Search

ObjectiveIn resource-constrained facilities or during resuscitation, immediate paediatric weight estimation remains a fundamental challenge. We aimed to develop and validate weight estimation models based on ulna length and forearm width and circumference measured by simple and portable tools; and to compare them against previous methods (advanced paediatric life support (APLS), Theron and Traub–Johnson formulas).DesignCross-sectional analysis of anthropometric measurements. Four ulna- and forearm-based weight estimation models were developed in the training set (n 1016). Assessment of bias, precision and accuracy was examined in the validation set (n 457).SettingNational Children’s Study-Formative Research in Anthropometry (2011–2012).SubjectsMulti-racial/ethnic infants and children aged n 1473).ResultsDeveloped Models 1–4 had high predictive precision (R2=0·91–0·97). Mean percentage errors between predicted and measured weight were significantly smaller across the developed models (0·1–0·7 %) v. the APLS, Theron and Traub–Johnson formulas (−1·7, 9·2 and −4·9 %, respectively). Root-mean-squared percentage error was overall smaller among Models 1–4 v. the three existing methods (range=7·5–8·7 v. 9·8–13·3 %). Further, Models 1–4 were within 10 and 20 % of actual weight in 72–87 and 95–99 % of the weight estimations, respectively, which outperformed any of the three existing methods.ConclusionsUlna length, forearm width and forearm circumference by simple and portable tools could serve as valid and reliable surrogate measures of weight among infants and children aged

Objective:To review the various biomarkers of dietary intakes of fatty acids in human populations, their measurement, limitations and analytical considerations.Design:Review of the literature.Results:Although there is no good biomarker of intake of total fat, a number of alternatives exist for assessing the intakes of exogenously produced fatty acids that are consumed. Adipose tissue, erythrocyte membrane concentrations and serum or plasma levels can reflect prior intakes over the past few hours to the past few years. The concentrations of individual fatty acids in these media generally reflect relative levels, and are influenced by a number of factors. Although relatively expensive to analyse, a single analysis by gas chromatography or high-performance liquid chromatography provides information on multiple fatty acids, and is superior to attempting to measure specific fatty acids using traditional dietary assessment methods.Conclusions:Biomarkers of fatty acids that reflect long-term intake are available for nutritional epidemiology purposes. Analytical methods have become very accurate and able to detect and quantify smaller families, such as trans-fatty acids.

Objective:This study examines the relationship between tea consumption and colon cancer risk in the US population.Design:Data from the NHANES I Epidemiologic Follow-up study (NHEFS) were used to examine the hypothesis. Cox proportional hazard models were used to examine the hypothesis of a protective effect of frequent tea consumption on colon cancer occurrence.Setting:Due to differences in the precision of the exposure data, we analysed two cohort periods based on the NHEFS. Cohort I was based on the survey conducted at the NHEFS baseline and Cohort II began at the first follow-up.Subjects:After excluding non-incidence cases and cases lost to follow-ups, there were 2359 tea users and 6498 non-tea users at baseline and 7656 tea users and 4514 non-tea users at the first follow-up.Results:After adjusting for confounders, the relative risks of colon cancer are 0.57 (95% confidence interval (CI) 0.42, 0.78) and 0.59 (95% CI = 0.35, 1.00) for subjects who consumed ≤1.5 cups and ≥1.5 cups per day, respectively, compared with non-tea users in Cohort II. Although more women consumed tea and the mean intake was higher, the preventive effect of tea consumption on colon cancer was found predominantly in men. The relative risks of colon cancer are 0.41 (95% CI = 0.25, 0.66) for men who consumed ≤1.5 cups day-1 and 0.30 (95% CI = 0.09, 0.98) for >1.5 cups day-1 of tea consumption (P-value for trend Conclusions:This study suggests an inverse association between colon cancer risk and habitual tea consumption.

Although clinical trials are needed to prove the efficacy of medicinal herbs and pharmacological studies are essential to the long-term goal of identifying the active ingredients in plants, these will not be forthcoming rapidly enough to meet the acute public health needs for knowledge on efficacy and safety since these substances are currently being widely consumed at various dosages. Resulting from the ongoing ‘natural experiment’ well-conducted observational epidemiology can bridge the gap and determine whether, as consumed its use is of benefit or detrimental, for whom and when in the course of disease prevention or minimization of disease severity. The classic study designs (cohort and case-control) and the more recent development of case-only studies can be put to service for these purposes. The challenges are in dose assessment, understanding mechanisms of effect, determining the relevant time period of exposure for a given disease or symptom, controlling for confounding factors such as disease status, and the special challenges presented by irregular use of medicinal herbs and concurrent use of multiple products and multiple sources.

ObjectiveTo examine the utility of using external estimates of within-person variation to adjust usual nutrient intake distributions.DesignAnalyses of the prevalence of inadequate intake of an example nutrient by the Estimated Average Requirement (EAR) cut-point method using three different methods of statistical adjustment of the usual intake distribution of a single 24-hour recall in Russian children in 1996, using the Iowa State University method for adjustment of the distribution. First, adjusting the usual intake distribution with day 2 recalls from the same 1996 sample (the correct method) second, adjusting the distribution using external variance estimates derived from US children in 1996; and third, adjusting the distribution using external estimates derived from Russian children of the same age in 2000. We also present prevalence estimates based on naïve statistical analysis of the unadjusted distribution of intakes.Setting/subjectsChildren drawn from the Russia Longitudinal Monitoring Survey in 1996 and 2000 and from the 1996 Continuing Survey of Food Intakes by Individuals.ResultsWhen the EAR cut-point method is applied to a single recall, the resulting prevalence estimate in this study is inflated by 100–1300%. When the intake distribution is adjusted using an external variance estimate, the prevalence estimate is much less biased, suggesting that any adjustment may give less biased estimates than no adjustment.ConclusionsIn moderately large samples, adjusting distributions with external estimates of variances results in more reliable prevalence estimates than using 1–day data.

Objective:Antioxidant intake has been associated with less progression of radiographic knee osteoarthritis (OA), but studies of carotenoid biomarkers and OA have not been done. We examined associations between serum concentrations of nine naturally occurring carotenoids and radiographic knee OA.Design:The study design was matched case–control. Sera were analysed by high-performance liquid chromatography for nine carotenoids: lutein, zeaxanthin, α- and β-cryptoxanthin,trans- andcis-lycopene, α-carotene, andtrans- andcis-β-carotene. Conditional logistic regression was used to estimate the association between tertiles of each carotenoid and radiographic knee OA, independent of body mass index, education, serum cholesterol, and the other carotenoids.Setting:Johnston County, North Carolina, United States of America.Subjects:Two-hundred cases with radiographic knee OA (Kellgren–Lawrence grades ≥2) and 200 controls (Kellgren–Lawrence grade = 0) were randomly selected from the Johnston County Osteoarthritis Project, and were matched on age, gender and race.Results:Participants with serum levels of lutein or β-cryptoxanthin in the highest tertile were approximately 70% less likely to have knee OA than controls {odds ratio (OR) [95% confidence interval (CI)] = 0.28 [0.11, 0.73] and 0.36 [0.14, 0.95], respectively}. Those in the highest tertile oftrans-β-carotene (OR = 6.40 [1.86, 22.1]) and zeaxanthin (OR = 3.06 [1.19, 7.85]) were more likely to have knee OA.Conclusions:While certain carotenoids may protect against knee OA, others may increase the odds of knee OA. Further study of carotenoids and knee OA are warranted before clinical recommendations about these substances and knee OA can be made.