Association between metabolic syndrome and gastric cancer risk: results from the Health Examinees Study.

BACKGROUND: Previous studies suggested that metabolic syndrome (MetS) might create a pro-cancer environment and increase cancer incidence. However, evidence on the risk of gastric cancer (GC) was limited. This study aimed to evaluate the association between MetS and its components and GC in the Korean population. METHODS: Included were 108,397 individuals who participated in the large-scale prospective cohort study, the Health Examinees-Gem study during 2004-2017. The multivariable Cox proportional was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) on the association between MetS and its components with GC risk. Age was used as the time scale in the analyses. The stratified analysis was performed to determine the joint effect of lifestyle factors and MetS on GC risk in different groups. RESULTS: During the mean follow-up of 9.1 years, 759 cases of newly diagnosed cancer (408 men and 351 women) were identified. Overall, participants with MetS had a 26% increased risk of GC than those without MetS (HR 1.26; 95% CI 1.07-1.47); the risk increased with the number of MetS components (p for trend 0.01). Hypertriglyceridemia, low HDL-cholesterol, and hyperglycemia were independently associated with the risk of GC. The potential joint effect of MetS and current smokers (p for interaction 0.02) and obesity (BMI ≥ 25.0) (p for interaction 0.03) in GC. CONCLUSIONS: In this prospective cohort study, we found that MetS were associated with an increased risk of GC in the Korean population. Our findings suggest that MetS may be a potentially modifiable risk factor for GC risk.

Soybean product consumption decreases risk of gastric cancer: results from the Health Examinees Study.

BACKGROUND: Epidemiological findings on the association between soybean product consumption and gastric cancer risk remain inconsistent. We evaluated the relationship between soybean product consumption and the risk of gastric cancer in a prospective cohort study in Korea. METHODS: This prospective cohort study included a total of 139,267 participants aged 40-69 years from the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Information on cancer diagnosis was retrieved from the Korea Central Cancer Registry until 31 December 2018. Multivariate hazard ratios (HRs) and 95% of confidence intervals (CIs) for the risk of gastric cancer according to the consumption of soybean products were estimated using Cox proportional hazards models. RESULTS: A total of 767 incident cases of gastric cancer occurred over an average follow-up period of 9.21 years. We found that men who consumed two servings per week had 37% lower risk of gastric cancer compared with who consume those who almost never consumed (HR for tofu consumption of more than two servings/week vs. almost never consumed was 0.63 (95% CI 0.45, 0.89); p for trend = 0.04). Among men with a BMI of less than 25 kg/m2, increased consumption of soybean paste (p for trend = 0.02) and tofu (HR 0.51 (95% CI 0.32, 0.82 for more than two servings/week vs. almost never consumed); p for trend = 0.01) was associated with decreased risk of gastric cancer. CONCLUSION: Our results suggest that a high consumption of soybean products has a protective effect against gastric cancer.

Mildly elevated diastolic blood pressure increases subsequent risk of breast cancer in postmenopausal women in the Health Examinees-Gem study.

Epidemiological evidence suggests that hypertension is associated with breast cancer risk. However, previous studies disregard blood pressure components in the healthy population. We aimed to examine the relationship between systolic and diastolic blood pressure and breast cancer risk in a Korean population-based prospective cohort. A total of 73,031 women from the Health Examinees Gem Study were followed from baseline (2004 to 2013) through 2018. Systolic and diastolic blood pressure were measured by trainee physicians at baseline recruitment and then categorized based on the international guidelines for clinical hypertension. Associations between systolic and diastolic blood pressure with overall breast cancer and stratified by premenopausal and postmenopausal status were evaluated using adjusted multivariable Cox proportional hazard regression. A total of 858 breast cancer cases were recorded for a median follow-up period of 9 years. Compared with the normal DBP category (< 85 mmHg), the normal-high category was positively associated with breast cancer risk in postmenopausal women (85-89 mmHg, HR 1.73 95% CI 1.28-2.33), but not in premenopausal women (85-89 mmHg, HR 0.87 95% CI 0.56-1.35). Similar results were found when all cases of self-reported hypertension were excluded. Results for SBP did not show a significant association with breast cancer risk. The association between DBP and breast cancer suggests DBP could be an important factor in cancer prevention, especially for women after menopause. Our study provides a first detailed approach to understanding the importance of diastolic blood pressure for breast cancer prevention and warrants further investigation.

