Communication of scientific uncertainty : international case studies on the development of folate and vitamin D Dietary Reference Values.

Transparent evidence-based decision making has been promoted worldwide to engender trust in science and policy making. Yet, little attention has been given to transparency implementation. The degree of transparency (focused on how uncertain evidence was handled) during the development of folate and vitamin D Dietary Reference Values was explored in three a priori defined areas: (i) value request; (ii) evidence evaluation; and (iii) final values.

Communication of scientific uncertainty: International case studies on the development of folate and vitamin D Dietary Reference Values

Objective Transparent evidence-based decision making has been promoted worldwide to engender trust in science and policy making. Yet, little attention has been given to transparency implementation. The degree of transparency (focused on how uncertain evidence was handled) during the development of folate and vitamin D Dietary Reference Values was explored in three a priori defined areas: (i) value request; (ii) evidence evaluation; and (iii) final values. Design Qualitative case studies (semi-structured interviews and desk research). A common protocol was used for data collection, interview thematic analysis and reporting. Results were coordinated via cross-case synthesis. Setting Australia and New Zealand, Netherlands, Nordic countries, Poland, Spain and UK. Subjects Twenty-one interviews were conducted in six case studies. Results Transparency of process was not universally observed across countries or areas of the recommendation setting process. Transparency practices were most commonly seen surrounding the request to develop reference values (e.g. access to risk manager/assessor problem formulation discussions) and evidence evaluation (e.g. disclosure of risk assessor data sourcing/evaluation protocols). Fewer transparency practices were observed to assist with handling uncertainty in the evidence base during the development of quantitative reference values. Conclusions Implementation of transparency policies may be limited by a lack of dedicated resources and best practice procedures, particularly to assist with the latter stages of reference value development. Challenges remain regarding the best practice for transparently communicating the influence of uncertain evidence on the final reference values. Resolving this issue may assist the evolution of nutrition risk assessment and better inform the recommendation setting process.

Establishing reference values for central blood pressure and its amplification in a general healthy population and according to cardiovascular risk factors

AIMS: Estimated central systolic blood pressure (cSBP) and amplification (Brachial SBP-cSBP) are non-invasive measures potentially prognostic of cardiovascular (CV) disease. No worldwide, multiple-device reference values are available. We aimed to establish reference values for a worldwide general population standardizing between the different available methods of measurement. How these values were significantly altered by cardiovascular risk factors (CVRFs) was then investigated. METHODS AND RESULTS: Existing data from population surveys and clinical trials were combined, whether published or not. Reference values of cSBP and amplification were calculated as percentiles for 'Normal' (no CVRFs) and 'Reference' (any CVRFs) populations. We included 45,436 subjects out of 82,930 that were gathered from 77 studies of 53 centres. Included subjects were apparently healthy, not treated for hypertension or dyslipidaemia, and free from overt CV disease and diabetes. Values of cSBP and amplification were stratified by brachial blood pressure categories and age decade in turn, both being stratified by sex. Amplification decreased with age and more so in males than in females. Sex was the most powerful factor associated with amplification with 6.6 mmHg (5.8-7.4) higher amplification in males than in females. Amplification was marginally but significantly influenced by CVRFs, with smoking and dyslipidaemia decreasing amplification, but increased with increasing levels of blood glucose. CONCLUSION: Typical values of cSBP and amplification in a healthy population and a population free of traditional CVRFs are now available according to age, sex, and brachial BP, providing values included from different devices with a wide geographical representation. Amplification is significantly influenced by CVRFs, but differently in men and women.

The politics of developing reference standards for nutrient intakes : the case of Australia and New Zealand

Objective Nutrient Reference Values (NRV) are evidence-based benchmarks for assessing the dietary adequacy of individuals and population groups as well as informing public health nutrition policies and programmes. The present paper presents the findings of an analysis of the views of submitters to a draft document associated with the development of the 2006 NRV for Australia and New Zealand. The aim of the study was to explore how these views were reflected in the policy-making process and final policy document.

Design The information necessary to fulfil this aim required access to stakeholder submissions to the NRV development process and this necessitated exploiting the provisions of the Commonwealth of Australia’s Freedom of Information (FOI) Act 1982. We understand that the present research represents the first time that an FOI request seeking information about a National Health and Medical Research Council food and nutrition policy process has been made and therefore is novel in its approach to public health nutrition policy analysis.

