Bo Youl Choi

Dietary factors and gastric cancer in Korea: A case-control study

To assess gastric cancer (GC) risk in relation to dietary intake in Korea, a case‐control study was performed. Trained dietitians interviewed 136 patients diagnosed with GC, and the same number of controls were selected by matching sex, age and hospital. A significant decrease in GC risk was observed with increased intake of Baiechu kimchi (prepared with salted Chinese cabbage and red pepper, etc.), Baiechu kimchi‐stew, garlic, mushroom and soybean milk. On the contrary, a significant increase in the risk of GC was observed with increased intake of cooked rice with bean, charcoal grilled beef, pollack soup, Kkakduki (a kind of kimchi prepared with salted radish and red pepper, etc.), Dongchimi (a kind of kimchi prepared with radish and a large quantity of salt water) and cooked spinach. In food groups, increased intake of soybean products was associated with decreased risk of GC. Intake of citrus fruits rather than total fruits was shown to have a protective effect on the risk of GC, but was not significant. In this study, intake of total vegetables was shown to have a protective effect, whereas high nitrate‐containing vegetables increased the risk of GC. In conclusion, our study suggests that the risk of GC decreased with high consumption of fresh vegetables and fruits, whereas high consumption of foods rich in nitrate and carcinogenic substances produced during the cooking process increased the risk of GC.

Prevalence of the Metabolic Syndrome and Its Association with Cardiovascular Diseases in Korea

This study aimed to estimate nationwide prevalence of the metabolic syndrome and to identify its association with cardiovascular diseases. The data on a national representative sample of 6,147 adults from 1998 Korea National Health and Nutrition Survey were analyzed. The syndrome was determined according to two kinds of modified definition from ATP III, in which abdominal obesity was determined by waist circumference (WC) standard for Asians and waist-to-hip ratio (WHR). Based on the former, prevalence was 22.1% in men and 27.8% in women. However, based on the latter, prevalence was 28.6% and 27.8%, respectively. Although age-specific prevalence was higher in men than in women among the younger group, it became higher in women among the older group because of its steeper rise with age. In multiple logistic regression, the syndrome was found to be positively associated with cardiovascular diseases (adjusted odds ratios (ORs)1.97 by WC and 1.48 by WHR in men, and 1.54 and 1.31 in women). Moreover, its effect size exceeded that of total cholesterol (adjusted ORs 1.21 in men, and 1.08 in women) or LDL cholesterol (1.58 in men and 1.22 in women). It is obvious that the metabolic syndrome prevails in Korea, and its importance regarding cardiovascular diseases is considerable. Prevention strategies should be implemented immediately to avoid cardiovascular epidemic in the near future.

Prevalence and Correlates of Depressive Symptoms in Korean Adults: Results of a 2009 Korean Community Health Survey

The aim of this study was to investigate the prevalence and correlates of depressive symptoms in the largest number of Korean individuals examined to date. We analyzed cross-sectional data collected from 229,595 Korean adults aged 19 yr and above who participated in a Korean Community Health Survey conducted in 2009. The Center for Epidemiologic Studies Depression Scale (CES-D) was used as the measurement tool for depressive symptoms (CES-D score over 16) and definite depression (CES-D score over 25). Multivariate logistic regression analysis was performed to identify associations between sociodemographic factors and depressive symptoms. The percentages of depressive symptoms and definite depression in the total study population were 11% (7.8% for men, 14.0% for women) and 3.7%, (2.4% for men, 5.0% for women), respectively. Female gender, older age, disrupted marital status, low education and income level, multigenerational household composition and metropolitan residence were associated with greater risk of depressive symptoms. The present study provides a valid prevalence and correlates of depressive symptoms, using the largest representative sample of the Korean general population to date. Various sociodemographic factors contribute to the prevalence and effects of depressive symptoms in Korea.

