Serum magnesium concentration and incident cognitive impairment: the reasons for geographic and racial differences in stroke study.

PURPOSE: To examine the prospective association between serum Mg level and the incidence of cognitive impairment. METHODS: A random sub-cohort (n = 2063) from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort was included in this study. Baseline serum Mg concentration was measured using inductively coupled plasma mass spectrometry. According to the current reference interval of serum magnesium (0.75-0.95 mmol/L), we classified participants below the interval as Level 1 and used it as the referent. The rest of the study population were equally divided into three groups, named Level 2 to 4. Incident cognitive impairment was identified using the Six-Item Screener. Multivariable-adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using logistic regression models. RESULTS: After adjustment for potential confounders, an inverse threshold association between serum Mg level and incident cognitive impairment was observed. Compared to those with hypomagnesemia (Level 1: < 0.75 mmol/L), the relative odds of incident cognitive impairment was reduced by 41% in the second level [OR (95% CI) = 0.59 (0.37, 0.94)]; higher serum Mg level did not provide further benefits [Level 3 and 4 versus Level 1: OR (95% CI) = 0.54 (0.34, 0.88) and 0.59 (0.36, 0.96), P for linear trend = 0.08]. CONCLUSIONS: Findings from this prospective study suggest that sufficient Mg status within the normal range may be beneficial to cognitive health in the US general population.

Physical activity and risk of bladder cancer among postmenopausal women.

Physical activity is associated with decreased risk for many cancers. Studies on the association between physical activity and risk of bladder cancer are limited, and findings are inconsistent. Postmenopausal women (mean age = 63.3) were recruited into the Women's Health Initiative from 1993 to 1998. Self-reported baseline information on physical activity and other covariates were available in 141 288 participants. Incident bladder cancer cases were collected through 2018 and centrally adjudicated. Hazard ratios (HRs) and 95% confidence intervals (CIs) were determined by Cox proportional hazard regression models. Effect modification due to smoking was assessed. During an average of 18.5 years of follow-up, 817 bladder cancer cases were identified. Compared to physically inactive women, those who engaged in ≥15 MET-hours/week of total physical activity, ≥8.75 MET-hours/week of walking or ≥11.25 MET-hours/week of moderate to vigorous physical activity had lower risk of bladder cancer (HR = 0.74, 95% CI: 0.59-0.94, P for linear trend = .02; HR = 0.79, 95% CI: 0.63-0.98, P for linear trend = .03; and HR = 0.76, 95% CI: 0.61-0.94, P for linear trend = .02, respectively). No effect modification was found by smoking status (P for interaction = .06, 0.91 and 0.27, respectively). We found that total physical activity, walking and moderate to vigorous physical activity were inversely associated with bladder cancer incidence among postmenopausal women in a dose-response manner. Physical activity may play a potential role in the primary prevention of bladder cancer. Further studies with objective measurements of physical activity are needed to confirm these findings.

Association between selenium intake and breast cancer risk: results from the Women's Health Initiative.

PURPOSE: It has been hypothesized that selenium (Se) can prevent cancer, and that Se deficiency may be associated with an increased risk of breast cancer. However, findings from epidemiological studies have been inconsistent. The objective of this study was to assess the association between Se intake and risk of breast cancer in the Women's Health Initiative (WHI). METHODS: This study included 145,033 postmenopausal women 50-79 years who completed baseline questionnaires between October 1993 and December 1998, which addressed dietary and supplemental Se intake and breast cancer risk factors. The association between baseline Se intake and incident breast cancer was examined in Cox proportional hazards analysis. RESULTS: During a mean follow-up of 15.5 years, 9487 cases of invasive breast cancer were identified. Total Se (highest versus lowest quartile: HR 1.00, 95% CI 0.92-1.09, Ptrend = 0.66), dietary Se (highest versus lowest quartile: HR 0.99, 95% CI 0.89-1.08, Ptrend = 0.61), and supplemental Se (yes versus no: HR 0.99, 95% CI 0.95-1.03) were not associated with breast cancer incidence. CONCLUSIONS: This study indicates that Se intake is not associated with incident breast cancer among postmenopausal women in the United States. Further studies are needed to confirm our findings by using biomarkers such as toenail Se to reduce the potential for misclassification of Se status.