Results The analysis of stakeholder submissions identified that stakeholders had particular concerns about the conduct of the review process and the future application of the nutrient values to policy and programmes. There is a lack of evidence that the majority of stakeholder comments were addressed in the final NRV document.

Conclusion Although these findings cannot be interpreted to assess the validity or otherwise of the set nutrient values, they do raise questions about the process for their development and the adequacy of the final document to reflect the views of key stakeholders.

Total and Appendicular Lean Mass Reference Ranges for Australian Men and Women: The Geelong Osteoporosis Study

The aim of this study was to develop reference ranges for total and appendicular lean mass measured using dual-energy X-ray absorptiometry (DXA) from a randomly selected population-based sample of men and women residing in southeastern Australia. Men (n = 1,411) and women (n = 960) aged 20–93 years, enrolled in the Geelong Osteoporosis Study, were randomly selected from the Barwon Statistical Division using the electoral roll as a sampling frame in 2001–2006 (67 % participation) and 1993–1997 (77 % participation), respectively. Using DXA (Lunar DPX-L or Prodigy Pro) at baseline for men and at the 10-year follow-up for women (2004–2008), total and appendicular lean mass were measured. Means and standard deviations for each lean mass measure (absolute and relative to height squared) were generated for each age decade, and cutpoints equivalent to T scores of −2.0 and −1.0 were calculated using data from young adult men and women aged 20–39 years. Young adult reference data were derived from 374 men and 308 women. Cutpoints for relative appendicular lean mass equal to T scores of −2.0 and −1.0 were 6.94 and 7.87 kg/m2 for men and 5.30 and 6.07 kg/m2 for women. The proportions of men and women aged ≥80 years with a T score less than −2.0 were 16.0 and 6.2 %, respectively. These reference ranges may be useful for identifying lean mass deficits in the assessment of muscle wasting and sarcopenia.

Growth of highly versus moderately trained competitive female artistic gymnasts

Purpose: To investigate whether growth was adversely affected in 137 young competitive female artistic gymnasts involved in different training volumes.

Methods: This was a 2-yr prospective cohort study in which height, sitting height, leg length, weight, skinfolds, and pubertal status were measured in competitive advanced (20–27 h·wk-1) and intermediate (7.5–22 h·wk-1) training level female gymnasts every 6–12 months. Biological parameters of the adolescent growth curve were estimated using the Preece–Baines growth model. Growth rates were estimated for both groups from the mixed-longitudinal data.

Results: Estimated ages at peak height velocity (PHV) (13–13.5 yr) and mean PHV (6.2–6.4 cm·yr-1) for the advanced- and intermediate-level gymnasts suggest that these gymnasts were later maturing and experienced a blunting of the growth spurt relative to reference values for U.S. youth. Comparison of growth velocities by pubertal status revealed that height velocity was lower in the advanced- versus the intermediate-level peripubertal gymnasts, which was due to a significant reduction in sitting height velocity (2.3 vs 3.1 cm·yr-1, P. < 0.05). No marked acceleration in height or sitting height velocity was detected in the advanced-level gymnasts from pre- to peripuberty. Inspection of individual growth rates revealed that over 35% of the pre- and peripubertal gymnasts experienced growth faltering (height velocity less than 4.5 cm·yr-1) during follow-up.

Conclusion: Advanced–and intermediate–training level competitive female gymnasts tend to exhibit an adolescent growth spurt that is similar in timing and tempo to short, normal, slowly maturing girls, but the high frequency of growth faltering suggests that training may alter the tempo of growth and maturation in some, but not all, female gymnasts.

24-Hour national dietary survey data : how do we interpret them most effectively?

Objective To illustrate the effect of common mistakes when using 24-hour national dietary survey data to estimate the prevalence of inadequate nutrient intakes.

Design Raw data on nutrient intake from the Australian 1995 National Nutrition Survey were adjusted for within-person variance using standard techniques and corrected for underreporting using the criteria of Goldberg et al. The distributions for six nutrients were compared with current dietary reference values from the UK, USA and Australia.

Setting A national sample of the Australian population with a 61.4% response rate.

Results Adjusting for within-person variance reduced the range of nutrient intakes to 66–80% of the raw data range and the proportion with intakes below the estimated average requirement (EAR) by up to 20%. Excluding underreporters further reduced the proportion below the EAR by up to 10%. Using the dietary reference values from different countries also resulted in some markedly different estimates. For example, the prevalence of low folate intakes ranged from <1 to 92% for adult women depending on the reference used. Except for vitamin A and protein, the prevalence of low intakes was invariably higher for women than for men.

