration of test and reference product, pharmacokinetic and pharmacodynamic parameters (absolute neutrophil count and CD34⁺ cell count) were compared. During the study, safety tests and adverse event monitoring were performed.

Results

The test and the reference products had a comparable pharmacokinetic, pharmacodynamic, and safety profile. In both 5 and 10 μg/kg dosing, the 90% CIs of the test to reference ratio for primary parameters (peak plasma concentration and area under the plasma concentration vs time curve from time 0 extrapolated to the infinite time for plasma filgrastim concentration; maximal effect and area under the time-effect curve from time 0 to time of the last quantifiable effect for absolute neutrophil count) were within the 0.8–1.25 range. In addition, safety profiles between the 2 products were similar without any serious adverse events.

Conclusion

This study has provided firm clinical evidence that the test filgrastim product is similar to its reference filgrastim product.

A comparison of the pharmacokinetic and pharmacodynamic properties of nitroglycerin according to the composition of the administration set: A preliminary study

BACKGROUND

There is a risk of drug sorption into an intravenous administration set composed of polyvinyl chloride (PVC), polyurethane (PU), or polyolefin (PO). This has implications on the dose of the active ingredient the patient receives, and thus therapeutic success. This study aimed to determine the plasma concentration of nitroglycerin and the effect of nitroglycerin on patients based on the composition of the administration set.

METHODS

Using a randomized, open-labeled, 3 × 3 crossover method, 9 volunteers were assigned to 3 groups. In period I, nitroglycerin (100 μg/mL) was infused via a PVC- (group A), PU- (group B), or PO-based (group C) administration set. In period II, PU- (group A), PO- (group B), and PVC-based (group C) administration sets were used, and in period III, PO- (group A), PVC- (group B), and PU-based (group C) administration sets were used. The rate of drug administration in all periods was 12 mL/hour for 30 minutes using an infusion pump. Blood samples were collected, and the plasma concentrations of nitroglycerin were analyzed using validated high-performance liquid chromatography coupled with tandem mass spectrometry. Blood pressure was determined using a sphygmomanometer applied to the other upper arm at an interval of 5 minutes.

RESULTS

We observed that the mean plasma concentration of nitroglycerin over time when administered using a PO-based tube was higher than that when using a PU- or PVC-based tube. When the percent change of the mean arterial pressure from baseline at each time point was compared among groups, there were statistically significant differences between PU and PO or PVC at most points during nitroglycerin infusion.

CONCLUSION

Our results showed higher nitroglycerin plasma concentration and lower arterial pressure when a PO-based administration set was used than when a PVC- or PU-based administration set was used. PO-based administration sets may be more appropriate for nitroglycerin administration compared to those composed of PVC or PU.

Pharmacokinetic drug interaction between atorvastatin and ezetimibe in healthy Korean volunteers

Atorvastatin and ezetimibe are frequently co-administered to treat patients with dyslipidemia for the purpose of low-density lipoprotein cholesterol control. However, pharmacokinetic (PK) drug interaction between atorvastatin and ezetimibe has not been evaluated in Korean population. The aim of this study was to investigate PK drug interaction between two drugs in healthy Korean volunteers. An open-label, randomized, multiple-dose, three-treatment, three-period, Williams design crossover study was conducted in 36 healthy male subjects. During each period, the subjects received one of the following three treatments for seven days: atorvastatin 40 mg, ezetimibe 10 mg, or a combination of both. Blood samples were collected up to 96 h after dosing, and PK parameters of atorvastatin, 2-hydroxyatorvastatin, total ezetimibe (free ezetimibe + ezetimibe-glucuronide), and free ezetimibe were estimated by non-compartmental analysis in 32 subjects who completed the study. Geometric mean ratios (GMRs) with 90% confidence intervals (CIs) of the maximum plasma concentration (C_max,ss) and the area under the curve within a dosing interval at steady state (AUC_τ,ss) of atorvastatin when administered with and without ezetimibe were 1.1087 (0.9799–1.2544) and 1.1154 (1.0079–1.2344), respectively. The corresponding values for total ezetimibe were 1.0005 (0.9227–1.0849) and 1.0176 (0.9465–1.0941). There was no clinically significant change in safety assessment related to either atorvastatin or ezetimibe. Co-administration of atorvastatin and ezetimibe showed similar PK and safety profile compared with each drug alone. The PK interaction between two drugs was not clinically significant in healthy Korean volunteers.

