Hao-Kuang Wang

Population based study on patients with traumatic brain injury suggests increased risk of dementia

Objective The relationship between traumatic brain injury (TBI) and the risk of dementia remains controversial. This population based study was designed to estimate and compare the risk of dementia in TBI and non-TBI individuals during the 5 year period after TBI. Methods This study was a retrospective cohort study. Data were obtained from the Longitudinal Health Insurance Database 2000. We included 44 925 patients receiving ambulatory or hospital care and 224 625 non-TBI patients; patients were matched for sex, age and year of index use of healthcare. Patients <15 years of age and those admitted to the intensive care unit were excluded. Each individual was studied for 5 years to identify the subsequent development of dementia. Data were analysed by Cox proportional hazard regression. Results During the 5 year follow-up period, 1196 TBI (2.66%) and 224 625 non-TBI patients (1.53%) patients developed dementia. During the 5 year follow-up period, TBI was independently associated with a 1.68 (range 1.57–1.80) times greater risk of dementia after adjusting for sociodemographic characteristics and selected comorbidities. Conclusions The findings of this study suggest an increased risk of dementia among individuals with TBI. We suggest the need for more intensive medical monitoring and health education in individuals with TBI.

Sleep apnea and the risk of chronic kidney disease: A nationwide population-based cohort study

STUDY OBJECTIVES Sleep apnea (SA) is characterized by apnea during sleep and is associated with cardiovascular diseases and an increase in all-cause mortality. Chronic kidney disease (CKD) is a global health problem that has placed a substantial burden on healthcare resources. However, the relationship between SA and the incidence of CKD is not clear. This study aimed to determine whether SA is an independent risk factor for the development of CKD. DESIGN Retrospective cohort study. SETTING National Health Insurance Research Database (NHIRD) of Taiwan. PATIENTS OR PARTICIPANTS A total of 4,674 adult patients (age ≥ 30 y) in whom SA was newly diagnosed from 2000 to 2010 were included, together with 23,370 non-SA patients as the comparison group. The two groups were frequency-matched for sex, age, and year of receiving medical service. Each individual was followed until 2011. INTERVENTIONS N/A. MEASUREMENTS AND RESULTS These two groups were monitored and observed for the occurrence of CKD. Patients with SA experienced a 1.94-fold increase (95% confidence interval [CI], 1.52-2.46; P < 0.001) in the incidence of CKD, which was independent of sex, age, and comorbid medical conditions. Additionally, they showed a 2.2-fold increase (95% CI, 1.31-3.69; P < 0.01) in the incidence of end-stage renal disease (ESRD). CONCLUSIONS Patients with sleep apnea are at increased risk for chronic kidney disease and end-stage renal disease compared with the general population. As such, screening renal function and treatment of chronic kidney disease is an important issue in patients with sleep apnea.

A case study of the highly time-resolved evolution of aerosol chemical and optical properties in urban Shanghai, China

Characteristics of the chemical and optical properties of aerosols in urban Shanghai and their relationship were studied over a three-day period in October 2011. A suite of real-time instruments, including an Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS), a Monitor for AeRosols and GAses (MARGA), a Cavity Ring Down Spectrometer (CRDS), a nephelometer and a Scanning Mobility Particle Sizer (SMPS), was employed to follow the quick changes of the aerosol properties within the 72 h sampling period. The origin of the air mass arriving in Shanghai during this period shifted from the East China Sea to the northwest area of China, offering a unique opportunity to observe the evolution of aerosols influenced by regional transport from the most polluted areas in China. According to the meteorological conditions and temporal characterizations of the chemical and optical properties, the sampling period was divided into three periods. During Period 1 (00:00–23:00 LT, 13 October), the aerosols in urban Shanghai were mainly fresh and the single scattering albedo varied negatively with the emission of elemental carbon, indicating that local sources dominated. Period 2 (23:00 LT on 13 October to 10:00 LT on 15 October) was impacted by regionally transported pollutants and had the highest particulate matter (PM) mass loading and the lowest particle acidity, characterized by large fractions of aged particles and high secondary ion (nitrate, sulfate and ammonium) mass concentrations. Comparison between ATOFMS particle acidity and quantitative particle acidity by MARGA indicated the significance of semi-quantitative calculation in ATOFMS. Two sub-periods were identified in Period 2 based on the scattering efficiency of PM 1 mass. Period 3 (from 10:00 LT on 15 October to 00:00 LT on 16 October) had a low PM1/PM10 ratio and a new particle formation event. The comparison of these sub-periods highlights the influence of particle mixing state on aerosol optical properties. We directly observed the influence of regionally transported pollutants on local aerosol properties and demonstrate that the PM mass extinction efficiency is largely determined by the mixing states of the aerosol.

