Korea Nurses' Health Study and the health of reproductive-aged women: a cohort profile.

The Korea Nurses' Health Study (KNHS) is an ongoing, large-scale, prospective cohort study of female nurses, focusing on the effects of occupational, environmental, and lifestyle factors on the health of women. The first KNHS survey was performed in 2013-2014 (n=20,613). As of December 2023, 11 follow-up surveys have been conducted. Participants who were pregnant were asked to participate in the early pregnancy survey (n=2,179) and postpartum survey after giving birth (n=2,790). The main variables included sociodemographic, work-related, lifestyle, physical, mental, and women's health factors. Blood, urine, and toenail samples were collected from a participant subgroup of the first survey (n=1,983). The subgroups of the second survey completed a food frequency questionnaire in 2019 (n=300) and 2021 (n=871). In 2020, a subgroup of the first survey answered a coronavirus disease 2019 (COVID-19)-related survey (n=975). To examine various health-related factors in young adults, new participants were added to the KNHS cohort in the 11th (n=1,000) and 12th (n=1,002) surveys. The KNHS cohort will help identify health and illness determinants in Korean women. Data can be accessed at https://coda.nih.go.kr/frt/index.do.

Adherence to the American Cancer Society guidelines on nutrition and physical activity for cancer survivors and biomarkers of inflammation among breast cancer survivors.

OBJECTIVES: This study investigated whether adherence to the overall lifestyle recommendations in the American Cancer Society (ACS) guidelines on nutrition and physical activity for cancer survivors was associated with inflammation in breast cancer survivors. METHODS: The study included 409 women who had undergone breast cancer surgery at least 1 year before enrollment. A generalized linear model was used to estimate the least square means and 95% confidence intervals of plasma levels of inflammatory markers according to lifestyle factors defined in terms of adherence to the ACS guidelines. RESULTS: Higher overall adherence scores were associated with lower levels of high-sensitivity C-reactive protein (hs-CRP) (p for trend=0.015) and higher levels of adiponectin (p for trend=0.009). Similar significant associations of hs-CRP (p for trend= 0.004) and adiponectin (p for trend=0.010) levels were observed with the score for the body mass index (BMI) component of the adherence score. A higher diet component score was associated with a higher adiponectin level (p for trend=0.020), but there was no significant association for the physical activity component score. CONCLUSIONS: The present study's findings suggest that maintaining a healthy lifestyle according to the ACS guidelines was associated with beneficial effects on inflammatory marker levels, especially hs-CRP and adiponectin, among breast cancer survivors. Among the 3 components of lifestyle guidelines, the BMI component exhibited the most similar tendency to the overall adherence score in relation to inflammatory indicators. Further prospective and intervention studies are needed to investigate longitudinal associations between lifestyle factors and inflammatory markers among breast cancer survivors.

Folate, vitamin B12, and homocysteine status in the Korean population: data from the 2013-2015 Korea National Health and Nutrition Examination Survey.

OBJECTIVES: We aimed to assess the serum folate, vitamin B12, and homocysteine status in Korean adolescents and adults using national data. METHODS: Blood samples were collected from participants aged ≥10 years in the Korea National Health and Nutrition Examination Survey 2013-2015. The stored serum samples were used to measure folate, vitamin B12, and homocysteine concentrations. A total of 8,016 participants were included in this analysis. Unweighted descriptive statistics and adjusted geometric means of the B vitamins and homocysteine concentrations were estimated. RESULTS: Females had higher serum folate and vitamin B12 concentrations and lower serum homocysteine concentrations than males. Folate deficiency (<6.8 nmol/L) and hyperhomocysteinemia (>15 µmol/L) were found in 8.6% and 11.8% of males, respectively. Approximately 3% of males had low or marginally low vitamin B12 status (≤221 pmol/L). Folate and vitamin B12 deficiencies and hyperhomocysteinemia were found in <2% of females. Suboptimal folate status was prevalent among adolescents and young adults, while suboptimal vitamin B12 status and hyperhomocysteinemia were relatively higher in older adults. Adjusted mean homocysteine concentrations were sharply decreased from the first to second decile of serum folate in males. CONCLUSIONS: In the Korean population, the proportion of males who achieved desirable folate and homocysteine concentrations were lower than those of females. Although most Koreans have adequate vitamin B12, a suboptimal folate status is common, particularly among adolescents and young adults. These findings could establish a foundation for public health initiatives aimed at improving folate levels in the Korean population.