The association between type 2 diabetes mellitus and bladder cancer risk among postmenopausal women.

INTRODUCTION: Evidence on the association between diabetes and risk of bladder cancer has been controversial. In addition, findings on the associations between duration of diabetes, diabetes treatment, and risk of bladder cancer have been inconsistent. METHODS: A total of 148,208 participants in Women's Health Initiative study were included. Information on diabetes status, diabetes duration, and treatment was collected both at baseline and during follow-up. Information on potential confounders including age, race/ethnicity, education, occupation, family history of cancer, smoking status, alcohol consumption, total physical activity, body mass index, and daily dietary intake were collected at baseline. Bladder cancer cases were collected and confirmed by a centralized review of pathology reports. Cox proportional hazard models with time-varying covariates were used to examine associations of diabetes status, duration of diabetes, and diabetes treatment with bladder cancer risk. RESULTS: During a median follow-up of 18.5 years, 865 bladder cancer cases were identified. There were no significant associations of diabetes, duration of diabetes, or diabetes treatment with risk of bladder cancer. Participants with prevalent diabetes did not have significantly higher risk of bladder cancer compared with those without diabetes. CONCLUSION: Diabetes was not significantly associated with risk of bladder cancer among postmenopausal women.

Intakes of long-chain omega-3 polyunsaturated fatty acids and non-fried fish in relation to incidence of chronic kidney disease in young adults: a 25-year follow-up.

PURPOSE: The prevalence of chronic kidney disease (CKD) is increasing rapidly in many countries and has become a major public health concern. Although intakes of long-chain omega-3 polyunsaturated fatty acids (LCω3PUFA) and its food source-fish-may have renal protective effects, little is known about the longitudinal association between these dietary factors and CKD incidence. METHODS: A total of 4133 healthy individuals of black and white race aged 18-30 at baseline (1985-1986) from the Coronary Artery Risk Development in Young Adults study were enrolled and followed up over 25 years. LCω3PUFA and fish intake were assessed by an interview-based dietary history questionnaire at baseline, year 7 (1992-1993) and 20 (2005-2006). RESULTS: Four hundred and eighty-nine incident cases of CKD were identified. After adjustment for potential confounders, LCω3PUFA intake was inversely associated with CKD incidence [HR = 0.73 (95% CI 0.60-0.89), P = 0.002, with one standard division (0.19 g/day) increment in LCω3PUFA]. This inverse association was persisted among females [0.64 (95% CI 0.48, 0.84; P = 0.002], but not males (Pinteraction = 0.070). A marginal significant inverse association was also found between non-fried fish consumption and CKD incidence (HR = 0.86, 95% CI 0.73, 1.01; P = 0.073). CONCLUSIONS: Dietary LCω3PUFA intake was inversely associated with incidence of CKD among American young adults over 25 years of follow-up. The suggestive evidence of the inverse association between non-fried fish consumption with CKD incidence needs further confirmation.

Magnesium intake is inversely associated with risk of obesity in a 30-year prospective follow-up study among American young adults.