Cross-sectional relationship between dietary carbohydrate, glycaemic index, glycaemic load and risk of the metabolic syndrome in a Korean population

Little is known about the effect of dietary carbohydrate, glycaemic index (GI) and glycaemic load (GL) on the risk of the metabolic syndrome, especially in populations with white rice as the staple food. The study examined the cross-sectional relationship between carbohydrate, GI, GL and risk of the metabolic syndrome. There were a total of 910 middle-aged Korean adults. Dietary carbohydrate, GI and GL were determined by an interview-administered FFQ. The metabolic syndrome was defined using the modified criteria published in the Third Report of the National Cholesterol Education Program Adult Treatment Panel III. The risk of developing the metabolic syndrome was positively related to dietary carbohydrate (P for trend = 0.03), GI (P for trend = 0.03) and GL intakes (P for trend = 0.02) in women after adjusting for potential confounding variables. Among the components of developing the metabolic syndrome, the risk of high TAG and low HDL-cholesterol were positively related to high GI and GL intakes in women. The risk of developing the metabolic syndrome was considerably higher in the highest quintiles of carbohydrate (OR 6.44; 95 % CI 2.16, 19.2), GI (OR 10.4; 95 % CI 3.24, 33.3) and GL intakes (OR 6.68; 95 % CI 2.30, 19.4) than in the lowest quintiles among women with a BMI >/= 25 kg/m2. However, there was no difference in risk across quintiles of carbohydrate, GI and GL among women with a BMI < 25 kg/m2. In conclusion, both the quantity and quality of carbohydrate intake has a positive relationship with the risk of the metabolic syndrome in women but this relationship was dependent on the BMI level.

Differences in Gastric Mucosal Microbiota Profiling in Patients with Chronic Gastritis, Intestinal Metaplasia, and Gastric Cancer Using Pyrosequencing Methods

Helicobacter pylori (H. pylori) infection plays an important role in the early stage of cancer development. However, various bacteria that promote the synthesis of reactive oxygen and nitrogen species may be involved in the later stages. We aimed to determine the microbial composition of gastric mucosa from the patients with chronic gastritis, intestinal metaplasia, and gastric cancer using 454 GS FLX Titanium.

Effect of nutrient intake and Helicobacter pylori infection on gastric cancer in Korea: a case-control study.

Abstract: To examine the effects of dietary factor and Helicobacter pylori (H. pylori) infection with emphasis on vitamin intake on the risk of gastric cancer (GC), we conducted a case-control study in South Korea, a high-risk area for GC. Trained dietitians interviewed 136 cases histologically diagnosed with GC. An equal number of hospital controls was selected by matching sex and age. High dietary intakes of vegetable fat [odds ratio (OR) = 0.35; 95% confidence interval (CI) = 0.15-0.83], folate (OR = 0.35; 95% CI = 0.13-0.96), and antioxidants, such as vitamin A (OR = 0.34; 95% CI = 0.13-0.83), β-carotene (OR = 0.33; 95% CI = 0.13-0.82), vitamin C (OR = 0.26; 95% CI = 0.09-0.72), and vitamin E (OR = 0.41; 95% CI = 0.17-1.01), were shown to have a protective effect on GC risk using a multivariate model adjusting for foods significantly related to GC in our previous study (charcoal grilled beef, spinach, garlic, mushroom, and a number of types of kimchi) and supplement use. When stratified according to H. pylori infection, high intakes of vitamin C (OR = 0.10; 95% CI = 0.02-0.63) and vitamin E (OR = 0.16; 95% CI = 0.03-0.83) exhibited highly significant inverse associations with GC among the H. pylori-infected subjects compared with noninfected individuals. GC risk was significantly decreased only when consumption levels for two of these vitamins were high. Our findings suggest that high intake of antioxidant vitamins contribute to the reduction of GC risk and that GC risk in Korea may be decreased by encouraging those with H. pylori infection to increase their intake of antioxidant vitamins.

Fresh and pickled vegetable consumption and gastric cancer in Japanese and Korean populations: a meta-analysis of observational studies.

It is widely known that vegetable consumption contributes to reducing the risk of gastric cancer (GC). However, the incidence rates of GC remain high in both Japanese and Korean populations, even though they have a high consumption of total vegetables. This may be due to the fact that Japanese and Koreans mainly consume processed vegetables, such as cooked, salted, or pickled vegetables, rather than fresh vegetables. To determine whether the intakes of fresh and pickled vegetables have different effects on the risk of GC in Japanese and Korean populations, we carried out a meta‐analysis of published epidemiological reports. Eight studies on the consumption of fresh vegetables and 14 studies on the consumption of pickled vegetables related to GC risk were included in this meta‐analysis. Four studies exploring differences in GC risk in men and women were considered separately. We observed that a high intake of fresh vegetables was significantly associated with a decreased risk of GC (overall summary OR = 0.62, 95% CI = 0.46–0.85) but that a high intake of pickled vegetables was significantly associated with an increased risk of GC (overall summary OR = 1.28, 95% CI = 1.06–1.53). The results of this meta‐analysis provide evidence that a high intake of pickled vegetables may increase GC risk and suggest that a high consumption of fresh vegetables, rather than a large total amount of vegetables including pickled vegetables, is important to reduce GC risk. (Cancer Sci 2009)

