Validation and reproducibility of food frequency questionnaire for Korean genome epidemiologic study

Grain Subtype and the Combination of Grains Consumed Are Associated with the Risk of Metabolic Syndrome: Analysis of a Community-Based Prospective Cohort

BACKGROUND

Evidence on the prospective association between grain consumption and metabolic syndrome (MetS) is lacking.

OBJECTIVE

This study explored the association between grain intake by subtype or various combinations of grain intake and the risk of developing MetS in South Korean adults using data from a community-based prospective cohort study.

METHODS

A total of 5717 participants (2984 men and 2733 women) aged 40-69 y without MetS were followed up for 10 y (2001-2012). Grain consumption was assessed using a semiquantitative FFQ at baseline (2001-2002) and a follow-up examination (2005-2006). A multivariate Cox proportional hazards model was used to examine the risk of incident MetS and its components according to grain consumption (<1, 1 to <3, or ≥3 servings/d) by sex.

RESULTS

In total, 2218 participants (38.8%) developed MetS. Frequent consumers of whole grains (≥3 servings/d) had a lower risk of incident MetS (men-HR: 0.51; 95% CI: 0.41, 0.63; P  = 0.0001; women-HR: 0.73; 95% CI: 0.60, 0.90; P = 0.0029), whereas frequent consumers of refined grains had a higher risk of incident MetS (men-HR: 1.63; 95% CI: 1.31, 2.03; P < 0.0001; women-HR: 2.25; 95% CI: 1.82, 2.78; P < 0.0001) compared with rare consumers (<1 serving/d). The combination of low whole grains (<2 servings/d) and high refined grains (≥2 servings/d) was associated with a higher risk of MetS than the combination of high whole grains and low refined grains (men-HR: 1.21; 95% CI: 1.04, 1.41; P = 0.012; women-HR: 1.43; 95% CI: 1.23, 1.66; P < 0.0001).

CONCLUSIONS

Higher consumption of whole grains was associated with lower risk of incident MetS, whereas higher refined-grain consumption was associated with a higher risk in a middle-aged and older Korean population.

Alcoholic and Nonalcoholic Fatty Liver Disease and Incident Hospitalization for Liver and Cardiovascular Diseases

BACKGROUND & AIMS

We compared the associations of nonalcoholic fatty liver disease (NAFLD) and alcohol-associated fatty liver disease (AFLD) with risk of incident hospitalization for liver and cardiovascular diseases.

METHODS

We collected data from the Kangbuk Samsung Health Study on 218,030 men and women in Korea who underwent a health examination from 2011 through 2016. Fatty liver disease (FLD) was detected by ultrasound during the initial examination. The Fibrosis-4 index was used to identify individuals with liver fibrosis. Participants were followed up for as long as 5.9 years and data on hospitalizations for liver and cardiovascular diseases were collected.

RESULTS

The prevalence of NAFLD was 22.0% and the prevalence of AFLD was 6.4%. Over a median follow-up period of 4.2 years, we observed 51 and 1097 incident cases of liver disease- or cardiovascular disease-related hospitalizations, respectively. After adjustment for potential confounders, the multivariable-adjusted hazard ratios for liver disease-related hospitalization, comparing NAFLD and AFLD with the reference category (no excessive alcohol intake and no FLD), were 1.73 (95% CI, 0.76-3.96) and 5.00 (95% CI, 2.12-11.83), respectively. The corresponding hazard ratios for cardiovascular disease hospitalization were 1.20 (95% CI, 1.02-1.40) and 1.08 (95% CI, 0.86-1.34), respectively. Among participants with FLD, the risk of liver disease-related hospitalization increased with high Fibrosis-4 index scores, whereas the risk of incident cardiovascular disease did not.

CONCLUSIONS

In a large cohort study, we found an increased risk of liver disease-related hospitalizations for patients with NAFLD or AFLD, especially among those with Fibrosis-4 index scores. An increased risk of cardiovascular disease-associated hospitalization was observed in patients with NAFLD but not AFLD.

Food Intake Behavior in Cancer Survivors in Comparison With Healthy General Population; From the Health Examination Center-based Cohort

Background

This study aimed to investigate the food intake behavior of cancer survivors based on main sources of energy intake from different food groups in comparison with healthy individuals.

Methods

Baseline survey data from the Health Examinee cohort, which recruited participants from 2014 to 2013 were applied. A total of 5,269 cancer survivors and 5,219 healthy subjects without comorbidities who were matched by age, sex, and enrollment center were included in the analysis. The proportion of energy intake for 17 food groups was devided into lower median and median or upper. OR and 95% CIs were determined to measure the difference of energy intake proportion in cancer survivors, five major types of cancer survivors versus healthy individuals.

Results

Generally, the proportion of calories intake from sugars and sweets, meat and poultry, oils and fats, and beverage was lower in cancer survivors than in healthy individuals (OR = 0.83 [95% CI = 0.79–0.88], 0.75 [95% CI = 0.71–0.80], 0.84 [95% CI = 0.80–0.89], and 0.93 [95% CI = 0.88–0.99], respectively) with more prominently shown in breast, colon, and thyroid cancer individuals. In contrast, cancer survivors tended to intake calories from potatoes and starches, legume, seeds and nuts, vegetables, mushrooms, fruits, and seasonings more than healthy individuals (OR = 1.09 [95% CI = 1.03–1.16], 1.13 [95% CI = 1.06–1.19], 1.15 [95% CI = 1.09–1.22], 1.07 [95% CI = 1.01–1.13], 1.07 [95% CI = 1.02–1.14], 1.15 [95% CI = 1.08–1.21], and 1.17 [95% CI = 1.10–1.23], respectively) which were more prominent in gastric and breast cancer survivors.

Conclusions

The dietary behavior measured by main sources of energy intake in cancer survivors was different from healthy individuals in terms of several food groups. Although there are nutrition guidelines for cancer survivors, because of the differences between Western population and Asian people in terms of food culture, the guidelines for balanced nutritious behavior should be established among Asian cancer survivors.

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.

Association of milk consumption frequency on muscle mass and strength: an analysis of three representative Korean population studies

PURPOSE

Sarcopenia is an involuntary loss of muscle mass, strength, and physical performance associated with aging. Sarcopenia contributes to adverse health outcomes. Milk contains essential amino acids important for maintaining muscle. We investigated the relationships among milk consumption frequency (MCF), muscle mass, and strength in Korean adults.

METHODS

We analyzed the data from 16,173 adults in the 2008-2011 Korean National Health and Nutrition Examination Survey (KNHANES), 13,537 adults in the 2014-2016 KNHANES, and 8254 adults in the Korean Genome and Epidemiology Study (KoGES). MCF was divided into two groups: (1) MCF less than once per day (MCF < 1 group) and (2) MCF greater than or equal to once per day (MCF ≥ 1 group). Low skeletal muscle mass index (LSMI) was defined using the Foundation for the National Institutes of Health sarcopenia project criteria for low muscle mass. Muscle strength was measured using the hand-grip strength test.

RESULTS

The odds ratio (95% confidence interval) for LSMI in the MCF < 1 group was 1.250 (1.013-1.543) after adjusting for confounding factors, compared with the MCF ≥ 1 group (2008-2011 KNHANES). The adjusted mean for hand-grip strength was higher in the MCF ≥ 1 group (2014-2016 KNHANES). After a mean follow-up of 9 years, fat-free mass/body mass index was higher in the MCF ≥ 1 group than the MCF < 1 group (KoGES).

CONCLUSION

We found that MCF ≥ 1 was significantly associated with higher skeletal muscle index and muscle strength than lower MCF. Milk consumption could help prevent sarcopenia in adults.

Evaluation of gene-environment interactions for colorectal cancer susceptibility loci using case-only and case-control designs

BACKGROUND

Genome-wide association studies (GWAS) have identified more than 40 colorectal cancer susceptibility loci, but only a small fraction of heritability was explained. To account for missing heritability, we investigated gene-environment interactions (G × Es) between GWAS-identified single-nucleotide polymorphisms (SNPs) and established risk or protective factors for colorectal cancer using both case-only and case-control study designs.

METHODS

Data on 703 colorectal cancer cases and 1406 healthy controls from the National Cancer Center in Korea were used. We tested interactions between 31 GWAS-identified SNPs and 13 established risk or protective factors for colorectal cancer (family history, body mass index, history of colorectal polyps, inflammatory bowel disease, and diabetes mellitus, alcohol drinking, smoking, regular exercise, regular aspirin use, postmenopausal hormone replace therapy, red meat and processed meat intake, and dairy consumption). Logistic regression models were used to assess G × Es for colorectal cancer risk.

RESULTS

The SNP rs4444235 at 14q22.2 interacted with regular exercise in colorectal cancer (p_case-only = 2.4 × 10^- 3, p_case-control = 1.5 × 10^- 3). The risk allele (C) of rs4444235 increased the risk of colorectal cancer in regularly exercising individuals (OR = 1.47, 95% CI = 1.02-2.10) but decreased the risk in non-exercising individuals (OR = 0.76, 95% CI = 0.62-0.94). Furthermore, the G × E between the SNP rs2423279 at 20p12.3 and regular aspirin use was statistically significant (p_case-only = 7.7 × 10^- 3, p_case-control = 1.6 × 10^- 3). The additive effect of the risk allele (T) of rs2423279 on colorectal cancer risk was increased among regular aspirin users (OR = 4.62, 95% CI = 1.97-10.80).

CONCLUSION

Our results suggest that SNP rs4444235 at 14q22.2 and SNP rs2423279 at 20p12.3 may interact with regular exercise and aspirin use in colorectal carcinogenesis.