PURPOSE: Although laboratory studies suggest a potential role of magnesium (Mg) in weight regulation, human studies relating Mg intake to body weight are limited. This study sought to prospectively examine the association between Mg intake and incidence of obesity and related anthropometric and biochemical indicators. METHODS: The Coronary Artery Risk Development in Young Adults (CARDIA) study recruited 5115 American young adults, aged 18-30 years, at baseline in 1985-6, and re-examined them in eight follow-ups. Incident obesity was defined as body mass index (BMI) ≥ 30 kg/m2. Dietary Mg intake was collected using the CARDIA Diet History at baseline and exam years 7 and 20. RESULTS: During the 30-year follow-up, 1675 incident cases of obesity were identified. After adjustment for potential confounders, Mg intake was inversely associated with incidence of obesity. The multivariable-adjusted hazard ratios (95% confidence interval) from quintile 1 (Q1) (lowest intake group) to quintile 5 (Q5) (highest intake group) were 1 (referent), 0.86 (0.74, 1.00), 0.83 (0.71, 0.97), 0.55 (0.46, 0.66), and 0.49 (0.40, 0.60); P for trend < 0.01. Consistently, Mg intake was inversely associated with the levels of BMI, triceps skinfold, suprailiac skinfold, subscapular skinfold, fasting insulin, and C-reactive protein. The observed associations were not materially modified by age, sex, race, or BMI at baseline. In addition, the intakes of foods rich in Mg, including whole grains, nuts and seeds, legumes, and dark-green vegetables, were associated with lower incidence of obesity. CONCLUSIONS: This longitudinal study suggests that Mg intake is inversely associated with incidence of obesity.

Intake of Vegetables and Fruits Through Young Adulthood Is Associated with Better Cognitive Function in Midlife in the US General Population.

BACKGROUND: Vegetables and fruits (VF) may differentially affect cognitive functions, presumably due to their various nutrient contents, but evidence from epidemiologic studies is limited. OBJECTIVES: The aim of this study was to examine the long-term association between VF intakes, including VF subgroups, in young adulthood and cognitive function in midlife. METHODS: A biracial cohort of 3231 men and women aged 18-30 y at baseline in 1985-1986 were followed up for 25 y in the Coronary Artery Risk Development in Young Adults Study. Diet was measured at baseline, and in examination years 7 and 20. Cognitive function was assessed at examination year 25 through the use of 3 tests: the Rey Auditory Verbal Learning Test (RAVLT), the Digit Symbol Substitution Test (DSST), and the Stroop test. The mean differences (MDs) with 95% CIs in cognitive scores across intake categories were estimated through the use of the multivariable-adjusted general linear regression model. RESULTS: Excluding potatoes, intake of whole vegetables was significantly associated with a better cognitive performance after adjustment for potential confounders in all 3 cognitive tests (quintile 5 compared with quintile 1-RAVLT, MD: 0.33; 95% CI: 0.01, 0.64; P-trend = 0.08; DSST, MD: 2.84; 95% CI: 0.93, 4.75; P-trend < 0.01; Stroop test, MD: -2.87; 95% CI: -4.24, -1.50; P-trend < 0.01]. Similarly, intake of fruits, except fruit juices, was significantly related to a better cognitive performance (quintile 5 compared with quintile 1-DSST, MD: 2.41; 95% CI: 0.70, 4.12; P-trend = 0.03). CONCLUSIONS: This study supports the long-term benefits of VF consumption on cognitive performance, except those VF with relatively low fiber content such as potatoes and fruit juices, among the middle-aged US general population.

Low to moderate toenail arsenic levels in young adulthood and incidence of diabetes later in life: findings from the CARDIA Trace Element study.

Some studies suggest a positive association between arsenic exposure and risk of diabetes. However, the findings are inconsistent and inconclusive, particularly at a low to moderate arsenic exposure level, and longitudinal data are lacking. We examined toenail arsenic at low to moderate level in young adulthood in relation to incidence of diabetes later in life. This study included 4102 black and white participants aged 20-32 at baseline (1987-88) who completed up to 7 follow-up exams through 2015-16. Toenail arsenic was measured by collision-cell inductively-coupled-plasma mass-spectrometry. Incident diabetes was defined as fasting glucose ≥ 126 mg/dL, non-fasting glucose ≥ 200 mg/dL, 2-h postchallenge glucose ≥ 200 mg/dL, hemoglobin A1c ≥ 6.5%, or use of glucose-lowering medications. Cox proportional hazards model and generalized estimating equations (GEEs) were used to determine the associations of quintiles of toenail arsenic with incident diabetes and other metabolic parameters. The median (inter-quartile range) toenail arsenic level was 0.097 (0.065-0.150) ppm in this study. During the follow-up period, 599 incident cases of diabetes were identified. After adjustment for potential confounders, the hazards ratio (95% confidence interval) was 0.96 (0.73, 1.27) (P for linear trend= 0.85) comparing the highest to the lowest quintile of toenail arsenic levels. No significant association was observed between toenail arsenic and levels of fasting glucose, insulin, homeostatic model assessment of insulin resistance, homeostatic model assessment of beta cell function, or C-reactive protein. The null associations persisted across subgroups of age, sex, race, and body mass index. Findings from this longitudinal study do not support the hypothesis that low to moderate toenail arsenic levels in young adulthood is associated with diabetes risk later in life.