Comparing Clinical Outcomes Following Percutaneous Vertebroplasty with Conservative Therapy for Acute Osteoporotic Vertebral Compression Fractures

OBJECTIVE To compare the efficacy of percutaneous vertebroplasty (PV) with conservative therapy for patients with acute vertebral compression fractures. DESIGN Prospective, nonrandomized, comparison study. BACKGROUND The efficacy of PV has not been well established because there have been few comparative studies with conservatively treated control groups. PATIENTS AND METHODS Fifty-five consecutive patients (8 men and 47 women, age 47-94) with osteoporosis and symptomatic acute vertebral compression fractures were enrolled. thirty-two patients received pv, whereas 23 received conservative therapy. OUTCOME MEASURES Changes in pain intensity, physical functioning, and pain medication requirement were evaluated. RESULTS Both PV and conservative therapy provided pain reduction (P < 0.001), improvements in physical functioning (P < 0.001), and decreased medication (P < 0.001). Reductions in visual analogue pain scores were more significant in the vertebroplasty group at 1 (P < 0.001) and 4 weeks (P < 0.001) but not at 12 months. Improvements in physical functioning were significant at 1 (P < 0.001) and 4 weeks (P < 0.001). Medication requirements were lower in the vertebroplasty group at all three time points. CONCLUSIONS Pain relief, physical functioning improvement, and medication requirement after vertebroplasty are immediately and significantly better when compared with conservative therapy.

The impact of tracheostomy timing in patients with severe head injury: An observational cohort study

STUDY DESIGN A retrospective analysis of 66 adults with severe head injury admitted to the neurosurgical intensive care unit (ICU) who required tracheostomy. OBJECTIVE The purpose of this cohort study was to examine the impact of the tracheostomy timing in patients with severe head injury. METHODS Patients were included in this study if they were admitted to the neurosurgical ICU because of severe head injury and if tracheostomy was performed. The patients were classified into 2 groups: early tracheostomy (ET) and late tracheostomy (LT). The timing of tracheostomy was considered early if it was performed by day 10 of mechanical ventilation and late if it was performed after day 10. We compared the duration of mechanical ventilation, length of stay (LOS) at ICU, hospital LOS, incidence of pneumonia, duration of antibiotics use, and mortality between the ET and LT groups. RESULTS Of the 2481 patients with severe head injury admitted to the neurosurgical ICU, 66 (2.7%) required tracheostomy; 16 of whom were in the ET group and 50 were in the LT group. The ICU LOS was significantly shorter in the ET group (p<0.001). The incidence of nosocomial pneumonia was lower in the ET group (p=0.04) and the duration of antibiotic use was significantly shorter in the ET group (p<0.001). The patients in the ET group had a lower incidence of pneumonia caused by gram-negative microorganisms (p=0.001). CONCLUSIONS ET in patients with severe head injury might contribute to a shorter duration of ICU LOS, lower incidence of gram-negative microorganism-related nosocomial pneumonia, and shorter duration of antibiotic use.