Dietary Isoflavone Intake and Breast Cancer Prognosis: A Prospective Analysis and Meta-Analysis.

We aimed to examine the association between dietary isoflavone intake and the risk of breast cancer recurrence and summarize evidence on the role of dietary isoflavone intake in breast cancer prognosis. This prospective study included 592 breast cancer survivors who completed a dietary assessment. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. Of the studies published until May 31, 2023, that were searched in PUBMED and EMBASE databases, 14 studies were selected. Adjusted HRs were combined using fixed- or random-effects models. During the median follow-up of 4.3 years, 47 recurrences were identified. The HR (95% CI) for recurrence comparing the highest versus the lowest tertile of isoflavones intake was 1.29 (0.60-2.78). In a meta-analysis of previously published data and ours, dietary isoflavone intake was associated with a better breast cancer prognosis. The combined HRs (95% CIs) comparing the extreme categories were 0.81 (0.67-0.98) for recurrence and 0.85 (0.76-0.96) for all-cause mortality. A nonlinear inverse association was observed between isoflavone intake and the risk of recurrence and all-cause mortality. Our study suggests that dietary isoflavone intake is associated with a favorable prognosis in breast cancer survivors and warrants further investigation.

The effects of dietary self-monitoring intervention on anthropometric and metabolic changes via a mobile application or paper-based diary: a randomized trial.

BACKGROUND/OBJECTIVES: Weight loss via a mobile application (App) or a paper-based diary (Paper) may confer favorable metabolic and anthropometric changes. SUBJECTS/METHODS: A randomized parallel trial was conducted among 57 adults whose body mass indices (BMIs) were 25 kg/m2 or greater. Participants randomly assigned to either the App group (n = 30) or the Paper group (n = 27) were advised to record their foods and supplements through App or Paper during the 12-week intervention period. Relative changes of anthropometries and biomarker levels were compared between the 2 intervention groups. Untargeted metabolic profiling was identified to discriminate metabolic profiles. RESULTS: Out of the 57 participants, 54 participants completed the trial. Changes in body weight and BMI were not significantly different between the 2 groups (P = 0.11). However, body fat and low-density lipoprotein (LDL)-cholesterol levels increased in the App group but decreased in the Paper group, and the difference was statistically significant (P = 0.03 for body fat and 0.02 for LDL-cholesterol). In the metabolomics analysis, decreases in methylglyoxal and (S)-malate in pyruvate metabolism and phosphatidylcholine (lecithin) in linoleic acid metabolism from pre- to post-intervention were observed in the Paper group. CONCLUSIONS: In the 12-week randomized parallel trial of weight loss through a App or a Paper, we found no significant difference in change in BMI or weight between the App and Paper groups, but improvement in body fatness and LDL-cholesterol levels only in the Paper group under the circumstances with minimal contact by dietitians or health care providers. Trial Registration: Clinical Research Information Service Identifier: KCT0004226.

Predicted pro-inflammatory hs-CRP score and non-alcoholic fatty liver disease.

Background: Non-alcoholic fatty liver disease (NAFLD) is a major contributor to liver diseases globally, yet there are limited studies investigating the impact of diet and lifestyle factors on its development. This study aimed to examine the association between the prevalence of NAFLD and predicted pro-inflammatory high-sensitivity C-reactive protein (hs-CRP) score. Methods: We included 1,076 Korean adults who underwent a medical examination at the Seoul National University Hospital Gangnam Healthcare Center in Korea between May and December 2011 and updated in 2021. The predicted pro-inflammatory hs-CRP score was derived from pro-inflammatory demographic, lifestyle, dietary, and anthropometric factors, and NAFLD was diagnosed using liver ultrasound. Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of NAFLD odds according to predicted pro-inflammatory hs-CRP score were estimated using logistic regression at a two-sided P < 0.05. Results: Among the 1,076 participants, 320 had NAFLD. The multivariable-adjusted ORs and 95% CIs for NAFLD by tertiles of predicted pro-inflammatory hs-CRP score were 1.00, 3.30 (2.06, 5.30), 18.25 (10.47, 31.81; P < 0.0001) in men and women combined, 1.00, 1.77 (1.10, 2.84), and 3.26 (2.02, 5.28; P < 0.0001) among men only, and 1.00, 3.03 (1.39, 6.62), and 16.71 (7.05, 39.63; P < 0.0001) among women only. Conclusions: Predicted pro-inflammatory hs-CRP score was associated with higher odds of NAFLD. Adopting dietary and lifestyle changes related to lower inflammation might be a valuable strategy for preventing NAFLD.