The association between parental weight status and risk of hypertension in children aged 6 to 12 years.

BACKGROUND AND OBJECTIVES: Parents may play important roles in the regulation of children's weight status and consequently the development of childhood hypertension. Thus, this study aimed to examine parental weight status, as a marker of parents' diet and lifestyle, in relation to risk of hypertension in their children. METHODS AND STUDY DESIGN: A total of 1,949 children aged 6 to 12 years (1,012 girls, 52%) and their parents were included. Information on demographics, anthropometrics, lifestyle, diet, and medical history were obtained from the participants and their parents through self-administered questionnaires. Childhood hypertension and elevated blood pressure were defined as SBP and/or DBP ≥95th and ≥90th age- and gender-specific percentile, respectively. Parental overweight was defined as BMI ≥24.0 kg/m2. RESULTS: The prevalence of childhood hypertension was 8.4%, with no significant gender difference (p=0.36). Parents' weight status, especially maternal, was associated with childhood hypertension. After adjustment for potential confounders, children with two parents being overweight were two times more likely to have hypertension as compared with children who had both parents being of normal weight [multivariable-adjusted odds ratio=2.09; 95% confidence interval: (1.26, 3.46)]. After further adjustment for children's body mass index, the observed association was substantially attenuated and became statistically non-significant. CONCLUSIONS: Findings from this study suggest that parental weight status is associated with the prevalence of hypertension in children presumably through influencing children's weight. Further studies are needed to establish causal inference. This study highlights the importance of parental lifestyle in children's health.

Arsenic Exposure in Relation to Ischemic Stroke: The Reasons for Geographic and Racial Differences in Stroke Study.

BACKGROUND AND PURPOSE: The purpose of this case-cohort study was to examine urinary arsenic levels in relation to incident ischemic stroke in the United States. METHODS: We performed a case-cohort study nested within the REGARDS (REasons for Geographic and Racial Differences in Stroke) cohort. A subcohort (n=2486) of controls was randomly sampled within region-race-sex strata while all incident ischemic stroke cases from the full REGARDS cohort (n=671) were included. Baseline urinary arsenic was measured by inductively coupled plasma-mass spectrometry. Arsenic species, including urinary inorganic arsenic and its metabolites monomethylarsonic acid and dimethylarsinic acid, were measured in a random subset (n=199). Weighted Cox's proportional hazards models were used to calculate hazard ratios and 95% confidence intervals of ischemic stroke by arsenic and its species. RESULTS: The average follow-up was 6.7 years. Although incident ischemic stroke showed no association with total arsenic or total inorganic arsenic, for each unit higher level of urinary monomethylarsonic acid on a log-scale, after adjustment for potential confounders, ischemic stroke risk increased ≈2-fold (hazard ratio=1.98; 95% confidence interval: 1.12-3.50). Effect modification by age, race, sex, or geographic region was not evident. CONCLUSIONS: A metabolite of arsenic was positively associated with incident ischemic stroke in this case-cohort study of the US general population, a low-to-moderate exposure area. Overall, these findings suggest a potential role for arsenic methylation in the pathogenesis of stroke, having important implications for future cerebrovascular research.

In utero exposure to 25-hydroxyvitamin D and risk of childhood asthma, wheeze, and respiratory tract infections: A meta-analysis of birth cohort studies.

