Time-specific impact of trace metals on breast density of adolescent girls in Santiago, Chile.

Whether trace metals modify breast density, the strongest predictor for breast cancer, during critical developmental stages such as puberty remains understudied. Our study prospectively evaluated the association between trace metals at Tanner breast stage B1 (n = 291) and at stages both B1 and B4 (n = 253) and breast density at 2 years post-menarche among Chilean girls from the Growth and Obesity Cohort Study. Dual-energy x-ray absorptiometry assessed the volume of dense breast tissue (absolute fibroglandular volume [FGV]) and percent breast density (%FGV). Urine trace metals included arsenic, barium, cadmium, cobalt, cesium, copper, magnesium, manganese, molybdenum, nickel, lead, antimony, selenium, tin, thallium, vanadium, and zinc. At B1, a doubling of thallium concentration resulted in 13.69 cm3 increase in absolute FGV (ß: 13.69, 95% confidence interval [CI]: 2.81, 24.52), while a doubling of lead concentration resulted in a 7.76 cm3 decrease in absolute FGV (ß: -7.76, 95%CI: -14.71, -0.73). At B4, a doubling of barium concentration was associated with a 10.06 cm3 increase (ß: 10.06, 95% CI: 1.44, 18.60), copper concentration with a 12.29 cm3 increase (ß: 12.29, 95% CI: 2.78, 21.56), lead concentration with a 9.86 cm3 increase (ß: 9.86, 95% CI: 0.73, 18.98), antimony concentration with a 12.97 cm3 increase (ß: 12.97, 95% CI: 1.98, 23.79) and vanadium concentration with a 13.14 cm3 increase in absolute FGV (ß: 13.14, 95% CI: 2.73, 23.58). Trace metals may affect pubertal breast density at varying developmental stages with implications for increased susceptibility for breast cancer.

Time-specific impact of mono-benzyl phthalate (MBzP) and perfluorooctanoic acid (PFOA) on breast density of a Chilean adolescent Cohort.

INTRODUCTION: High mammographic density is among the strongest and most established predictors for breast cancer risk. Puberty, the period during which breasts undergo exponential mammary growth, is considered one of the critical stages of breast development for environmental exposures. Benzylbutyl phthalate (BBP) and perfluorooctanoic acid (PFOA) are pervasive endocrine disrupting chemicals that may increase hormone-sensitive cancers. Evaluating the potential impact of BBP and PFOA exposure on pubertal breast density is important to our understanding of early-life environmental influences on breast cancer etiology. OBJECTIVE: To prospectively assess the effect of biomarker concentrations of monobenzyl phthalate (MBzP) and PFOA at specific pubertal window of susceptibility (WOS) on adolescent breast density. METHOD: This study included 376 Chilean girls from the Growth and Obesity Cohort Study with data collection at four timepoints: Tanner breast stages 1 (B1) and 4 (B4), 1- year post- menarche (1YPM) and 2-years post-menarche (2YPM). Dual-energy X-ray absorptiometry was used to assess the absolute fibroglandular volume (FGV) and percent breast density (%FGV) at 2YPM. We used concentrations of PFOA in serum and MBzP in urine as an index of exposure to PFOA and BBP, respectively. Parametric G-formula was used to estimate the time-specific effects of MBzP and PFOA on breast density. The models included body fat percentage as a time-varying confounder and age, birthweight, age at menarche, and maternal education as fixed covariates. RESULTS: A doubling of serum PFOA concentration at B4 resulted in a non-significant increase in absolute FGV (ß:11.25, 95% confidence interval (CI): -0.28, 23.49)), while a doubling of PFOA concentration at 1YPM resulted in a decrease in % FGV (ß:-4.61, 95% CI: -7.45, -1.78). We observed no associations between urine MBzP and breast density measures. CONCLUSION: In this cohort of Latina girls, PFOA serum concentrations corresponded to a decrease in % FGV. No effect was observed between MBzP and breast density measures across pubertal WOS.

The Impact of Prebiotic, Probiotic, and Synbiotic Supplements and Yogurt Consumption on the Risk of Colorectal Neoplasia among Adults: A Systematic Review.