Risk of uterine leiomyomata with menstrual and reproductive factors in premenopausal women: Korea nurses' health study.

BACKGROUND: Uterine leiomyomata (UL) are benign smooth muscle tumors that may cause significant morbidity in women of reproductive age. This study aimed to investigate the relationship of menstrual and reproductive factors with the risk of UL in premenopausal women. METHODS: This prospective study included 7,360 premenopausal women aged 22-48 years who were part of the Korea Nurses' Health Study. Information on the menstrual cycle and reproductive history was assessed between 2014 and 2016, and self-reported cases of UL were obtained through 2021. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: During 32,072 person-years of follow-up, 447 incident cases of UL were reported. After adjusting for other risk factors, women with late age at menarche had a lower incidence of UL (≥ 16 vs. 12-13 years: HR 0.68; 95% CI 0.47-0.99; p for trend = 0.026). The risk of UL was inversely associated with current menstrual cycle length (≥ 40 or too irregular to estimate vs. 26-31 days: HR 0.40; 95% CI 0.24-0.66) and cycle length at ages 18-22 years (HR 0.45; 95% CI 0.31-0.67; p for trend < 0.001, each). Parous women had lower risk of UL than nulliparous women (HR 0.40; 95% CI 0.30-0.53) and women who were aged 29-30 years at first birth had a lower risk of UL than those who were aged ≤ 28 years at first birth (HR 0.58; 95% CI 0.34-0.98). There was no significant association of the number of births or breastfeeding with the risk of UL among parous women. Neither a history of infertility nor oral contraceptive use was associated with the risk of UL. CONCLUSIONS: Our results suggest that age at menarche, menstrual cycle length, parity, and age at first birth are inversely associated with the risk of UL in premenopausal Korean women. Future studies are warranted to confirm the long-term effects of menstrual and reproductive factors on women's health.

Associations of Serum Folate and Homocysteine Concentrations with All-Cause, Cardiovascular Disease, and Cancer Mortality in Men and Women in Korea: the Cardiovascular Disease Association Study.

BACKGROUND: Evidence on the association of serum folate and homocysteine concentrations with risk of mortality in the general population is unclear. OBJECTIVES: This study aimed to examine the associations of serum folate and homocysteine concentrations with all-cause, CVD, and cancer mortality risk in Korean men and women aged ≥40 y. METHODS: In this population-based prospective cohort study, serum folate and homocysteine concentrations were measured in a subset of participants enrolled between 2005 and 2012. A total of 21,260 participants were linked to mortality data from the survey date to 31 December 2019. Cox proportional hazards models and restricted cubic splines were used to identify the associations of serum folate and homocysteine concentrations with mortality. RESULTS: During a median follow-up of 12.3 y, 2501, 549, and 842 deaths were attributed to all-cause, CVD, and cancer, respectively. The prevalence of folate deficiency and hyperhomocysteinemia were higher in men than in women. In men, a nonlinear inverse association was observed between serum folate concentrations and all-cause mortality. Men in the third quartile of serum folate concentrations exhibited a lower risk of all-cause mortality (HR: 0.85; 95% CI: 0.73, 0.99) than those in the lowest quartile. Serum homocysteine concentration was positively associated with all-cause and CVD mortality. Men and women in the highest compared with those in the lowest serum homocysteine quartile showed a higher risk of CVD mortality (HR: 1.60; 95% CI: 1.07, 2.39; and HR: 1.79; 95% CI: 1.11, 2.89, respectively). Hyperhomocysteinemia combined with folate deficiency was associated with increased all-cause, CVD, and cancer-related mortality rates. CONCLUSIONS: Higher serum homocysteine and lower serum folate concentrations were associated with an increased risk of all-cause, CVD, and cancer-related mortality in Korean adults. The finding of a nonlinear inverse relationship between serum folate concentration and mortality in men warrants further investigation.

Associations of body mass index and weight change with circulating levels of high-sensitivity C-reactive protein, proinflammatory cytokines, and adiponectin among breast cancer survivors.

