Monitoring the South African population’s salt intake: spot urine v. 24 h urine

The Global Burden of Disease (GBD) 2010 study estimated national salt intake for 187 countries based on data available up to 2010. The purpose of this review was to identify studies that have measured salt intake in a nationally representative population using the 24‐hour urine collection method since 2010, with a view to updating evidence on population salt intake globally. Studies published from January 2011 to September 2018 were searched for from MEDLINE, Scopus, and Embase databases using relevant terms. Studies that provided nationally representative estimates of salt intake among the healthy adult population based on the 24‐hour urine collection were included. Measured salt intake was extracted and compared with the GBD estimates. Of the 115 identified studies assessed for eligibility, 13 studies were included: Four studies were from Europe, and one each from the United States, Canada, Benin, India, Samoa, Fiji, Barbados, Australia, and New Zealand. Mean daily salt intake ranged from 6.75 g/d in Barbados to 10.66 g/d in Portugal. Measured mean population salt intake in Italy, England, Canada, and Barbados was lower, and in Fiji, Samoa, and Benin was higher, in recent surveys compared to the GBD 2010 estimates. Despite global targets to reduce population salt intake, only 13 countries have published nationally representative salt intake data since the GBD 2010 study. In all countries, salt intake levels remain higher than the World Health Organization's recommendation, highlighting the need for additional global efforts to lower salt intake and monitor salt reduction strategies.

Section: Discussionmentioning

confidence: 99%

The Science of Salt: Updating the evidence on global estimates of salt intake

Thout

Santos

McKenzie

et al. 2019

“…In particular, the use of inadequate sodium intake assessment in observational studies is problematic. Six studies used spot urine collections to estimate usual sodium intake, despite the large body of literature showing that spot urine collections lack precision and accuracy for assessment of usual sodium intake in individuals . The risk of misclassification is high in these studies as demonstrated by Bland‐Altman analyses consistently showing poor agreement between measures of spot and 24‐hour urinary excretion for individuals .…”

Section: Discussionmentioning

confidence: 99%

Science of Salt: A regularly updated systematic review of salt and health outcomes studies (April to October 2018)

McLean

Petersen

Arcand

et al. 2019

The Science of Salt reviews identify, summarize, and critically appraise published studies on dietary salt and health outcomes according to pre‐specified methods. This review covers the period April 3 to October 30, 2018. Here, nineteen studies that fit pre‐specified criteria for review and summary are included. Three of these, one prospective cohort study, one randomized controlled trial, and a post hoc analysis of the Dietary Approaches to Stop Hypertension (DASH) sodium trial fulfilled the quality criteria for detailed critical appraisal, including risk of bias assessment, and commentary. Two trials demonstrated a positive association between salt intake and blood pressure. In a cohort of older Italians, increased risk of total mortality was observed with salt intake less than ~16 g/d (6300 mg sodium/d) at baseline; no association existed for incident cardiovascular disease (CVD) or CVD mortality. The paucity of published studies which met our criteria for methodological quality is of concern.

“…Several formulae used to estimate 24‐hour urine sodium from spot collections have relatively small systematic errors in estimating average population sodium intake; however, some formulae used in different settings result in more substantive systematic error (>400 mg sodium) . Currently, all commonly used formulae systematically overestimate sodium intake at lower 24‐hour urine sodium and underestimate intake at higher 24‐hour urine sodium . Thus, changes in dietary sodium intake at the population level (both increases and decreases) will be systematically underestimated when assessed by spot urine samples.…”

Section: Use Of Spot Urine and Short Duration Timed Urine Collectionsmentioning

confidence: 99%

“…The TAG recommended to only consider using spot and short duration timed urine collections if there was a robust baseline calibration study with 24‐hour urine collections. The impact of the systematic error inherent in the use of spot urine collections in assessing changes in population averages over time, as planned in surveillance programs, remains to be established . A few studies have examined the average error of multiple spot or short‐term timed urine collections for assessing a population average sodium intake.…”

Section: Use Of Spot Urine and Short Duration Timed Urine Collectionsmentioning

confidence: 99%

“…When analyzed appropriately, using Bland‐Altman plots, a systematic review found all the formulae used to convert sodium in spot urine and short duration timed urine samples to 24‐hour urine sodium reported overestimation of 24‐hour urine sodium at lower absolute levels of 24‐hour urine sodium and underestimation at higher absolute levels of 24‐hour sodium. This indicates that formulae based on spot urine collections should not be used to predict 24‐hour sodium in an individual or as an estimate of sodium intake in studies of sodium association with health outcomes . Using a spot urine collection to assess an individual's sodium intake will be influenced by both random and systematic error, and hence, large inaccuracies occur.…”

Section: Use Of Spot and Short Duration Timed Urine Collections To Asmentioning

confidence: 99%

See 1 more Smart Citation

The International Consortium for Quality Research on Dietary Sodium/Salt (TRUE) position statement on the use of 24‐hour, spot, and short duration (<24 hours) timed urine collections to assess dietary sodium intake

Campbell

Tan

et al. 2019

108

132

The International Consortium for Quality Research on Dietary Sodium/Salt (TRUE) is a coalition of intentional and national health and scientific organizations formed because of concerns low‐quality research methods were creating controversy regarding dietary salt reduction. One of the main sources of controversy is believed related to errors in estimating sodium intake with urine studies. The recommendations and positions in this manuscript were generated following a series of systematic reviews and analyses by experts in hypertension, nutrition, statistics, and dietary sodium. To assess the population's current 24‐hour dietary sodium ingestion, single complete 24‐hour urine samples, collected over a series of days from a representative population sample, were recommended. To accurately estimate usual dietary sodium at the individual level, at least 3 non‐consecutive complete 24‐hour urine collections obtained over a series of days that reflect the usual short‐term variations in dietary pattern were recommended. Multiple 24‐hour urine collections over several years were recommended to estimate an individual's usual long‐term sodium intake. The role of single spot or short duration timed urine collections in assessing population average sodium intake requires more research. Single or multiple spot or short duration timed urine collections are not recommended for assessing an individual's sodium intake especially in relationship to health outcomes. The recommendations should be applied by scientific review committees, granting agencies, editors and journal reviewers, investigators, policymakers, and those developing and creating dietary sodium recommendations. Low‐quality research on dietary sodium/salt should not be funded, conducted, or published.