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2.  Biomarkers of folate status in NHANES: a roundtable summary123456 
A roundtable to discuss the measurement of folate status biomarkers in NHANES took place in July 2010. NHANES has measured serum folate since 1974 and red blood cell (RBC) folate since 1978 with the use of several different measurement procedures. Data on serum 5-methyltetrahydrofolate (5MTHF) and folic acid (FA) concentrations in persons aged ≥60 y are available in NHANES 1999–2002. The roundtable reviewed data that showed that folate concentrations from the Bio-Rad Quantaphase II procedure (Bio-Rad Laboratories, Hercules, CA; used in NHANES 1991–1994 and NHANES 1999–2006) were, on average, 29% lower for serum and 45% lower for RBC than were those from the microbiological assay (MA), which was used in NHANES 2007–2010. Roundtable experts agreed that these differences required a data adjustment for time-trend analyses. The roundtable reviewed the possible use of an isotope-dilution liquid chromatography–tandem mass spectrometry (LC-MS/MS) measurement procedure for future NHANES and agreed that the close agreement between the MA and LC-MS/MS results for serum folate supported conversion to the LC-MS/MS procedure. However, for RBC folate, the MA gave 25% higher concentrations than did the LC-MS/MS procedure. The roundtable agreed that the use of the LC-MS/MS procedure to measure RBC folate is premature at this time. The roundtable reviewed the reference materials available or under development at the National Institute of Standards and Technology and recognized the challenges related to, and the scientific need for, these materials. They noted the need for a commutability study for the available reference materials for serum 5MTHF and FA.
doi:10.3945/ajcn.111.013011
PMCID: PMC3127517  PMID: 21593502
3.  Biomarkers of vitamin B-12 status in NHANES: a roundtable summary123456 
A roundtable to discuss the measurement of vitamin B-12 (cobalamin) status biomarkers in NHANES took place in July 2010. NHANES stopped measuring vitamin B-12–related biomarkers after 2006. The roundtable reviewed 3 biomarkers of vitamin B-12 status used in past NHANES—serum vitamin B-12, methylmalonic acid (MMA), and total homocysteine (tHcy)—and discussed the potential utility of measuring holotranscobalamin (holoTC) for future NHANES. The roundtable focused on public health considerations and the quality of the measurement procedures and reference methods and materials that past NHANES used or that are available for future NHANES. Roundtable members supported reinstating vitamin B-12 status measures in NHANES. They noted evolving concerns and uncertainties regarding whether subclinical (mild, asymptomatic) vitamin B-12 deficiency is a public health concern. They identified the need for evidence from clinical trials to address causal relations between subclinical vitamin B-12 deficiency and adverse health outcomes as well as appropriate cutoffs for interpreting vitamin B-12–related biomarkers. They agreed that problems with sensitivity and specificity of individual biomarkers underscore the need for including at least one biomarker of circulating vitamin B-12 (serum vitamin B-12 or holoTC) and one functional biomarker (MMA or tHcy) in NHANES. The inclusion of both serum vitamin B-12 and plasma MMA, which have been associated with cognitive dysfunction and anemia in NHANES and in other population-based studies, was preferable to provide continuity with past NHANES. Reliable measurement procedures are available, and National Institute of Standards and Technology reference materials are available or in development for serum vitamin B-12 and MMA.
doi:10.3945/ajcn.111.013243
PMCID: PMC3127527  PMID: 21593512
4.  URINARY 6-SULPHATOXYMELATONIN LEVELS AND RISK OF BREAST CANCER IN PREMENOPAUSAL WOMEN: THE ORDET COHORT 
Background
Lower urinary melatonin levels are associated with a higher risk of breast cancer in postmenopausal women. Literature for premenopausal women is scant and inconsistent.
Methods
In a prospective case–control study we measured the concentration of 6-sulphatoxymelatonin (aMT6s), in the 12-hour overnight urine of 180 premenopausal women with incident breast cancer and 683 matched controls.