AIM: This study examined the associations of body mass index (BMI) and weight change with inflammatory markers among breast cancer survivors in Korea. METHODS: A total of 495 women were included who had been diagnosed with primary breast cancer and survived for at least 6 months since the surgery. Information on the body weight and height of the participants was collected both at the study enrollment and diagnosis. The plasma levels of inflammatory markers were measured, including high-sensitivity C-reactive protein, interleukin (IL)-6, IL-8, tumor necrosis factor-α, and adiponectin. A summary z-score was calculated by summing up the z-scores of each biomarker. The least-square means and 95% confidence intervals (CIs) were calculated using a generalized linear model and odds ratios (ORs) and 95% CIs for the elevated levels of inflammatory markers with a multivariate logistic regression model. RESULTS: Participants with a BMI ≥27.5 kg/m2 at the study enrollment and at diagnosis were significantly associated with elevated summary z-scores compared to those with a BMI < 23 kg/m2 ; the ORs (95% CIs) were 5.42 (2.15-13.71) for current BMI and 3.66 (1.68-7.98) for BMI at diagnosis, respectively. Additionally, a weight loss > 5% since diagnosis was associated with a lower prevalence of high summary z-scores; the OR (95% CI) was .20 (.08-.52) compared to a stable weight. CONCLUSIONS: A high BMI at diagnosis and current BMI with a greater degree were associated with unfavorable levels of inflammatory markers among breast cancer survivors. Additionally, weight loss since diagnosis was inversely associated with these markers.

Validity and reproducibility of a food frequency questionnaire for breast cancer survivors in Korea.

BACKGROUND/OBJECTIVES: The aim of this study was to examine the validity and reproducibility of a food frequency questionnaire (FFQ) developed in Korea for breast cancer survivors. SUBJECTS/METHODS: Ninety-nine breast cancer survivors who completed an FFQ twice and three 3-day dietary records (DRs) between 2016-2017 were included. Energy and 14 nutrient intakes were calculated from FFQs and DRs. To determine the validity of the FFQ, energy-adjusted de-attenuated Pearson correlations between two FFQ assessments and the average of the three 3-day DRs were calculated, and to determine reproducibility, energy-adjusted Pearson correlations and degrees of agreement were calculated between the first and second FFQ assessments. RESULTS: Correlation coefficients of validity ranged from 0.29 (protein) to 0.47 (fat) (median value = 0.36) for the FFQ assessment and from 0.20 (riboflavin) to 0.53 (calcium) (median value = 0.37) for the second. Correlation coefficients of reproducibility ranged from 0.22 (sodium) to 0.62 (carbohydrate) (median value = 0.36). Regarding FFQ reproducibilities, percentage classifications of exact agreements for energy-adjusted nutrients ranged from 27.3% (sodium) and 45.5% (fat). A median 76.8% of participants were classified into the same or adjacent quartiles, while a median of 5.6% of participants were classified in extreme quartiles. Bland-Atman plots for the majority of data points of three macronutrients, calcium and vitamins A and C fell within limits of agreement. CONCLUSIONS: These results indicated that the newly developed FFQ for Korean breast cancer survivors has acceptable validity and reproducibility as compared with three 3-day DRs collected over a one-year period.

Factors associated with regularity and length of menstrual cycle: Korea Nurses' Health Study.

BACKGROUND: Menstrual cycle characteristics are linked to reproductive function and long-term health outcomes. This study aimed to evaluate menstrual cycle patterns, characterized by regularity and length, and associated factors among women in the Korea Nurses' Health Study. METHODS: A total of 9335 premenopausal women aged 22-45 years were included in this cross-sectional study. Regularity and length of menstrual cycles were self-reported, and their associations with reproductive, lifestyle, and occupational factors were examined using binomial and multinomial logistic regression models. Adjusted least-square means of menstrual distress, depressive symptoms, stress, fatigue, anxiety, and sleep problems were estimated according to menstrual cycle characteristics using generalized linear models. RESULTS: Twenty-one percent of nurses reported having irregular menstrual cycles (variability > 7 days). Ten percent, 64%, and 26% had menstrual cycle length of < 26, 26-31, and 32-50 days, respectively. Variability and length of cycles decreased with age and increased with age at menarche. Parous women showed low tendency of irregular cycles. Women with body mass index (BMI) > 25 kg/m2 had higher odds of irregular (odds ratio [OR] 1.68; 95% confidence interval [CI] 1.40-2.03) and long cycles (OR 1.31; 95% CI 1.08-1.58) than those with BMI 18.5- < 23 kg/m2. Irregular cycles were less common in women performing vigorous physical activity, but more common in those with prolonged standing or frequent heavy lifting at work. Frequent rotating night shift was associated with irregular cycles among nulliparous women. Levels of menstrual and premenstrual distress, depressive symptoms, perceived stress, physical and mental fatigue, anxiety, and sleep problems were higher in women with irregular cycles than in those with regular cycles (p < 0.001, each). CONCLUSIONS: The study suggests that irregular and long menstrual cycles are associated with reproductive, lifestyle, and occupational factors; also with menstrual distress and perceived health status. Our findings contribute to a better understanding of potential risk factors for menstrual dysfunction, and thus, may help improve women's health.