Plasma inflammatory biomarkers and modifiable lifestyle factors associated with colorectal cancer risk

BACKGROUND & AIMS

Chronic inflammation is a leading cause of colorectal cancer (CRC). Inflammatory biomarkers are considered indicators of occult malignancy. To contribute to the investigation of CRC prevention strategies, we aimed to identify associations between inflammatory biomarkers (insulin-like growth factor-1 (IGF-1), soluble tumor necrosis factor receptor 2 (sTNFR-2), and interleukin-8 (IL-8)) and modifiable lifestyle factors including body mass index (BMI), prior BMI, smoking status, alcohol consumption status, physical activity, and dietary inflammatory index (DII) score in terms of CRC risk.

METHODS

In a hospital-based case-control study, we explored the associations of plasma IGF-1, sTNFR-2, and IL-8 levels with CRC risk in 697 cases and 1845 controls. Unconditional logistic regression was performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for CRC with the inflammatory biomarkers adjusted for confounders.

RESULTS

CRC patients had significantly higher levels of sTNFR-2 and IL-8 than the controls (P < 0.001). In multivariate models, the levels of IGF-1, sTNFR-2, and IL-8 were significantly associated with CRC risk after adjusting for confounders (IGF-1 OR (95% CI) = 1.39 (1.02-1.89), P for trend = 0.018; sTNFR-2 = 2.14 (1.59-2.90), P for trend < 0.001; IL-8 = 1.95 (1.43-2.66), P for trend < 0.001, highest vs. lowest quartiles). The biomarkers showed either positive or negative trends when modifiable lifestyle factors were stratified. In particular, the inverse associations of CRC risk with the biomarkers were significant among subjects who engaged in regular physical activity and had an anti-inflammatory diet pattern.

CONCLUSIONS

Elevated levels of inflammatory biomarkers were associated with CRC risk and could be modified by risk and protective lifestyle factors. Our findings may provide a strategy to identify CRC risk based on the associations between inflammatory biomarkers and lifestyle factors.

Association between Serum Gamma-Glutamyltransferase and Prevalence of Metabolic Syndrome Using Data from the Korean Genome and Epidemiology Study

BACKGROUND

The aim of this study was to determine whether there is a positive correlation between gamma-glutamyltransferase (GGT) levels and the prevalence of metabolic syndrome and whether GGT can be used as an easily checkable metabolic index using data from the large-scale Korean Genome and Epidemiology Study (KoGES).

METHODS

We obtained data of 211,725 participants of the KoGES. The collected data included age, sex, height, weight, waist circumference, and various biochemical characteristics, including serum GGT levels. The data of study participants who ingested more than 40 g/day of alcohol and who were diagnosed with metabolic syndrome at baseline was excluded. We analyzed the prevalence of metabolic syndrome according to GGT quartiles in both genders.

RESULTS

The GGT level was significantly higher in subjects with metabolic syndrome compared to normal subjects (37.92±48.20 mg/dL vs. 25.62±33.56 mg/dL). The prevalence of metabolic syndrome showed a stepwise increase with GGT quartiles in both male and female subjects. Compared to the lowest GGT quartile, the odds ratio was 1.534 (95% confidence interval [CI], 1.432 to 1.643), 1.939 (95% CI, 1.811 to 2.076), and 2.754 (95% CI, 2.572 to 2.948) in men and 1.155 (95% CI, 1.094 to 1.218), 1.528 (95% CI, 1.451 to 1.609), and 2.022 (95% CI, 1.921 to 2.218) in women with increasing GGT quartile. The cutoff value of GGT predicting risk of metabolic syndrome was 27 IU/L in men and 17 IU/L in women.

CONCLUSION

We suggested that GGT could be an easily checkable marker for the prediction of metabolic syndrome.

Circulating Interleukin-6 Level, Dietary Antioxidant Capacity, and Risk of Colorectal Cancer

Chronic inflammation is one of the causes of colorectal cancer (CRC), and circulating levels of inflammatory biomarkers have been linked to tumor promotion and progression. We aimed to evaluate the interleukin-6 (IL-6) level in CRC patients and determine whether a diet rich in antioxidants was associated with CRC. This study included 654 cases and 1312 controls matched for age and sex. We measured the plasma IL-6 concentration and estimated dietary antioxidant capacity based on oxygen radical absorbance capacity (ORAC) combined with a 106-item semiquantitative food frequency questionnaire. The IL-6 concentration was significantly increased in individuals with CRC (OR _{Q4 vs. Q1}, 95% CI = 6.23, 4.10-9.45, p < 0.001). High dietary ORAC showed an inverse association with CRC (total ORAC OR _{Q4 vs. Q1}, 95% CI = 0.26, 0.16-0.40, p < 0.001; total phenolics = 0.32, 0.21-0.50, p < 0.001). We found that low dietary ORAC was associated with a significant increase in CRC in the group with elevated IL-6 levels (total ORAC OR _{Q4 vs. Q1}, 95% CI = 4.34, 3.12-6.02, p < 0.001; total phenolics = 4.61, 3.33-6.39, p < 0.001). This study suggested an inverse association between dietary antioxidant capacity and IL-6 level among patients with CRC.

Subcutaneous fat mass is associated with genetic risk scores related to proinflammatory cytokine signaling and interact with physical activity in middle-aged obese adults

Background and aims

Subcutaneous fat mass is negatively correlated with atherogenic risk factors, but its putative benefits remain controversial. We hypothesized that genetic variants that influence subcutaneous fat mass would modulate lipid and glucose metabolism and have interactions with lifestyles in Korean middle-aged adults with high visceral fat.

Materials and methods

Subcutaneous fat mass was categorized by dividing the average of subscapular skin-fold thickness by BMI and its cutoff point was 1.2. Waist circumferences were used for representing visceral fat mass with Asian cutoff points. GWAS of subjects aged 40–65 years with high visceral fat (n = 3303) were conducted and the best gene-gene interactions from the genetic variants related to subcutaneous fat were selected and explored using the generalized multifactor dimensionality reduction. Genetic risk scores (GRS) were calculated by weighted GRS that was divided into low, medium and high groups.

Results

Subjects with high subcutaneous fat did not have dyslipidemia compared with those with low subcutaneous fat, although both subject groups had similar amounts of total fat. The best model to influence subcutaneous fat included IL17A_rs4711998, ADCY2_rs326149, ESRRG_rs4846514, CYFIP2_rs733730, TCF7L2_rs7917983, ZNF766_rs41497444 and TGFBR3_rs7526590. The odds ratio (OR) for increasing subcutaneous fat was higher by 2.232 folds in the high-GRS group, after adjusting for covariates. However, total and LDL cholesterol, triglyceride and C-reactive protein concentrations in the circulation were not associated with GRS. Subjects with high-GRS had higher serum HDL cholesterol levels than those with low-GRS. Physical activity and GRS had an interaction with subcutaneous fat. In subjects with low physical activity, the odds ratio for high subcutaneous fat increased by 2.232, but subcutaneous fat deposition was not affected in the high-GRS group with high physical activity.

Conclusion

Obese adults with high-GRS had more subcutaneous fat, but they did not show more dyslipidemia and inflammation compared to low-GRS. High physical activity prevented subcutaneous fat deposition in subjects with high GRS for subcutaneous fat.

Prospective associations between total, animal, and vegetable calcium intake and metabolic syndrome in adults aged 40 years and older

BACKGROUND & AIMS

Calcium (Ca) consumption may contribute to a decreased risk of developing metabolic syndrome (MetS). However, epidemiologic evidence on the association between Ca intake and MetS is limited. This study aimed to evaluate the association between dietary Ca intake (animal-based Ca and vegetable-based Ca separately, as well as total Ca intake) and the incidence risk of MetS and its components in the Korean Multi-Rural Communities Cohort (MRCohort).

METHODS

A total of 5509 participants who did not have MetS were enrolled. Dietary Ca intake was calculated using a food frequency questionnaire composed of 106 items.

RESULTS

After 18,880 person-years of follow-up, 876 participants had developed de novo MetS. A significant inverse association between dietary total Ca intake and MetS were observed (incidence rate ratio (IRR) = 0.62, 95% confidence interval (CI) = 0.48-0.81, P for trend = 0.002 for the highest quartile of total Ca intake compared with the lowest quartile). Trends for animal Ca (IRR = 0.77, 95% CI = 0.62-0.97, P for trend = 0.039) and vegetable Ca (IRR = 0.54, 95% CI = 0.40-0.73, P for trend <0.001) were similar. The individual components of overall MetS were also inversely related to total, animal, and vegetable Ca. The tendency for an inverse association was more evident in the group with two of any of the metabolic abnormalities of MetS at baseline than in the group with no more than one MetS component.

CONCLUSIONS

Our findings indicate that a relatively high dietary intake of Ca is associated with lower risk of MetS.

Association between dietary calcium intake and the risk of cardiovascular disease among Korean adults

BACKGROUND/OBJECTIVES

Although dietary calcium intake is associated with a risk of cardiovascular disease (CVD), it has not been studied extensively in Asian populations. We therefore investigated the association between dietary calcium intake and CVD among Korean adults and the effect of obesity on this association.

