title: Predicting 24-hour urinary protein excretion in Afro-Caribbean Barbadians by comparing urine protein excretion over different durations versus spot collection.
abstract: OBJECTIVE
  The gold standard for the determination of proteinuria, an independent risk factor for cardiovascular and renal disease, is the measurement of protein in a 24-hour urine collection. However this method has been shown to be unreliable mainly due to poor compliance of sampling by patients. This study investigates other appropriate means of predicting 24-hour urinary protein excretion in a sample of Afro-Caribbeans in Barbados by assessing the correlation of actual and estimated urinary protein excretion between a 24-hour urine collection sample, 12-hour (AM and PM) and spot (AM and PM) urine collections.
  
  
  METHODS
  A convenient sample of 30 healthy participants of Afro-Caribbean origin between the ages of21 and 55 years was recruited for the study The 24-hour urine samples and anthropometric data were collected as documented in the study s standard clinical procedure. A 24-hour urine sample was collected as two separate 12-hour AM and PM samples. In addition, two spot samples (AM and PM) were taken during each 12-hour sample collection period. Analysis of the urinary protein and creatinine was done with a Roche/Hitachi Modular System (Roche Diagnostics, IN, USA). SPSS version 19 was used to analyse the data to make inferences.
  
  
  RESULTS
  Thirty Afro-Caribbean persons participated in the study: 16 females and 14 males. The average age and body mass index (BMI) were 38 +/- 17 years and 25.32+/- 5.98 kg/m2, respectively. The Spearman Rho 's correlation was used to interpret associations of the urinary parameters in 24-hour collected sample and the other samples. The strongest correlation of the protein:creatinine ratio in the 24-hour collected sample to the other samples was observed with the 12-hour AM sample (r = + 0.743, p < O.01)followed by the 12-hour PM sample (r = +0.672, p < 0.01). On analysing gender, the more significant correlations found were among the males for the 12-hour timed samples with r = +0.945, p < 0.01 and r = +0.736, p < 0.01 for the AM and PM samples, respectively. There were very strong correlations between the 24-hour urinary protein excretion and the estimated 24-hour protein excretion from the 12-hour AM and PM samples (r = +0.846, p < 0.01 and r = +0.637, p < 0.01, respectively). Both males and females had the strongest correlation for the estimation of 24-hour protein excretion in the 12-hour AM sample (r = +0.795, p < 0.01 and r = +0.965, p < 0.01, respectively).
  
  
  CONCLUSIONS
  The use ofa 12-hour timed sample, specifically the morning sample, may be a more convenient way to assess proteinuria in the Afro-Caribbean population. This method allows for a quicker assessment of proteinuria which not only allows earlier diagnosis of renal disease but may also reduce the clinical cost of the disease s management.
authors.affiliation: University of the West Indies, Cave Hill, Barbados, damian.cohall@cavehill.uwi.edu
authors.forename: D H
authors.initials: DH
authors.lastname: Cohall
authors.affiliation: University of the West Indies, Cave Hill, Barbados,
authors.forename: T
authors.initials: T
authors.lastname: Scantlebury-Manning
authors.affiliation: Department of Dietetics, McGill University, Montreal, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Tavernese
authors.affiliation: Barbados Community College, St Michael, Barbados.
authors.forename: S
authors.initials: S
authors.lastname: James
authors.affiliation: University of the West Indies, Cave Hill, Barbados,
authors.forename: K
authors.initials: K
authors.lastname: Hall
mesh_terms: D000328:Adult; D001460:Barbados; D044383:Black People; D003404:Creatinine / Q000378:metabolism / Q000652:urine*; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000378:metabolism / Q000652:urine*; D013997:Time Factors; D059349:Urine Specimen Collection / Q000379:methods; D055815:Young Adult
chemical_list: D003404:Creatinine