Joongyub Lee

Pediatric moyamoya disease: An analysis of 410 consecutive cases

Moyamoya disease (MMD) is a cerebrovascular occlusive disease of the bilateral internal carotid arteries that causes a compensatory abnormal vascular network at the base of brain. The rare incidence and various surgical techniques applied have limited the clinical research on MMD.

Radiosurgical treatment of vestibular schwannomas in patients with neurofibromatosis type 2: tumor control and hearing preservation.

The radiosurgical treatment of vestibular schwannomas in patients with neurofibromatosis type 2 (NF2) is controversial. The authors investigated the radiologically proven tumor control rate after gamma knife radiosurgery. The factors that affect tumor control and serviceable hearing preservation were analyzed.

Zolpidem Use and Risk of Fracture in Elderly Insomnia Patients

Objectives To evaluate the risk of fractures related with zolpidem in elderly insomnia patients. Methods Health claims data on the entire South Korean elderly population from January 2005 to June 2006 were extracted from the Health Insurance Review and Assessment Service database. We applied a case-crossover design. Cases were defined as insomnia patients who had a fracture diagnosis. We set the hazard period of 1 day length prior to the fracture date and four control periods of the same length at 5, 10, 15, and 20 weeks prior to the fracture date. Time independent confounding factors such as age, gender, lifestyle, cognitive function level, mobility, socioeconomic status, residential environment, and comorbidity could be controlled using the casecrossover design. Time dependent confounding factors, especially co-medication of patients during the study period, were adjusted by conditional logistic regression analysis. The odds ratios and their 95% confidence intervals (CIs) were estimated for the risk of fracture related to zolpidem. Results One thousand five hundred and eight cases of fracture were detected in insomnia patients during the study period. In our data, the use of zolpidem increased the risk of fracture significantly (adjusted odds ratio [aOR], 1.72; 95% CI, 1.37 to 2.16). However, the association between benzodiazepine hypnotics and the risk of fracture was not statistically significant (aOR, 1.00; 95% CI, 0.83 to 1.21). Likewise, the results were not statistically significant in stratified analysis with each benzodiazepine generic subgroup. Conclusions Zolpidem could increase the risk of fracture in elderly insomnia patients. Therefore zolpidem should be prescribed carefully and the elderly should be provided with sufficient patient education.

Prevalence Rate and Associated Factors of Sarcopenic Obesity in Korean Elderly Population

This study was conducted to estimate the prevalence rates and to explore associated factors of sarcopenic obesity (SO) in 2,221 Koreans over 60 yr-of age from the Fourth Korea National Health and Nutrition Examination Survey (2009). Participants were assessed by dual energy X-ray absorptiometry. Appendicular skeletal muscle mass divided by body weight was used to define sarcopenia and waist circumference was used to define obesity. We estimated the prevalence rates of SO according to age-groups, sex and region. In addition, each group was compared by demographic characteristics, metabolic status, nutrition, and physical activity. The prevalence rates of SO were 6.1% (95% confidential interval [CI] = 6.1-6.2) for men and 7.3% (95% CI = 7.3-7.3) for women, respectively. SO was positively associated with no current working and the number of combined medical conditions. High serum insulin level was positively associated with SO, whereas vitamin D was negatively associated with SO in both men and women. In conclusion, the prevalence rates of SO are 6.1% in men and 7.3% in women. SO is associated with insulin resistance, inappropriate nutrition, and low physical activity.

Differential Cardiovascular Outcomes after Dipeptidyl Peptidase-4 Inhibitor, Sulfonylurea, and Pioglitazone Therapy, All in Combination with Metformin, for Type 2 Diabetes: A Population-Based Cohort Study

Background/Objectives Data on the comparative effectiveness of oral antidiabetics on cardiovascular outcomes in a clinical practice setting are limited. This study sought to determine whether a differential risk of cardiovascular disease (CVD) exists for the combination of a dipeptidyl peptidase-4 (DPP-4) inhibitor plus metformin versus a sulfonylurea derivative plus metformin or pioglitazone plus metformin. Methods We conducted a cohort study of 349,476 patients who received treatment with a DPP-4 inhibitor, sulfonylurea, or pioglitazone plus metformin for type 2 diabetes using the Korean national health insurance claims database. The incidence of total CVD and individual outcomes of myocardial infarction (MI), heart failure (HF), and ischemic stroke (IS) were assessed using the hazard ratios (HRs) estimated from a Cox proportional-hazards model weighted for a propensity score. Results During follow-up, 3,881 patients developed a CVD, including 428 MIs, 212 HFs, and 1,487 ISs. The adjusted HR with 95% confidence interval (CI) for a sulfonylurea derivative plus metformin compared with a DPP-4 inhibitor plus metformin was 1.20 (1.09-1.32) for total CVD; 1.14 (1.04-1.91) for MI; 1.07 (0.71-1.62) for HF; and 1.51 (1.28-1.79) for IS. The HRs with 95% CI for total CVD, MI, HF, and IS for pioglitazone plus metformin were 0.89 (0.81-0.99), 1.05 (0.76-1.46), 4.81 (3.53-6.56), and 0.81 (0.67-0.99), respectively. Conclusions Compared with a DPP-4 inhibitor plus metformin, treatment with a sulfonylurea drug plus metformin was associated with increased risks of total CVD, MI, and IS, whereas the use of pioglitazone plus metformin was associated with decreased total CVD and IS risks.