Association of lipid profile with obesity among breast cancer survivors: a cross-sectional study.

BACKGROUND: The role of lipid metabolism in obesity and cancer manifestations cannot be underestimated, but whether alterations in lipid metabolism can manipulate the vasculature to promote obesity among breast cancer (BC) survivors is yet to be clearly understood. This study quantified plasma lipid and particle sizes using high-throughput proton (1H) nuclear magnetic resonance (NMR) and tested their associations with obesity among breast cancer (BC) survivors. METHODS: A total of 348 (225 premenopausal and 123 postmenopausal) BC survivors enrolled from five hospitals in Korea were included. We assessed thirty-four plasma lipid biomarkers using 1H NMR, and obesity status was defined as a body mass index (BMI) of 25 kg/m2 or greater. Generalized linear and logistic regression models were applied to estimate the least-square means of BMI (kg/m2) and odds ratio (OR)s of obesity, respectively, and the corresponding 95% confidence interval (CI)s across plasma lipid levels. RESULTS: Mean (SD) values of BMI was 23.3 (3.2) kg/m2 and 90 (25.9%) had BMI of ≥ 25 kg/m2. BMI levels increased with increasing total triglycerides (TG), TG in lipoproteins and very-low-density lipoprotein (VLDL) subfractions. However, BMI levels decreased with increasing tertiles of high-density lipoprotein (HDL)-cholesterol (C) and HDL particle size (HDL-p). Similar associations were observed in the logistic regression models. The increasing and decreasing BMI trends with TG and HDL profiles respectively were predominantly limited to premenopausal BC survivors. CONCLUSIONS: Increasing levels of plasma total TG and TG in lipoproteins were associated with increasing levels of BMI among premenopausal BC survivors. High HDL-C levels and large HDL-p were inversely associated with obesity among premenopausal BC survivors. Due to the cross-sectional design of this study, longitudinal studies are necessary to examine the association between obesity and lipid profile among BC survivors.

Reproducibility of a food frequency questionnaire: Korea Nurses' Health Study.

BACKGROUND/OBJECTIVES: This study aimed to examine the reproducibility of food frequency questionnaires (FFQs) designed for young female nurses in the Korea Nurses' Health Study. SUBJECTS/METHODS: The reproducibility of web-based, self-administered FFQs was evaluated among 243 Korean female nurses. The first FFQ (FFQ1) was administered from March 2014 to February 2019 and the second FFQ (FFQ2) from November 2019, with a mean interval of 2.8 years between the FFQs (range, 9 months-5.6 years). Pearson and Spearman correlation coefficients (r values) and quartile agreements between FFQ1 and FFQ2 were calculated for intakes of energy, nutrients, and foods. RESULTS: Pearson correlation coefficients ranged from 0.41 to 0.55 (median r = 0.51) for energy and raw nutrients and from 0.16 to 0.46 (median r = 0.36) for energy-adjusted nutrients. Spearman correlation coefficients ranged from 0.25 to 0.72 (median r = 0.41) for food items. The percentages of women who were classified into the same or adjacent quartile were 77% to 84% (median = 82%) for raw nutrients and 69% to 86% (median = 78%) for foods. CONCLUSIONS: The results indicated that the web-based FFQ used in the Korea Nurses' Health Study has acceptable reproducibility.

Nutrient intakes from supplement and factors associated with supplement use among breast cancer survivors: A cross-sectional study.