Comparison of pharmacokinetics and safety of fixed-dose combination of SKI306X and aceclofenac versus separate tablets in healthy subjects

JOINS (SKI306X) is an herbal anti-arthritic medicine that is widely used with aceclofenac for treating osteoarthritis in Korea. A fixed-dose combination (FDC) tablet containing SKI306X and aceclofenac was developed to improve patient compliance. This study aimed to compare the pharmacokinetics (PK) and safety of the FDC tablet with those of co-administered SKI306X and aceclofenac in healthy subjects. In this randomized, open-label, two-way crossover, single-dose study, the FDC tablet (SKI306X 300 mg/aceclofenac 100 mg) (test) was given or co-administration of 300 mg of SKI306X and 100 mg of aceclofenac (reference) was performed followed by a 7-day wash-out period. Blood samples were collected before and after drug administration to evaluate aceclofenac PK parameters, and safety was assessed throughout the study. A total of 54 healthy male subjects were enrolled in and completed the study. Tmax and t1/2 of aceclofenac of the FDC tablet were similar to those of aceclofenac co-administered with SKI306X (Tmax: test 2.96 h and reference 2.14 h; t1/2: test 3.46 h and reference 4.04 h). The geometric mean ratios (90% confidence intervals) of Cmax and AUClast (T/R) were 0.85 (0.81 to 0.91) and 1.03 (1.01 to 1.06) respectively; these results were within the predefined range (0.8 to 1.25). There was only one drug-related adverse event (dizziness) occurred after administration of the FDC tablet; however, it was mild in severity and resolved without any complications. The FDC tablet was well tolerated and exhibited an absorption rate and extent comparable to those of SKI306X and aceclofenac administered simultaneously.

Pharmacokinetic interactions between glimepiride and rosuvastatin in healthy Korean subjects: does the SLCO1B1 or CYP2C9 genetic polymorphism affect these drug interactions?

To improve cardiovascular outcomes, dyslipidemia in patients with diabetes needs to be treated. Thus, these patients are likely to take glimepiride and rosuvastatin concomitantly. Therefore, this study aimed to evaluate the pharmacokinetic (PK) interactions between these two drugs in healthy males and to explore the effect of SLCO1B1 and CYP2C9 polymorphisms on their interactions in two randomized, open-label crossover studies. Glimepiride was studied in part 1 and rosuvastatin in part 2. Twenty-four participants were randomly assigned to each part. All subjects (n=24) completed part 1, and 22 subjects completed part 2. A total of 38 subjects among the participants of the PK interaction studies were enrolled in the genotype study to analyze their SLCO1B1 and CYP2C9 polymorphisms retrospectively (n=22 in part 1, n=16 in part 2). Comparison of the PK and safety of each drug alone with those of the drugs in combination showed that both glimepiride and rosuvastatin did not interact with each other and had tolerable safety profiles in all subjects. However, with regard to glimepiride PK, the SLCO1B1 521TC group had a significantly higher maximum plasma concentration (C_max,ss) and area under the plasma concentration–time curve during the dose interval at steady state (AUC_τ,ss) for glimepiride in combination with rosuvastatin than those for glimepiride alone. However, other significant effects of the SLCO1B1 or CYP2C9 polymorphism on the interaction between the two drugs were not observed. In conclusion, there were no significant PK interactions between the two drugs; however, the exposure to glimepiride could be affected by rosuvastatin in the presence of the SLCO1B1 polymorphism.