Prebiotic and probiotic supplementation and yogurt consumption (a probiotic food) alter gut microbial diversity, which may influence colorectal carcinogenesis. This systematic review evaluates the existing literature on the effect of these nutritional supplements and yogurt consumption on colorectal neoplasia incidence among adults. We systematically identified ten randomized controlled trials and observational studies in adults age ≥ 18 without baseline gastrointestinal disease. Prebiotics included inulin, fructooligosaccharides, galactooligosaccharides, xylooligosaccharides, isomaltooligosaccharides, and ß-glucans. Probiotics included bacterial strains of Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Bacillus, Pediococcus, Leuconostoc, and Escherichia coli. Synbiotic supplements, a mixture of both prebiotic and probiotic supplements, and yogurt, a commonly consumed dietary source of live microbes, were also included. We defined colorectal neoplasia as colorectal adenomas, sessile serrated polyps, and colorectal cancer (CRC). Overall, findings suggest a moderate decrease in risk of adenoma and CRC for high levels of yogurt consumption compared to low or no consumption. Prebiotic supplementation was not associated with colorectal neoplasia risk. There was some evidence that probiotic supplementation may be associated with lower risk of adenomas but not with CRC incidence. Higher yogurt consumption may be associated with lower incidence of colorectal neoplasia. We found little evidence to suggest that prebiotic or probiotic supplements are associated with significant decreases in CRC occurrence.

Association between indicators of systemic inflammation biomarkers during puberty with breast density and onset of menarche.

BACKGROUND: Systemic inflammation may play a role in shaping breast composition, one of the strongest risk factors for breast cancer. Pubertal development presents a critical window of breast tissue susceptibility to exogenous and endogenous factors, including pro-inflammatory markers. However, little is known about the role of systemic inflammation on adolescent breast composition and pubertal development among girls. METHODS: We investigated associations between circulating levels of inflammatory markers (e.g., interleukin-6 (IL-6), tumor necrosis factor receptor 2 (TNFR2), and C-reactive protein (CRP)) at Tanner stages 2 and 4 and breast composition at Tanner stage 4 in a cohort of 397 adolescent girls in Santiago, Chile (Growth and Obesity Cohort Study, 2006-2018). Multivariable linear models were used to examine the association between breast composition and each inflammatory marker, stratifying by Tanner stage at inflammatory marker measurement. Accelerated failure time models were used to evaluate the association between inflammatory markers concentrations at each Tanner stage and time to menarche. RESULTS: In age-adjusted linear regression models, a doubling of TNFR2 at Tanner 2 was associated with a 26% (95% CI 7-48%) increase in total breast volume at Tanner 4 and a 22% (95% CI 10-32%) decrease of fibroglandular volume at Tanner 4. In multivariable models further adjusted for body fatness and other covariates, these associations were attenuated to the null. The time to menarche was 3% (95% CI 1-5%) shorter among those in the highest quartile of IL-6 at Tanner 2 relative to those in the lowest quartile in fully adjusted models. Compared to those in the lowest quartile of CRP at Tanner 4, those in the highest quartile experienced 2% (95% CI 0-3%) longer time to menarche in multivariable models. CONCLUSIONS: Systemic inflammation during puberty was not associated with breast volume or breast density at the conclusion of breast development among pubertal girls after adjusting for body fatness; however, these circulating inflammation biomarkers, specifically CRP and IL-6, may affect the timing of menarche onset.

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.

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

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

Association between sleep duration and metabolic syndrome: a cross-sectional study.

BACKGROUND: Both short and long sleep duration have been consistently studied as a risk factor for obesity, hyperglycemia and hypertension. In this cross-sectional study, we provide an updated analysis of the Health Examinees (HEXA) study on the association between sleep duration and metabolic syndrome (MetS) occurrence among Koreans age 40-69 year olds. METHODS: A total of 133,608 subjects (44,930 men, 88,678 women) were enrolled in the HEXA study 2004-2013. Sleep duration was categorized into 4 sleep categories (< 6 h, 6 to < 8 h, 8 to < 10 h, ≥10 h). MetS criterion was based on the National Cholesterol Education Program, Adult Treatment Panel III. Logistic regression was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Compared with individuals sleeping 6 to < 8 h per day, less than 6 h of sleep was associated with MetS (multivariable adjusted OR: 1.12, 95% CI: 1.05-1.19) and elevated waist circumference (1.15, 1.08-1.23) among men; with elevated waist circumference (1.09, 1.04-1.14) among women. Greater than 10 h of sleep was associated with MetS (1.28, 1.08-1.50) and elevated triglycerides (1.33, 1.14-1.56) among men; with MetS (1.40, 1.24-1.58), elevated waist circumference (1.14, 1.02-1.27), elevated triglycerides (1.41, 1.25-1.58), reduced high-density lipoprotein cholesterol (HDL-C) (1.24, 1.12-1.38), and elevated fasting glucose (1.39, 1.23-1.57) among women. CONCLUSIONS: Less than 6 h of sleep is associated with elevated waist circumference among both men and women and with MetS among men only. Greater than 10 h of sleep is associated with MetS and elevated triglycerides among both men and women and with elevated waist circumference, reduced HDL-C, and elevated fasting glucose among women only.