SUBJECTS/METHODS

In total, 9186 participants were included in the analysis after excluding 844 with prevalent CVD/cancer or implausible energy intake. Nutrient intake, including dietary calcium, was estimated using a validated semi-quantitative food frequency questionnaire. CVD included myocardial infarction, coronary artery disease, and stroke per the World Health Organization criteria. Cox proportional hazards models were used to calculate multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

In the fully adjusted model, HRs of CVD across increasing quintiles of dietary calcium intake were 1.0 (reference), 0.85 (95% CI: 0.66-1.10), 0.77 (95% CI: 0.58-1.02), 0.59 (95% CI: 0.42-0.83), and 0.72 (95% CI: 0.48-1.08); a significant linear trend was detected (p for trend = 0.04). However, this association varied according to the obesity status. High dietary calcium intake was associated with a reduced CVD risk among nonobese participants (body mass index [BMI] < 25 kg/m²; p for trend = 0.02), whereas this was not significant among obese participants (BMI ≥ 25 kg/m²; p for trend = 0.88).

CONCLUSIONS

The association between dietary calcium intake and incident CVD may be influenced by obesity status. We provide evidence for developing dietary calcium intake guidelines for Koreans, allowing for the effects of obesity.

Protective Effect of Green Tea Consumption on Colorectal Cancer Varies by Lifestyle Factors

The inconsistent findings regarding green tea intake and colorectal cancer (CRC) risk in several epidemiological studies might result from variations in lifestyle factors. Therefore, we examined whether increased green tea intake was associated with a decreased risk of CRC and how the risk of CRC was altered by the protective effect of green tea consumption and five health-related factors. A case-control study including 2742 participants (922 cases and 1820 controls) was conducted in Korea. Green tea consumption was assessed using a semiquantitative food frequency questionnaire. The risk of CRC was approximately 40% less in the participants in the highest green tea intake tertile than in participants in the lowest green tea intake tertile. Of the five lifestyle factors examined, high body mass index and physical inactivity were independent risk factors for CRC. Regarding the interactions between tea consumption and lifestyle factors, high green tea consumption was associated with a decreased risk of CRC, with or without considering lifestyle factors. However, moderate green tea consumption increased the risk of CRC among ever-smokers, ever-drinkers and the high-inflammatory diet group. Increased consumption of green tea might be helpful to reduce the risk of CRC in those with an unhealthy lifestyle.

Association between the prevalence of metabolic syndrome and coffee consumption among Korean adults: results from the Health Examinees study

The aim of this study was to evaluate the association between the frequency and quantity of coffee consumption and metabolic syndrome (MetS) in the Health Examinees study. A total of 130 420 participants (43 682 men and 86 738 women) were included in our study. Coffee consumption was categorized into 5 categories (0, <1, 1, 2-3, and ≥4 cups/day). We calculated odds ratios (ORs) and 95% confidence intervalS (CIs) using multivariate logistic regression. In this study population, the prevalence of MetS was 12 701 (29.1%) in men and 21 338 (24.6%) in women. High coffee consumption (≥4 cups/day) was associated with a lower prevalence of MetS compared with non-coffee consumers (OR = 0.79, 95% CI = 0.70-0.90, p for trend <0.0001 in men; OR = 0.70, 95% CI = 0.62-0.78, p for trend <0.0001 in women). The multivariable-adjusted ORs for high fasting glucose decreased with increasing levels of coffee consumption in men (OR = 0.60, 95% CI = 0.54-0.67, p for trend <0.0001) and women (OR = 0.70, 95% CI = 0.63-0.79, p for trend <0.0001). For women, the multivariable-adjusted ORs for hypertriglyceridemia (OR = 0.84, 95% CI = 0.75-0.93, p for trend = 0.0007) decreased with increasing levels of coffee consumption. We found that coffee consumption was inversely associated with the prevalence of metabolic syndrome among Korean men and women. Our study warrants further prospective cohort studies.

The Association between Dietary Inflammatory Index (DII) and Cancer Risk in Korea: A Prospective Cohort Study within the KoGES-HEXA Study

Several epidemiological studies have shown that there are consistent positive associations between dietary inflammatory index (DII®) and cancer incidence in Western populations. However, few DII-cancer studies have been conducted in East Asian populations. In a large cohort representative of the general Korean population, we investigated whether the DII is associated with overall cancer risk. A total of 163,660 participants (56,781 males and 106,879 females) had evaluable data for analyses. This follow-up study was carried out over the course of 7.9 years. DII was calculated based on Semi-Quantitative Food-Frequency Questionnaire (SQ-FFQ) data for 106 food items. Cancers were self-reported based on notification by the participants' medical doctors. Multivariable Cox proportional hazard regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). After the follow-up, 1,643 cases of cancer (520 males and 1123 females) had developed. In a fully adjusted model, women in the highest DII quintile showed a 44% increased risk of getting cancer (HRQ5vsQ1 = 1.44; 95% CI = 1.14-1.82; p-trend = 0.0006), while men showed no apparent association (HRQ5vsQ1 = 0.80; 95% CI = 0.58-1.10). These results indicate that in Korean women, a more pro-inflammatory diet is associated with a higher risk of cancer incidence.

Dietary Patterns May Be Nonproportional Hazards for the Incidence of Type 2 Diabetes: Evidence from Korean Adult Females

This study aimed to examine the association between the incidence of type 2 diabetes and various risk factors including dietary patterns based on the rigorous proportional hazards assumption tests. Data for 3335 female subjects aged 40–69 years from the Korea Genome and Epidemiology Study were used. The assumption of proportional hazards was tested using the scaled Schoenfeld test. The stratified Cox regression was used to adjust the nonproportionality of diabetic risk factors, and the regression was adjusted for potential confounding variables, such as age, marital status, physical activity, drinking, smoking, BMI, etc. Metabolic syndrome and meat and fish pattern variables were positively associated with diabetes. However, dietary patterns and metabolic syndrome variables violated the proportional hazards assumption; therefore, the stratified Cox regression with the interaction terms was applied to adjust the nonproportionality and to allow the possible different parameters over each stratum. The highest quartile of meat and fish pattern was associated with diabetes only in subjects aged over 60 years. Moreover, subjects who were obese and had metabolic syndrome had higher risk in bread and snacks (HR: 1.85; 95% CI: 1.00–3.40) and meat and fish pattern (HR: 1.82; 95% CI: 1.01–3.26), respectively. In conclusion, a quantitative proportional hazards assumption test should always be conducted before the use of Cox regression because nonproportionality of risk factors could induce limited effect on diabetes incidence.

Identification of Dietary Patterns Related to Metabolic Diseases and Their Association with Cardiovascular Disease: From the Korean Genome and Epidemiology Study

Using data from the community-based cohort of the Korean Genome and Epidemiology Study (KoGES), we evaluated the dietary patterns (DPs) related to metabolic diseases and their associations with the incidence of non-fatal cardiovascular disease (CVD). After excluding those with a history of CVD or cancer, we analyzed the data of 8352 subjects aged 40-69 years. Based on their daily intake of 26 food groups at baseline, the DPs of the subjects with metabolic diseases (n = 1679, 20.1%) were analyzed using principal component analysis. Due to regional differences in the effect of DPs on CVD, we performed analyses stratified by region. The association between DPs and the incidence of non-fatal CVD was evaluated by calculating the hazard ratio (HR) and 95% confidence interval (CI) using the Cox proportional hazards model. During the 12-year follow-up, the incidence of non-fatal CVD was 5.4 per 1000 person-years (n = 431). An animal-based DP made the greatest contribution to the total variance and was characterized by a high intake of pork, beef, chicken, fish, and shellfish. The effect of DP on CVD differed by region (industrial/rural regions, p < 0.05) and was dominant in industrial regions, irrespective of metabolic disease status. In industrial regions, subjects in the top quintile of DP had a 0.42-fold (95% CI = 0.24-0.74) lower risk of incident CVD than those in the bottom quintile, even after adjusting for various covariates. In addition, the risk of CVD was high in individuals with a history of metabolic disease in both regions (HR = 1.74, 95% CI = 1.24-2.43 in industrial regions; HR = 1.88, 95% CI = 1.42-2.48 in rural regions). DP and a history of metabolic diseases, but not their interaction, were independently associated with incident CVD. In our study, an animal-based DP related to metabolic disease was independently associated with incident CVD, and this effect was noticeable only in industrial regions.

Association between Change in Alcohol Consumption and Metabolic Syndrome: Analysis from the Health Examinees Study

BACKGROUND

The association between change in alcohol intake and metabolic syndrome is unclear.

METHODS

This retrospective cohort consisted of 41,368 males and females from the Health Examinees-GEM study. Participants were divided into non-drinkers (0.0 g/day), light drinkers (male: 0.1 to 19.9 g/day; female: 0.1 to 9.9 g/day), moderate drinkers (male: 20.0 to 39.9 g/day; female: 10.0 to 19.9 g/day), and heavy drinkers (male: ≥40.0 g/day; female: ≥20.0 g/day) for each of the initial and follow-up health examinations. Logistic regression analysis was used to determine the adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for developing metabolic syndrome according to the change in alcohol consumption between the initial and follow-up health examinations. Adjusted mean values for the change in waist circumference, fasting serum glucose (FSG), blood pressure, triglycerides, and high density lipoprotein cholesterol (HDL-C) levels were determined according to the change in alcohol consumption by linear regression analysis.

RESULTS

Compared to persistent light drinkers, those who increased alcohol intake to heavy levels had elevated risk of metabolic syndrome (aOR, 1.45; 95% CI, 1.09 to 1.92). In contrast, heavy drinkers who became light drinkers had reduced risk of metabolic syndrome (aOR, 0.61; 95% CI, 0.44 to 0.84) compared to persistent heavy drinkers. Increased alcohol consumption was associated with elevated adjusted mean values for waist circumference, FSG, blood pressure, triglycerides, and HDL-C levels (all P<0.05). Reduction in alcohol intake was associated with decreased waist circumference, FSG, blood pressure, triglycerides, and HDL-C levels among initial heavy drinkers (all P<0.05).

