Correcting for Intra-Individual Variability in Sodium Excretion in Spot Urine Samples Does Not Improve the Ability to Predict 24 h Urinary Sodium Excretion.

Given a global focus on salt reduction efforts to reduce cardiovascular risk, it is important to obtain accurate measures of salt intake on a population level. This study determined firstly whether adjustment for intra-individual variation in urinary sodium (Na) excretion using three repeated 24 h collections affects daily estimates and whether the use of repeated spot urine samples results in better prediction of 24 h Na compared to a single collection. Twenty three community-dwelling men and women from South Africa (mean age 59.7 years (SD = 15.6)) participating in the World Health Organization Study on global AGEing and adult health (WHO-SAGE) Wave 3 study collected 24 h and spot early morning urine samples over three consecutive days to assess urinary Na excretion. INTERSALT, Tanaka, and Kawasaki prediction equations, with either average or adjusted spot Na values, were used to estimate 24 h Na and compared these against measured 24 h urinary Na. Adjustment was performed by using the ratio of between-person (sb) and total (sobs) variability obtained from repeated measures analysis of variance. Sensitivity of the equations to predict daily urinary Na values below 5 g salt equivalent was calculated. The sb/sobs for urinary Na using three repeated samples for spot and 24 h samples were 0.706 and 0.798, respectively. Correction using analysis of variance for 3 × 24 h collections resulted in contraction of the upper end of the distribution curve (90th centile: 157 to 136 mmoL/day; 95th centile: 220 to 178 mmoL/day). All three prediction equations grossly over-estimated 24 h urinary Na excretion, regardless of whether a single spot urine or repeated collections corrected for intra-individual variation were used. Sensitivity of equations to detect salt intake equivalent values of ≤5 g/day was 13% for INTERSALT, while the other two equations had zero sensitivity. Correcting for intra-individual variability in Na excretion using three 24 h urine collections contracted the distribution curve for high intakes. Repeated collection of spot samples for urinary Na analysis does not improve the accuracy of predicting 24 h Na excretion. Spot urine samples are not appropriate to detect participants with salt intakes below the recommended 5 g/day.

Development of nutrition science competencies for undergraduate degrees in Australia.

BACKGROUND AND OBJECTIVES: The need for updated competencies for nutrition scientists in Australia was identified. The aim of this paper is to describe the process of revising of these competencies for undergraduate nutrition science degrees in Australia. METHODS AND STUDY DESIGN: An iterative multiple methods approach comprising three stages was undertaken: 1. Scoping study of existing competencies; 2. Exploratory survey; and, 3. Modified Delphi process (2 rounds) involving 128 nutrition experts from industry, community, government and academia. A ≥70% consensus rule was applied to Rounds 1 and 2 of the Delphi process in order to arrive at a final list of competencies. RESULTS: Stage 1: Scoping study resulted in an initial list of 71 competency statements, categorised under six core areas. Stage 2: Exploratory survey-completed by 74 Nutrition Society of Australia (NSA) members; 76% agreed there was a need to update the current competencies. Standards were refined to six core areas and 36 statements. Stage 3: Modified Delphi process-revised competencies comprise five core competency areas, underpinned by fundamental knowledge, skills, attitudes and values: Nutrition Science; Food and the Food System; Nutrition Governance, Sociocultural and Behavioural Factors; Nutrition Research and Critical Analysis; and Communication and Professional Conduct; and three specialist competency areas: Food Science; Public Health Nutrition; and Animal Nutrition. CONCLUSIONS: The revised competencies provide an updated framework of nutrition science knowledge for graduates to effectively practice in Australia. They may be used to benchmark current and future nutrition science degrees and lead to improved employability skills of nutrition science graduates.