Area and individual socioeconomic status, race and progressive chronic kidney disease

Introduction. Socioeconomic status (SES) is known to be inversely associated with chronic kidney disease (CKD), a focus area of Healthy People 2010 because of its increasing prevalence, substantial mortality and impact on quality of life.; Objectives. This non-concurrent multi-level study examined the associations between individual and area-level SES and progressive chronic kidney disease (pCKD).; Methods. The population included participants from the Atherosclerosis Risk in Communities Study (ARIC) and the Cardiovascular Health Study (CHS), including men and women ages 45–64 (ARIC) and 65 and older (CHS), sampled from 6 communities in the U.S.: Forsyth NC, Jackson MS, Minneapolis, MN, Washington County, MD, Sacramento, CA and Pittsburgh, PA. The main outcome was pCKD, defined as creatinine elevation >=0.4 mg/dL, over a 3–9 year follow-up, CKD hospitalization or death. SES measures included income, wealth, education and occupation with area-level SES measured according to 1990 US Census block groups of residence. Cox proportional hazards models were used to assess the independent associations between individual and area-level SES and pCKD. Additional individual and area-level variables were considered as potential mediators of the SES-pCKD association; these included health awareness, health care access, behavioral and physiological factors and area-level crime incidence.; Results. This study found 60–110% greater risk of pCKD associated with the lowest individual-level SES levels among middle-aged participants; no significant individual-level SES-pCKD associations were found among the elderly. With regard to area-level SES, there was a 60% greater risk of pCKD associated with living in a low SES area among white middle aged men, and over twice the pCKD risk associated with low area-level SES among elderly white participants, after adjusting for individual-level SES. No statistically significant independent associations were found regarding area-level SES in other race/gender groups in ARIC and among African Americans in CHS. Overall, adjustment for potential mediators did not seem to significantly modify the SES-pCKD associations.; Discussion. This study suggests that low SES individuals and communities represent high-risk populations for pCKD. Future research, as well as policy and program initiatives that target these populations may contribute to reducing morbidity and mortality related to CKD.