Complete mitochondrial DNA profile in stroke: A geographical matched case-control study in Spanish population.

INTRODUCTION: Stroke, the second leading cause of death worldwide, is a complex disease influenced by many risk factors among which we can find reactive oxygen species (ROS). Since mitochondria are the main producers of cellular ROS, nowadays studies are trying to elucidate the role of these organelles and its DNA (mtDNA) variation in stroke risk. The aim of the present study was to perform a comprehensive evaluation of the association between mtDNA mutations and mtDNA content and stroke risk. MATERIAL AND METHODS: Homoplasmic and heteroplasmic mutations of the mtDNA were analysed in a case-controls study using 110 S cases and their corresponding control individuals. Mitochondrial DNA copy number (mtDNA-CN) was analysed in 73 of those case-control pairs. RESULTS: Our results suggest that haplogroup V, specifically variants m.72C > T, m.4580G > A, m.15904C > T and m.16298 T > C have a protective role in relation to stroke risk. On the contrary, variants m.73A > G, m.11719G > A and m.14766C > T appear to be genetic risk factors for stroke. In this study, we found no statistically significant association between stroke risk and mitochondrial DNA copy number. CONCLUSIONS: These results demonstrate the possible role of mtDNA genetics on the pathogenesis of stroke, probably through alterations in mitochondrial ROS production.

Stroke in Spain: epidemiologic incidence and patterns; a health sentinel network study.

INTRODUCTION: Cerebrovascular disease is among the 4 main causes of mortality in Spain. The objective of this study was to estimate the incidence of stroke and to describe the principal risk factors and other clinical and epidemiologic patterns found in patients. METHODS: Doctors from the Spanish sentinel health network recorded the episodes of acute cerebrovascular diseases in 2005 in a population of 201,205 inhabitants older than 14 years. The information of the patients (age and sex) and the episode (e.g., duration, symptoms, origin, medical attention, risk factors) was collected on a standard form. RESULTS: The estimated incidence rate of stroke was 141 cases per 100,000 inhabitants (confidence interval [CI] 95%: 125-158), 134 (95% CI: 112-157) in women and 148 (95% CI: 124-172) in men. The incidence increases significantly from the age of 65 years and men younger than this have higher rates than women. In all, 12% of patients with stroke die within the first 24 hours. CONCLUSIONS: Incidence of cerebrovascular disease in Spain is below that recorded in other countries. There is no difference according to sex, but incidence among young and middle-aged men is greater than that among women. Significant variations from some population groups to others are observed, maybe because of the difference in the prevalence of risk factors.

Involvement of mitochondrial haplogroups in myocardial infarction and stroke: A case-control study in Castile and Leon (Spain) population.

There are strong evidences that common mitochondrial DNA (mtDNA) haplogroups may influence the pathogenesis of cardiovascular diseases (CVDs). In this matched case-control study, we investigate the association between mtDNA haplogroups and two CVDs, myocardial infarction (MI) and stroke, and classical cardiovascular risk factors. Data obtained show that haplogroup H constitute a susceptibility risk factor for MI (p=0.001; OR=2.379, 95% CI [1.440-3.990]). Otherwise, our data also suggest a beneficial role of haplogroup J against hypertension (p=0.019; OR=0.348, 95% CI [0.144-0.840]). These results may provide some guidance for predicting the genetic risk of these diseases in different human populations through the differences in energy efficiency between haplogroups.

Viral Etiology of Chronic Obstructive Pulmonary Disease Exacerbations during the A/H1N1pdm09 Pandemic and Postpandemic Period.

Viral infections are one of the main causes of acute exacerbations of chronic obstructive pulmonary disease (AE-COPD). Emergence of A/H1N1pdm influenza virus in the 2009 pandemic changed the viral etiology of exacerbations that were reported before the pandemic. The aim of this study was to describe the etiology of respiratory viruses in 195 Spanish patients affected by AE-COPD from the pandemic until the 2011-12 influenza epidemic. During the study period (2009-2012), respiratory viruses were identified in 48.7% of samples, and the proportion of viral detections in AE-COPD was higher in patients aged 30-64 years than ≥65 years. Influenza A viruses were the pathogens most often detected during the pandemic and the following two influenza epidemics in contradistinction to human rhino/enteroviruses that were the main viruses causing AE-COPD before the pandemic. The probability of influenza virus detection was 2.78-fold higher in patients who are 30-64 years old than those ≥65. Most respiratory samples were obtained during the pandemic, but the influenza detection rate was higher during the 2011-12 epidemic. There is a need for more accurate AE-COPD diagnosis, emphasizing the role of respiratory viruses. Furthermore, diagnosis requires increased attention to patient age and the characteristics of each influenza epidemic.

Influenza surveillance in Europe: establishing epidemic thresholds by the moving epidemic method.

BACKGROUND: Timely influenza surveillance is important to monitor influenza epidemics. OBJECTIVES: (i) To calculate the epidemic threshold for influenza-like illness (ILI) and acute respiratory infections (ARI) in 19 countries, as well as the thresholds for different levels of intensity. (ii) To evaluate the performance of these thresholds. METHODS: The moving epidemic method (MEM) has been developed to determine the baseline influenza activity and an epidemic threshold. False alerts, detection lags and timeliness of the detection of epidemics were calculated. The performance was evaluated using a cross-validation procedure. RESULTS: The overall sensitivity of the MEM threshold was 71·8% and the specificity was 95·5%. The median of the timeliness was 1 week (range: 0-4·5). CONCLUSIONS: The method produced a robust and specific signal to detect influenza epidemics. The good balance between the sensitivity and specificity of the epidemic threshold to detect seasonal epidemics and avoid false alerts has advantages for public health purposes. This method may serve as standard to define the start of the annual influenza epidemic in countries in Europe.