CONCLUSION

Heavy drinkers who reduce alcohol consumption could benefit from reduced risk of metabolic syndrome.

Association between the relative abundance of gastric microbiota and the risk of gastric cancer: a case-control study

The human gut hosts a diverse community of bacteria referred to as the gut microbiome. We investigated the association between the relative abundance of gastric microbiota and gastric cancer (GC) risk in a Korean population. The study participants included 268 GC patients and 288 controls. DNA was extracted from gastric biopsies, and 16S rRNA gene analysis was performed. Unconditional logistic regression models were used to observe the associations. Of the participants, those who had the highest level (highest tertile) of relative Helicobacter pylori and Propionibacterium acnes abundances showed a significantly higher risk for GC after adjusting for potential confounding variables (odds ratio (OR) = 1.86, 95% confidence interval (CI) = 1.17–2.97, p for trend = 0.017 and OR = 4.77, 95% CI = 2.94–7.74, p for trend <0.001, respectively). Subjects who carried Prevotella copri had a significantly higher risk of GC than noncarriers (OR = 2.54, 95% CI = 1.42–4.55, p for trend = 0.002). There was a lower risk of GC in subjects carrying Lactococcus lactis than in noncarriers (OR = 0.21, 95% CI = 0.10–0.44, p for trend <0.001). H. pylori, P. acnes and P. copri are strong risk factors, whereas L. lactis is a protective factor, for GC development in Koreans. Further microbiome studies are warranted to verify the findings of the current study.

Alcohol Consumption Reduces the Beneficial Influence of Protein Intake on Muscle Mass in Middle-Aged Korean Adults: A 12-Year Community-Based Prospective Cohort Study

The influence of alcohol consumption on the association of protein intake with muscle mass was assessed using data from the Korean Genome and Epidemiology Study. Dietary protein intakes of 4412 middle-aged participants with normal baseline muscle mass were assessed using a semi-quantitative Food Frequency Questionnaire, and baseline alcohol consumption data (e.g., frequency and amount) were collected using a structured questionnaire. The skeletal muscle mass index (SMI), defined as the weight-adjusted skeletal muscle mass, was measured using multi-frequency bioelectrical impedance analyses every 2 years until the study endpoint. Low muscle mass was defined as a SMI <2 standard deviations below the sex-specific normal mean for a young reference group. During a 12-year follow-up, 395 subjects developed a low SMI. After multivariate adjustments, high protein intake (≥1.2 g/kg body weight (BW)) was shown to reduce the risk of low SMI development in both men (hazard ratio (HR): 0.24; 95% confidence interval (CI): 0.12, 0.51; p for trend < 0.001) and women (HR: 0.29; 95% CI: 0.16, 0.53; p for trend < 0.001), compared with low protein intake (<0.8 g/kg BW). Alcohol consumption attenuated the protective influence of protein intake against low SMI development in women (HR: 0.64; 95% CI: 0.18, 2.25; p for trend = 0.478). Among the total subjects, heavy drinkers with high protein intake were not significantly associated with the development of a low SMI (HR: 0.20; 95% CI: 0.03, 1.50; p = 0.117). Additional research should clarify the dose-response effects of alcohol consumption on muscle mass relative to daily protein intake.

Alcoholic and non-alcoholic fatty liver disease and associations with coronary artery calcification: evidence from the Kangbuk Samsung Health Study

OBJECTIVE

Recent evidence suggests that alcoholic fatty liver disease (AFLD) and non-alcoholic fatty liver disease (NAFLD) may differentially affect risk of cardiovascular mortality. To investigate whether early liver disease due to AFLD or NAFLD have similar or dissimilar effects on risk of early coronary artery atherosclerosis, we have investigated the associations between AFLD and NAFLD and coronary artery calcium (CAC).

DESIGN

A cross-sectional study was performed in 105 328 Korean adults who attended a health check-up programme. CAC score was assessed using CT, daily alcohol intake was recorded as grams/day and liver fat by ultrasound. Logistic regression model was used to calculate ORs with 95% CIs for prevalent CAC.

RESULTS

Both NAFLD and AFLD were positively associated with CAC score. After adjusting for potential confounders, multivariable-adjusted OR (95% CIs) for CAC >0 comparing NAFLD and AFLD to the reference (absence of both excessive alcohol use and fatty liver disease) were 1.10 (95% CI 1.05 to 1.16) and 1.20 (95% CI 1.11 to 1.30), respectively. In post hoc analysis, OR (95% CI) for detectable CAC comparing AFLD to NAFLD was 1.09 (95% CI 1.01 to 1.17). Associations of NAFLD and AFLD with CAC scores were similar in both non-obese and obese individuals without significant interaction by obesity (p for interaction=0.088). After adjusting for homeostasis model assessment of insulin resistance and high-sensitivity C reactive protein, the associations between fatty liver disease and CAC scores remained statistically significant.

CONCLUSION

In this large sample of young and middle-aged individuals, early liver disease due to NAFLD and AFLD were both significantly associated with the presence of coronary artery calcification.

Relationship between daily coffee intake and suicidal ideation

OBJECTIVE

Caffeine is the most widely-used psychoactive substance in the world. The present study investigates the relationship between caffeine intake and suicide risk according to gender.

METHOD

Analysis of the Kangbuk Samsung Cohort Study (KSCS) data from 80,173 individuals was performed using Chi-square tests and t-tests to determine the relationships between psychosocial constructs and gender. The relationship between caffeine intake and suicidal ideation was analyzed by obtaining odds ratios with multivariate logistic regression in which depression and sleep problems were adjusted for age.

RESULTS

In both men and women with suicidal ideation, the proportion of those who consume four or more cups of coffee per day was highest among the groups of various coffee intake levels. The results on the relationship between daily coffee intake and suicidal ideation revealed that suicide risk was high in both men and women who consume four or more cups of coffee a day. However, once the age, depression and sleep problems were adjusted for, suicide risk decreased in women of 1-4 cups of coffee intake per day, whereas no change was observed in men.

CONCLUSION

Regardless of psychiatric problems such as depression or sleep problems, regular and moderate caffeine intake likely reduces suicide risk as well as depression in women.

Dietary Inflammatory Index and Risk of Breast Cancer Based on Hormone Receptor Status: A Case-Control Study in Korea

Breast cancer is the most common cancer in women globally, and the risk of developing breast cancer is associated with inflammation. The present study aimed to examine the association between the Dietary Inflammatory Index (DII^®) and breast cancer in Korean women and investigate whether the tumor’s hormone receptor status affects this association. In this case-control study, we enrolled 364 breast cancer patients and 364 age-matched controls. DII scores were calculated from dietary intake evaluated by a 106-item food frequency questionnaire. The DII score was significantly higher in cases than in controls. After adjusting for potential confounders, the odds ratio (OR) of breast cancer was higher in the highest DII tertile (OR = 3.68, 95% confidence interval (CI): 2.34–5.80, p for trend < 0.0001) than in the lowest tertile. We found that higher DII scores were related to an increased risk of breast cancer for estrogen receptor (ER)+/progesterone receptor (PR)+ tumors regardless of menopausal status (OR = 2.59, 95% CI: 1.37–4.88 in the highest DII category, p for trend = 0.01 for premenopausal women; OR = 11.00, 95% CI: 2.93–41.30 in the highest DII category, p for trend = 0.0004 for postmenopausal women), but not for ER−/PR− status. Our results suggested that the DII scores are positively associated with breast cancer risk in Korean women and that this relationship is more robust in ER+/PR+ tumors.

Protective Effects of Dietary MUFAs Mediating Metabolites against Hypertension Risk in the Korean Genome and Epidemiology Study

Background and Aims: Metabolites related to dietary factors can be used to identify biological markers to prevent metabolic disease. However, most studies have been conducted in the United States and Europe, and those in the Asian region are limited. We investigated the effects of dietary monounsaturated fatty acids (MUFAs) and metabolites on new-onset hypertension in the Korean Genome and Epidemiology Study. Method and Results: A total of 1529 subjects without hypertension were divided into tertiles of dietary MUFAs intake. After a 4-year follow-up, 135 serum metabolites were measured using the AbsoluteIDQ p180 kit. During the 4-year follow-up period, 193 new-onset hypertension incidences were observed. The highest MUFAs intake group was inversely associated with the risk of hypertension compared with the lowest MUFAs intake group (odds ratio (OR) = 0.49, (95% confidence interval (CI) = 0.29–0.82)). Of the 135 metabolites, eight were significantly associated with MUFAs intake. Phosphatidylcholine-diacyl (PC aa) C 38:1 and hydroxysphingomyelin (SM OH) C 16:1 were associated with a decrease in hypertension risk (PC aa C 38:1, OR = 0.60 (95% CI = 0.37–0.96); SM OH C 16:1, OR = 0.42 (95% CI = 0.20–0.90)). The highest MUFAs intake group had a significantly decreased risk of hypertension, even considering PC aa C 38:1 and SM (OH) C 16:1 as a mediator. Conclusion: We confirmed that dietary MUFAs intake, and PC aa C 38:1 and SM (OH) C 16:1 had protective effects against hypertension. Furthermore, high MUFAs intake combined with PC aa C 38:1 and SM (OH) C 16:1 has the most significant effect on reducing the risk hypertension.

Optimal Target Blood Pressure and Risk of Cardiovascular Disease in Low-Risk Younger Hypertensive Patients

BACKGROUND

This study aimed to examine longitudinal associations between blood pressure (BP) categories and incident cardiovascular disease (CVD) in treated hypertensive patients without CVD.