Frequent low dose alcohol intake increases gastric cancer risk: the Health Examinees-Gem (HEXA-G) study.

OBJECTIVE: Epidemiological studies indicate that alcohol increases gastric cancer (GC) risk, yet most studies have focused on heavy alcohol intake, leaving other factors understudied. A comprehensive investigation of the effects of the frequency and amount of alcohol intake may help elucidate the GC risk associated with drinking behavior. METHODS: The Health Examinees-Gem (HEXA-G) study, a community-based large-scale prospective cohort study, enrolled Korean adults 40-69 years of age between the years 2004 and 2013. Incident GC cases were identified through linkage to Korea Central Cancer Registry data until December 31, 2017. Self-reported questionnaires were used to survey alcohol consumption-related factors (duration, frequency, amount, and type of alcoholic beverages). The frequency and amount of alcohol consumption were combined to explore GC risk according to 4 drinking patterns: "infrequent-light", "frequent-light", "infrequent-heavy", and "frequent-heavy". We used Cox proportional hazard models to estimate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs), and investigate the relationship between alcohol intake and GC incidence. RESULTS: A total of 128,218 participants were included in the analysis. During an average follow-up period of 8.6 years, 462 men and 385 women were diagnosed with GC. In men, current drinkers showed a 31% greater risk of GC than non-drinkers (HR 1.31, 95% CI 1.03-1.66), whereas no significant association was observed in women. In men, GC risk was associated with a higher frequency (P trend 0.02) and dose of ethanol intake in grams (P trend 0.03). In men, the "frequent-light" (≥5 times/week and <40 g ethanol/day) drinking pattern was associated with a 46% greater risk of GC (HR 1.46, 95% CI 1.02-2.07) than the "infrequent-light" pattern (<5 times/week and <40 g ethanol/day). CONCLUSIONS: This study suggests that frequent intake of alcohol, even in low quantities per session, increases GC risk. Further research is warranted to evaluate the relationship between alcohol and GC in detail.

Obesity at early adulthood increases risk of gastric cancer from the Health Examinees-Gem (HEXA-G) study.

Emerging evidence has indicated a possible link between obesity in early life with subsequent cancer risks, but its association with gastric cancer remains unknown. This study aimed to investigate the association of obesity at ages 18-20 and 35 with the later risk of gastric cancer among the Korean population. Included were 122,724 individuals who participated in the large-scale prospective cohort study, the Health Examinees-Gem (HEXA-G) study, during 2004-2017. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for gastric cancer risk associated with body mass index (BMI) at ages 18-20 and 35 years. During a mean follow-up period of 8.6±2.1 years, a total 927 gastric cancer cases (531 men and 396 women) were identified. When compared to normal BMI (18.5-23.0 kg/m2), obesity (BMI ≥30 kg/m2) at age 35 was significantly associated with increased risk of gastric cancer later in life among total participants (HR 1.94, 95% CI 1.26-2.97, p 0.01). When analyzed separately by sex, obesity at 35 years of age was significantly associated with increased risk of gastric cancer among both men (HR 1.79, 95% CI 1.02-3.13, p 0.05) and women (HR 2.35, 95% CI 1.21-4.60, p 0.02). No significant associations were found for obesity at late adolescence in both men and women. Our findings suggest that obesity in early adulthood may be associated with an increased risk of gastric cancer. The results may aid in understanding the etiology of GC in a population with a divergent trend of gastric cancer.

Urinary estrogen metabolites and gastric cancer risk among postmenopausal women.