Frequency of Loud Snoring and Metabolic Syndrome among Korean Adults: Results from the Health Examinees (HEXA) Study.

Studies regarding the association between snoring and metabolic abnormalities have been inconsistent. We examine whether snoring frequency and obstructive sleep apnea markers are associated with metabolic syndrome (MetS) among Koreans aged 40-69 years. A total of 72,885 subjects (24,856 men, 48,029 women) from the Health Examinees Gem study between 2009 and 2013 were included. Snoring frequency was grouped into five categories (never, 1-3/month, 1-3/week, 4-5/week, 6+/week). Obstructive sleep apnea markers included breathing interruptions and awakenings. Adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated through logistic regression. Compared with non-snorers, those who snore 6+/week were associated with increased odds for MetS (OR: 2.07, 95% CI: 1.91-2.25, p-trend < 0.0001 among men; OR: 1.45, CI: 1.33-1.58, p-trend < 0.0001 among women). Snoring frequency is associated with MetS and its components in both men and women. Snoring and obstructive sleep apnea markers are important indicators of sleep quality, which may facilitate early detection of sleep disorders and further complications such as MetS.

Association between Milk Consumption and Metabolic Syndrome among Korean Adults: Results from the Health Examinees Study.

It has been suggested that a greater dairy consumption, particularly of milk, may have contributed in lowering the prevalence of metabolic syndrome (MetS). A cross-sectional analysis was conducted to examine the association between milk consumption and MetS, and its components among Korean adults aged 40-69. A total of 130,420 subjects (43,682 men and 86,738 women) from the Health Examinees Study were selected for the final analysis. Milk consumption was estimated using a validated 106-item food frequency questionnaire. MetS was defined using the National Cholesterol Education Program, Adult Treatment Panel III (NCEP III). Logistic regression analyses were performed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) between milk consumption and MetS after adjusting for potential confounders. In this study, the average milk consumption was 77.9 g/day, with the overall prevalence of MetS being 26.1% (29.1% in men and 24.6% in women). We found that the prevalence of the MetS was significantly lower in subjects with higher milk consumption (p < 0.0001). Adjusted OR for MetS was significantly lower in the highest milk consumption category (≥1 serving/day among men; ≥2 serving/day among women) than those in the lowest milk consumption category (OR: 0.92 95%CI: 0.86-0.99, p trend = 0.0160 in men; OR: 0.68, 95%CI: 0.60-0.76, p trend < 0.0001 in women). Overall, higher milk consumption was inversely associated with the MetS components: elevated waist circumference, elevated triglyceride, and reduced high-density lipoprotein cholesterol (HDL-C) (all p trend < 0.05). This study concludes that higher milk consumption is associated with the lower odds of MetS in Korean adults.

Egg Consumption and Risk of Metabolic Syndrome in Korean Adults: Results from the Health Examinees Study.

Metabolic syndrome (MetS) is defined as a cluster of metabolic alterations such as abdominal obesity, dyslipidemias, elevated fasting glucose, and hypertension. Studies on the association between egg consumption and MetS are limited and inconsistent. A cross-sectional analysis was conducted to examine the association of egg consumption with MetS among Korean adults aged 40-69 years. A total of 130,420 subjects (43,682 men and 86,738 women) from the Health Examinees Study were selected for the final analysis. Egg consumption was estimated using a validated 106-item food frequency questionnaire. MetS was defined using the National Cholesterol Education Program, Adult Treatment Panel III. Logistic regression analyses were performed to identify the association of egg consumption with MetS via odds ratios (ORs) and 95% confidence intervals (CIs) after adjusting for potential variables. Among 130,420 subjects, 34,039 (26.1%) people had MetS. Consumption of more than 7 eggs/week was associated with a lower odds of MetS risk compared to those who consumed less than one egg/week in women (OR: 0.77, 95%CI: 0.70-0.84, p trend < 0.0001). Higher egg consumption was inversely associated with the MetS components: elevated waist circumference (OR: 0.80, 0.75-0.86), elevated triglyceride (OR: 0.78, 0.72-0.85), reduced high-density lipoprotein cholesterol (HDL-C) (OR: 0.82, 0.77-0.88), elevated blood pressure (OR: 0.86, 0.80-0.92), and elevated fasting glucose (OR: 0.94, 0.83-0.99) in women; reduced HDL-C (OR: 0.89, 0.80-1.00) in men. Our results suggest that higher egg consumption may be associated with a reduction in the odds for MetS and all five metabolic components in women, and the risk of reduced HDL-C in men.