The CDC's Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population is a valuable tool for researchers and policy makers.

The CDC's National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population (Nutrition Report) is a serial publication that provides ongoing assessment of the population's nutritional status. The Nutrition Report presents data on blood and urine biomarker concentrations (selected water- and fat-soluble vitamins and nutrients, trace elements, dietary bioactive compounds) from a representative sample of the population participating in the NHANES. The Second Nutrition Report (released in 2012) contains reference information (means and percentiles) for 58 biomarkers measured during all or part of 2003-2006, stratified by age, sex, and race-ethnicity. Where available, we presented cutoff-based prevalence data during 2003-2006 and data on changes in biomarker concentrations or prevalence since 1999. Blood vitamin concentrations were generally higher in older (≥ 60 y) than in younger (20-39 y) adults and lower in Mexican Americans and non-Hispanic blacks than in non-Hispanic whites. Nearly 80% of Americans (aged ≥ 6 y) were not at risk of deficiencies in any of the 7 vitamins studied (vitamins A, B-6, B-12, C, D, and E and folate). Deficiency rates varied by age, sex, and race-ethnicity. Approximately 90% of women (aged 12-49 y) were not at risk of iron deficiency, but only 68% were not at risk of deficiencies in iron and all 7 vitamins. Young women (20-39 y) had median urine iodine concentrations bordering on insufficiency. First-time data are presented on plasma concentrations of 24 saturated and mono- and polyunsaturated fatty acids. Tabulation and graphical presentation of NHANES data in the Second Nutrition Report benefits those organizations involved in developing and evaluating nutrition policy.

Selected physiologic variables are weakly to moderately associated with 29 biomarkers of diet and nutrition, NHANES 2003-2006.

The physiologic status of an individual may influence biomarkers of nutritional status. To help researchers with planning studies and interpreting data, we assessed the associations between common physiologic variables (fasting, inflammation, renal function, and pregnancy) and 29 biomarkers of diet and nutrition measured in blood or urine in a representative sample of the adult U.S. population (aged ≥ 20 y; pregnancy variable and iron indicators limited to women aged 20-49 y) participating in NHANES 2003-2006. We compared simple linear regression (model 1) with multiple linear regression [model 2, controlling for age, sex, race-ethnicity, smoking, supplement use, and the physiologic factors (and urine creatinine for urine biomarkers)] and report significant findings from model 2. Not being fasted was positively associated with most water-soluble vitamins (WSVs) and related metabolites (RMs). Some WSV, fat-soluble vitamin (FSV) and micronutrient (MN), and phytoestrogen concentrations were lower in the presence of inflammation (C-reactive protein ≥ 5 mg/L), whereas fatty acids and most iron indicators were higher. Most WSVs and RMs were higher when renal function was impaired [estimated glomerular filtration rate <60 mL/(min · 1.73 m(2))]. Most WSV, FSV and MN, and fatty acid concentrations were higher in pregnant compared with nonpregnant women, but vitamins A and B-12 and most iron indicators were lower. The estimated changes in biomarker concentrations with different physiologic status were mostly small to moderate (≤ 25%) and generally similar between models; renal function, however, showed several large differences for WSV and RM concentrations. This descriptive analysis of associations between physiologic variables and a large number of nutritional biomarkers showed that controlling for demographic variables, smoking, and supplement use generally did not change the interpretation of bivariate results. The analysis serves as a useful basis for more complex future research.

Relationship between markers of inflammation and anaemia in children of Papua New Guinea.

OBJECTIVE: To assess the association of the acute-phase protein biomarkers, C-reactive protein (CRP) and α1-acid glycoprotein (AGP), with anaemia in children aged 6-59·9 months in Papua New Guinea. DESIGN: A nationally representative household-based cross-sectional survey of children aged 6-59·9 months was used to assess the relationships between various combinations of elevated CRP (>5 mg/l) and AGP (>1·2 g/l) with anaemia. Logistic regression was used to determine if other factors, such as age, sex, measures of anthropometry, region, urban/rural residence and household size, modified or confounded the acute-phase protein-anaemia association. SETTING: Papua New Guinea. SUBJECTS: A total of 870 children aged 6-59·9 months from the 2005 Papua New Guinea National Micronutrient Survey were assessed. RESULTS: The following prevalence estimates were found: anaemia 48 %; elevated CRP 32 %; and elevated AGP 33 %. Children with elevated CRP had a prevalence of anaemia of 66 % compared with children with normal CRP who had a prevalence of 40 %. Corresponding estimates for AGP were 61 % and 42 %, respectively. Similar results were found with combinations of elevated CRP and AGP. The higher prevalence of anaemia in children with elevated CRP and/or AGP was still present after controlling for confounders. CONCLUSIONS: Elevated levels of CRP and AGP were significantly associated with a higher prevalence of anaemia in the children surveyed. There are no expert group recommendations on whether to or how to account for markers of inflammation in presenting results on anaemia prevalence. Additional research would be helpful to clarify this issue.

Brownian dynamics simulation of the diffusion of rods and wormlike chains in a gel modeled as a cubic lattice: application to DNA.

The translational diffusion constant of a particle, D, in a congested medium or a gel can be written as the product of two terms that account for long-range hydrodynamic interaction between the gel or congested medium and the particle, DEM, and a short-range "steric" term, S. For particles of arbitrary shape, DEM has been examined previously within the framework of the effective medium, EM, model (S. Allison et al., J. Phys. Chem. B 2008, 112, 5858-5866). In the present work, we examine S for rod- and wormlike chain models of duplex DNA in the size range of 100 to over 2000 base pairs. The gel is modeled explicitly as a cubic lattice, and Brownian dynamics simulation is used to examine S for a wide range of rod/wormlike chain and gel parameters. For wormlike chains with P = 50 nm, an empirical formula is derived for S that should be valid over a wide range of wormlike chain/gel parameters. For duplex DNA in the size of several hundred to several thousand base pairs in an agarose gel of 2% or less, fair agreement between modeling and experiment is obtained. However, modeling overestimates the length dependence of D observed experimentally. Finally, the reduction of D of DNA (100 to over 1000 base pairs in length) in cytoplasm relative to water can be accounted for quite well using the effective medium plus steric correction approach.

The CDC VITAL-EQA program, external quality assurance for serum retinol, 2003-2006.

BACKGROUND: With approximately 127 million preschool children currently suffering from vitamin A deficiency globally, it is important for affected countries to have the capacity to determine the prevalence of vitamin A deficiency and to monitor the progress being made to eradicate this problem through supplementation and fortification programs. The VITamin A Laboratory-External Quality Assurance program (VITAL-EQA) administered by the US Centers for Disease Control and Prevention was developed in 2003 to help predominantly less developed countries to assess and improve their ability to accurately and precisely measure serum retinol, and more recently other nutritional indicators. METHODS: Twice each year, laboratories test serum samples in duplicate over the course of 3 days. Results are returned and troubleshooting is performed if needed. RESULTS: Measurement accuracy improved for 2 laboratories and declined for 2 laboratories, whereas the remainder of laboratories participating in >1 round showed consistently acceptable performance. Precision improved for 7 laboratories, declined for 4 laboratories, and remained at