BACKGROUND: The overall incidence of gastric cancer in women is half that in men for most global populations. Sex hormone pathways may be involved in carcinogenesis and estrogens have been postulated to protect women against gastric cancer. AIM: To evaluate associations of gastric cancer with estrogen metabolites in postmenopausal women. METHODS AND RESULTS: We performed an analysis of 233 gastric cancer cases and 281 age-matched controls from three prospective cohorts and two case-control studies of early-stage gastric cancer, mainly conducted in high-risk Asian populations. Fifteen estrogen-parent (estrone and estradiol) and -metabolite analytes (2-hydroxyestrone, 2-hydroxyestradiol, 2-hydroxyestrone-3-methyl ether, 4-hydroxyestrone; 4-methoxyestrone, 4-methoxyestradiol, 2-methoxyestrone, 2-methoxyestradiol, estriol, 16α-hydroxyestrone, 16-ketoestradiol, 16-epiestriol, and 17-epiestriol) were measured in spot urines using liquid chromatography-tandem mass spectrometry. Odds ratios for association with each marker were estimated by logistic regression. Heterogeneity was assessed by Cochran's Q test. Study-specific odds ratios were pooled by fixed-effects meta-analysis. Urinary levels of estrogen-related molecules were not associated with gastric cancer (adjusted odds ratios ranged from 0.87 to 1.27; p-values >.05), with low between-study heterogeneity (p-values >.1) for all but two metabolites (2-hydroxyestrone-3-methyl ether and 2-methoxyestradiol). CONCLUSION: To date, this is the first comprehensive assessment of endogenous estrogens with gastric cancer risk in women. Estrogens do not appear to have an etiologic role in gastric cancer risk among postmenopausal women. Given the complex network of sex steroid hormones and their extreme variation over the lifespan, further evaluation of this hypothesis is warranted.

Multi-Grain Rice Diet Decreases Risk of Breast Cancer in Korean Women: Results from the Health Examinees Study.

Although a number of studies explain the association between dietary patterns, which take into account that foods are eaten in combination, and breast cancer risk, the findings are inconsistent. We examined the association between dietary patterns and multi-grain rice intake, and the risk of breast cancer in a large-scale prospective cohort study in Korean women. A total of 93,306 women aged 40-69 years from the Health Examinees-Gem (HEXA-G) study (2004 and 2013) were included. We obtained Information on cancer diagnosis via linkage to the Korea Central Cancer Registry. Factor analysis was conducted to obtain dietary patterns, and Cox proportional models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CI) for breast cancer risk. For 494,490 person-years, 359 new cases of breast cancer occurred. We identified three major dietary patterns, that explained 23.9% of the total variance based on daily total food intake (g/day) from 37 food groups: the meat dietary pattern (higher intake of bread and red meat), the white rice dietary pattern (higher intake of white rice and lower intake of multi-grain rice), and the other pattern. Women who had higher white rice dietary pattern scores had a 35% higher risk of breast cancer, than did women with lower white rice dietary pattern scores (multivariable HR 1.35; 95% CI 1.00-1.84 for the highest vs. lowest quartile of the white rice dietary pattern scores, p for trend = 0.0384). We found that women who consumed three or more servings of multi-grain rice per day had 33% lower risk of breast cancer than did those who consumed one or less multi-grain rice serving per day among women under 50 years of age (multivariable HR 0.67; 95% CI 0.45-0.99, p for trend = 0.0204). Our study suggests that a multi-grain rice diet may be associated with lower risk of breast cancer in Korean women.

Milk Consumption Decreases Risk for Breast Cancer in Korean Women under 50 Years of Age: Results from the Health Examinees Study.

Epidemiologic studies regarding breast cancer risk related to milk consumption remain controversial. The aim of this study was to evaluate the association between milk consumption and the risk for breast cancer. A total of 93,306 participants, aged 40-69 years, were included in the prospective cohort study in the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Dietary intake was assessed using a validated food frequency questionnaire. Information on cancer diagnosis in the eligible cohort was retrieved from the Korea Central Cancer Registry through 31 December 2014. The Cox proportional hazards model was used to estimate multivariate hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 359 breast cancer cases were observed over a median follow-up period of 6.3 years. Milk consumption was not associated with decreased risk for breast cancer in the total population (p for trend = 0.0687). In women under 50 years of age, however, milk consumption was inversely associated with breast cancer risk. In the comparison between highest (≥1 serving/day) and lowest (<1 serving/week) intake categories of milk, the multivariate HR (95% CI) was 0.58 (0.35-0.97, p for trend = 0.0195)) among women under 50 years of age. In conclusion, our findings show that milk consumption in Korean women aged 50 or younger is associated with a decreased risk for breast cancer, when compared to those who never or rarely consumed milk. Further studies need to be conducted to assess this relationship and confirm these results.

An association between diet quality index for Koreans (DQI-K) and total mortality in Health Examinees Gem (HEXA-G) study.