OBJECTIVE: We investigated the contribution of supplement use to total nutrient intake, the prevalence of inadequate nutrient intake and the factors associated with supplement use among breast cancer survivors. METHODS: A total of 701 Korean breast cancer survivors were included. We calculated the contribution of dietary supplements to total nutrient intake and the proportion of the population below the estimated average requirements (EARs) or exceeding the tolerable upper intake levels (ULs). Stepwise logistic regression was used to identify factors associated with dietary supplement use. RESULTS: A total of 66.5% of the survivors used dietary supplements, with multivitamins and minerals being the most commonly consumed ones. The per cent contribution of supplement to the total intake was the highest for vitamin C. 28.2%-55.4% of the non-users consumed below the EAR of riboflavin, folate and calcium; 6.1%, 4.9% and 6.5% of the supplement users consumed above the UL of vitamins A and C, and iron, respectively. Supplement users had higher education levels or longer survival time. CONCLUSION: 66.5% of Korean breast cancer survivors used dietary supplements. A higher education level or prolonged survival time was associated with higher use of dietary supplements.

The association between predicted inflammatory status and colorectal adenoma.

We developed a diet and lifestyle score based on high sensitivity C-reactive protein (hsCRP), and investigated its association with odds of adenoma. We performed stepwise linear regression to develop the predicted hsCRP score among 23,330 participants in the Health Examinee Study and examined its association with colorectal adenoma among 1,711 participants in a cross-sectional study of colorectal adenoma. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) of colorectal adenoma using logistic regression models. Variances in hsCRP explained by body mass index were 61.1% in men and 64.5% in women in the prediction model. The increasing predicted hsCRP score was positively associated with colorectal adenoma (ORquartile 4 VS quartile 1 1.71, 95% CI: 1.12-2.62; Ptrend = 0.011 in men; ORquartile 4 VS quartile 1 2.86, 95% CI: 1.26-6.49; Ptrend = 0.019 in women). In subgroups, the associations differed by age and menopausal status among women, with stronger associations among women aged less than 50 years (OR≥median VS

Adherence to the American Cancer Society Guidelines for Cancer Survivors and Health-Related Quality of Life among Breast Cancer Survivors.

The development and validation of guidelines for breast cancer survivors are of importance due to the increased survival rate for breast cancer. In this cross-sectional study, we aimed to examine the association between adherence to the American Cancer Society (ACS) guidelines for cancer survivors and health-related quality of life (HRQoL). A total of 618 breast cancer survivors aged 30 to 81 years who had been diagnosed with stage I to III primary breast cancer and had surgery at least a year before enrollment were included. The participants completed the 36 Item Short-Form Health Survey (SF-36) to evaluate HRQoL, and adherence scores were calculated based on the Nutrition and Physical Activity Guidelines for Cancer Survivors, which were released by the ACS. Increasing adherence scores were associated with increasing scores on the physical component summary (PCS) and the physical functioning (PF), bodily pain (BP), and vitality (VT) domains (p for trend <0.001 for PCS and PF, 0.01 for BP, and 0.02 for VT); these scores were mainly driven by the associations among survivors with stage II-III cancer. Further prospective studies are needed to evaluate whether adherence to these guidelines improves HRQoL scores among breast cancer survivors.

Dietary Patterns Related to Triglyceride and High-Density Lipoprotein Cholesterol and the Incidence of Type 2 Diabetes in Korean Men and Women.

We aimed to examine whether dietary patterns that explain the variation of triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio were associated with the incidence of type 2 diabetes in Korean adults. We included a total of 5097 adults without diabetes at baseline with a mean follow-up of 11.54 years. Usual diet was assessed by a validated food frequency questionnaire, and serum levels of TG and HDL-C were measured at baseline. We derived dietary pattern scores using 41 food groups as predictors and the TG/HDL-C ratio as a response variable in a stepwise linear regression. We calculated the odds ratio (OR) with the 95% confidence interval (CI) of type 2 diabetes according to pattern scores using multivariate logistic regression. A total of 1069 incident cases of type 2 diabetes were identified. A list of foods characterizing the dietary pattern differed by sex. Higher dietary pattern scores were associated with an increased risk of type 2 diabetes; ORs (95% CIs) comparing extreme quintiles were 1.53 (1.12⁻2.09; p for trend = 0.008) for men and 1.33 (0.95⁻1.86; p for trend = 0.011) for women. Our study suggests the evidence that dietary patterns associated with low levels of TG/HDL-C ratio may have the potential to reduce the burden of type 2 diabetes.

Sex consideration in diet-biomarker-related indices: a systematic review.

