Dietary Habits, Poverty, and Chronic Kidney Disease in an Urban Population

Background: Poverty is associated with chronic kidney disease (CKD) in the United States and worldwide. Poor dietary habits may contribute to this disparity.

Study Design: Cross-sectional study.

Setting And Participants: A total of 2,058 community-dwelling adults aged 30 to 64 years residing in Baltimore City, Maryland.

Predictors: Adherence to the Dietary Approaches to Stop Hypertension (DASH) diet. DASH scoring based on 9 target nutrients (total fat, saturated fat, protein, fiber, cholesterol, calcium, magnesium, sodium, and potassium); adherence defined as score ≥4.5 of maximum possible score of 9. Poverty (self-reported household income <125% of 2004 Department of Health and Human Services guideline) and nonpoverty (≥125% of guideline).

Outcomes And Measurements: CKD defined as estimated glomerular filtration rate <60 mL/minute/1.73 m(2) (CKD epidemiology collaboration equation). Multivariable logistic regression was used to calculate adjusted odds ratios (AORs) for relation of DASH score tertile and CKD, stratified by poverty status.

Results: Among 2,058 participants (mean age 48 years; 57% black; 44% male; 42% with poverty), median DASH score was low, 1.5 (interquartile range, 1-2.5). Only 5.4% were adherent. Poverty, male sex, black race, and smoking were more prevalent among the lower DASH score tertiles, whereas higher education and regular health care were more prevalent among the highest DASH score tertile (P < .05 for all). Fiber, calcium, magnesium, and potassium intake were lower, and cholesterol higher, among the poverty compared with nonpoverty group (P < .05 for all), with no difference in sodium intake. A total of 5.6% of the poverty and 3.8% of the nonpoverty group had CKD (P = .05). The lowest DASH tertile (compared with the highest) was associated with more CKD among the poverty (AOR 3.15, 95% confidence interval 1.51-6.56), but not among the nonpoverty group (AOR 0.73, 95% confidence interval 0.37-1.43; P interaction = .001).

Conclusions: Poor dietary habits are strongly associated with CKD among the urban poor and may represent a target for interventions aimed at reducing disparities in CKD.