METHODS

A cohort study was performed in Korean adults who underwent a comprehensive health examination from 1 January 2011 to 31 December 2016 and was followed for incident CVD via linkage to the Health Insurance and Review Agency database until the end of 2016, with a median follow-up of 4.3 years.

RESULTS

Among 263,532 participants, 8,418 treated hypertensive patients free of CVD at baseline were included. The incident CVD end point was defined as new hospitalization for CVD, including ischemic heart disease, stroke, and transient ischemic attack. During 32,975.6 person-years of follow-up, 200 participants developed new-onset CVD (incidence rate of 60.6 per 104 person-years). The multivariable-adjusted hazard ratio (HR; 95% confidence intervals [CI]) for CVD according to systolic blood pressure (SBP) levels (comparing SBP < 110, SBP = 120-129, SBP = 130-139, SBP = 140-149, SBP = 150-159, and SBP ≥160 to SBP 110-119 mm Hg [reference]) were 0.83 (0.53-1.30), 1.31 (0.91-1.89), 1.18 (0.74-1.87), 1.46 (0.79-2.72), 3.19 (1.25-8.12), and 5.60 (2.00-15.70), respectively. In multivariable analysis for CVD according to diastolic blood pressure (DBP) levels, HR (95% CI) of DBP < 60, DBP = 70-79, DBP = 80-89, DBP = 90-99, and DBP ≥100 compared to DBP = 60-69 mm Hg [reference]) were 0.51 (0.12-2.14), 1.13 (0.76-1.67), 1.26 (0.83-1.92), 1.62 (0.89-2.97), and 1.68 (0.51-5.55), respectively.

CONCLUSIONS

In this large cohort of middle-aged treated hypertensive patients, SBP < 120 mm Hg and/or DBP < 70 mm Hg were acceptable and showed a trend of protection of incident CVD.

Higher Pro-Inflammatory Dietary Score is Associated with Higher Hyperuricemia Risk: Results from the Case-Controlled Korean Genome and Epidemiology Study_Cardiovascular Disease Association Study

In previous studies, the elevated dietary inflammatory index (DII®) scores have been consistently associated with several chronic diseases. However, the relationship with hyperuricemia remains unknown. The aim of this study was to determine if the DII is associated with hyperuricemia risk. The study included 13,701 participants (men 5102; women 8599) in a large-scale cross-sectional study in South Korea. A validated semi-quantitative food frequency questionnaire (SQFFQ) was used to measure dietary intake, and blood samples were obtained to determine hyperuricemia. As the DII score increased, the hyperuricemia risk increased among women (OR 1.35, 95% CI 1.03-1.77, p trend = 0.02). However, no significant results were found for men. Women with lower BMI scores had higher risks of hyperuricemia with higher DII scores (OR 1.62, 95% CI 1.05-2.52, p trend = 0.03). As the DII increased, however, only women who consumed alcohol ("past or current drinkers") had higher risks of hyperuricemia (OR 1.92, 1.22-3.02, p trend = 0.004). Among the DII components, intake of flavonoids showed a significant association with the hyperuricemia risk in women (OR 0.75, 0.59-0.96, p trend = 0.03). Our results suggest that higher intake of pro-inflammatory diet is significantly associated with higher risk of hyperuricemia among women. These results reinforce the importance of less pro-inflammatory habitual dietary patterns in lowering the risk of hyperuricemia and secondary afflictions such as cardiovascular diseases.

Identification of Dietary Patterns Associated with Incidence of Hyperglycemia in Middle-Aged and Older Korean Adults

Little is known about the association between dietary patterns and hyperglycemia incidence among Korean adults. Hence, we aimed to prospectively investigate the major dietary patterns associated with hyperglycemia among middle-aged and older Korean adults. In total, 55,457 adults (18,292 men and 37,165 women) aged 40 to 79 years, who were previously enrolled in the Health Examinee Study of the Korean Genome and Epidemiology Study and had no history of type 2 diabetes mellitus (T2DM) or cancer at baseline, were included. Dietary patterns were identified by a factor analysis based on dietary data, which were assessed at baseline using a validated food-frequency questionnaire. Participants were classified as having hyperglycemia if fasting blood glucose levels were ≥126 mg/dL or physician diagnosed T2DM during follow-up. Multivariable Cox proportional hazard models were used to examine the associations between each dietary pattern and future hyperglycemia risk after adjusting for potential confounders. After a mean follow-up of 4.9 years, 2574 new cases of hyperglycemia were identified. Using a factor analysis, four distinct dietary patterns were identified: “prudent;” “fatty fish, meat, and flour-based food;” “coffee and sweets;” and “whole grain (men)” or “white rice (women).” The “prudent” pattern was inversely associated with hyperglycemia risk only in women (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.63–0.89; p for trend = 0.0003). Conversely, women in the highest quintile of the “fatty fish, meat, and flour-based food” pattern showed an increased risk of hyperglycemia (HR, 1.22; 95% CI, 1.03–1.44; p for trend = 0.0210) compared with those in the lowest quintile. The “coffee and sweets” and “white rice” patterns were not associated with hyperglycemia risk in women. The dietary patterns observed in men had no associations with hyperglycemia incidence. Our findings suggest that a diet rich in vegetables, mushrooms, seaweeds, fruits, and soy products and low in fatty fish and high-fat meat may potentially play a protective role in T2DM development with sex differences in middle-aged and older Korean adults.

Association between Peptic Ulcer Disease and Osteoporosis: The Population-Based Longitudinal Cohort Study in Korea

OBJECTIVES

The association between peptic ulcer disease (PUD) and osteoporosis remains unclear. We investigated the association between PUD and osteoporosis by classifying individuals based on gender in a prospective study on 10,030 adults in Korea at a 12-year follow-up examination.

DESIGN AND SETTING

The baseline survey of the Ansung-Ansan cohort studies was conducted from May 2001 to February 2003, and 10,030 participants (5018 from the Ansung study and 5012 from the Ansan study) completed the examination.

PRIMARY OUTCOME MEASURES

The risk of developing osteoporosis was higher in both men and women in the PUD group than in the control group.

RESULTS

At the 12-year follow-up, osteoporosis had developed in 11.1% (21/189) and 29.9% (56/187) of men and women in the PUD group, respectively. Meanwhile, in the control group, 4.8% (70/1464) and 16.5% (271/1639) of men and women, respectively, were presented with osteoporosis. The incidence rates per 1000 person-years were 20.5% and 68.5% in men and women in the PUD group and 11.2% and 42.3% of men and women in the control group, respectively. The risk of developing osteoporosis was higher in both men and women in the PUD group than in the control group (men: hazard ratio [HR] = 1.72, 95% confidence interval [CI] = 1.02-2.92; women: HR = 1.62, 95% CI = 1.20-2.18).

CONCLUSION

The risk of developing osteoporosis was significantly higher in both men and women in the PUD group than in the control group.

The association between dietary pattern and depression in middle-aged Korean adults

BACKGROUND/OBJECTIVES

The association between dietary patterns and depression has been reported but the results have been inconsistent. This study was conducted to investigate the association between dietary patterns and depression in middle-aged Korean adults.

SUBJECTS/METHODS

The participants were selected from a community-based cohort, a subset of the Korean Genome and Epidemiology Study. Depression was assessed using the Korean version of the Beck Depression Inventory (BDI) and those with a BDI score ≥ 16 were defined as having depression. The subjects' food intakes over the year preceding the survey were estimated by using a validated semi-quantitative food frequency questionnaire. Dietary patterns were identified by using factor analysis. Multiple logistic regression was used to assess the association of dietary pattern with depression.

RESULTS

Among 3,388 participants, 448 (13.2%) were identified as having depression. We identified two major dietary patterns: 'Healthy' dietary pattern was characterized by high intakes of vegetables, soybeans, mushroom, seaweeds, white fish, shellfish and fruits and a low intake of white rice. 'Unhealthy' dietary pattern was characterized by high intakes of white rice, meats, ramen, noodles, bread and coffee and a low intake of rice with other grains. Compared with subjects in the lowest quartiles, those in the highest quartiles of the healthy dietary pattern had a significantly lower odds ratio (OR = 0.59, 95% CI: 0.42-0.82, P for trend = 0.0037) after adjusting for potential confounders. In contrast, the unhealthy dietary pattern was negatively associated with depression (OR = 1.65, 95% CI: 1.19-2.28, P for trend = 0.0021).

CONCLUSION

This results suggest that a healthy dietary pattern (rich in vegetables, soybeans, mushroom, seaweeds, white fish, shellfish, and fruits) is associated with low risk of depression. Whereas an unhealthy dietary pattern (rich in white rice, meats, ramen, noodles, bread, and coffee) is associated with a high risk of depression in middle-aged Korean adults.

The association between metabolic syndrome and peanuts, pine nuts, almonds consumption: The Ansan and Ansung Study

BACKGROUND

Previous studies reported an inverted relationship between nut consumption and the incidence of metabolic syndrome (MetS). The present study investigated the incidental risk for MetS according to peanut, almond, and fine nut consumption in the Korean population.

METHODS

In a community-based Korean cohort, 5306 Korean adults were divided into four groups according to their peanut, almond, and fine nut intake (<1/month, 1/month-0.5/week, 0.5-1/week, and ≥1/week, in which one serving = 15 g) and were followed-up for 10 years. A Cox proportional hazard model was used to evaluate the hazard ratios (HRs) with confidence intervals (CI) for MetS in each study group. Age subgroup (≥50 or <50 years) analysis was also conducted.