Results
In logistic regression models, the multivariate odds ratio (OR) of invasive breast cancer for women in the highest quartile of total overnight aMT6s output compared with the lowest was 1.43 [95% confidence interval (CI) = 0.83–2.45; Ptrend = 0.03]. Among current non-smokers no association was existent (OR, 1.00, 95% CI, 0.52–1.94; Ptrend = 0.29). We observed an OR of 0.68 between overnight urinary aMT6s level and breast cancer risk in women with invasive breast cancer diagnosed >2 years after urine collection and a significant inverse association in women with a breast cancer diagnosis >8 years after urine collection (OR, 0.17, 95% CI = 0.04–0.71; Ptrend = 0.01). There were no important variations in ORs by tumor stage or hormone receptor status of breast tumors.
Conclusion
Overall we observed a positive association between aMT6s and risk of breast cancer. However, there was some evidence to suggest that this might be driven by the influence of subclinical disease on melatonin levels, with a possible inverse association among women diagnosed further from recruitment. Thus, the influence of lagtime on the association between melatonin and breast cancer risk needs to be evaluated in further studies.
doi:10.1158/1055-9965.EPI-09-1229
PMCID: PMC2837369  PMID: 20200429
melatonin; aMT6s; premenopausal; night work; breast cancer
6.  Urinary 6-Sulfatoxymelatonin Levels and Risk of Breast Cancer in Postmenopausal Women 
Background
Low urinary melatonin levels have been associated with a high risk of breast cancer in premenopausal women. However, the association between melatonin levels and breast cancer risk in postmenopausal women remains unclear.
Methods
We investigated the association between melatonin levels and breast cancer risk in postmenopausal women in a prospective case–control study nested in the Hormones and Diet in the Etiology of Breast Cancer Risk cohort. The concentration of melatonin’s major metabolite, 6-sulfatoxymelatonin, was measured in a baseline 12-hour overnight urine sample from 178 postmenopausal women who later developed incident breast cancer and from 710 matched control subjects. We used multivariable-adjusted conditional logistic regression models to investigate associations. Relative risks are reported as odds ratios (ORs). All statistical tests were two-sided.
Results
Increased melatonin levels were associated with a statistically significantly lower risk of invasive breast cancer (for women in the highest quartile of total overnight 6-sulfatoxymelatonin output vs. the lowest quartile, multivariable OR also adjusted for testosterone = 0.56, 95% confidence interval [CI] = 0.33 to 0.97; Ptrend = .02). This association was strongest among current non-smokers (OR = 0.38, 95% CI = 0.20 to 0.74; Ptrend = .001) and among women who were diagnosed with invasive breast cancer more than 4 years after urine collection (OR = 0.34, 95% CI = 0.15 to 0.75; Ptrend = .002). We did not observe substantial variation in relative risks by hormone receptor status of breast tumors. Among the 992 women in the highest 6-sulfatoxymelatonin quartile, 40 developed breast cancer during follow-up, compared with 56 of the 992 of women in the lowest 6-sulfatoxymelatonin quartile.
Conclusion
Results from this prospective study provide evidence for a statistically significant, inverse association between melatonin levels, as measured in overnight morning urine, and invasive breast cancer risk in postmenopausal women.
doi:10.1093/jnci/djn171
PMCID: PMC2630389  PMID: 18544743
melatonin; aMT6s; breast cancer
7.  Urinary 6-Sulfatoxymelatonin Levels and Risk of Breast Cancer in Postmenopausal Women 
Background
Low urinary melatonin levels have been associated with an increased risk of breast cancer in premenopausal women. However, the association between melatonin levels and breast cancer risk in postmenopausal women remains unclear.
Methods
We investigated the association between melatonin levels and breast cancer risk in postmenopausal women in a prospective case–control study nested in the Hormones and Diet in the Etiology of Breast Cancer Risk cohort, which included 3966 eligible postmenopausal women. The concentration of melatonin's major metabolite, 6-sulfatoxymelatonin, was measured in a baseline 12-hour overnight urine sample from 178 women who later developed incident breast cancer and from 710 matched control subjects. We used multivariable-adjusted conditional logistic regression models to investigate associations. Relative risks are reported as odds ratios (ORs). All statistical tests were two-sided.
