ABSTRACT
Objectives: The purposes of this study were to determine whether men and women differ in risk factors for acute myocardial infarction (AMI) during the four seasons of the year. Materials and methods: Medical records of 2,086 (women: 693) patients hospitalized with a confirmed AMI were reviewed retrospectively from the region’s only medical center in eastern Taiwan. The onset date of 544 patients (women: 178) was in spring, 493 patients (women: 165) in summer, 474 patients (women: 155) in autumn, and 575 patients (women: 195) in winter. Risk factors of age, percentage of smoking (smoking%), percentage of diabetes (diabetes%), percentage of hypertension (hypertension%), total cholesterol, and body mass index were assessed. In each season, logistic regression model was used to calculate the odds ratio (OR) and 95% conference interval (CI) of women compared to men by risk factors. Results: In spring, women presented significantly higher values in age (OR 1.022; 95%CI 1.012-1.031 ) and diabetes% (OR2.373；95%CI 1.554-3.625), significantly lower in smoking% (OR 0.187；95%CI 0.145-0.240). In summer, women presented significantly lower values in body mass index (OR 0.907；95%CI 0.856-0.960) and smoking% (OR 0.222; 95%CI 0.134-0.367). In autumn, women presented significantly higher values in age (OR 1.033；95%CI 1.012-1.053) and total cholesterol (OR 1.009；95%CI 1.004-1.013), significantly lower in smoking% (OR 0.168；95%CI 0.098-0.289). In winter, women presented significantly higher values in diabetes% (OR 1.845；95%CI 1.250-2.725), hypertension% (OR1.550；95%CI 1.001-2.402), and total cholesterol (OR 1.008；95%CI 1.004-1.012), significantly lower in smoking% (OR 0.188；95%CI 0.119-0.297). Conclusion: The differences between women and men in risk factors for AMI did present seasonal variation in eastern Taiwan. This finding would provide further insight into medical climatology in preventing serious cardiovascular events.
ABSTRACT
Objectives: The early local vasodilator response to local warming is predominantly dependent on neural reflexes. However, it is suggested that systemic vasomotor activities are unaffected by a local warming at early stage. The purposes of this study were to assess the hypothesis that systemic vasomotor activities might make an adjustment at early stage of hand warming. Materials and Methods: Thirty-nine young volunteers who were healthy were recruited. Each participant received a right hand bathing at 40°C for 10 minutes. Doppler ultrasound technique was used to monitor the brachial artery mean blood velocity (aMBV) at the heated arm, and changes in aMBV were used to evaluate local vasodilator response to hand warming. Photoplethysmographic technique was used to monitor digital volume pulse (DVP) at the unheated finger, and changes in the DVP derived peak amplitude (DVPampl), reflection index (DVPRI), stiffness index (DVPSI), and heart rate (HR) were used to evaluate vascular distensibility of the unheated upper limb, small artery tone in the lower body, large artery stiffness, and cardiac regulation respectively. The data collected in each minute were averaged as an interval. Comparisons of aMBV, DVPRI, DVPSI, and HR at each interval with their respective baseline values were performed using one-way ANOVA. Results: Plots of one-minute intervals versus aMBV, DVPampl, DVPRI, DVPSI, and HR were shown in Figure. aMBV values presented significant increases with a early peak at the third minute. DVPampl presented significant decrease in the first minute and then reversed to a significant increase at the sixth minute. DVPRI presented a significant increase in the first three minutes, and then returned to the level of baseline. DVPSI and HR did not present any significant changes. Conclusion: At the period of early local vasodilator response to hand warming, systemic vasomotor activities did make a significant adjustment by decreasing vascular distensibility of the unheated upper limb and increasing small artery tone of the lower body, though the activities in heart rate and large artery tone were unaffected. Later, vascular distensibility of the unheated upper limb made a reverse adjustment and reached a significant increase.
ABSTRACT
<b>Objectives:</b> The early local vasodilator response to local warming is predominantly dependent on neural reflexes. However, it is suggested that systemic vasomotor activities are unaffected by a local warming at early stage. The purposes of this study were to assess the hypothesis that systemic vasomotor activities might make an adjustment at early stage of hand warming. <BR><b>Materials and Methods:</b> Thirty-nine young volunteers who were healthy were recruited. Each participant received a right hand bathing at 40°C for 10 minutes. Doppler ultrasound technique was used to monitor the brachial artery mean blood velocity (aMBV) at the heated arm, and changes in aMBV were used to evaluate local vasodilator response to hand warming. Photoplethysmographic technique was used to monitor digital volume pulse (DVP) at the unheated finger, and changes in the DVP derived peak amplitude (DVPampl), reflection index (DVPRI), stiffness index (DVPSI), and heart rate (HR) were used to evaluate vascular distensibility of the unheated upper limb, small artery tone in the lower body, large artery stiffness, and cardiac regulation respectively. The data collected in each minute were averaged as an interval. Comparisons of aMBV, DVPRI, DVPSI, and HR at each interval with their respective baseline values were performed using one-way ANOVA. <BR><b>Results: </b>Plots of one-minute intervals versus aMBV, DVPampl, DVPRI, DVPSI, and HR were shown in Figure. aMBV values presented significant increases with a early peak at the third minute. DVPampl presented significant decrease in the first minute and then reversed to a significant increase at the sixth minute. DVPRI presented a significant increase in the first three minutes, and then returned to the level of baseline. DVPSI and HR did not present any significant changes. <BR><b>Conclusion:</b> At the period of early local vasodilator response to hand warming, systemic vasomotor activities did make a significant adjustment by decreasing vascular distensibility of the unheated upper limb and increasing small artery tone of the lower body, though the activities in heart rate and large artery tone were unaffected. Later, vascular distensibility of the unheated upper limb made a reverse adjustment and reached a significant increase.