RESULTS

The age and multivariable-adjusted HRs with 95% CIs for MetS showed a significant inverse dose-response relationship between peanut, almond, and fine nut intake and the incidence of MetS in men and women (multivariable-adjusted HRs [95% CI] in men; 0.91 [0.76-1.09] in 1/month-0.5/week, 1.03 [0.80-1.31] in 0.5-1/week, 0.72 [0.56-0.93] in ≥1/week and in women; 0.81 [0.65-1.003] in 1/month-0.5/week, 0.76 [0.54-1.07] in 0.5-1/week, 0.57 [0.41-0.79] ≥1/week)). Subgroup analysis showed a significant difference in middle-aged men (≥1/week) and old-aged women (≥0.5/week).

CONCLUSION

The results of the present study suggested that peanut, almond, and fine nut intake (≥15 g/week) may be inversely related to incidence risk of MetS in the Korean general population. Additionally, the association between nut consumption and MetS incidence risk may differ in sex and age subgroups.

Associations among dietary seaweed intake, c-MYC rs6983267 polymorphism, and risk of colorectal cancer in a Korean population: a case-control study

PURPOSE

The effects of seaweed compounds have been studied in relation to colorectal cancer (CRC) based on their ability to modulate carcinogen metabolism in vivo and in vitro. However, no epidemiological studies on the interaction between edible seaweed and genetic variants relevant to CRC have been reported. This study examined the associations among dietary seaweed intake (gim, miyeok, and dashima), single-nucleotide polymorphisms (SNPs; rs6983267, rs7014346, and rs719725), and CRC risk in a Korean population.

METHODS

The participants comprised 923 CRC patients and 1846 controls who visited the National Cancer Center Korea. We used a Semiquantitative Food Frequency Questionnaire and genotyped SNPs using genomic DNA samples.

RESULTS

The intake of total seaweed, miyeok, and dashima showed a significant inverse association with CRC risk after adjusting for potential confounding factors (total seaweed odds ratio (OR) [95% CI] = 0.65 [0.50-0.85], P for trend < 0.001; miyeok = 0.82 [0.62-1.09], P for trend < 0.05; dashima = 0.58 [0.44-0.76], P for trend < 0.001, highest vs. lowest tertile). We confirmed that the homozygous T/T allele of rs6983267 c-MYC indicated an interaction between dietary seaweed intake and both overall CRC and rectal cancer (CRC OR [95% CI] = 0.52 [0.34-0.81], P for interaction = 0.015; rectal cancer = 0.45 [0.25-0.79], P for interaction = 0.007, T/T carriers with high total seaweed intake vs. T/T carriers with low total seaweed intake).

CONCLUSIONS

This study provides evidence of the effect of dietary seaweed intake on CRC risk with respect to c-MYC gene variants.

Effect of 'rice' pattern on high blood pressure by gender and obesity: using the community-based KoGES cohort

OBJECTIVE

The present study aimed to examine the association between dietary pattern and the risk of high blood pressure (BP) and to estimate the attenuated effect by gender and obesity on the association using data from a prospective cohort study in Korea.

DESIGN

Prospective study. Diet was assessed using a validated 103-item FFQ and was input into factor analysis after adjustment for total energy intake.

SETTING

Community-based Korean Genome Epidemiology Study (KoGES) cohort.

PARTICIPANTS

Healthy individuals (n 5151) without high BP at recruitment from the community-based cohort study.

RESULTS

Dietary pattern was not associated with the risk of high BP regardless of the type of covariates, with the exception of the 'rice' pattern. The effect of the 'rice' pattern was observed in both men (Ptrend = 0·013) and women (Ptrend < 0·001), but the statistical significance remained only in women after adjustment for confounders (Ptrend = 0·004). The positive association of the 'rice' pattern with high BP risk was attenuated by obesity. After stratification by gender and obese status, in particular, the harmful effect of the 'rice' pattern was predominantly observed in obese women (Ptrend < 0·001) only.

CONCLUSIONS

This longitudinal study in Korean adults found a positive association of the 'rice' pattern with long-term development of incident high BP, predominantly in women. The association is likely to be attenuated by gender and obese status.

Utilization of bioelectrical impedance analysis for detection of lymphedema in breast Cancer survivors: a prospective cross sectional study

Background

Breast cancer survivors are at risk of developing breast cancer-related lymphedema (BCRL) after surgical treatment, which may have a negative effect on quality of life. The purpose of this study was to investigate the clinical role of bioelectrical impedance analysis (BIA) and the relationship between the development of BCRL in breast cancer survivors who have undergone axillary surgery.

Methods

A total of 228 patients with breast cancer were enrolled in the study between May 2016 and January 2017. BCRL was assessed by measuring the circumference of both arms at 15 cm below the acromion process and the olecranon process. Patients were classified as BCRL (n = 22) and non-BCRL (n = 206) based on the difference of the arm circumference of 2 cm. Data including lymphedema, anthropometry, BIA measurements, food frequency questionnaire, type of surgery, total number of dissected lymph nodes, and post-operative treatment were collected.

Results

Of the breast cancer survivors, 10.4% had BCRL by the definition. The BCRL group contained 22 patients, while the non-BCRL group contained 206 patients. Compared to the non-BCRL group, the BCRL group had a higher body mass index, a larger percentage of ideal body weight, more dissected lymph nodes, and higher single frequency BIA (SFBIA) ratio (P = 0.027, P = 0.031, P < 0.001, and P < 0.001, respectively). The SFBIA ratio provided 63.64% sensitivity and 95.15% specificity in estimating the risk of BCRL.

Conclusion

Our data provides evidence to support that the use of SFBIA ratio can serve as an alternative method to monitor and/or diagnose BCRL.

Trial registration

This trial was retrospectively registered at Clinicaltrials.gov identifier (NCT03391206) on the 5 January 2018.

Metabolic Obesity Phenotypes and Risk of Cellulitis: A Cohort Study

No cohort studies have evaluated the effect of obesity on the risk of cellulitis according to metabolic health status. We investigated an association of BMI and metabolic health status with the development of cellulitis. We conducted a cohort study of 171,322 Korean adults who underwent a health checkup examination and were followed from 2011 to 2016 for cellulitis and hospital admission related to cellulitis, which were ascertained through the linkage to the Health Insurance and Review Agency database. Being metabolically healthy was defined as not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance <2.5. During 638,240.4 person-years of follow-up, 14,672 cases of incident cellulitis were identified with 225 cases of cellulitis-related admission. After adjustment for possible confounders, the multivariable-adjusted hazard ratios (95% CI) for incident cellulitis comparing BMIs 23–24.9, 25–29.9, and ≥30 with a BMI of 18.5–22.9 kg/m² as the reference were 1.07 (1.02–1.11), 1.09 (1.04-1.13), and 1.19 (1.08–1.31), respectively, whereas the corresponding multivariable-adjusted hazard ratios (95% CI) for cellulitis-related admission were 1.55 (1.05–2.3), 2.47 (1.73–3.53), and 4.8 (2.86–8.05), respectively. These associations were consistently observed in both metabolically healthy and unhealthy individuals with no significant interaction. In a large cohort of apparently healthy adults, increased BMI was associated with an increased risk of cellulitis and hospitalization for cellulitis in both metabolically healthy and unhealthy individuals. Obesity appears to be an independent risk factor for cellulitis regardless of metabolic phenotype.

Dietary Vitamin B6 Intake Associated with a Decreased Risk of Cardiovascular Disease: A Prospective Cohort Study

Although the biological mechanisms underlying the beneficial effects of vitamin B₆ on cardiovascular disease (CVD) have been reported on, epidemiological studies have yielded controversial results, and data on the Korean population are limited. This study examined the association between dietary vitamin B₆ intake and CVD incidence in Koreans. A total of 9142 participants of the Korean Genome and Epidemiology Study, aged 40–69 years, who did not have CVD or cancer at the baseline were included in the analysis. Dietary data were assessed using a validated semi-quantitative food frequency questionnaire. CVD incidence was assessed using biennial questionnaires and confirmed through repeated personal interviews. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard regression models. After multivariate adjustment, a higher vitamin B₆ intake was significantly associated with a decreased CVD risk in men (HR: 0.44; 95% CI: 0.25–0.78); no such association was observed in women. Dose-response analysis confirmed the presence of inverse linearity between vitamin B₆ intake and CVD incidence in men (p for nonlinearity = 0.3). A higher dietary intake level of vitamin B₆ was associated with a reduced CVD risk in Korean men. These observations require further verification in other populations.

Impact of dietary protein intake and obesity on lean mass in middle-aged individuals after a 12-year follow-up: the Korean Genome and Epidemiology Study (KoGES)

The present study investigated the association between protein intake and lean mass according to obesity status over a 12-year period. Data on 4412 participants aged 40-69 years were obtained from the Korean Genome and Epidemiology Study. The usual dietary protein intake of these participants was assessed at baseline using a semi-quantitative FFQ. Body composition was measured using bioelectrical impedance analysis at baseline and after a 12-year follow-up. Linear mixed-effects models were used to examine the associations between lean mass after a 12-year follow-up and protein intake at baseline. After adjusting for covariates and lean mass at baseline, comparisons between the highest and lowest tertiles revealed that dietary protein intake was positively associated with lean mass in both men (β = 0·79, P = 0·001) and women (β = 0·28, P = 0·082) after the 12-year period; however, those differences were attenuated after additional adjustment for fat mass at baseline and were stronger in the normal-weight group (men, β = 0·85, P = 0·002; women, β = 0·97, P < 0·001) but were not detected in the obese group. In the obese group, age (men, β = 4·08, P < 0·001; women, β = 2·61, P < 0·001) and regular physical activity (men, β = 0·88, P = 0·054; women, β = 0·76, P < 0·001) were significantly associated with lean mass after 12 years of follow-up. The results of the present study showed that protein intake may contribute to the prevention of ageing-related lean mass loss; however, the impact of this intake may vary depending on obesity status. Therefore, the maintenance of a healthy body weight during ageing through enhanced protein intake is likely to confer health benefits.