An Outbreak of Gastroenteritis Caused by Norovirus-Contaminated Groundwater at a Waterpark in Korea

In January 2008, an outbreak of acute gastroenteritis at a waterpark was reported to the Bundang-gu Public Health Center in Seongnam, Korea. To determine the etiological agent and mode of transmission, a retrospective cohort study was done using structured questionnaires and stool samples from patients who had current gastrointestinal symptoms and three food handlers were tested. A total of 67 (31.0%) students and teachers developed acute gastroenteritis. No food items were associated with an increased risk of the illness. Norovirus was detected in 3 stool specimens collected from 6 patients who had severe diarrhea using semi-nested RT-PCR. All the specimens contained the genogroup I strains of the norovirus. Norovirus was also detected in the groundwater samples from the waterpark. In the nucleotide sequencing analysis, all the genogroup I noroviruses from the patients and groundwater samples were identified as the norovirus genotype I-4 strain. They were indistinguishable by DNA sequencing with a 97% homology. We conclude the outbreak of acute gastroenteritis caused by the norovirus was closely related to the contaminated groundwater.

The impact of serum uric acid level on arterial stiffness and carotid atherosclerosis: The Korean Multi-Rural Communities Cohort study

OBJECTIVE Serum uric acid level has been found to be associated with a risk factor for cardiovascular diseases. However, the topic has not been explored in the general population, especially in Korea. This study was designed to determine whether serum uric acid is associated with carotid atherosclerosis and arterial stiffness in the Korean Multi-Rural Communities Cohort study. METHODS A total of 5568 participants from the Korean Multi-Rural Communities Cohort were evaluated for the risk of hyperuricemia in cardiovascular atherosclerosis. Important surrogates for cardiovascular atherosclerosis such as intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV) were assessed. We evaluated the association between these atherosclerosis indices and serum uric acid level or hyperuricemia through multivariate-adjusted logistic and linear regression analyses. RESULTS There was a significant difference of carotid IMT and baPWV between males and females (p < 0.0001, respectively). Both male and female subjects with hyperuricemia showed higher baPWV than subjects without hyperuricemia (p = 0.0004 for males; p = 0.001 for females). Serum uric acid level was positively correlated with baPWV in males (β = 0.0006, p < 0.0001) and in females (β = 0.0001, p = 0.04), whereas no association between serum uric acid and carotid IMT was found in either gender. A linear relationship of baPWV with increasing serum uric acid level was observed in males (p = 0.0005) and in females (p = 0.004). CONCLUSION Serum uric acid level could be considered an important risk factor for arterial stiffness in Korean population, whereas carotid IMT is not associated with serum uric acid in either gender when using data from the Korean Multi-Rural Communities Cohort study.

Dietary zinc intake is inversely related to subclinical atherosclerosis measured by carotid intima-media thickness.

The relationship between dietary Zn intake and the risk of atherosclerosis remains unclear, and no epidemiological studies have been reported on the effects of dietary Zn intake on morphological changes in the vascular wall. We examined the relationship between dietary Zn intake and common carotid intima-media thickness (IMT) as a marker of subclinical atherosclerosis among the middle-aged and elderly populations. A cross-sectional analysis of a prospective cohort baseline study was performed with 4564 adults aged 40-89 years and free of clinical CVD. Dietary data were collected by trained interviewers using an FFQ. Common carotid IMT was measured using a B-mode ultrasound imaging technique. Subclinical atherosclerosis was determined using carotid IMT, and defined as > 80th percentile of carotid IMT or ≥ 1 mm of carotid IMT. After adjustment for potential confounders, the mean carotid IMT in the low Zn intake group was higher than that in the high Zn intake group. When subclinical atherosclerosis was defined as > 80th percentile value of IMT or ≥ 1 mm of carotid IMT, after adjustment for potential confounders, Zn intake was inversely related to subclinical atherosclerosis (5th v. 1st quintile, OR 0.64, 95% CI 0.45, 0.90, P for trend = 0.069; 5th v. 1st quintile, OR 0.34, 95% CI 0.16, 0.70, P for trend = 0.005, respectively). In persons free of clinical CVD, dietary Zn intake was inversely correlated with subclinical atherosclerosis. The present findings suggest a putative protective role of dietary Zn intake against the development of atherosclerosis.