BACKGROUND: Studies of the associations between in utero 25-hydroxyvitamin D (25[OH]D) exposure and risk of childhood asthma, wheeze, and respiratory tract infections are inconsistent and inconclusive. OBJECTIVES: We sought to assess associations between 25(OH)D levels in cord blood or maternal venous blood and risk of offspring's asthma, wheeze, and respiratory tract infections. METHODS: Data were derived from PubMed, Embase, Google Scholar, references from relevant articles, and de novo results from published studies until December 2015. A random-effects meta-analysis was conducted among 16 birth cohort studies. RESULTS: Comparing the highest with the lowest category of 25(OH)D levels, the pooled odds ratios were 0.84 (95% CI, 0.70-1.01; P = .064) for asthma, 0.77 (95% CI, 0.58-1.03; P = .083) for wheeze, and 0.85 (95% CI, 0.66-1.09; P = .187) for respiratory tract infections. The observed inverse association for wheeze was more pronounced and became statistically significant in the studies that measured 25(OH)D levels in cord blood (0.43; 95% CI, 0.29-0.62; P < .001). CONCLUSIONS: Accumulated evidence generated from this meta-analysis suggests that increased in utero exposure to 25(OH)D is inversely associated with the risk of asthma and wheeze during childhood. These findings are in keeping with the results of 2 recently published randomized clinical trials of vitamin D supplementation during pregnancy.

Genome-wide association study of selenium concentrations.

Selenium (Se) is an essential trace element in human nutrition, but its role in certain health conditions, particularly among Se sufficient populations, is controversial. A genome-wide association study (GWAS) of blood Se concentrations previously identified a locus at 5q14 near BHMT. We performed a GW meta-analysis of toenail Se concentrations, which reflect a longer duration of exposure than blood Se concentrations, including 4162 European descendants from four US cohorts. Toenail Se was measured using neutron activation analysis. We identified a GW-significant locus at 5q14 (P < 1 × 10(-16)), the same locus identified in the published GWAS of blood Se based on independent cohorts. The lead single-nucleotide polymorphism (SNP) explained ∼1% of the variance in toenail Se concentrations. Using GW-summary statistics from both toenail and blood Se, we observed statistical evidence of polygenic overlap (P < 0.001) and meta-analysis of results from studies of either trait (n = 9639) yielded a second GW-significant locus at 21q22.3, harboring CBS (P < 4 × 10(-8)). Proteins encoded by genes at 5q14 and 21q22.3 function in homocysteine (Hcy) metabolism, and index SNPs for each have previously been associated with betaine and Hcy levels in GWAS. Our findings show evidence of a genetic link between Se and Hcy pathways, both involved in cardiometabolic disease.

Antioxidant Supplementation Is Not Associated with Long-term Quality of Life in Stage-II Colorectal Cancer Survivors: A Follow-up of the Study of Colorectal Cancer Survivors Cohort.

Cancer survivors are motivated to change lifestyle following diagnosis, but studies investigating the outcomes are scarce. The purpose of this study was to examine the associations between antioxidant supplementation and quality of life (QoL) in stage-II colorectal cancer survivors. Four-hundred-fifty-three survivors were enrolled from the North Carolina Cancer Registry from 2009 to 2011. Interview data on demography, treatment, health behaviors, and QoL were collected at diagnosis, and at 12 and 24 mo post-diagnosis. Antioxidant supplementation was self-reported as use of selenium, zinc, beta-carotene, vitamin A, vitamin E, or vitamin C at baseline. Two-hundred-sixty-one subjects completed the 24-mo interview. After adjusting for multiple confounders, there was no association between antioxidant use and the Functional Assessment of Cancer Treatment-Colorectal [ß = 1.41; 95% confidence interval (CI): -2.48, 5.30] or the medical outcomes 12-item short form (physical composite score: ß = 0.84; 95% CI: -1.39, 3.07; mental composite score: ß = -0.61; 95% CI: -2.65, 1.43). This study revealed no benefit of antioxidant use among survivors, possibly explained by a limited sample size of antioxidant users. More prospective studies are necessary to assess the benefits of antioxidants.

