title: Feasibility of collecting 24-h urine to monitor sodium intake in the National Health and Nutrition Examination Survey.
abstract: BACKGROUND
  Twenty-four-hour urine sodium excretion is recommended for monitoring population sodium intake. Because of concerns about participation and completion, sodium excretion has not been collected previously in US nationally representative surveys.
  
  
  OBJECTIVE
  We assessed the feasibility of implementing 24-h urine collections as part of a nationally representative survey.
  
  
  METHODS
  We selected a random half sample of nonpregnant US adults aged 20-69 y in 3 geographic locations of the 2013 NHANES. Participants received explicit instructions, started and ended the urine collection in a urine study mobile examination center, and answered questions about their collection. Among those with a complete 24-h urine collection, a random one-half were asked to collect a second 24-h urine sample. Sodium, potassium, chloride, and creatinine excretion were analyzed.
  
  
  RESULTS
  The final NHANES examination response rate for adults aged 20-69 y in these 3 study locations was 71%. Of those examined (n = 476), 282 (59%) were randomly selected to participate in the 24-h urine collection. Of these, 212 persons [75% of those selected for 24-h urine collection; 53% (equal to 71% × 75% of those selected for the NHANES)] collected a complete initial 24-h specimen and 92 persons (85% of 108 selected) collected a second complete 24-h urine sample. More men than women completed an initial collection (P = 0.04); otherwise, completion did not vary by sociodemographic characteristics, body mass index, education, or employment status for either collection. Mean 24-h urine volume and sodium excretion were 1964 ± 1228 mL and 3657 ± 2003 mg, respectively, for the first 24-h urine sample, and 2048 ± 1288 mL and 3773 ± 1891 mg, respectively, for the second collection.
  
  
  CONCLUSIONS
  Given the 53% final component response rate and 75% completion rate, 24-h urine collections were deemed feasible and implemented in the NHANES 2014 on a subsample of adults aged 20-69 y to assess population sodium intake. This study was registered at clinicaltrials.gov as NCT02723682.
authors.affiliation: Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD; auc5@cdc.gov.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Terry
authors.affiliation: Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA; and.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Cogswell
authors.affiliation: Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD;
authors.forename: Chia-Yih
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD;
authors.forename: Te-Ching
authors.initials: TC
authors.lastname: Chen
authors.affiliation: Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Loria
authors.affiliation: Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD.
authors.forename: Jacqueline D
authors.initials: JD
authors.lastname: Wright
authors.affiliation: Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD;
authors.forename: Xinli
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, MD;
authors.forename: David A
authors.initials: DA
authors.lastname: Lacher
authors.affiliation: Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA; and.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Merritt
authors.affiliation: Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA; and.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Bowman
mesh_terms: D000328:Adult; D000368:Aged; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D012964:Sodium / Q000008:administration & dosage* / Q000652:urine; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage* / Q000652:urine; D014481:United States; D016482:Urinalysis; D059349:Urine Specimen Collection; D055815:Young Adult
chemical_list: D017673:Sodium Chloride, Dietary; D012964:Sodium
keywords: 24-hour urine; NHANES; biomarker; hypertension; sodium excretion; sodium intake