Pharmacokinetics, pharmacodynamics and safety of CKD-519, a CETP inhibitor, in healthy subjects

CKD-519 is a selective and potent cholesteryl ester transfer protein (CETP) inhibitor being developed for the treatment of dyslipidemia to raise high-density lipoprotein cholesterol. We investigated the safety, tolerability, pharmacokinetics, and pharmacodynamics of single doses of CKD-519 in healthy adult subjects. A randomized, double-blinded, placebo-controlled, single ascending dose study was performed. Eight healthy subjects were enrolled in each CKD-519 dose group (25, 50, 100, 200, or 400 mg) and randomized to CKD-519 (n=6) or matching placebo (n=2). CKD-519 reached the maximum plasma concentration (C_max) at 5–6 h post-dose, and had a long terminal half-life ranging between 40–70 h. The area under the plasma concentration–time curve (AUC) and C_max increased with the dose, however, C_max and AUC normalized by dose decreased with each incremental dose. CETP activity decreased with dose, and the maximum decrease (63%–83%) was observed at 6–8 h post-dose. A sigmoid E_max model best described the relationship between CKD-519 plasma concentrations and CETP activity with an EC₅₀ of 17.3 ng/mL. Overall, 11 adverse events (AEs) were observed. All AEs were mild or moderate in intensity, and resolved without any complications. There were no clinically significant effects on blood pressure. In conclusion, single doses of CKD-519 up to 400 mg were well tolerated and showed potent inhibition of CETP activity.

Verapamil decreases the glucose-lowering effect of metformin in healthy volunteers

AIM

The organic cation transporter 1 (OCT1) plays a key role in the cellular transport of metformin and its subsequent glucose-lowering effect. A recent non-clinical study reported that metformin uptake into hepatocytes is regulated via OCT1, and that uptake was strongly inhibited by verapamil. Therefore, we investigated the effects of verapamil co-administration on the pharmacokinetics and pharmacodynamics of metformin in humans.

METHODS

We evaluated the pharmacokinetics and the anti-hyperglycaemic effects of metformin using an oral glucose tolerance test (OGTT) in 12 healthy participants, before (day 1) and after metformin treatment (day 2), and again on days 15 and 16 after co-administration with verapamil.

RESULTS

Verapamil inhibited the ability of metformin to reduce maximum blood glucose concentrations (ΔGmax ) by 62.5% (P = 0.008) and decreased the area under the glucose concentration-time curve (ΔAUCgluc ) by 238% (P = 0.015). However, verapamil did not significantly alter the Cmax and the AUC of metformin, nor its renal clearance.

CONCLUSIONS

Our results suggest that verapamil remarkably decreases the glucose-lowering effect of metformin, possibly by acting as a competitive inhibitor of OCT1.

Pharmacokinetic Interaction Between Amlodipine and Lobeglitazone, a Novel Peroxisome Proliferator-activated Receptor-γ Agonist, in Healthy Subjects

PURPOSE

Lobeglitazone, a peroxisome proliferator-activated receptor-γ agonist, was developed for the treatment of diabetes mellitus. Because the prevalence of hypertension is high among patients with diabetes mellitus, lobeglitazone is likely to be used with the antihypertensive drug amlodipine. We evaluated the pharmacokinetic interactions between lobeglitazone and amlodipine in healthy male Korean subjects.

METHODS

The study used a randomized, open-label, multiple-dose, 3-treatment, 3-period, 6-sequence crossover design. A total of 24 healthy subjects were enrolled. Blood samples for pharmacokinetic analysis were collected according to a planned schedule after 0.5 mg of lobeglitazone and 10 mg of amlodipine were administered alone or concomitantly once per day for 10 days.