Accumulated evidence on Helicobacter pylori infection and the risk of asthma: A meta-analysis.

BACKGROUND: Helicobacter pylori (H pylori) infection has been suggested to be related to a decreased risk of asthma, but findings in the literature are inconsistent. OBJECTIVE: To quantitatively summarize the existing evidence on the association between H pylori infection and asthma risk. METHODS: The PubMed database was searched for observational studies of H pylori infection in relation to the risk of asthma published in English through May 2017. Measurements of association were pooled using a meta-analytic approach and expressed as odds ratios (ORs) with 95% confidence intervals (95% CIs). RESULTS: Twenty-four studies were identified in this meta-analysis, including 8 case-control studies composed of 1,247 cases and 2,410 controls, and 16 cross-sectional studies composed of 50,290 participants (4,185 cases and 46,105 noncases). The average H pylori infection rates were 40.01% and 48.74% in case-control and cross-sectional studies, respectively. Five studies subcategorized H pylori infection according to CagA status, in which 59.37% of H pylori-infected participants were identified as having CagA positivity. Helicobacter pylori infection was significantly inversely associated with the risk of asthma in case-control studies (OR 0.83, 95% CI 0.71-0.98) but was borderline significant in cross-sectional studies (OR 0.88, 95% CI 0.76-1.02). The observed inverse association persisted for CagA-positive H pylori infection (OR 0.77, 95% CI 0.63-0.93, P for interaction = .03) but not for CagA-negative strains (OR 1.08, 95% CI 0.66-1.78). No significant difference was observed across age or region subgroups. CONCLUSION: The accumulated evidence supports that H pylori infection, especially CagA-positive H pylori infection, is inversely associated with the risk of asthma.

Circulating magnesium levels and incidence of coronary heart diseases, hypertension, and type 2 diabetes mellitus: a meta-analysis of prospective cohort studies.

BACKGROUND: Data on the associations between circulating magnesium (Mg) levels and incidence of coronary heart diseases (CHD), hypertension, and type 2 diabetes mellitus (T2DM) are inconsistent and inconclusive. The aim of this study was to examine circulating Mg levels in relation to incidence of CHD, hypertension, and T2DM. METHODS: Prospective cohort studies published before May 2017 were searched through PubMed, EmBase, SCOPUS, and Google Scholar. A total of 11 studies that reported multivariable-adjusted associations of interest were identified. Information on the characteristics of study and participants, exposure, main outcomes, risk estimates, and cofounders was extracted and analyzed. RESULTS: Of the 11 included studies, 5 reported results on CHD (38,808 individuals [4437 cases] with an average 10.5-year follow-up), 3 on hypertension (14,876 participants [3149 cases] with a 6.7-year follow-up), and 4 on T2DM (31,284 participants [2680 cases] with an 8.8-year follow-up). Comparing the highest to the lowest category of circulating Mg concentration, the pooled relative risks [RRs] (95% confidence intervals [CIs]) were 0.86 (0.74, 0.996), 0.91 (0.80, 1.02), and 0.64 (0.50, 0.81) for incidence of CHD, hypertension, and T2DM, respectively. Every 0.1 mmol/L increment in circulating Mg levels was associated with 4% (RR, 0.96; 95% CI: 0.94, 0.99) reduction in hypertension incidence. No significant linear association was found between circulating Mg levels and incidence of CHD (RR, 0.89; 95% CI: 0.77, 1.03) and T2DM (RR, 0.90; 95% CI: 0.81, 1.002). The observed associations of interest were sensitive to exclusion of individual studies. CONCLUSIONS: Findings in this meta-analysis suggest that circulating Mg levels are inversely associated with incidence of CHD, hypertension, and T2DM. Additional studies are needed to provide more solid evidence and identify the optimal range of circulating Mg concentration with respect to primary prevention of CHD, hypertension, and T2DM.

The geographic distribution of trace elements in the environment: the REGARDS study.

