Szu-Yuan Li

Matrix metalloproteinase-9 deficiency attenuates diabetic nephropathy by modulation of podocyte functions and dedifferentiation

Diabetic nephropathy is characterized by excessive deposition of extracellular matrix protein and disruption of the glomerular filtration barrier. Matrix metalloproteinases (MMPs) affect the breakdown and turnover of extracellular matrix protein, suggesting that altered expression of MMPs may contribute to diabetic nephropathy. Here we used an MMP-9 gene knockout mouse model, with in vitro experiments and clinical samples, to determine the possible role of MMP-9 in diabetic nephropathy. After 6 months of streptozotocin-induced diabetes, mice developed markedly increased albuminuria, glomerular and kidney hypertrophy, and thickening of the glomerular basement membrane. Gelatin zymographic analysis and western blotting showed that there was enhanced MMP-9 protein production and activity in the glomeruli. However, MMP-9 knockout in diabetic mice significantly attenuated these nephropathy changes. In cultured podocytes, various cytokines related to diabetic nephropathy including TGF-β1, TNF-α, and VEGF stimulated MMP-9 secretion. Overexpression of endogenous MMP-9 induced podocyte dedifferentiation. MMP-9 also interrupted podocyte cell integrity, promoted podocyte monolayer permeability to albumin, and extracellular matrix protein synthesis. In diabetic patients, the upregulation of urinary MMP-9 concentrations occurred earlier than the onset of microalbuminuria. Thus, MMP-9 seems to play a role in the development of diabetic nephropathy.

Proton pump inhibitor use represents an independent risk factor for myocardial infarction

BACKGROUND There is substantial debate regarding the development of acute coronary syndrome in patients using proton pump inhibitors (PPIs) combined with clopidogrel. However, data remain limited to address the effect of PPIs alone on the subsequent risk of myocardial infarction (MI). We aimed to explore the subsequent risk of MI in PPI users who had no previous history of MI. METHODS The records of inpatients and outpatients with PPI prescriptions were retrieved from the Taiwan National Health Insurance Research Database between 2000 and 2009. We conducted two different study designs, the first using propensity score (PS)-matching analyses and the second using case-crossover analyses. The risk of developing MI for PPI users was analyzed in the PS-matched study. The association between risk of MI and prior PPI exposure was further validated in the case-crossover study. RESULTS In the PS-matched study, we included 126,367 PPI users and 126,367 PS-matched PPI non-users. After 120 days of follow-up, PPI use was associated with a 1.58-fold greater risk of MI (adjusted hazard ratio [HR] = 1.58, 95% confidence interval [CI] = 1.11 to 2.25). In the case-crossover study, adjusted odds ratios of PPI for MI risk were 4.61 (95% CI = 1.76 to 12.07) for the 7-day window and 3.47 (95% CI = 1.76 to 6.83) for the 14-day window. CONCLUSIONS Use of PPIs may be independently associated with an increased risk of MI. However, the benefits of PPIs may greatly outweigh the risks of adverse cardiovascular effects, with number needed to harm of 4357.

The Effect of Cold Temperature on Increased Exacerbation of Chronic Obstructive Pulmonary Disease: A Nationwide Study

Background Seasonal variations in the acute exacerbation of chronic obstructive pulmonary disease (COPD) have been reported. However, the influence of air temperature and other meteorological factors on COPD exacerbation remains unclear. Methods National Health Insurance registry data from January 1, 1999 to December 1, 2009 and meteorological variables from the Taiwan Central Weather Bureau for the same period were analyzed. A case-crossover study design was used to investigate the association between COPD exacerbation and meteorological variables. Results A total of 16,254 cases who suffered from COPD exacerbation were enrolled. We found that a 1°C decrease in air temperature was associated with a 0.8% increase in the exacerbation rate on event-days (95% confidence interval (CI), 1.015–1.138, p = 0.015). With a 5°C decrease in mean temperature, the cold temperature (28-day average temperature) had a long-term effect on the exacerbation of COPD (odds ratio (OR), 1.106, 95% CI 1.063–1.152, p<0.001). In addition, elderly patients and those who did not receive inhaled medication tended to suffer an exacerbation when the mean temperature dropped 5°C. Higher barometric pressure, more hours of sunshine, and lower humidity were associated with an increase in COPD exacerbation. Conclusions This study demonstrated the effect of cold temperatures on the COPD exacerbation rate. Elderly patients and those without inhaled medicine before the exacerbation event were affected significantly by lower mean temperatures. A more comprehensive program to prevent cold stress in COPD patients may lead to a reduction in the exacerbations rate of COPD.