OBJECTIVE: An index of biomarkers derived from dietary factors (diet-biomarker-related index) identifies foods and nutrients that encompass physiological potentials and provides scientific evidence for dietary patterns that increase the risk of disease associated with specific biomarkers. Although men and women have different dietary patterns and physiological characteristics, sex is not often considered when investigators develop a diet-biomarker-related index. We aimed to review whether epidemiological studies developed diet-biomarker-related indices in a sex-specific way. DESIGN: We systematically searched for epidemiological studies that developed diet-biomarker-related indices, including (i) biomarker prediction indices that include dietary factors as explanatory variables and (ii) dietary patterns to explain biomarker variations, in the PubMed and EMBASE databases. We qualitatively reviewed the sex consideration in index development. RESULTS: We identified seventy-nine studies that developed a diet-biomarker-related index. We found that fifty-four studies included both men and women. Of these fifty-four studies, twenty-nine (53·7 %) did not consider sex, eleven (20·3 %) included sex in the development model, seven (13·0 %) considered sex but did not include sex in the development model, and seven (13·0 %) derived a diet-biomarker-related index for men and women separately. A list of selected dietary factors that explained levels of biomarkers generally differed by sex in the studies that developed a diet-biomarker-related index in a sex-specific way. CONCLUSIONS: Most studies that included both men and women did not develop the diet-biomarker-related index in a sex-specific way. Further research is needed to identify whether a sex-specific diet-biomarker-related index is more predictive of the disease of interest than an index without sex consideration.

Dietary pattern and health-related quality of life among breast cancer survivors.

BACKGROUND: There is limited evidence for the association between dietary pattern and quality of life among breast cancer survivors. We examined the association between dietary patterns and health-related quality of life (HRQoL) among Korean breast cancer survivors. METHODS: Our study included a total of 232 women, aged 21 to 79 years, who had been diagnosed with stage I to III breast cancer and who underwent breast cancer surgery at least 6 months prior to our baseline evaluation. We assessed HRQoL using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and the Quality of Life Questionnaire Breast Cancer Module 23 (QLQ-BR23). We conducted a factor analysis to identify the major dietary patterns and used a generalized linear model to obtain the least squares mean (LS mean) and 95% confidence interval (CI) for HRQoL according to the dietary pattern scores. RESULTS: We identified 2 major dietary patterns: the Healthy dietary pattern and the Western dietary pattern. We found that breast cancer survivors who had higher Healthy dietary pattern scores tended to have lower dyspnea scores but higher insomnia scores, compared to breast cancer survivors with lower Healthy dietary pattern scores. For dyspnea, the LS mean (95% CI) was 8.86 (5.05-15.52) in the bottom quartile and 2.87 (1.62-5.08) in the top quartile (p for trend = 0.005). This association was limited to survivors with stage I for dyspnea or survivors with stage II or III for insomnia. CONCLUSIONS: Healthy dietary patterns were associated with better scores for dyspnea but worse scores for insomnia among breast cancer survivors. Other components of EORTC QLQ did not vary by dietary patterns overall, but they warrant further investigation for subgroups of breast cancer survivors.

Weight change and risk of uterine leiomyomas: Korea Nurses' Health Study.

OBJECTIVE: This study examined the associations between anthropometric measures and uterine leiomyomas. METHODS: This study included a total of 5,062 women (median age of 35.5 years) who had experienced pregnancy and, of these women, 210 reported a diagnosis of uterine leiomyomas within the past 2 years prior to baseline in the Korea Nurses' Health Study. Participants were asked about their anthropometric factors. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using logistic regression models. RESULTS: Mean body mass index (BMI) was 21.8 kg/m2 among non-cases. An increase in weight from the age of 18 years to the present was associated with increased risk of uterine leiomyomas (p for trend = .002); compared to women whose weight remained stable, the multivariate ORs (95% CIs) were 1.84 (1.22-2.76) for weight gain of 5-10 kg and 2.00 (1.25-3.20) for weight gain of more than 10 kg since age 18. A similar pattern was observed when the analysis was limited to women with a BMI of 18.5-25 kg/m2. Current weight was associated with higher odds of uterine leiomyomas. No associations were found for body size in childhood or in adolescence, weight at age 18, current BMI, or current body size. CONCLUSIONS: Weight gain in adulthood was associated with increased risk of uterine leiomyomas in Korean women, even in those with normal weight.