Research on trace elements and the effects of their ingestion on human health is often seen in scientific literature. However, little research has been done on the distribution of trace elements in the environment and their impact on health. This paper examines what characteristics among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study are associated with levels of environmental exposure to arsenic, magnesium, mercury, and selenium. Demographic information from REGARDS participants was combined with trace element concentration data from the US Geochemical Survey (USGS). Each trace element was characterized as either low (magnesium and selenium) or high (arsenic and mercury) exposure. Associations between demographic characteristics and trace element concentrations were analyzed with unadjusted and adjusted logistic regression models. Individuals who reside in the Stroke Belt have lower odds of high exposure (4th quartile) to arsenic (OR 0.33, CI 0.31, 0.35) and increased exposure to mercury (OR 0.65, CI 0.62, 0.70) than those living outside of these areas, while the odds of low exposure to trace element concentrations were increased for magnesium (OR 5.48, CI 5.05, 5.95) and selenium (OR 2.37, CI 2.22, 2.54). We found an association between levels of trace elements in the environment and geographic region of residence, among other factors. Future studies are needed to further examine this association and determine whether or not these differences may be related to geographic variation in disease.

The Circulating Concentration and 24-h Urine Excretion of Magnesium Dose- and Time-Dependently Respond to Oral Magnesium Supplementation in a Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Accurate determination of Mg status is important for improving nutritional assessment and clinical risk stratification. OBJECTIVE: We aimed to quantify the overall responsiveness of Mg biomarkers to oral Mg supplementation among adults without severe diseases and their dose- and time responses using available data from randomized controlled trials (RCTs). METHODS: We identified 48 Mg supplementation trials (n = 2131) through searches of MEDLINE and the Cochrane Library up to November 2014. Random-effects meta-analysis was used to estimate weighted mean differences of biomarker concentrations between intervention and placebo groups. Restricted cubic splines were used to determine the dose- and time responses of Mg biomarkers to supplementation. RESULTS: Among the 35 biomarkers assessed, serum, plasma, and urine Mg were most commonly measured. Elemental Mg supplementation doses ranged from 197 to 994 mg/d. Trials ranged from 3 wk to 5 y (median: 12 wk). Mg supplementation significantly elevated circulating Mg by 0.04 mmol/L (95% CI: 0.02, 0.06) and 24-h urine Mg excretion by 1.52 mmol/24 h (95% CI: 1.20, 1.83) as compared to placebo. Circulating Mg concentrations and 24-h urine Mg excretion responded to Mg supplementation in a dose- and time-dependent manner, gradually reaching a steady state at doses of 300 mg/d and 400 mg/d, or after ~20 wk and 40 wk, respectively (all P-nonlinearity ≤ 0.001). The higher the circulating Mg concentration at baseline, the lower the responsiveness of circulating Mg to supplementation, and the higher the urinary excretion (all P-linearity < 0.05). In addition, RBC Mg, fecal Mg, and urine calcium were significantly more elevated by Mg supplementation than by placebo (all P-values < 0.05), but there is insufficient evidence to determine their responses to increasing Mg doses. CONCLUSIONS: This meta-analysis of RCTs demonstrated significant dose- and time responses of circulating Mg concentration and 24-h urine Mg excretion to oral Mg supplementation.

Hair and Nails as Noninvasive Biomarkers of Human Exposure to Brominated and Organophosphate Flame Retardants.

After the phase-out of polybrominated diphenyl ethers (PBDEs), the use of alternative flame retardants (AFRs), such as FireMaster 550, and of organophosphate esters (OPEs) has increased. However, little is known about human exposure to these chemicals. This lack of biomonitoring studies is partially due to the absence of reliable noninvasive biomarkers of exposure. Human hair and nails can provide integrated exposure measurements, and as such, these matrices can potentially be used as noninvasive biomarkers of exposure to these flame retardants. Paired human hair, fingernail, toenail, and serum samples obtained from 50 adult participants recruited at Indiana University Bloomington campus were analyzed by gas chromatographic mass spectrometry for 36 PBDEs, 9 AFRs, and 12 OPEs. BDE-47, BDE-99, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), di(2-ethylhexyl) tetrabromophthalate (TBPH), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP), and triphenyl phosphate (TPHP) were the most abundant compounds detected in almost all hair, fingernail, and toenail samples. The concentrations followed the order OPEs > TBB+TBPH > Σpenta-BDE. PBDE levels in the hair and nail samples were significantly correlated with their levels in serum (P < 0.05), suggesting that human hair and nails can be used as biomarkers to assess human exposure to PBDEs.