FINDINGS

A total of 24 healthy male subjects participated in the study (mean [SD] age, 26.6 [3.9] years; weight, 67.8 [5.7] kg; and height, 173.6 [6.4] cm). Three participants voluntarily withdrew after the second period, and 1 participant dropped out because of increased creatinine kinase levels caused by strenuous exercise before the start of the third period. Thus, 21 participants completed the study schedule to compare the pharmacokinetic parameters of lobeglitazone, and 22 participants completed the study of amlodipine. The geometric mean ratio (with 90% CIs) of Cmax,ss and AUCτ,ss for lobeglitazone administered concomitantly with amlodipine versus lobeglitazone administered alone was 1.01 (0.93-1.09) and 1.06 (0.92-1.23), respectively. The geometric mean ratio (with 90% CIs) of Cmax,ss and AUCτ,ss for amlodipine administered concomitantly with lobeglitazone versus amlodipine administered alone was 0.98 (0.94-1.02) and 1.00 (0.96-1.05). No serious drug-induced adverse events were reported in the study, and no clinically significant changes in vital signs, physical examination results, clinical laboratory results, or ECGs were noted.

IMPLICATIONS

The coadministration of lobeglitazone and amlodipine did not affect the pharmacokinetics of lobeglitazone or amlodipine in these healthy male Korean subjects. ClinicalTrials.gov identifier: NCT01341392.

Effect of ketoconazole on lobeglitazone pharmacokinetics in Korean volunteers

PURPOSE

Lobeglitazone, a peroxisome proliferator-activated receptor-γ agonist, is metabolized primarily by the cytochrome P450 (CYP) 3A4 isoenzyme. Individuals concomitantly taking lobeglitazone and a CYP3A4 inhibitor may experience some adverse effects secondary to increased systemic exposure to lobeglitazone. To address such potential concern, we evaluated the effects of ketoconazole, a prototypic CYP3A4 inhibitor, on the pharmacokinetic (PK) properties and associated adverse effects of lobeglitazone.

METHODS

A PK drug-drug interaction study was conducted in healthy individuals between 20 and 45 years old in a randomized, open-label, 2-way crossover design. Even though the PK study was performed on a single dose of lobeglitazone, multiple ketoconazole doses were given to ensure that the full extent of inhibition of CYP3A4 was maintained during the PK sampling. All study participants received a single oral dose of lobeglitazone 0.5 mg with or without 9 oral 200-mg doses of ketoconazole pretreatment twice daily. The primary PK parameter end points (AUC and Cmax) were estimated using noncompartmental analysis, and the 90% CIs for the geometric mean ratios (ratio of lobeglitazone and ketoconazole to lobeglitazone alone) were investigated. Tolerability (adverse events, vital signs, ECG, and laboratory tests) was also assessed.

FINDINGS

A total of 24 Korean men (mean age, 26 years; age range, 20-32 years; mean weight, 68 kg; weight range, 59-81 kg) completed the study and were evaluable for lobeglitazone PK properties and tolerability. The mean (SD) Cmax values of lobeglitazone with and without ketoconazole were 49 (7) ng/mL and 48 (6) ng/mL at 1.5 and 1.0 hours after dosing, respectively. The mean (SD) AUC∞ values were 532 (117) ng·h/mL and 405 (110) ng·h/mL, respectively. Although the Cmax was not significantly affected, the geometric mean ratio for AUC∞ was increased by a point estimate of 1.33 (90% CI, 1.23-1.44). A single oral administration of lobeglitazone 0.5 mg with or without ketoconazole pretreatment did not produce any clinically significant adverse effects on vital signs, 12-lead ECG profiles, or laboratory tests.

IMPLICATIONS

The administration of lobeglitazone, 0.5 mg alone or in combination with multiple doses of ketoconazole, was generally well tolerated. The systemic exposure of lobeglitazone was increased to a modest extent by pretreatment with 9 twice-daily doses of ketoconazole. Clinicaltrials.gov identifier: NCT01330563.

