TY - JOUR
T1 - Can methods based on spot urine samples be used to estimate average population 24 h sodium excretion? Results from the Isfahan Salt Study
AU - Mohammadifard, Noushin
AU - Marateb, Hamidreza
AU - Mansourian, Marjan
AU - Khosravi, Alireza
AU - Abdollahi, Zahra
AU - Campbell, Norman R.C.
AU - Webster, Jacqui
AU - Petersen, Kristina
AU - Sarrafzadegan, Nizal
N1 - Funding Information:
Acknowledgements: This study was conducted by the Cardiovascular Research Institute, Isfahan University of Medical Sciences and was supported by the Department of Nutrition, the Ministry of Health and Medical Education in Iran. Financial support: This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Conflict of interest: N.R.C.C. is a paid consultant to the Novartis Foundation to support its programme to improve hypertension control in low- and middle-income countries which includes travel support for site visits and a contract to develop a survey. N.R.C.C. has provided paid consultative advice on accurate blood pressure assessment to Midway Corporation and is an unpaid member of World Action on Salt and Health (WASH). J.W. is Director of the WHO Collaborating Centre on Population Salt Reduction. Other authors report no conflict of interest. Authorship: N.M., N.S., Z.A., N.R.C.C., J.W. and K.P. designed the research; N.M. and A.K. conducted the research; N.M., M.M. and H.M. analysed the data; and N.M. wrote the paper. All authors read and approved the final manuscript. Ethics of human subject participation: This study was conducted according to the guidelines laid down in the Declaration of Helsinki and all procedures involving research study participants were approved by the Isfahan Cardiovascular Research Institute ethics committee. Written informed consent was obtained from all participants.
Funding Information:
This study was conducted by the Cardiovascular Research Institute, Isfahan University of Medical Sciences and was supported by the Department of Nutrition, the Ministry of Health and Medical Education in Iran.
Publisher Copyright:
© 2019 The Authors.
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Objective: To assess agreement between established methods of estimating salt intake from spot urine collections and 24 h urinary Na (24hUNa) and then to develop a valid formula that can be used in the Iranian population to estimate salt intake from spot urine samples.Design: A validation study. Three spot urine samples were collected (fasting second-void morning; afternoon; evening) on the same day as a 24 h urine collection. We estimated 24hUNa from spot specimens using the Kawasaki, Tanaka and INTERSALT equations. Two new formulas were developed, the Iran formula 1 (Iran 1) and Iran formula 2 (Iran 2), based on our population characteristics.Setting: Iranian adults recruited in 2014-2015.Participants: Healthy volunteer adults aged ≥18 years.Results: With all three spot urine specimens, predicted population 24hUNa was underestimated based on the INTERSALT equation (-469 to -708 mg/d; all P < 0·05) and conversely overestimation occurred with the Kawasaki equation (926 to 1080 mg/d; all P < 0·01). The Tanaka equation produced comparable estimates to measured 24hUNa (-151 to 86 mg/d; all P > 0·49). The newly derived formulas, Iran 1 and Iran 2, showed less mean bias than the established equations (Iran 1: 43 to 80 mg/d, all P > 0·55; Iran 2: 22 to 90 mg/d, all P > 0·50).Conclusions: In this Iranian sample, the Tanaka equation and newly derived formulas produced group-level estimates comparable to measured 24hUNa. The newly developed formulas showed less mean bias than established equations; however, they need to be tested for generalization in a larger sample.
AB - Objective: To assess agreement between established methods of estimating salt intake from spot urine collections and 24 h urinary Na (24hUNa) and then to develop a valid formula that can be used in the Iranian population to estimate salt intake from spot urine samples.Design: A validation study. Three spot urine samples were collected (fasting second-void morning; afternoon; evening) on the same day as a 24 h urine collection. We estimated 24hUNa from spot specimens using the Kawasaki, Tanaka and INTERSALT equations. Two new formulas were developed, the Iran formula 1 (Iran 1) and Iran formula 2 (Iran 2), based on our population characteristics.Setting: Iranian adults recruited in 2014-2015.Participants: Healthy volunteer adults aged ≥18 years.Results: With all three spot urine specimens, predicted population 24hUNa was underestimated based on the INTERSALT equation (-469 to -708 mg/d; all P < 0·05) and conversely overestimation occurred with the Kawasaki equation (926 to 1080 mg/d; all P < 0·01). The Tanaka equation produced comparable estimates to measured 24hUNa (-151 to 86 mg/d; all P > 0·49). The newly derived formulas, Iran 1 and Iran 2, showed less mean bias than the established equations (Iran 1: 43 to 80 mg/d, all P > 0·55; Iran 2: 22 to 90 mg/d, all P > 0·50).Conclusions: In this Iranian sample, the Tanaka equation and newly derived formulas produced group-level estimates comparable to measured 24hUNa. The newly developed formulas showed less mean bias than established equations; however, they need to be tested for generalization in a larger sample.
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U2 - 10.1017/S136898001900257X
DO - 10.1017/S136898001900257X
M3 - Article
C2 - 31547894
AN - SCOPUS:85072654861
VL - 23
SP - 202
EP - 213
JO - Public Health Nutrition
JF - Public Health Nutrition
SN - 1368-9800
IS - 2
ER -