Intake of fish and long-chain omega-3 polyunsaturated fatty acids and incidence of metabolic syndrome among American young adults: a 25-year follow-up study.

PURPOSE: Studies suggest that long-chain ω-3 polyunsaturated fatty acid (LCω3PUFA) intake and its primary food source-fish-may have beneficial effects on the individual components of metabolic syndrome (MetS). We examined the longitudinal association between fish or LCω3PUFA intake and MetS incidence. METHODS: We prospectively followed 4356 American young adults, free from MetS and diabetes at baseline, for incident MetS and its components in relation to fish and LCω3PUFA intake. MetS was defined by the National Cholesterol Education Program/Adult Treatment Panel III criteria. Cox proportional hazards model was used for analyses, controlling for socio-demographic, behavioral, and dietary factors. RESULTS: During the 25-year follow-up, a total of 1069 incident cases of MetS were identified. LCω3PUFA intake was inversely associated with the incidence of MetS in a dose-response manner. The multivariable adjusted hazards ratio (HR) [95 % confidence interval (CI)] of incident MetS was 0.54 (95 % CI 0.44, 0.67; P for linear trend < 0.01) as compared the highest to the lowest quintile of LCω3PUFA intake. A threshold inverse association was found between non-fried fish consumption and the incidence of MetS. The multivariable adjusted HRs (95 % CIs) from the lowest to the highest quintile were 1.00, 0.70 (0.51, 0.95), 0.68 (0.52, 0.91), 0.67 (0.53, 0.86), and 0.71 (0.56, 0.89) (P for linear trend = 0.49). The observed inverse associations were independent of the status of baseline individual components of MetS. CONCLUSIONS: Our findings suggest that intakes of LCω3PUFAs and non-fried fish in young adulthood are inversely associated with the incidence of MetS later in life.

Effects of adjuvant chemotherapy on recurrence, survival, and quality of life in stage II colon cancer patients: a 24-month follow-up.

PURPOSE: The purpose of this cohort study was to investigate the association of adjuvant chemotherapy with quality of life (QoL), survival, and recurrence over the 24 months following diagnosis in stage II colon cancer patients. METHODS: Overall, 453 patients were recruited from North Carolina from 2009 to 2011 and interviewed with a closed-ended survey detailing quality of life, health behaviors, treatment, and cancer recurrence at three times points: diagnosis, 12-, and 24-months post-diagnosis; mortality was obtained via the National Death Index. RESULTS: In sum, 265 patients received chemotherapy. Receipt of chemotherapy exhibited an inverse association with total Functional Assessment of Cancer Treatment (FACT)-General (P < 0.01), FACT-Colorectal (P < 0.01), physical (P < 0.01), emotional (P = 0.02), and functional (P < 0.01) well-being; the inverse association between receiving chemotherapy and emotional well-being persisted for Caucasians but not African Americans (P interaction = 0.049). Those who received chemotherapy demonstrated significantly higher odds of cancer recurrence (odds ratio (OR) 2.74; 95 % confidence interval (CI) 1.18, 6.35) and all-cause mortality (OR: 1.95; 95 % CI: 1.05, 3.62). CONCLUSIONS: In this study, stage II colon cancer patients who received chemotherapy treatment were more likely to have poor QoL, recurrence, and all-cause mortality after 24 months compared to those who did not receive chemotherapy. Future research focusing on subtypes of chemotherapy treatment, as well as a longer follow-up period, is needed.