BACKGROUND/OBJECTIVES: Diet quality scores or indices, based on dietary guidelines, are used to summarize dietary intake into a single numeric variable. The aim of this study was to examine the association between the modified diet quality index for Koreans (DQI-K) and mortality among Health Examinees-Gem (HEXA-G) study participants. SUBJECTS/METHODS: The DQI-K was modified from the original diet quality index. A total of 134,547 participants (45,207 men and 89,340 women) from the HEXA-G study (2004 and 2013) were included. The DQI-K is based on eight components: 1) daily protein intake, 2) percent of energy from fat, 3) percent of energy from saturated fat, 4) daily cholesterol intake, 5) daily whole-grain intake, 6) daily fruit intake, 7) daily vegetable intake, and 8) daily sodium intake. The association between all-cause mortality and the DQI-K was examined using Cox proportional hazard regression models. Hazard ratios and confidence intervals were estimated after adjusting for age, gender, income, smoking status, alcohol drinking, body mass index, and total energy intake. RESULTS: The total DQI-K score was calculated by summing the scores of the eight components (range 0-9). In the multivariable adjusted models, with good diet quality (score 0-4) as a reference, poor diet quality (score 5-9) was associated with an increased risk of all-cause mortality (hazard ratios = 1.23, 95% confidence intervals = 1.06-1.43). Moreover, a one-unit increase in DQI-K score resulted in a 6% higher mortality risk. CONCLUSIONS: A poor diet quality DQI-K score was associated with an increased risk of mortality. The DQI-K in the present study may be used to assess the diet quality of Korean adults.

What Are the Major Determinants in the Success of Smoking Cessation: Results from the Health Examinees Study.

Understanding mechanisms underlying smoking-related factors should be prioritized in establishing smoking prevention and cessation policy. The aim of this study was to identify factors significantly associated with smoking initiation and/or smoking cessation as well as the most important determinants of successful smoking cessation in a developed non-Western setting. Based on multiple logistic regression models, the odds ratios (ORs) for smoking initiation and cessation were estimated among males (N = 24,490) who had participated in the Health Examinees (HEXA) study. The Cox proportional hazards regression model was used to assess the association between selected predictors of smoking cessation and the likelihood of reaching this goal. Finally, Kaplan-Meier curves were constructed to illustrate the distribution of time from age at smoking initiation to age at smoking cessation. We found that the ORs for successfully quitting smoking increased with age, married status, educational achievement, having a non-manual job, drinking cessation and disease morbidity. Those exposed to secondhand smoking showed less likelihood of quitting smoking. A continual decrease in the ORs for successfully quitting smoking was observed according to increased smoking duration, smoking dose per day and lifetime tobacco exposure (ptrend <0.001). Among the selected predictors, lifetime tobacco exposure, educational attainment, alcohol drinking status and birth cohort were the major determinants in the success of smoking cessation. Our findings suggest that lifetime tobacco exposure, educational attainment, alcohol drinking status and birth cohort can determine success in smoking cessation. Public interventions promoting a smoke-free environment are needed to reinforce discouraging the initiation of, reducing, and quitting cigarette smoking.

Short Sleep Duration and Its Correlates among Cancer Survivors in Korea: the Korea National Health and Nutrition Examination Surveys.

BACKGROUND: Though a large proportion of cancer survivors are assumed to be commonly affected by sleep disturbance, few studies have focused on short sleep problems and its correlates among Korean cancer survivors. The purpose of this study was to evaluate the prevalence of short sleep in adult cancer survivors from a nationwide population-based sample and to identify risk factors for short sleep duration. MATERIALS AND METHODS: Based on the fourth and fifth Korea National Health and Nutrition Examination Surveys (2007-2012), 1,045 cancer survivors and 33,929 non-cancer controls were analyzed. The prevalence of short sleep was compared between these two groups. Associations between short sleep and its correlates were evaluated using multiple logistic regression among cancer survivors: odds ratios (ORs) and 95% confidence intervals (95%CIs) were estimated after adjusting for sociodemographic factors, lifestyle factors, psychological conditions, and cancer-related factors. RESULTS: About 8.1% of cancer survivors slept for less than 5 hours per day (6.2% men and 9.3% women), whereas this was the case for only 3.7% of non-cancer controls. Cancer survivors who had the lowest household income level showed a significantly higher likelihood for short sleep (adjusted OR 2.82, 95%CI 1.06-7.54). Self-reported poor health and depressive symptoms were found to be associated with significantly increased likelihood for short sleep in cancer survivors (adjusted OR 3.60, 95%CI 1.40-9.26 and adjusted OR 2.00, 95%CI 1.17-3.42). Gastric cancer survivors had a 3.97-fold increased risk for short sleep (95%CI 1.60-9.90). CONCLUSIONS: The prevalence of short sleep occurs at a high rate among the Korean cancer survivors, which may indicate a poorer quality of life and a higher risk of future complications in survivorship. Targeted interventions that can assist cancer survivors to cope with sleep disturbances as well as ensuring psychological stability are warranted to reduce the latent disease burden.