Risks of Death and Stroke in Patients Undergoing Hemodialysis With New-Onset Atrial Fibrillation A Competing-Risk Analysis of a Nationwide Cohort

Background— Whether oral anticoagulant use should be considered in patients undergoing hemodialysis with atrial fibrillation (AF) remains controversial because of the uncertainty regarding risk-benefit assessments. The purpose of this study was to investigate the risk of ischemic stroke in patients undergoing hemodialysis with new-onset AF, in comparison with those without arrhythmia. Methods and Results— This nationwide, population-based, propensity score–matched cohort study used data from Taiwan’s National Health Insurance Research Database during 1998 to 2011 for patients on hemodialysis with new-onset nonvalvular AF and matched subjects without arrhythmia. The clinical end points were ischemic stroke (fatal or nonfatal), all-cause death, and other serious adverse cardiovascular events. In comparison with the matched cohort, patients with AF (n=6772) had higher risks of ischemic stroke (adjusted hazard ratio [aHR], 1.27; 95% confidence interval [CI], 1.13–1.43), all-cause death (aHR, 1.59; 95% CI, 1.52–1.67), in-hospital cardiovascular death (aHR, 1.83; 95% CI, 1.71–1.94), myocardial infarction (aHR, 1.33; 95% CI, 1.17–1.51), and hospitalization for heart failure (aHR, 1.90; 95% CI, 1.76–2.05). After considering in-hospital death as a competing risk, AF significantly increased the risk of heart failure (HR, 1.56; 95% CI, 1.45–1.68), but not those of ischemic stroke and myocardial infarction. Additionally, the predictive value of the CHA2DS2–VASc score for ischemic stroke was diminished in the competing-risk model. Conclusions— The risk of stroke was only modestly higher in patients undergoing hemodialysis with new-onset AF than in those without AF, and it became insignificant when accounting for the competing risk of in-hospital death.

Association Between Recent Use of Fluoroquinolones and Rhegmatogenous Retinal Detachment: A Population-Based Cohort Study

BACKGROUND An association between use of oral fluoroquinolones (FQs) and retinal detachment remains controversial. This study was to determine the association of recent use of oral FQs and rhegmatogenous retinal detachment (RRD) after adjustment for confounding factors known to be associated with RRD. METHODS This retrospective population-based cohort study with parallel groups included adults treated with an oral FQ (FQ cohort = 178 179 prescriptions) and propensity score-matched adults treated with oral amoxicillin (amoxicillin cohort = 178 179 prescriptions). The data were extracted from the Taiwan National Health Insurance Research Database from 1998 to 2010. Interaction terms were used to identify populations at risk. RRD was defined according to the International Classification of Diseases, Ninth Revision, Clinical Modification. RESULTS During the 90-day follow-up period, 96 patients (0.054%) in the FQ cohort developed RRD compared to 46 (0.026%) among the matched amoxicillin cohort. The overall adjusted hazard ratio (HR) for FQ use and RRD was 2.07 (95% confidence interval [CI], 1.45-2.96). The interval between use of oral FQs and onset of RRD was 35.5 days (interquartile range, 14-57 days). Interaction terms were not significant for age, sex, diabetes, indications for antimicrobials, or underlying ophthalmic conditions. The adjusted HRs differed for specific FQs. These were 10.68 (95% CI, 3.28-34.82) for ciprofloxacin, 2.41 (95% CI, .76-7.68) for levofloxacin, 2.00 (95% CI, 1.06-3.79) for norfloxacin, and 1.17 (95% CI, .59-2.31) for ofloxacin. CONCLUSIONS The use of oral FQs was associated with the subsequent occurrence of RRD. The FQ risk was independent of age, sex, diabetes, indications for antimicrobials, and underlying ophthalmic conditions. Certain FQs carried higher risk of RRD.

Migraine is associated with a higher risk of transient global amnesia: a nationwide cohort study.

The association between migraine and transient global amnesia (TGA) is not determined. Only two clinic‐based studies showed that TGA patients had a higher frequency of migraine history. Our population‐based study aimed to investigate whether migraine patients were associated with a higher risk of developing TGA.

Comparison of peptic ulcer disease risk between peritoneal and hemodialysis patients.

Background: Compared to the general population, patients with end-stage renal disease (ESRD) have increased peptic ulcer and upper GI bleeding complication rates. However, the risk factors for peptic ulcer among ESRD patients are unknown. Methods: In this retrospective study, we enrolled 827 incident dialysis patients and diagnosed peptic ulcer on the basis of endoscopic findings; information on the morbidities and medical prescription were obtained directly from medical records. A Cox regression hazard model was used to identify risk factors for peptic ulcer. Results: During the 10-year study period, 481 patients underwent an endoscopic exam. Peptic ulcers were detected in 153 patients. Age (p = 0.025), peritoneal dialysis (p = 0.022), diabetes mellitus (p = 0.020), congestive heart failure (p = 0.015), low serum albumin (p = 0.008) and high gamma-glutamyl transpeptidase (γ-GT) levels (p = 0.002) are risk factors for peptic ulcers among ESRD patients. Ulcer severity (p = 0.004) and aspirin prescription (p = 0.043), but not Helicobacter pylori infection, influenced the ulcer recurrence rate. Conclusion: The risk factors for peptic ulcer have some differences between ESRD patients and general population. In patients with high risk of upper GI bleeding, peritoneal dialysis and aspirin should be prescribed with caution.