High-protein diet with renal hyperfiltration is associated with rapid decline rate of renal function: a community-based prospective cohort study

Background

The effect of a high-protein diet with renal hyperfiltration (RHF) on decline of kidney function has rarely been explored. We investigated the association between a high-protein diet, RHF and declining kidney function.

Methods

A total of 9226 subjects from the Korean Genome and Epidemiology Study, a community-based prospective study (2001–14), were enrolled and classified into quartiles according to daily amount of protein intake based on food frequency questionnaires. RHF was defined as estimated glomerular filtration rate (eGFR) with residuals of >95th percentile after adjustment for age, sex, history of hypertension or diabetes, height and weight. Rapid decline of renal function was defined as decline rate of eGFR >3 mL/min/1.73 m2/year.

Results

The relative risk of RHF was 3.48-fold higher in the highest than in the lowest protein intake quartile after adjustment for confounding factors [95% confidence interval (CI) 1.39–8.71]. The mean eGFR decline rate was faster as quartiles of protein intake increased. Furthermore, the highest quartile was associated with 1.32-fold increased risk of rapid eGFR decline (95% CI 1.02–1.73). When subjects were divided into two groups with or without RHF, the highest quartile was associated with a rapid decline in renal function only in RHF subjects (odds ratio 3.35; 95% CI 1.07–10.51). The sensitivity analysis using the Korean National Health and Nutrition Examination Survey (2008–15) data with 40 113 subjects showed that higher quartile was associated with increased risk for RHF.

Conclusions

A high-protein diet increases the risk of RHF and a rapid renal function decline in the general population. These findings suggest that a high-protein diet has a deleterious effect on renal function in the general population.

Association between fruit and vegetable consumption and risk of metabolic syndrome determined using the Korean Genome and Epidemiology Study (KoGES)

PURPOSE

This study examined the association between fruit and vegetable consumption and the risk of metabolic syndrome (MetS) and its components in middle-aged and older adults using data from the Korean Genome and Epidemiology Study.

METHODS

A total of 5688 participants aged 40-69 years without MetS at baseline were recruited and followed for 8 years. Fruit and vegetable consumption was assessed using a semi-quantitative food-frequency questionnaire at baseline and after 4 years. A multivariate Cox proportional hazards model was used to examine the risk of incident MetS and its components according to fruit and vegetable consumption.

RESULTS

A total of 2067 participants (1020 men and 1047 women) developed MetS during the 8-year follow-up period. Frequent fruit consumers (≥ 4 servings/day) had a lower risk of incident MetS than did rare consumers (< 1 serving/day) in both men and women (hazard ratio (HR) = 0.55, 95% CI 0.44-0.67, p < 0.0001 for men; HR = 0.57, 95% CI 0.47-0.70, p for trend < 0.0001 for women) after adjusting for confounders. Frequent fruit consumption was inversely associated with incidence of abdominal obesity, hypertriglyceridemia, and elevated blood pressure. Frequent vegetable consumption was inversely associated with a risk of hyperglycemia only in men (HR = 0.65, 95% CI 0.44-0.96, p for trend = 0.0275), but no association was observed with risk of incident MetS.

CONCLUSIONS

High fruit consumption was associated with a reduced risk of incident MetS and its components, whereas high vegetable consumption was associated with a reduced risk of incident hyperglycemia, but not with MetS in middle-aged and older adults.

Carbohydrate-Rich Diet Is Associated with Increased Risk of Incident Chronic Kidney Disease in Non-Diabetic Subjects

Despite the potential relationship with metabolic derangements, the association between dietary carbohydrate intake and renal function remains unknown. The present study investigated the impact of dietary carbohydrate intake on the development of incident chronic kidney disease (CKD) in a large-scale prospective cohort with normal renal function. A total of 6746 and 1058 subjects without and with diabetes mellitus (DM) were analyzed, respectively. Carbohydrate intake was assessed by a 24-h dietary recall food frequency questionnaire. The primary endpoint was CKD development, defined as a composite of estimated glomerular filtration rate (eGFR) of ≤60 mL/min/1.73 m2 and the development of proteinuria. CKD newly developed in 20.1% and 36.0% of subjects during median follow-ups of 140 and 119 months in the non-DM and DM subjects, respectively. Categorization of non-DM subjects into dietary carbohydrate density quartiles revealed a significantly higher risk of CKD development in the third and fourth quartiles than in the first quartile (P = 0.037 for first vs. third; P = 0.001 for first vs. fourth). A significant risk elevation was also found with increased carbohydrate density when carbohydrate density was treated as a continuous variable (P = 0.008). However, there was no significant difference in the incident CKD risk among those with DM according to dietary carbohydrate density quartiles. Carbohydrate-rich diets may increase the risk of CKD development in non-DM subjects.

Relationship of the Blood Pressure Categories, as Defined by the ACC/AHA 2017 Blood Pressure Guidelines, and the Risk of Development of Cardiovascular Disease in Low-Risk Young Adults: Insights From a Retrospective Cohort of Young Adults

Background There are limited outcome studies of hypertension among young adults, especially using the new blood pressure ( BP ) categories from the American College of Cardiology and the American Heart Association. We examined associations between the new BP categories and the risk of incident cardiovascular disease ( CVD ) in low-risk and young adults. Methods and Results A cohort study was performed in 244 837 Korean adults (mean age, 39.0 years; SD , 8.9 years) who underwent a comprehensive health examination at Kangbuk Samsung Hospital from January 1, 2011, to December 31, 2016; they were followed up for incident CVD via linkage to the Health Insurance and Review Agency database until the end of 2016, with a median follow-up of 4.3 years. BP was categorized according to the new American College of Cardiology/American Heart Association (ACC/AHA) hypertension guidelines. During 924 420.7 person-years, 1435 participants developed new-onset  CVD (incidence rate of 16.0 per 104 person-years). The multivariable-adjusted hazard ratios (95% CI s ) for CVD comparing elevated BP , stage 1 hypertension, stage 2 hypertension, treated and strictly controlled (systolic BP /diastolic BP <130/80 mm Hg with antihypertensive use), treated and controlled (systolic BP 130-139 and diastolic BP 80 to 89 mm Hg with antihypertensive use), treated uncontrolled, and untreated hypertension to normal BP were 1.37 (1.11-1.68), 1.45 (1.26-1.68), 2.12 (1.74-2.58), 1.41 (1.12-1.78), 1.97 (1.52-2.56), 2.29 (1.56-3.37) and 1.93 (1.53-2.45), respectively. Conclusions In this large cohort of low-risk and young adults, all categories of higher BP were independently associated with an increased risk of CVD compared with normal BP , underscoring the importance of BP management even in these low-risk populations.

Cardiovascular Health Metrics in the Development and Regression of Nonalcoholic Fatty Liver Disease: A Cohort Study

Cardiovascular Health (CVH) metrics scores are associated with cardiovascular disease but whether CVH scores are associated with nonalcoholic fatty liver disease (NAFLD) is uncertain. Our aim was to investigate associations between CVH scores and development or regression of NAFLD. A cohort study was performed in Korean adults who underwent a comprehensive health examination. The CVH metrics were defined according to the American Heart Association Life’s Simple 7 metrics, ranging from 0 (all metrics considered unhealthy) to 7 (all metrics considered healthy). Fatty liver was diagnosed by ultrasound, and liver fibrosis assessed using NAFLD fibrosis score (NFS). Among 93,500 participants without NAFLD or fibrosis at baseline, 15,899 developed NAFLD, and 998 developed NAFLD plus intermediate/high NFS. Healthy CVH metrics were inversely associated with NAFLD and also NAFLD with fibrosis. In time-dependent models after updating the CVH score and confounders as time-varying covariate, the multivariable-adjusted hazard ratio (95% confidence intervals) for incident NAFLD plus intermediate/high NFS participants with CVH metrics score 2, 3, 4, 5, or 6–7 to those with score 0–1 were 0.86 (0.59–1.25), 0.51 (0.36–0.73), 0.44 (0.31–0.62), 0.20 (0.14–0.29) and 0.09 (0.05–0.14), respectively. Regression of NAFLD occurred in 9742/37,517 participants who had NAFLD at baseline with positive association with CVH metrics. Higher CVH scores were significantly associated with both (a) decreased incidence of NAFLD, and (b) regression of existing NAFLD. Promoting adherence to ideal CVH metrics can be expected to reduce the burden of NAFLD as well as cardiovascular disease.

Changes in Weight and Health-Related Behavior Using Smartphone Applications in Patients With Colorectal Polyps

OBJECTIVE

To assess the effectiveness of using a smartphone application for weight loss as well as a change in health-related behavior in patients with colorectal polyps over 3 months.

DESIGN

Randomized, controlled pilot trial.

SETTING

The Department of Family Medicine, Myongji Hospital, Hanyang University College of Medicine, Goyang, Korea.

PARTICIPANTS

Adults aged 25-65 years who were diagnosed with colorectal polyps.

INTERVENTIONS

A comparison of smartphone application data, with exercise and food intake diary data over 3 months.

MAIN OUTCOME MEASURES

Primary outcomes were weight reduction and an increase in physical activity. Secondary outcomes included changes in dietary intake, such as that of vegetables, fruits, and fatty food.

