TY - JOUR
T1 - The Validity of Predictive Equations to Estimate 24-Hour Sodium Excretion
AU - Allen, Norrina B.
AU - Zhao, Lihui
AU - Loria, Catherine M.
AU - Van Horn, Linda
AU - Wang, Chia Yih
AU - Pfeiffer, Christine M.
AU - Cogswell, Mary E.
AU - Wright, Jacqueline
AU - Liu, Kiang
N1 - Funding Information:
This research was supported by the National Heart, Lung, and Blood Institute (Multi-Ethnic Study of Atherosclerosis: N01-HC-95164 and Coronary Artery Risk Development in Young Adults Study: HHSN268201300027C). The Coronary Artery Risk Development in Young Adults Study is conducted and supported by the National Heart, Lung, and Blood Institute in collaboration with the University of Alabama at Birmingham (grants HHSN268201300025C and HHSN268201300026C), Northwestern University (grant HHSN268201300027C), University of Minnesota (grant HHSN268201300028C), Kaiser Foundation Research Institute (grant HHSN268201300029C), and Johns Hopkins University School of Medicine (grant HHSN268200900041C). Coronary Artery Risk Development in Young Adults is also partially supported by the Intramural Research Program of the National Institute on Aging and an intra-agency agreement between National Institute on Aging and National Heart, Lung, and Blood Institute (grant AG0005). This manuscript has been reviewed by the Coronary Artery Risk Development in Young Adults group for scientific content. The Multi-Ethnic Study of Atherosclerosis is supported by the National Heart, Lung, and Blood Institute (contracts N01-HC-95159 through N01-HC-95169) and the National Center for Research Resources (grants UL1-RR-024156 and UL1-RR-025005). The findings and conclusions in this manuscript are those of the authors and do not necessarily represent the official views or positions of the Centers for Disease Control and Prevention, Agency for Toxic Substances and Disease Registry, the National Institutes of Health, or the Department of Health and Human Services. Conflict of interest: none declared.
PY - 2017/7/15
Y1 - 2017/7/15
N2 - We examined the population distribution of urinary sodium concentrations and the validity of existing equations predicting 24-hour sodium excretion from a single spot urine sample among older adults with and without hypertension. In 2013, 24-hour urine collections were obtained from 554 participants in the Multi-Ethnic Study of Atherosclerosis and the Coronary Artery Risk Development in Young Adults study, who were aged 45-79 years and of whom 56% were female, 58% were African American, and 54% had hypertension, in Chicago, Illinois. One-third provided a second 24-hour collection. Four timed (overnight, morning, afternoon, and evening) spot urine specimens and the 24-hour collection were analyzed for sodium and creatinine concentrations. Mean 24-hour sodium excretion was 3,926 (standard deviation (SD), 1,623) mg for white men, 2,480 (SD, 1,079) mg for white women, 3,454 (SD, 1,651) mg for African-American men, and 3,397 (SD, 1,641) mg for African-American women, and did not differ significantly by hypertensive status. Mean bias (difference) in predicting 24-hour sodium excretion from the timed spot urine specimens ranged from -182 (95% confidence interval: -285, -79) to 1,090 (95% confidence interval: 966, 1,213) mg/day overall. Although the Tanaka equation using the evening specimen produced the least bias overall, no single equation worked well across subgroups of sex and race/ethnicity. A single spot urine sample is not a valid indicator of individual sodium intake. New equations are needed to accurately estimate 24-hour sodium excretion for older adults.
AB - We examined the population distribution of urinary sodium concentrations and the validity of existing equations predicting 24-hour sodium excretion from a single spot urine sample among older adults with and without hypertension. In 2013, 24-hour urine collections were obtained from 554 participants in the Multi-Ethnic Study of Atherosclerosis and the Coronary Artery Risk Development in Young Adults study, who were aged 45-79 years and of whom 56% were female, 58% were African American, and 54% had hypertension, in Chicago, Illinois. One-third provided a second 24-hour collection. Four timed (overnight, morning, afternoon, and evening) spot urine specimens and the 24-hour collection were analyzed for sodium and creatinine concentrations. Mean 24-hour sodium excretion was 3,926 (standard deviation (SD), 1,623) mg for white men, 2,480 (SD, 1,079) mg for white women, 3,454 (SD, 1,651) mg for African-American men, and 3,397 (SD, 1,641) mg for African-American women, and did not differ significantly by hypertensive status. Mean bias (difference) in predicting 24-hour sodium excretion from the timed spot urine specimens ranged from -182 (95% confidence interval: -285, -79) to 1,090 (95% confidence interval: 966, 1,213) mg/day overall. Although the Tanaka equation using the evening specimen produced the least bias overall, no single equation worked well across subgroups of sex and race/ethnicity. A single spot urine sample is not a valid indicator of individual sodium intake. New equations are needed to accurately estimate 24-hour sodium excretion for older adults.
KW - Blood pressure
KW - Epidemiologic methods
KW - Hypertension
KW - Sodium
KW - Validation
UR - http://www.scopus.com/inward/record.url?scp=85029686831&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85029686831&partnerID=8YFLogxK
U2 - 10.1093/aje/kwx056
DO - 10.1093/aje/kwx056
M3 - Article
C2 - 28838062
AN - SCOPUS:85029686831
VL - 186
SP - 149
EP - 159
JO - American Journal of Epidemiology
JF - American Journal of Epidemiology
SN - 0002-9262
IS - 2
ER -