Evaluation of Focal Cortical Dysplasia and Mixed Neuronal and Glial Tumors in Pediatric Epilepsy Patients Using 18F-FDG and 11C-Methionine PET

Focal cortical dysplasia (FCD) and mixed neuronal and glial tumors share many clinical characteristics; therefore, the presurgical differential diagnosis of these diseases using MRI is difficult in some cases. The aim of this study was to determine whether 11C-methionine PET, compared with 18F-FDG PET, was useful for the evaluation of these diseases. Methods: The clinical and imaging data of 30 pediatric lesional epilepsy patients pathologically diagnosed with FCD, dysembryoplastic neuroepithelial tumor (DNT), or ganglioglioma were reviewed. Eleven patients had FCD, 8 patients had a DNT, and 11 patients had a ganglioglioma. 18F-FDG and 11C-methinine PET scans were obtained from 25 patients and 15 patients, respectively. Visual grading analysis and quantitative assessment of 18F-FDG and 11C-methionine PET, represented as a lesion–to–gray matter ratio (LGR), were performed. Results: In the visual grading analysis, both 18F-FDG PET and 11C-methionine PET detected a significant difference among the 3 disease groups (P = 0.033 and P = 0.016, respectively), but discrimination of FCD from mixed neuronal and glial tumors was possible only with 11C-methionine PET. The mean LGR of 18F-FDG PET was 0.502 ± 0.119 for FCD, 0.631 ± 0.107 for DNTs, and 0.620 ± 0.196 for gangliogliomas; there was no significant difference in LGR among the groups (P = 0.111). However, the mean LGR of 11C-methionine PET was 1.078 ± 0.182 for FCD, 1.564 ± 0.368 for DNT, and 2.114 ± 0.723 for gangliogliomas; there was a significant difference in LGR among the groups (P = 0.014). Post hoc analysis revealed that the LGR of FCD was significantly different from that of DNTs and gangliogliomas. The mean LGR value of DNTs fell between those of FCD and gangliogliomas. Conclusion: Although 18F-FDG plays a major role in the preoperative work-up of epilepsy surgery patients, it appears from this study that 18F-FDG does not contribute to the differential diagnosis and that another tracer such as 11C-methinine is required. 11C-methinine PET results correlated well with the pathologic spectrum in pediatric lesional epilepsy patients.

Risk of intracranial haemorrhage in antidepressant users with concurrent use of non-steroidal anti-inflammatory drugs: nationwide propensity score matched study

Objective To define the risk of intracranial haemorrhage among patients treated with antidepressants and non-steroid anti-inflammatory drugs (NSAIDs), compared with the risk among those treated with antidepressants without NSAIDs. Design Retrospective nationwide propensity score matched cohort study. Setting Korean nationwide health insurance database between 1 January 2009 and 31 December 2013. Participants Patients who began receiving antidepressants for the first time (index date) without a history of having received a prescription for antidepressants during the preceding year. Patients who had been diagnosed as having cerebrovascular diseases within a year before the index date were excluded. Main outcome measure Time to first hospital admission with intracranial haemorrhage within 30 days after drug use. Matched Cox regression models were used to compare the risk of intracranial haemorrhage among patients who were treated with antidepressants with and without NSAIDs, after propensity score matching with a 1:1 ratio. Results After propensity score estimation and matching in a 1:1 ratio, the cohort used in the analysis included 4 145 226 people. The 30 day risk of intracranial haemorrhage during the entire study period was higher for combined use of antidepressants and NSAIDs than for use of antidepressants without NSAIDs (hazard ratio 1.6, 95% confidence interval 1.32 to 1.85). No statistically meaningful differences were found in risk of intracranial haemorrhage between the antidepressant drug classes. Conclusions Combined use of antidepressants and NSAIDs was associated with an increased risk of intracranial haemorrhage within 30 days of initial combination.

Use of osteoporosis medications after hospitalization for hip fracture: a cross-national study.

