Background: Despite the presence of a strong association between influenza infection and stroke, whether influenza vaccination reduces the risk of stroke is yet a matter of controversy. We conducted a meta-analysis to determine whether influenza vaccination protects against stroke. Methods: We searched PubMed, EMBASE, and the Cochrane Library from database inception date to November 18, 2016, without language restrictions, to identify studies investigating the effect of influenza vaccination on subsequent risk of stroke. We conducted a meta-analysis to quantify the risk of stroke in overall and subgroup analyses and calculated a pooled OR for developing stroke with a 95% CI. Publication bias was assessed by Begg's rank correlation test. Results: Eleven studies fulfilled our inclusion criteria. In a random-effects model, vaccinated individuals had a decreased risk of stroke compared with unvaccinated individuals (OR 0.82; 95% CI 0.75-0.91; p < 0.001). The relationship between influenza vaccination and stroke risk remained robust in subgroup analyses. The significant effect of influenza vaccination was associated with ascertainment of vaccination status and stage of prevention. Conclusion: Vaccination against influenza is associated with a lower risk of stroke. Well-designed prospective studies are needed to provide stronger evidence of the protective effect of influenza vaccination against stroke.
BACKGROUND: Vascular endothelial dysfunction (VED) plays a pivotal role in the pathogenesis of atherosclerosis and is associated with insulin resistance and visceral obesity. We examined the predicting factors of VED in uncomplicated premenopausal obese women using analysis of endothelium-dependent vasodilation by radial artery pulse wave obtained through applanation tonometry. METHODS: The subjects included a group of 33 obese women body mass index ((BMI)Z25) and another age-matched control group of 25 nonobese women (BMI: 18.5-22.9) of Asian origin. All uncomplicated premenopausal (20-45 y) obese women were sedentary (o1 h/week of physical activity). Anthropometric measurements were performed, and regional distributions of adipose tissue and metabolic variables were measured. Endothelial function was measured by pulse wave analysis after salbutamol administration, which reflects endothelium-mediated vasodilation, contributed partially by nitric oxide release from b2-adrenergic stimulation. Radial artery wave forms were recorded and from a derived aortic wave forms augmentation index (AIx, defined as the pressure difference between the first and second peaks of the central arterial wave form, expressed as a percentage of the pulse pressure) was calculated. The subjects received sublingual nitroglycerine (NTG) (0.6 mg), followed by nebulized salbutamol (2.5 mg). RESULTS: AIx fell significantly after the administration of salbutamol, which causes endothelium-dependent vasodilatation. This value was significantly reduced in obese women compared with the controls (10.376.7 vs 17.276.8%, P ¼ 0.0003). NTG, which causes endothelium-independent vasodilatation, did not produce significant changes (P ¼ 0.917). As for our obese subjects, the visceral adipose tissue area was a significant predictor of VED independent of BMI, percent body fat, and other metabolic variables including high-sensitivity C-reactive protein ( ¼ À0.141, P ¼ 0.002, Adj-R 2 ¼ 0.41). CONCLUSION: Increased abdominal adiposity is a powerful independent predictor of VED in uncomplicated obese women. Further studies are warranted to determine the pathophysiological link between visceral adipose tissue and VED.
BackgroundAssociation of arterial stiffness and osteoporosis has been previously reported in women. However, this association is still controversial for men. Therefore, we investigated correlation of arterial stiffness and osteoporosis by measuring brachial-ankle (ba) pulse wave velocity (PWV) and bone mineral density (BMD).MethodsWe reviewed medical charts of 239 people (women: 128, men: 111) who visited the Health Promotion Center, retrospectively. ba-PWV was measured by automatic wave analyzer. Lumbar spine (L1-L4) BMD and femur BMD were measured by dual energy X-ray absorptiometry. Metabolic syndrome was based on the National Cholesterol Education Program (NCEP)-Adult Treatment Panel (ATPIII) definition. Body mass index (BMI)>25 kg/m2 was used instead of waist circumference.ResultsIn Pearson's correlation analysis, PWV and femur BMD (Neck, total) had a significant inverse relationship in men (r=-0.254, P=0.007; r=-0.202, P=0.034). In women, PWV and the L-spine, femur (Neck, total) had a significant inverse relationship. (r=-0.321, P<0.001; r=-0.189, P=0.032; r=-0.177, P=0.046) Age and PWV showed the greatest association in both men and women (r=0.46 P<0.001; r=0.525, P<0.001) In multiple regression analysis, the L-spine BMD and PWV had an independent relationship in women after adjusting for age, metabolic syndrome, BMI, smoking, drinking and exercise. (r=-0.229, P=0.015). No independent association was found between PWV and BMD in men.ConclusionsThe association between arterial stiffness and BMD was confirmed in women. However, this association was not statistically significant for men.
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