Association between meat consumption and carotid intima-media thickness in Korean adults with metabolic syndrome

OBJECTIVES: The effect of meat consumption on cardiometabolic risk has been continuously studied, but their associations are not conclusive. The aim of this study is to examine the association between the consumption of meat or red meat and carotid intima-media thickness (IMT) in healthy Korean adults. METHODS: This study evaluated 2374 community-dwelling adults (933 men and 1441 women) who were free of cardiovascular disease or cancer, living in a rural area in Korea. Total meat and red meat intakes were assessed with a validated 103 item-food frequency questionnaire. Carotid IMT was evaluated ultrasonographically, IMTmax was defined as the highest value among IMT of bilateral common carotid arteries. RESULTS: After adjustment for potential confounding factors, the mean IMTmax tended to increase in higher meat consumption groups in both men and women with metabolic syndrome (p for trend= 0.027 and 0.049, respectively), but not in participants without metabolic syndrome. Frequent meat consumption (≥5 servings/week) was significantly associated with higher IMTmax in men with metabolic syndrome (by 0.08 mm, p=0.015). Whereas, the association was not significant in women (by 0.05 mm, p=0.115). Similar but attenuated findings were shown with red meat intake. CONCLUSIONS: Our findings suggest that a higher meat consumption may be associated with a higher carotid IMT in Korean adults with metabolic syndrome. The frequent meat consumption (≥5 servings/week), compared with the others, was associated with a higher carotid IMTmax only in men with metabolic syndrome. Further research is required to explore optimal meat consumption in people with specific medical conditionsope

Mathematical Modeling of the Novel Influenza A (H1N1) Virus and Evaluation of the Epidemic Response Strategies in the Republic of Korea

Objectives: The pandemic of novel influenza A (H1N1) virus has required decision-makers to act in the face of the substantial uncertainties. In this study, we evaluated the potential impact of the pandemic response strategies in the Republic of Korea using a mathematical model. Methods: We developed a deterministic model of a pandemic (H1N1) 2009 in a structured population using the demographic data from the Korean population and the epidemiological feature of the pandemic (H1N1) 2009. To estimate the parameter values for the deterministic model, we used the available data from the previous studies on pandemic influenza. The pandemic response strategies of the Republic of Korea for novel influenza A (H1N1) virus such as school closure, mass vaccination (70% of population in 30 days), and a policy for anti-viral drug (treatment or prophylaxis) were applied to the deterministic model. Results: The effect of two-week school closure on the attack rate was low regardless of the timing of the intervention. The earlier vaccination showed the effect of greater delays in reaching the peak of outbreaks. When it was no vaccination, vaccination at initiation of outbreak, vaccination 90 days after the initiation of outbreak and vaccination at the epidemic peak point, the total number of clinical cases for 400 days were 20.8 million, 4.4 million, 4.7 million and 12.6 million, respectively. The pandemic response strategies of the Republic of Korea delayed the peak of outbreaks (about 40 days) and decreased the number of cumulative clinical cases (8 million). Conclusions: Rapid vaccination was the most important factor to control the spread of pandemic influenza, and the response strategies of the Republic of Korea were shown to delay the spread of pandemic influenza in this deterministic modelope

Stationary and β-mixing for a certain asymmetric power GARCH model

Engle(1982) introduced the autoregressive conditional heteroskedasticity (ARCH) model and Bollerslev(1986) introduced a generalization of the ARCH(GARCH) model. Since then, numerous GARCH-type models have been developed and successfully applied in finance and macroeconomics. There are conditions for a stationarity, ergodicity and an existence of moments of the ARCH and GARCH models. In this paper, first, we arrange these conditions. Then we consider an asymmetric power GARCH(r, s) model that was introduced in Ding et al.(1993). And we show a condition on a stationarity and β-mixing with exponential decay rates of an asymmetric power GARCH(r, s)model by using the theorem in Mokkadem(1990). ;Engle이 1982년 ARCH(autoregressive conditional heteroskedasticity)모형을 소개하였고 1986년에는 Bollerslev가 일반화된 ARCH모형을 소개하였다. 그 이후 여러 종류의 GARCH 모형이 소개되었고 이모형들은 거시경제학과 재정학 분야에 적용되어왔다. 지금까지 ARCH/GARCH 모형의 stationarity와 ergodicity, moment의 존재성에 관한 여러 조견들이 제시되어왔다. 이 논문에서는 우선 이러한 조건들을 정리하였다. 그리고 Ding et. al.(1993)의 asymmetric power GARCH 모형을 소개하고 Mokkadem(1990)의 정리를 이용하여 이 모형의stationarity와 β-mixing with exponential decay rates에 관한 조건을 보이겠다.CHAPTER 1 Introduction = 1 CHAPTER 2 The Previous Results = 4 CHAPTER 3 Generalized Random Coefficient Autoregressive model = 10 CHAPTER 4 Main Results and Proofs = 13 References = 2