Correlates of self-reported sleep duration in middle-aged and elderly Koreans: from the Health Examinees Study.

Though various factors related to fluctuations in sleep duration have been identified, information remains limited regarding the correlates of short and long sleep duration among the Korean population. Thus, we investigated characteristics that could be associated with short and/or long sleep duration among middle-aged and elderly Koreans. A total of 84,094 subjects (27,717 men and 56,377 women) who participated in the Health Examinees Study were analyzed by using multinomial logistic regression models. To evaluate whether sociodemographic factors, lifestyle factors, psychological conditions, anthropometry results, and health conditions were associated with short and/or long sleep duration, odds ratios (ORs) and 95% confidence intervals (CIs) were estimated with sleep duration of 6-7 hours as the reference group, accounting for putative covariates. Regardless of sexual differences, we found that adverse behaviors and lifestyle factors including low educational attainment, unemployment, being unmarried, current smoking status, lack of exercise, having irregular meals, poor psychosocial well-being, frequent stress events, and poor self-rated health were significantly associated with abnormal sleep duration. Similarly, diabetes mellitus and depression showed positive associations with abnormal sleep duration in both men and women. Our findings suggest that low sociodemographic characteristics, adverse lifestyle factors, poor psychological conditions, and certain disease morbidities could be associated with abnormal sleep duration in middle-aged and elderly Koreans.

Obesity at adolescence and gastric cancer risk.

BACKGROUND AND OBJECTIVE: During the last few decades, prevalence of obesity has risen rapidly worldwide, markedly in children and adolescents. Epidemiologic studies have associated obesity to several cancer types, yet little is known for the effect of early life exposure to obesity on cancer risk in later life, especially in gastric cancer. Thus, the present study aimed to investigate the association of body mass index (BMI) of adolescence and the risk of gastric cancer. METHODS: A multicenter case-control study was conducted between 2010 and 2014 in Korea with 1,492 incident gastric cancer cases and 1,492 controls matched by age and sex. The BMI at age 18 was calculated by using weight and height from questionnaire. The association with the risk of gastric cancer was evaluated using odds ratios by logistic regression model adjusted for potential confounding factors. RESULTS: Compared with BMI 21.75 kg/m(2), higher BMI at age 18 was associated with higher risk of gastric cancer showing a nonlinear, threshold effect. Statistically significant odds ratio was observed in men with BMI higher than 25.3 kg/m(2) (OR 1.13, 95 % CI 1.01-1.27) and in women with BMI 25.3 kg/m(2) and above (OR 1.25, 95 % CI 1.01-1.55). CONCLUSION: Similar to some other cancer types, overweight or obese in adolescence was found to be associated with the increased risk of gastric cancer. The results imply for stratified approach of tactics in prevention of gastric cancer in different population.

The potential application of personalized preventive research.

With increases in life expectancy, the focus has shifted to living a healthier, longer life. By concentrating on preventing diseases before occurrence, researchers aim to diminish the increasing gap in medical costs and health inequalities prevalent across many nations. Although we have entered an era of post-genomics, we are still in infancy in terms of personalized preventive research. Personalized preventive research has and will continue to improve with advancements in the use of biomarkers and risk assessment. More evidence based on well-designed epidemiologic studies is required to provide comprehensive preventive medical care based on genetic and non-genetic profile data. The realization of personalized preventive research requires building of evidence through appropriate methodology, verification of results through translational studies as well as development and application of prediction models.