Results
Increased melatonin levels were associated with a statistically significantly lower risk of invasive breast cancer in postmenopausal women (for women in the highest quartile of total overnight 6-sulfatoxymelatonin output vs the lowest quartile, multivariable OR also adjusted for testosterone = 0.56, 95% confidence interval [CI] = 0.33 to 0.97; Ptrend = .02). This association was strongest among never and past smokers (OR = 0.38, 95% CI = 0.20 to 0.74; Ptrend = .001) and after excluding women who were diagnosed with invasive breast cancer within 4 years after urine collection (OR = 0.34, 95% CI = 0.15 to 0.75; Ptrend = .002). We did not observe substantial variation in relative risks by hormone receptor status of breast tumors. Among the 3966 women in the cohort, 40 of the 992 women in the highest quartile of 6-sulfatoxymelatonin developed breast cancer during follow-up, compared with 56 of the 992 women in the lowest quartile of 6-sulfatoxymelatonin.
Conclusion
Results from this prospective study provide evidence for a statistically significant inverse association between melatonin levels, as measured in overnight morning urine, and invasive breast cancer risk in postmenopausal women.
doi:10.1093/jnci/djn171
PMCID: PMC2630389  PMID: 18544743
8.  Ethnic variation in validity of classification of overweight and obesity using self-reported weight and height in American women and men: the Third National Health and Nutrition Examination Survey 
Nutrition Journal  2005;4:27.
Background
Few data have been published on the validity of classification of overweight and obesity based on self-reported weight in representative samples of Hispanic as compared to other American populations despite the wide use of such data.
Objective
To test the null hypothesis that ethnicity is unrelated to bias of mean body mass index (BMI) and to sensitivity of overweight or obesity (BMI >= 25 kg/m2) derived from self-reported (SR) versus measured weight and height using measured BMI as the gold standard.
Design
Cross-sectional survey of a large national sample, the Third National Health and Nutrition Examination Survey (NHANES III) conducted in 1988–1994.
Participants
American men and women aged 20 years and over (n = 15,025).
Measurements
SR height, weight, cigarette smoking, health status, and socio-demographic variables from home interview and measured weight and height.
Results
In women and Mexican American (MA) men SR BMI underestimated true prevalence rates of overweight or obesity. For other men, no consistent difference was seen. Sensitivity of SR was similar in non-Hispanic European Americans (EA) and non-Hispanic African Americans (AA) but much lower in MA. Prevalence of obesity (BMI >= 30 kg/m2) is consistently underestimated by self-report, the gap being greater for MA than for other women, but similar for MA and other men. The mean difference between self-reported and measured BMI was greater in MA (men -0.37, women -0.76 kg/m2) than in non-Hispanic EA (men -0.22, women -0.62 kg/m2). In a regression model with the difference between self-reported and measured BMI as the dependent variable, MA ethnicity was a significant (p < 0.01) predictor of the difference in men and in women. The effect of MA ethnicity could not be explained by socio-demographic variables, smoking or health status.
Conclusion
Under-estimation of the prevalence of overweight or obesity based on height and weight self-reported at interview varied significantly among ethnic groups independent of other variables.
doi:10.1186/1475-2891-4-27
PMCID: PMC1262765  PMID: 16209706
Overweight; Obesity; Hispanics; Mexican Americans; Body weight; Blacks
9.  Recent Mortality Patterns Associated With Economic Development in Eastern Europe and the USSR 
Adult male mortality has turned sharply upward in Eastern Europe and the Soviet Union. Excluding the German Democratic Republic, for which data are not available, agestandardized death rates for men aged 40 to 69 years increased an average of 12 percent from the early 1960s to the mid-1970s. These secular trends were associated with consistent economic growth. At least for adult men, this period of social development has led to a marked deterioration in health.
PMCID: PMC2561738  PMID: 6708124

Results 1-9 (9)