Conclusions Estimates of the prevalence of low nutrient intakes based on raw 24-hour survey data are invariably misleading. However, even after adjustment for within-person variance and underreporting, estimates of the prevalence of low nutrient intakes may still be misleading unless interpreted in the light of the reference criteria used and supported by relevant biochemical and physiological measures of nutritional status.

Osmoregulatory balance in Murray cod, Maccullochella peelii peelii (Mitchell), affected with chronic ulcerative dermatopathy

This study examined the osmoregulatory capability of Murray cod, Maccullochella peelii peelii, affected by chronic ulcerative dermatopathy (CUD) in intensive aquaculture. This condition appears to arise only in facilities utilizing groundwater, with the causative agent suggested to be a water-borne factor. Healthy Murray cod (~ 700 g) were transferred to a CUD-affected farm to monitor the progression of the syndrome and began to show signs of CUD after approximately five months. In order to evaluate possible effects of CUD on osmoregulation; plasma electrolyte concentrations, osmolality, and Na⁺,K⁺-ATPase activities were measured, and gill histology and immunohistochemistry were analyzed. Plasma electrolyte concentrations and osmolality of CUD-affected Murray cod were consistent with reference values determined for non CUD-affected fish. A greater number of gill mucous cells were observed in Murray cod cultured at the CUD-affected farm compared to non CUD-affected fish. We also found an un-identified cell type that was present solely in the gills of CUD-affected Murray cod. Gill Na⁺,K⁺-ATPase activity was significantly higher in severely CUD-affected Murray cod compared to individuals transferred to the CUD-affected farm. While there appeared to be some minor changes in the gills of CUD-affected fish, this study demonstrated that Murray cod were able to effectively osmoregulate, although, perhaps at an energetic cost.

Whole blood analysis of phagocytosis, apoptosis, cytokine production, and leukocyte subsets in healthy older men and women: the ZENITH study

Few studies to date have examined age-related changes in markers of immune status in healthy older individuals. The immune status of 93 healthy individuals aged 55–70 years was assessed by two- and three-color flow cytometry and biochemical analysis. There were significant age effects (p ≤.05) on monocyte phagocytic activity and cluster of differentiation (CD) 3/human leukocyte antigen-D-related (HLA-DR) late-activated T lymphocytes (% expression). There was a significant (p ≤ 0.1) Age x Sex interaction in absolute counts (x 10⁹/L) of CD3/CD8 total cytotoxic T lymphocytes (CTL), the CD4 T- helper to CD8 CTL ratio, the CD3/CD4/CD45RA naïve T helper to CD3/CD4/CD45RO memory T helper lymphocyte ratio, and interleukin (IL)-1ß (% expression) by activated monocytes. The study shows that alterations in markers of immune status occur between 55 and 70 years, and provides reference values for the lymphocyte measures in healthy men and postmenopausal women in this age group. The study further highlights the need for sex-specific reference ranges for such markers.

Proceedings of the rank forum on vitamin D

The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations>75 nmol/l). Any discussion of ‘optimal’ concentration of serum 25(OH)D needs to define ‘optimal’ with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations.

In-situ cadmium phytoremediation using solanum nigrum L. : the bio-accumulation characteristics trail

In this study, Solanum nigrum L. was used in-situ for Cd phytoremediation in Cd polluted soil on Shenyang Zhangshi Irrigation area (SZIA) in 2008. The performance of the plant over the whole growth stage was assessed. Results showed, during the whole experimental stage, the aboveground biomass of single Solanum nigrum L. grew by a factor of 190, from 1.6 ± 0.4 g to 300.3 ± 30.2 g with 141.2 times extracted Cd increase from 0.025 ± 0.001 to 3.53 ± 0.16 mg. Both the distribution of biomass and amount of extracted Cd in the aboveground part of the plant changed according to the growth of the plant. Particularly, the percentage of biomass and extracted Cd in the stem increased from 20% to 80% and from 11% to 69%, respectively. The bioconcentration factor and transfer factor both varied significantly during the growth of the plant and the lowest values were measured at the flowering stage (0.94 ± 0.31 and 3.48 ± 1.14 respectively). The results in this paper provide reference values for the future research on the application of Solanum nigrum L. in phytoremediation and on chemical or/and agricultural strategies for phytoextraction efficiency enhancement.