Risk of tuberculosis among healthcare workers in an intermediate-burden country: A nationwide population study

OBJECTIVE The potential association between healthcare workers (HCWs) and the risk of clinically active tuberculosis (TB) in countries with intermediate TB burdens remains unclear. METHODS A nationwide, population-based cohort study was performed by using Taiwan National Health Insurance Database during 2000-2010. We included HCWs and non-HCWs without history of tuberculosis matched at a 1:1 ratio according to age, sex, monthly income, underlying comorbidities, and concomitant medications. All subjects were followed from the date of enrollment until TB occurrence, death, or 31 December 2010. RESULTS The study population comprised 11,811 healthcare workers and 11,811 matched subjects. 62 HCWs and 38 control subjects developed TB during a median follow-up period of 9.4 years. The incidence of TB was higher among HCWs than among matched subjects (61.08 vs. 37.81 per 100,000 person-years). The risk of TB was also greater among HCWs (adjusted hazard ratio [aHR], 1.62; 95% confidence interval [CI], 1.08-2.43), particularly for pulmonary TB in comparison with extrapulmonary TB (aHR, 1.56; 95% CI, 1.02-2.39). Among different job categories of HCWs, we found that only nurses had a significantly increased risk of developing TB (aHR, 2.55; 95% CI, 1.37-4.72) compared to the matched cohort. CONCLUSIONS HCWs are associated independently with a higher risk of developing TB in this intermediate-burden country. Therefore, the importance of TB surveillance among HCWs should be emphasized.

The Risk of Cancer in Patients with Congenital Heart Disease: A Nationwide Population-Based Cohort Study in Taiwan

Background The relationship between congenital heart disease (CHD) and malignancies has not been determined. This study aimed to explore the association of CHD with malignancies and examine the risk factors for the development of cancer after a diagnosis of CHD. Patients and Methods This nationwide, population-based cohort study on cancer risk evaluated 31,961 patients with newly diagnosed CHD using the Taiwan National Health Insurance Research Database (NHIRD) between 1998 and 2006. The standardized incidence ratios (SIRs) for all and specific cancer types were analyzed, while the Cox proportional hazard model was used to evaluate risk factors of cancer occurrence. Results Among patients with newly diagnosed CHD regardless of ages, 187 (0.6%) subsequently developed cancers after a diagnosis of CHD. Patients with CHD had increased risk of cancer (SIR, 1.45; 95% CI, 1.25–1.67), as well as significantly elevated risks of hematologic (SIR, 4.04; 95% CI, 2.76–5.70), central nervous system (CNS) (SIR, 3.51; 95% CI, 1.92–5.89), and head and neck (SIR, 1.81; 95% CI, 1.03–2.94) malignancies. Age (HR, 1.06; 95% CI, 1.05–1.06) and co-morbid chronic liver disease (HR, 1.91; 95% CI, 1.27–2.87) were independent risk factors for cancer occurrence among CHD patients. Conclusion Patients with CHD have significantly increased cancer risk, particularly hematologic, CNS, and head and neck malignancies. Physicians who care for patients with CHD should be aware of their predisposition to malignancy after the diagnosis of CHD. Further studies are warranted to clarify the association between CHD and malignancies.

Effect of add-on direct renin inhibitor aliskiren in patients with non-diabetes related chronic kidney disease

BackgroundThe renin-angiotensin-aldosterone system (RAAS) plays an important role in the progression of chronic kidney disease (CKD). Although dual RAAS inhibition results in worse renal outcomes than monotherapy in high risk type 2 diabetes patients, the effect of dual RAAS inhibition in patients with non-DM CKD is unclear. The aim of this study was to evaluate the potential renoprotective effect of add-on direct renin inhibitor in non-DM CKD patients.MethodsWe retrospectively enrolled 189 non-DM CKD patients who had been taking angiotensin II receptor blockers (ARBs) for more than six months. Patients were divided into an add-on aliskiren group and an ARB monotherapy group. The primary outcomes were a decline in glomerular filtration rate (GFR) and a reduction in urinary protein-to-creatinine ratio at six months.ResultsThe baseline characteristics of the two groups were similar. Aliskiren 150 mg daily reduced the urinary protein-to-creatinine ratio by 26% (95% confidence interval, 15 to 37%; p < 0.001). The decline in GFR was smaller in the add-on aliskiren group (−2.1 vs. -4.0 ml/min, p = 0.038). Add-on aliskiren had a neutral effect on serum potassium in the non-DM CKD patients. In subgroup analysis, the proteinuria-reducing effect of aliskiren was more prominent in patients with a GFR less than 60 ml/min, and in patients with a urinary protein-to-creatinine ratio greater than 1.8. The effect of aliskiren in retarding the decline in GFR was more prominent in patients with hypertensive nephropathy than in those with glomerulonephritis.ConclusionAdd-on direct renin inhibitor aliskiren (150 mg daily) safely reduced proteinuria and attenuated the decline in GFR in the non-DM CKD patients who were receiving ARBs.