Chronic kidney disease among adult participants of the ELSA-Brasil cohort: association with race and socioeconomic position.
BACKGROUND
There is increased interest in understanding why chronic kidney disease (CKD) rates vary across races and socioeconomic groups. We investigated the distribution of estimated glomerular filtration rate (eGFR), urinary albumin-creatinine ratio (ACR) and CKD according to these factors in Brazilian adults.


METHODS
Using baseline data (2008-2010) of 14,636 public sector employees (35-74 years) enrolled in the Brazilian Longitudinal Study of Adult Health (ELSA)-Brasil multicentre cohort, we estimated the prevalence of CKD by sex, age, race and socioeconomic factors. CKD was defined as ACR ≥ 30 mg/g and/or eGFR < 60 mL/min/1.73 m(2). GFR was estimated by CKD epidemiology collaboration without correction for race. We used logistic regression to estimate the association of race and socioeconomic position (education, income, social class and occupational nature) with CKD after adjusting for sex, age and several health-related factors.


RESULTS
The prevalence of high ACR or low eGFR, in isolation and combined, increased with age, and was higher in individuals with lower socioeconomic position and among black individuals and indigenous individuals. The overall prevalence of CKD was 8.9%. After full adjustments, it was similar in men and women (OR=0.90; 95% CI 0.79 to 1.02) and increased with age (OR=1.07; 95% CI 1.06 to 1.08). Compared to white individuals, black individuals (OR=1.23; 95% CI 1.03 to 1.47), 'pardos' (OR=1.16; 95% CI 1.00 to 1.35) and Indigenous (OR=1.72; 95% CI 1.07 to 2.76) people had higher odds for CKD. Having high school (OR=1.15; 95% CI 1.00 to 1.34) or elementary education (OR=1.23; 95% CI 1.03 to 1.47) increased the odds for CKD compared to those having a university degree.


CONCLUSIONS
There were marked discrepancies in the increases in reduced eGFR and high ACR with age and race. The higher prevalences of CKD in individuals with lower educational status and in non-whites were not explained by differences in health-related factors.
Medical School & Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Sandhi M
http://orcid.org/0000-0003-4392-5428
SM
Barreto
Medical School & Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil Department of Health, Belo Horizonte, Brazil.
Roberto M
RM
Ladeira
Medical School, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Bruce B
BB
Duncan
Medical School, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Maria Ines
MI
Schmidt
Department of Internal Medicine, Universidade Federal da Bahia, Salvador, Brazil.
Antonio A
AA
Lopes
Center for Clinical and Epidemiologic Research, Universidade de São Paulo, São Paulo, Brazil.
Isabela M
IM
Benseñor
National School of Public Health, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Dora
D
Chor
Laboratory of Health and Environment Education, Fundação Oswaldo Cruz, Brazil.
Rosane H
RH
Griep
Medical School & Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Pedro G
PG
Vidigal
Medical School & Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Antonio L
AL
Ribeiro
Center for Clinical and Epidemiologic Research, Universidade de São Paulo, São Paulo, Brazil.
Paulo A
PA
Lotufo
Department of Physiological Sciences, Universidade Federal do Espírito Santo, Brazil.
José Geraldo
JG
Mill
D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000453:epidemiology; D044383:Black People / Q000208:ethnology / Q000706:statistics & numerical data*; D001938:Brazil / Q000453:epidemiology; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000208:ethnology* / Q000503:physiopathology; D012959:Socioeconomic Factors; D044465:White People / Q000706:statistics & numerical data*
AGEING; AVOIDABLE DEATHS; CHRONIC DI; RENAL; SOCIAL INEQUALITIES