Impact of ABCC2, ABCG2 and SLCO1B1 polymorphisms on the pharmacokinetics of pitavastatin in humans

Pitavastatin, a 3-hydroxyl-3-methylglutaryl-coenzyme A reductase inhibitor is distributed to the liver, a target organ of action and excreted mainly into the bile. To investigate the impact of influx (OATP1B1) and efflux (MRP2, BCRP) transporter alleles on its disposition, the pharmacokinetic (PK) parameters were compared among the following groups: SLCO1B1 (*15 carrier and non-carrier), ABCC2 (G1249A, C3972T, C-24T, G1549A, and G1774T), and ABCG2 (C421A) single nucleotide polymorphisms in 45 healthy Korean volunteers. Pitavastatin AUC(last) was higher in individuals carrying the SLCO1B1*15 allele than those not carrying it (144.1 ± 55.3 vs. 84.7 ± 25.7 h·ng/mL [mean ± SD], p = 0.002). The AUC(last) varied significantly according to the ABCC2 C-24T allele (103.4 ± 42.2, 80.2 ± 23.8, and 39.0 h·ng/mL in CC, CT and TT, respectively; p = 0.027). Other SNPs of ABCC2 and ABCG2 were not significant. The effect of these transporters and body weight on the AUC(last) and C(max) were tested, and only SLCO1B1 and ABCC2 C-24T genotypes were significant factors by analysis of covariance. These variants accounted for almost 50% of the variation in AUC(last) and C(max) of pitavastatin. Therefore, ABCC2 C-24T was significantly associated with pitavastatin human PK when the known effect of SLCO1B1*15 was also considered.

Is abdominal obesity associated with the 2009 influenza A (H1N1) pandemic in Korean school-aged children?

Please cite this paper as: Kim et al. (2012) Is abdominal obesity associated with the 2009 influenza A (H1N1) pandemic in Korean school‐aged children? Influenza and Other Respiratory Viruses 6(5), 313–317.

Objective  Given their medical vulnerabilities, we investigated the epidemiological factors related to H1N1 infection in school‐aged children.

Methods  This study analyzed data collected on 7448 school‐aged children in South Korea between 18 November and 8 December 2009.

Results  We found that H1N1 infection was associated with body mass index (BMI), waist circumference (WC), the use of facemasks, contact history with H1N1‐infected persons, and overseas travel history (P < 0·05). In addition, WC quartiles were significantly associated with H1N1 infection after adjusting for BMI and other confounding variables [OR (95% CI): 1·00, 1·10 (0·72–1·45), 1·13 (0·76–1·67), and 2·71 (1·74–4·24), respectively).

Conclusions  Abdominal obesity and the use of facemasks appear to be independently associated with H1N1 infection in school‐aged children. We infer that providing education on wearing facemasks and specific planning for abdominally obese children and adolescents may be effective means of reducing the spread of the influenza pandemic in school‐aged children.

Clinical predictors of novel influenza A (H1N1)infection in Korea

PURPOSE

Pandemic influenza A (H1N1) virus has spread rapidly and prompt diagnosis is needed for successful treatment and prevention of transmission. We investigated clinical predictors, validated the use of previous criteria with laboratory tests, and evaluated the clinical criteria for H1N1 infection in the Korean population.

MATERIALS AND METHODS

We analyzed clinical and laboratory evaluation data from outpatient clinics at Severance Hospital in Seoul, Korea between November 11 and December 5, 2009.

RESULTS

This analysis included a total of 828 patients. Of these, 372 (44.9%) patients were confirmed with H1N1 infection by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The most common and predictive symptom was cough (90.3%, OR 8.87, 95% CI 5.89- 13.38) and about 40% of H1N1-positive patients were afebrile. The best predictive model of H1N1 infection was cough plus fever or myalgia. The sensitivities, specificities, positive predictive values, and negative predictive values of our suggested criteria were 73.9%, 69.5%, 66.4%, and 76.6%, respectively.

CONCLUSION

Cough was the most common independent symptom in patients with laboratory-confirmed H1N1 infection, and while not perfect, the combination of cough plus fever or myalgia is suggested as clinical diagnostic criteria. Health care providers in Korea should suspect a cough without fever to be an early symptom of H1N1 infection.