BACKGROUND Although current osteoporosis management guidelines recommend use of pharmacologic treatment after hip fracture, the care of such patients has been suboptimal. The objective of this cross-national study was to quantify the use of and adherence to osteoporosis medication after hip fracture in 3 countries with different healthcare systems—the United States, Korea, and Spain. METHODS In 3 cohorts of patients aged ≥65 years hospitalized for hip fracture, we calculated the proportion receiving ≥1 osteoporosis drug after discharge. Adherence to osteoporosis treatment was measured as the proportion of days covered (PDC) during the first year after the hip fracture. RESULTS We identified 86,202 patients with a hip fracture: 4704 (US Medicare), 6700 (US commercial), 57,631 (Korea), and 17,167 (Spain). The mean age was 77-83 years, and 74%-78% were women. In the year before the index hip fracture, 16%-18% were taking an osteoporosis medication. Within 3 months after the index hip fracture, 11% (US Medicare), 13% (US commercial), 39% (Korea), and 25% (Spain) of patients filled ≥1 prescription for osteoporosis medication. For those who filled ≥1 prescriptions for an osteoporosis medication, the mean PDC in the year after the fracture was 0.70 (US Medicare), 0.67 (US commercial), 0.43 (Korea), and 0.66 (Spain). CONCLUSIONS Regardless of differences in healthcare delivery systems and medication reimbursement plans, the use of osteoporosis medications for the secondary prevention of osteoporotic fracture was low. Adherence to osteoporosis treatment was also suboptimal, with the PDC <0.70 in all 3 countries.

β1 selectivity of β-blockers and reduced risk of fractures in elderly hypertension patients

INTRODUCTION Hypertension and osteoporosis are prevalent in the elderly population. Treatments beneficial to both conditions would be helpful. We examined the protective effect of β-blockers (BBs) and their receptor selectivity against fractures compared to other antihypertensives. MATERIALS AND METHODS A retrospective cohort was assembled using the Korean Health Insurance Review and Assessment Service database from January 2005 to June 2006. The cohort consisted of 501,924 patients (ages 65 and older) on single-drug therapy for hypertension. Participants were followed to either the date of the first fracture, date of death or end of the study period (30 June 2006), whichever came first. Coxs proportional hazard model was used to calculate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) by sex, adjusting for confounders. Risk of fractures by BBs according to β1 selectivity was compared to non BBs measured in aHR. RESULTS Among 501,924 (65% female), the incidence density of fractures in non BB users was 29.3 and 48.2 per 1000 person-years for men and women, respectively, which was higher than in BB users (17.2 for men and 30.5 for women). Compared to BB users, non BB users showed an increased risk of all fracture [aHR 1.56 (95% CI, 1.42-1.72) in men and 1.44 (95% CI, 1.36-1.51) in women] and hip fracture [aHR 2.17 (95% CI 1.45-3.24) in men and 1.61 (95% CI 1.31-1.98) in women] after adjusting for confounding variables. Compared to BBs, the risks of all fractures in α-blockers, calcium channel blockers, diuretics, and renin-angiotensin-aldosterone system blockers were significantly higher (1.72, 1.77, 1.58, 1.29 in men; 2.11, 1.50, 1.46, 1.22 in women, respectively). Compared to non BBs, β1 selective BBs showed a lower risk of fracture (39% for men and 33% for women) after adjusting for confounding factors. On the contrary, non-selective BBs were not protective against fracture. CONCLUSION Our results suggested that β1 selective BBs reduce the risk of fractures compared to other classes of antihypertensives in an elderly population, which could have practical applications for strategies to control and prevent adverse outcomes from both hypertension and osteoporosis in this population.

Risk of ischemic stroke with the use of risperidone, quetiapine and olanzapine in elderly patients: a population-based, case-crossover study.

We conducted a case-crossover study to evaluate the comparative risk of ischemic stroke associated with the use of risperidone, quetiapine and olanzapine in geriatric patients using the Korean Health Insurance Review and Assessment Service database. Cases included elderly patients >64 years old who had experienced their first ischemic stroke (International Classification of Disease, Tenth Revision (ICD-10), I63) hospitalization from July 2005 to June 2006 and who had been without prior cerebrovascular diseases (ICD-10, I60–I69), or transient ischemic attack (ICD-10, G45). Exposures to risperidone, quetiapine and olanzapine were assessed during the 30 days prior to the stroke episode. We set two control periods with lengths which were the same as the hazard periods. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were estimated by conditional logistic regression. A total of 1601 cases of ischemic stroke with a mean age of 75.6 (±6.7) years were identified, among which 933 (58.3%) were female. An increased risk of ischemic stroke was associated with the use of risperidone (aOR=3.5, 95% CI 3.3–4.6) and quetiapine (aOR=2.7, 95% CI 2.0–3.6) during the 30 days prior to stroke: however, no significant risk was observed with olanzapine (aOR=1.2, 95% CI 0.7–2.0). The increased stroke risk in demented patients, assessed within 30 days after exposure, was also observed with olanzapine. However, the sample of olanzapine users was small and underpowered.