Increased risk of hip fractures in patients with dementia: a nationwide population-based study

BackgroundDementia has been associated with an increased risk of hip fracture. However, little research has been conducted on the impact of dementia on wrist or vertebral fracture development. The aim of this study was to investigate whether dementia is a risk factor for different types of fracture in Taiwan.MethodsThe study sample was drawn from Taiwans National Health Insurance Research Database of reimbursement claims, and comprised 1408 patients who visited ambulatory care centers or were hospitalized with a diagnosis of dementia. The comparison group consisted of 7040 randomly selected individuals. Cox proportional hazard regression model was used to examine associations between dementia and the risk of different types of fracture.ResultsDuring a 3-year follow-up period, 264 patients with dementia (18.75%) and 1098 patients without dementia (15.60%) developed fractures. Dementia was independently associated with increased risk of hip fracture [adjusted hazard ratio (HR) 1.92, 95% CI 1.48-2.49]. Patients with dementia and osteoporosis had the highest risk of developing hip fracture (adjusted HR 2.27, 95% CI 1.28-4.01). Dementia did not increase wrist fracture or vertebral fracture risk when compared to the control group, even in patients with osteoporosis.ConclusionsIndividuals with dementia are at greater risk of developing hip fracture, particularly if they also have osteoporosis. Early mental screening programs and health education should be initiated to decrease disability and dependence in patients with dementia.

Magnesium sulfate and nimesulide have synergistic effects on rescuing brain damage after transient focal ischemia.

Magnesium sulfate and nimesulide are commonly used drugs with reported neuroprotective effects. Their combination as stroke treatment has the potential benefits of decreasing individual drug dosage and fewer adverse effects. This study evaluated their synergistic effects and compared a low-dose combination with individual drug alone and placebo. Sprague-Dawley rats underwent 90 min of focal ischemia with intraluminal suture occlusion of the middle cerebral artery followed by reperfusion. The rats were randomly assigned to receive one of the following treatments: placebo, magnesium sulfate (MgSO₄; 45 mg/kg) intravenously immediately after the induction of middle cerebral artery occlusion, nimesulide (6 mg/kg) intraperitoneally before reperfusion, and combined therapy. Three days after the ischemia-reperfusion insult, therapeutic outcome was assessed by 2,3,5-triphenyltetrazolium chloride staining and a 28-point neurological severity scoring system. Cyclooxygenase-2, prostaglandin E₂, myeloperoxidase, and caspase-3 expression after treatment were evaluated using Western blot analyses and immunohistochemical staining, followed by immunoreactive cell analysis using tissue cytometry. Only the combination treatment group showed a significant decrease in infarction volume (10.93±6.54% versus 26.43±7.08%, p<0.01), and neurological severity score (p<0.05). Low-dose MgSO₄ or nimesulide showed no significant neuroprotection. There was also significant suppression of cyclooxygenase-2, prostaglandin E₂, myeloperoxidase, and caspase-3 expression in the combination treatment group, suggesting that the combination of the two drugs improved the neuroprotective effects of each individual drug. MgSO₄ and nimesulide have synergistic effects on ischemia-reperfusion insults. Their combination helps decrease drug dosage and adverse effects. Combined treatment strategies may help to combat stroke-induced brain damage in the future.

Memantine Alleviates Brain Injury and Neurobehavioral Deficits after Experimental Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) causes brain injury via glutamate excitotoxicity, which leads to an excessive Ca2+ influx and this starts an apoptotic cascade. Memantine has been proven to reduce brain injury in several types of brain insults. This study investigated the neuro-protective potential of memantine after SAH and explored the underlying mechanisms. An endovascular perforation rat model of SAH was used and Sprague–Dawley rats were randomized into sham surgery, SAH + vehicle, and SAH + memantine groups. The effects of memantine on SAH were evaluated by assessing the neuro-behavioral functions, blood–brain barrier (BBB) permeability and neuronal cell preservation. The mechanisms of action of memantine, with its N-methyl-d-aspartate (NMDA) antagonistic characteristics on nitric oxide synthase (NOS) expression and peroxynitrite formation, were also investigated. The apoptotic cascade after SAH was suppressed by memantine. Neuronal NOS (nNOS) expression, peroxynitrite formation, and subsequent oxidative/nitrosative stress were also reduced. Memantine effectively preserved BBB integrity, rescued neuronal injury, and improved neurological outcome in experimental SAH. Memantine has neuro-protective potential in experimental SAH and may help combat SAH-induced brain damage in the future.