Self-assembled growth and luminescence of crystalline Si/SiOx core-shell nanowires

Crystalline Si/SiOx core/shell nanowires (NWs) are self-assembled by annealing Ni-coated hydrogenated Si-rich SiOx (SRO:H) films at 1100 degrees C in the presence of Si powder. Plasma-enhanced chemical vapor deposition is used to grow 100 nm SRO:H thin films with varying silicon concentration (n(Si)). The NWs vary from SiOx nanowires to Si/SiOx core/shell structures depending on the composition of the SRO:H substrate, with the fraction of core/shell structures increasing with increasing Si concentration. As n(Si) increases from 37 to 43 at.%, the average diameter of the NWs also increases from 48 to 157 nm. A growth model based on the diffusion-assisted vapor-liquid-solid mechanism is proposed to explain how the core/shell structures are self-assembled. Photoluminescence (PL) spectra of the individual NWs have two major emission bands in the near UV (381 nm) and blue (423 nm) ranges at n(Si) = 43 at.%, named as UV and BL PL bands, respectively. In contrast, only the BL PL band is observed at n(Si) < or = 39 at.%. These results suggest that the BL and UV PL bands can be attributed to the defect states in the SiOx shell and at the Si core/SiOx shell interface, respectively, and that the BL band is closely related to the growth process of the NWs.

Relationship Between Earlobe Crease and Brachial-ankle Pulse Wave Velocity in Non-hypertensive, Non-diabetic Adults in Korea

OBJECTIVES

Several studies have found a significant association between the presence of earlobe crease (ELC) and cardiovascular disease (CVD). Brachial-ankle Pulse Wave Velocity (baPWV) is a non-invasive and useful measure of arterial stiffness predicting cardiovascular events and mortality. However, few studies have reported the relationship between ELC and baPWV as a new measure of arterial stiffness. The purpose of this study was to determine whether ELC is related to baPWV in non-diabetic, non-hypertensive, and apparently healthy Korean adults.

METHODS

A cross-sectional study was conducted on 573 non-hypertensive, non-diabetic Korean adults aged 20-80 yr. Subjects were stratified into three groups according to gender and menopausal status. baPWV was measured by an automatic waveform analyser. The association between ELC and baPWV was assessed by multiple linear regression analysis after adjusting for conventional cardiovascular disease risk factors including age, gender, blood pressure, lipid profile, and smoking status etc.

RESULTS

The overall frequency of ELC was 19.02% and the subjects with ELC showed significantly higher mean baPWV (p<0.0001). Multiple linear regression of subjects revealed that the presence of ELC was independently associated with baPWV (male, p<0.0001; premenopausal female p=0.0162; postmenopausal female p=0.0208).

CONCLUSION

ELC had a significant correlation with baPWV, independently controlling for other classical cardiovascular risk factors in adults aged 20 yr or older. ELC is an important surrogate marker of increased arterial stiffness as measured by baPWV in Korean adults.

Improved search for nu(mu) --> nu(e) oscillation in a long-baseline accelerator experiment

We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level.

Search for coherent charged pion production in neutrino-carbon interactions

We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.

Mortality risk factors of Acinetobacter baumannii bacteraemia

BACKGROUND

Acinetobacter baumannii is one of the most important nosocomial pathogens, and its multiple antibiotic resistance has emerged as an obstacle in the treatment of these infections worldwide.

AIMS

To identify risk factors of mortality for A. baumannii bacteraemia.

METHODS

A retrospective cohort study of 72 patients with significant A. baumannii bacteraemia was conducted to evaluate risk factors for mortality.

RESULTS

The median age of the 72 enrolled patients was 48 years, 96% of the cases were hospital-acquired, and the bacteraemia-related mortality rate was 29% (21 of 72 patients). Univariate analysis revealed that the risk factors for mortality included: an elevated acute physiology and chronic health evaluation (APACHE II) score, receipt of in vitro ineffective definitive antimicrobial therapy, in vitro A. baumannii resistance to cefoperazone/ sulbactam, neutropenia, and presentation with septic shock. Multivariate analysis reveals that the independent risk factors for mortality are neutropenia and elevated APACHE II scores.