Estimating the impact of mandatory folic acid fortification on the folic acid intake of Australian women of childbearing age

Objective: The primary aim of this study was to estimate the impact of mandatory folic acid (FA) fortification of bread-making flour on the FA intake of Australian women of childbearing age (16-44 years). The secondary objective was to investigate the relationship between estimated FA intake and socio-economic status (SES) and age.

Method: Dietary modelling was used to estimate FA intake under four mandatory fortification scenarios – no supplement use, supplement use unrelated to FA intake, supplement use only among the highest consumers of bread, and increased supplement use. Data were obtained from the 1995 National Nutrition Survey for food intake patterns, the 2007 Victorian Population Health Survey for FA supplement use, and a marketplace survey.

Results: It is estimated that the National Health and Medical Research Council (NHMRC) recommendation for an additional 400 mg/day FA will be achieved by a minimum of 3.9, 25.4, 21.7 and 30% of the target population under scenarios 1-4, respectively. The FA upper level of intake is exceeded by a maximum of 0.1, 1.7, 6.1 and 4.1% of the target population for scenarios 1-4, respectively.

Conclusions: Mandatory FA fortification is not sufficient for the NHMRC recommendations for minimum and maximum intakes to be met by all of the target population under a number of plausible behaviour scenarios.

Implications: Targeted nutrition education campaigns are needed for SES and age sub-groups and research of this nature should be extended to other population groups. Monitoring and evaluation of this policy will be important to ensure appropriate FA intake.

Rapid determination of protein contents in microencapsulated fish oil supplements by ATR-FTIR spectroscopy and partial least square regression (PLSR) analysis

Following the recent success in quantitative analysis of essential fatty acid compositions in a commercial microencapsulated fish oil (?EFO) supplement, we extended the application of portable attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic technique and partial least square regression (PLSR) analysis for rapid determination of total protein contents-the other major component in most commercial ?EFO powders. In contrast to the traditional chromatographic methodology used in a routine amino acid analysis (AAA), the ATR-FTIR spectra of the ?EFO powder can be acquired directly from its original powder form with no requirement of any sample preparation, making the technique exceptionally fast, noninvasive, and environmentally friendly as well as being cost effective and hence eminently suitable for routine use by industry. By optimizing the spectral region of interest and number of latent factors through the developed PLSR strategy, a good linear calibration model was produced as indicated by an excellent value of coefficient of determination R2 = 0.9975, using standard ?EFO powders with total protein contents in the range of 140-450 mg/g. The prediction of the protein contents acquired from an independent validation set through the optimized PLSR model was highly accurate as evidenced through (1) a good linear fitting (R2 = 0.9759) in the plot of predicted versus reference values, which were obtained from a standard AAA method, (2) lowest root mean square error of prediction (11.64 mg/g), and (3) high residual predictive deviation (6.83) ranked in very good level of predictive quality indicating high robustness and good predictive performance of the achieved PLSR calibration model. The study therefore demonstrated the potential application of the portable ATR-FTIR technique when used together with PLSR analysis for rapid online monitoring of the two major components (i.e., oil and protein contents) in finished ?EFO powders in the actual manufacturing setting.

Which measures of adiposity are related to Australian adolescent's perception of their weight?

Aim
To determine which measurement of adiposity – standardised body mass index (BMI-z), waist circumference or body fat percentage – is most closely correlated with adolescents' weight perception and whether this differs by gender.

Methods
Weight and height (used to calculate BMI-z), waist circumference and body fat percentage were measured in 2278 adolescents aged between 12 and 16 and compared with self-reported weight status.

Results
The distribution of subjects across the three weight categories (underweight, healthy weight and overweight) differed significantly between BMI-z, waist circumference and body fat percentage (p < 0.001). BMI-z was most closely aligned with perceived weight status in boys and girls, and waist circumference was also a good correlate of weight perception in boys. Boys were more likely than girls to underestimate their weight when it was defined by BMI-z; however, girls were equally likely to underestimate their weight when it was defined by waist circumference. The majority of adolescents underestimated their weight status when it was defined by BF%.

Conclusion
BMI-z is the closest correlate of self-perceived weight status. In the absence of internationally accepted reference values for waist circumference, BMI-z is the most appropriate measure to verify weight perception.