The GLP-1 receptor agonists exendin-4 and liraglutide alleviate oxidative stress and cognitive and micturition deficits induced by middle cerebral artery occlusion in diabetic mice

BackgroundGlucagon-like peptide 1 (GLP-1) analogs protect a variety of cell types against oxidative damage and vascular and neuronal injury via binding to GLP-1 receptors. This study aimed to investigate the effects of the GLP-1 analogs exendin-4 and liraglutide on cerebral blood flow, reactive oxygen species production, expression of oxidative stress-related proteins, cognition, and pelvic sympathetic nerve-mediated bladder contraction after middle cerebral artery occlusion (MCAO) injury in the db/db mouse model of diabetes.ResultsSixty minutes of MCAO increased blood and brain reactive oxygen species counts in male db/db mice, as revealed by dihydroethidium staining. MCAO also increased nuclear factor-κB and intercellular adhesion molecule-1 expression and decreased cerebral microcirculation. These effects were attenuated by treatment with exendin-4 or liraglutide. MCAO did not affect basal levels of phosphorylated Akt (p-Akt) or endothelial nitric oxide synthase (p-eNOS); however, exendin-4 and liraglutide treatments significantly enhanced p-Akt and p-eNOS levels, indicating activation of the p-Akt/p-eNOS signaling pathway. MCAO-induced motor and cognitive deficits and micturition dysfunction, indicated by reduced pelvic nerve-mediated voiding contractions and increased nonvoiding contractions, were also partially attenuated by exendin-4 treatment.ConclusionsThe above data indicate that treatment with GLP-1 agonists exerts protective effects against oxidative, inflammatory, and apoptotic damage in brain areas that control parasympathetic/pelvic nerve-mediated voiding contractions and cognitive and motor behaviors in a diabetic mouse model.

Mood disorders after traumatic brain injury in adolescents and young adults: a nationwide population-based cohort study.

OBJECTIVE To delineate the relationship between traumatic brain injury (TBI) and mood disorders from population-based data in Taiwan. STUDY DESIGN This prospectively followed cohort study involved a subset of the National Health Insurance Research Database containing complete inpatient and outpatient data of 1 million randomly drawn beneficiaries. We included 10- to 24-year-old patients (n = 15,203) receiving the diagnosis of TBI in ambulatory visits or hospitalization from 2000-2004 and their age- and sex-matched comparison insureds using health service in the same year (n = 76,015). Diagnosis of mood disorders was recorded within 5 years after the traumatic event or index use of health service. Baseline demographics, clinical characteristics, and premorbid psychiatric conditions were compared using χ(2) analysis. Increased risk during the 5-year follow-up period was represented by crude and adjusted hazard ratios with 95% CI using a Cox proportional hazard regression. RESULTS A total of 451/15,203 patients with TBI (2.97%) received a diagnosis of mood disorders in the 5-year follow-up period compared with 1153/97,445 individuals (1.52%) without antecedent TBI. After adjusting for select premorbid comorbidities, TBI remained a significant predisposing factor with a 1.96-fold (95% CI 1.74-2.22) increase in risk of mood disorders. CONCLUSIONS Our findings show a higher likelihood of manifesting mood disorders in adolescents and young adults who sustained a prior TBI. Health professionals should carefully monitor both the physical and psychological impacts of head trauma.