CONCLUSION

Risk factors such as neutropenia and elevated APACHE II scores are found to be associated with higher mortality rates of A. baumannii bacteraemia. Further study is necessary for the determination of optimal strategies for both the prevention and treatment of these infections.

Evidence for muon neutrino oscillation in an accelerator-based experiment

We present results for nu(mu) oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced nu(mu) beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy-dependent disappearance of nu(mu), which we presume have oscillated to nu(tau). The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).

Search for electron neutrino appearance in a 250 km long-baseline experiment

We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2).

Indications of neutrino oscillation in a 250 km long-baseline experiment

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.

Observation of a (6)(LambdaLambda)He double hypernucleus

A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.

Simultaneous ureterocystoplasty and living related renal transplantation

Enterocystoplasty in preparation for renal transplantation in children with severely dysfunctional bladders is widely accepted by pediatric urologists and transplant surgeons alike. The risk for septic and other complications in this immunosuppressed population remains elevated however, since problems inherent to the use of bowel or stomach in the urinary tract become magnified in these patients. In addition, simultaneous enterocystoplasty and transplantation carry a significant risk, and we must therefore subject these children to two major operations within a short time span. We herein describe our experience with combining simultaneously ureterocystoplasty and renal transplantation in a child. We believe this procedure has major relevance, in particular in the group of patients with posterior urethral valves and chronic renal failure.

Ureterocystoplasty with preservation of ipsilateral renal function

Recently the ureter has been used for bladder augmentation in selected patients with abnormal bladders and dilated upper tracts. The ureter has several advantages over other forms of bladder augmentation because it alleviates electrolyte disturbances, mucous production, and the disruption of the gastrointestinal tract. Initial reports emphasized the use of the entire ureter and renal pelvis in patients with an ipsilateral dilated nonfunctioning renal unit. Herein the authors report five cases of ureterocystoplasties performed since July 1993, in which the ipsilateral renal unit was preserved. All patients underwent preoperative videourodynamic studies, which showed small-for-age bladder capacity and poor compliance. Three patients underwent unilateral ureterocystoplasty, and two had bilateral ureterocystoplasty. Transureteroureterostomy (TUU) was performed in all patients, and most of the ipsilateral dilated ureter was used for augmentation. In two patients who had partial unilateral duplication, ipsilateral upper-to-lower ureteropyelostomy was done in addition to the TUU to maximize the amount of ureter available for augmentation. The follow-up period ranges from 6 to 24 months. All patients are continent and free of vesicoureteral reflux. All show stabilization or improvement of their upper tracts. Pressure-specific bladder capacity (bladder capacity at 30 cm of water pressure) increased by 350% (from a mean of 142 mL to 500 mL). The ureter is an excellent choice for augmentation cystoplasty in selected patients. An ipsilateral functioning renal unit is not a contraindication for ureterocystoplasty.

Ureterocystoplasty

Augmentation cystoplasty is the treatment of choice for the hyperreflexic, poorly compliant bladder unresponsive to medical treatment. While the etiology for such bladders is multiple, the clinical manifestations are few and include urinary incontinence, urinary tract infections, and upper tract deterioration. When such bladders are accompanied by hydroureteronephrosis with or without reflux, the dilated ureter and pelvis may be used to augment the bladder. Ureterocystoplasty is rapidly gaining acceptance among pediatric urologic surgeons. Dilated ureter is clearly the best tissue available for augmentation. It is lined with transitional cell epithelium, and the muscular backing provides the necessary properties for a compliant reservoir. The lack of mucous production and absorptive or secretory properties of urothelium prevents some of the most common problems encountered with other forms of augmentation cystoplasty (e.g., metabolic abnormalities, mucous production, lithiasis, and recurrent infections). The use of urothelium also eliminates the long-term concern of malignant degeneration of bowel used in augmentation.