ANALYSIS

Student t test was used for continuous variables, and chi-square test for categorical variables.

RESULTS

Participants using the smartphone application experienced significant weight reduction compared with participants in the control group (mean change = -1.25 vs -0.42 kg; SD = 0.42 vs 1.23 kg). Moreover, use of the application and strict adherence to it significantly increased the level of physical activity (mean change = 1.57 vs 0.71 strenuous exercises/wk; SD = 1.09 vs 0.96 strenuous exercise/wk).

CONCLUSIONS AND IMPLICATIONS

Smartphone applications could be potential tools for weight control and physical activity in patients with colorectal polyps. Future larger randomized, controlled trials over a prolonged period are warranted to confirm these findings.

Cigarette smoking, alcohol consumption, and risk of colorectal cancer in South Korea: A case-control study

The current case-control study comprehensively evaluated the status, quantity, and duration of smoking and alcohol drinking for both men and women, considering the subsites of colorectal cancer. A total of 925 colorectal cancer cases and 2775 controls were included in the analysis. Odds ratios (OR) and 95% confidence intervals (CI) were computed by logistic regression models adjusting for potential confounders. In men, the risk of colorectal cancer significantly increased for heavy smokers who smoked ≥40 pack-years (OR 1.74, 95% CI 1.22-2.50), ≥40 years (OR 1.50, 95% CI 1.05-2.16), or ≥40 cigarettes/day (OR 1.92, 95% CI 1.04-3.54). Men showed a significant increase in risk, especially for rectal cancer with an increasing amount or duration of smoking. In women, distal colon cancer risk increased in smokers who smoked ≥20 years (OR 3.21, 95% CI 1.27-8.14) or ≥20 cigarettes/day (OR 4.75, 95% CI 1.09-20.57). Additionally, female smokers who smoked ≥20 cigarettes/day had an increased risk of rectal cancer (OR 6.46, 95% CI 1.64-25.46). Regarding the association of cigarettes smoked per day and the risk of rectal cancer, there was no significant difference between men and women (gender interaction p value = 0.14). Compared with never-drinkers, those who consumed alcohol at ≥40 g/day in men and ≥20 g/day in women had an OR of 2.39 (95% CI 1.68-3.41) and 3.52 (95% CI 1.56-7.96), respectively. The effect of daily alcohol consumption (g of ethanol/day) on cancer risk was not significantly different among subsites. Association of alcohol consumption quantity (g of ethanol/day) and the risk of proximal and distal colon cancer were stronger in women than in men (gender interaction p value < 0.01). There was no significant interaction in the multiplicative level when alcohol consumption and cigarette smoking were combined. The duration and amount of smoking as well as the amount of alcohol consumption were associated with an elevated risk of colorectal cancer in both men and women.

Spontaneous ketonuria and risk of incident diabetes: a 12 year prospective study

AIMS/HYPOTHESIS

Ketones may be regarded as a thrifty fuel for peripheral tissues, but their clinical prognostic significance remains unclear. We investigated the association between spontaneous fasting ketonuria and incident diabetes in conjunction with changes in metabolic variables in a large population-based observational study.

METHODS

We analysed 8703 individuals free of diabetes at baseline enrolled in the Korean Genome and Epidemiology Study, a community-based 12 year prospective study. Individuals with (n = 195) or without fasting ketonuria were matched 1:4 by propensity score. Incident diabetes was defined as fasting plasma glucose ≥7.0 mmol/l, post-load 2 h glucose ≥11.1 mmol/l on biennial OGTTs, or current use of glucose-lowering medication. Using Cox regression models, HRs for developing diabetes associated with the presence of ketonuria at baseline were analysed.

RESULTS

Over 12 years, of the 925 participants in the propensity score-matched cohort, 190 (20.5%) developed diabetes. The incidence rate of diabetes was significantly lower in participants with spontaneous ketonuria compared with those without ketonuria (HR 0.63; 95% CI 0.41, 0.97). Results were virtually identical when participants with fasting ketonuria were compared against all participants without ketonuria (after multivariate adjustment, HR 0.66; 95% CI 0.45, 0.96). During follow-up, participants with baseline ketonuria maintained lower post-load 1 h and 2 h glucose levels and a higher insulinogenic index despite comparable baseline values.

CONCLUSIONS/INTERPRETATION

The presence of spontaneous fasting ketonuria was significantly associated with a reduced risk of diabetes, independently of metabolic variables. Our findings suggest that spontaneous fasting ketonuria may have a potential preventive role in the development of diabetes.

A Diet Rich in Vegetables and Fruit and Incident CKD: A Community-Based Prospective Cohort Study

RATIONALE & OBJECTIVE

A diet rich in vegetables and fruit can lower blood pressure and may reduce cardiovascular risk. However, the association between this dietary pattern and incident chronic kidney disease in the general population is unknown.

STUDY DESIGN

A community-based prospective cohort study.

SETTING & PARTICIPANTS

9,229 study participants with normal kidney function from the Korean Genome and Epidemiology Study database.

PREDICTORS

Daily consumption of nonfermented and fermented vegetables and fruit classified into tertiles based on a validated semiquantitative food-frequency questionnaire.

OUTCOMES

Incident occurrence of estimated glomerular filtration rate (eGFR) < 60mL/min/1.73m², incident proteinuria (≥1+ by dipstick test), and repeated measures of estimated net endogenous acid production.

ANALYTICAL APPROACH

Multivariable cause-specific hazards model to assess the association of vegetable and fruit intake with incident chronic kidney disease.

RESULTS

During a mean follow-up of 8.2 years, 1,741 (21.9/1,000 person-years [PY]) participants developed eGFRs < 60mL/min/1.73m². Incident eGFR < 60mL/min/1.73m² occurred less frequently with higher intake of nonfermented vegetables, occurring at rates of 22.8/1,000 PY, 22.7/1,000 PY, and 20.1/1,000 PY for the lowest, middle, and highest tertiles, respectively; P for trend < 0.001. The incidence of proteinuria was also lower in the middle and highest tertiles. In a multivariable cause-specific hazards model, the highest tertile of nonfermented vegetable intake was associated with 14% lower risk for incident eGFR < 60mL/min/1.73m² than the lowest tertile. The highest tertile was also associated with 32% lower risk for proteinuria than the lowest tertile. There were no associations of fermented vegetable and fruit intake with incidence of eGFR < 60mL/min/1.73m². However, the highest tertiles of both fermented vegetable and fruit intake were associated with 14% and 45% lower risks for incident proteinuria compared with the lowest tertiles (both P < 0.001). During follow-up, estimated net endogenous acid production increased in the lowest tertile of intake of nonfermented or fermented vegetables and fruit, whereas it decreased in the highest tertile.

LIMITATIONS

Self-reported dietary intake, single ethnicity population.

CONCLUSIONS

A diet rich in vegetables and fruit may reduce the risk for kidney disease.

Association between Green Tea Consumption and Risk of Stroke in Middle-Aged and Older Korean Men: The Health Examinees (HEXA) Study

Green tea consumption is known to have varying effects on health and disease. The aim of this study was to investigate the association between green tea consumption and risk of stroke in Korean adult men. Data were obtained from the Health Examinees (HEXA) Study, which included 50,439 subjects aged 40 years and older. Information regarding dietary intake was collected from semi-quantified food frequency questionnaires consisting of 106 items. Green tea consumption was categorized as none, <1 cup/d, 1 to <3 cups/d, and ≥3 cups/d. Binary logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CIs) to examine a possible association between green tea consumption and risk of stroke by controlling for potential confounders. Subgroup analyses by age, body mass index, hypertension, diabetes mellitus, smoking status, and alcohol consumption were also performed. Compared with green tea non-drinkers, individuals that consumed 1 to <3 cups/d or ≥3 cups/d of green tea had multivariable adjusted OR (CI) of stroke of 0.75 (0.59~0.97) and 0.62 (0.39~0.98), respectively, after adjusting for age and various confounders. In the subgroup analyses, an inverse association between green tea consumption and risk of stroke was identified among younger, non-hypertensive, and non-diabetic men. Higher consumption of green tea was inversely associated with stroke risk in middle-aged and older Korean men.

Diffusely Increased 18F-FDG Uptake in the Thyroid Gland and Risk of Thyroid Dysfunction: A Cohort Study

The impact of incidentally identified diffuse thyroid FDG uptake on ¹⁸F-FDG PET/CT scan on the incidence of thyroid dysfunction remains unclear. We examined the association of diffuse thyroid FDG uptake with the development of thyroid dysfunction. This cohort study involved 39,098 Korean adults who were free of malignancy and thyroid disease at baseline and underwent regular health checkup examinations including an ¹⁸F-FDG whole body PET/CT scan, thyroid-stimulating hormone and free thyroxine. The participants were annually or biennially followed for up to 5 years. A parametric proportional hazard model was used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (CI). Diffuse thyroid uptake was positively associated with increased risk of thyroid dysfunction in both the cross-sectional and cohort studies. During 104,261.4 person-years of follow-up, 102 incident hypothyroidism cases and 172 hyperthyroidism cases were identified. Multivariable-adjusted HR (95% CI) for incident hypothyroidism or hyperthyroidism comparing diffuse thyroid uptake to no uptake were 15.72 (9.23–26.77) and 7.38 (4.23–12.87), respectively. In this large cohort, incidentally, identified diffuse thyroid uptake on ¹⁸F-FDG PET/CT was associated with increased risk of both prevalent and incident thyroid dysfunction. Therefore, baseline and follow-up evaluations in individuals with diffuse thyroid uptake may help identify individuals with thyroid dysfunction.