title: Low socioeconomic status associates with higher serum phosphate irrespective of race.
abstract: Hyperphosphatemia, which associates with adverse outcomes in CKD, is more common among blacks than whites for unclear reasons. Low socioeconomic status may explain this association because poverty both disproportionately affects racial and ethnic minorities and promotes excess intake of relatively inexpensive processed and fast foods enriched with highly absorbable phosphorus additives. We performed a cross-sectional analysis of race, socioeconomic status, and serum phosphate among 2879 participants in the Chronic Renal Insufficiency Cohort Study. Participants with the lowest incomes or who were unemployed had higher serum phosphate concentrations than participants with the highest incomes or who were employed (P < 0.001). Although we also observed differences in serum phosphate levels by race, income modified this relationship: Blacks had 0.11 to 0.13 mg/dl higher serum phosphate than whites in the highest income groups but there was no difference by race in the lowest income group. In addition, compared with whites with the highest income, both blacks and whites with the lowest incomes had more than twice the likelihood of hyperphosphatemia in multivariable-adjusted analysis. In conclusion, low socioeconomic status associates with higher serum phosphate concentrations irrespective of race. Given the association between higher levels of serum phosphate and cardiovascular disease, further studies will need to determine whether excess serum phosphate may explain disparities in kidney disease outcomes among minority populations and the poor.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA. ogutierrez2@med.miami.edu
authors.forename: Orlando M
authors.initials: OM
authors.lastname: Gutiérrez
authors.forename: Cheryl
authors.initials: C
authors.lastname: Anderson
authors.forename: Tamara
authors.initials: T
authors.lastname: Isakova
authors.forename: Julia
authors.initials: J
authors.lastname: Scialla
authors.forename: Lavinia
authors.initials: L
authors.lastname: Negrea
authors.forename: Amanda Hyre
authors.initials: AH
authors.lastname: Anderson
authors.forename: Keith
authors.initials: K
authors.lastname: Bellovich
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Nancy
authors.initials: N
authors.lastname: Robinson
authors.forename: Akinlolu
authors.initials: A
authors.lastname: Ojo
authors.forename: James
authors.initials: J
authors.lastname: Lash
authors.forename: Harold I
authors.initials: HI
authors.lastname: Feldman
authors.forename: Myles
authors.initials: M
authors.lastname: Wolf
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People / Q000208:ethnology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004032:Diet / Q000009:adverse effects; D005260:Female; D006801:Humans; D054559:Hyperphosphatemia / Q000097:blood / Q000208:ethnology*; D007182:Income; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010710:Phosphates / Q000097:blood*; D011446:Prospective Studies; D012923:Social Class; D014481:United States; D044465:White People / Q000208:ethnology*; D001741:Black or African American
chemical_list: D010710:Phosphates