Food Access, Chronic Kidney Disease, and Hypertension in the U.S

Abstract

Introduction: Greater distance to full-service supermarkets and low income may impair access to healthy diets and contribute to chronic kidney disease (CKD) and hypertension. The study aim was to determine relationships among residence in a "food desert," low income, CKD, and blood pressure.

Methods: Adults in the 2003-2010 National Health and Nutrition Examination Survey (N=22,173) were linked to food desert data (www.ers.usda.gov) by Census Tracts. Food deserts have low median income and are further from a supermarket or large grocery store (>1 mile in urban areas, >10 miles in rural areas). Weighted regression was used to determine the association of residence in a food desert and family income with dietary intake; systolic blood pressure (SBP); and odds of CKD. Data analysis was performed in 2014-2015.

Results: Compared with those not in food deserts, participants residing in food deserts had lower levels of serum carotenoids (p<0.01), a biomarker of fruit and vegetable intake, and higher SBP (1.53 mmHg higher, 95% CI=0.41, 2.66) after adjustment for demographics and income. Residence in a food desert was not associated with odds of CKD (OR=1.20, 95% CI=0.96, 1.49). Lower, versus higher, income was associated with lower serum carotenoids (p<0.01) and higher SBP (2.00 mmHg higher for income-poverty ratio ≤1 vs >3, 95% CI=1.12, 2.89), but also greater odds of CKD (OR=1.76 for income-poverty ratio ≤1 vs >3, 95% CI=1.48, 2.10).

Conclusions: Limited access to healthy food due to geographic or financial barriers could be targeted for prevention of CKD and hypertension.

Figure 1

Difference in mean systolic blood pressure according to residence in a food desert and income among (A) all participants; (B) participants not using medications for high blood pressure; and (C) among all participants stratified by income-poverty ratio ≤ vs. >2. Differences are adjusted using linear regression with the following covariates age, sex, race/ethnicity, food desert, income/poverty ratio. Differences in mean systolic blood pressure are represented by black squares. Bars represent 95% CI of the difference.

Figure 1

Difference in mean systolic blood pressure according to residence in a food desert and income among (A) all participants; (B) participants not using medications for high blood pressure; and (C) among all participants stratified by income-poverty ratio ≤ vs. >2. Differences are adjusted using linear regression with the following covariates age, sex, race/ethnicity, food desert, income/poverty ratio. Differences in mean systolic blood pressure are represented by black squares. Bars represent 95% CI of the difference.

Figure 1

Difference in mean systolic blood pressure according to residence in a food desert and income among (A) all participants; (B) participants not using medications for high blood pressure; and (C) among all participants stratified by income-poverty ratio ≤ vs. >2. Differences are adjusted using linear regression with the following covariates age, sex, race/ethnicity, food desert, income/poverty ratio. Differences in mean systolic blood pressure are represented by black squares. Bars represent 95% CI of the difference.

Figure 2

OR of chronic kidney disease and albuminuria according to residence in a food desert (A) and income (B). Chronic kidney disease is defined as estimated GFR <60 ml/min/1.73m² or urine albumin to creatinine ratio (UACR)>30 mg/g. Albuminuria is defined by UACR >30 mg/g. ORs are adjusted using logistic regression with the following covariates age, sex, race/ethnicity, food desert, income/poverty ratio. Black square represents odds ratio estimates and bars represent 95% CI.

Figure 2

OR of chronic kidney disease and albuminuria according to residence in a food desert (A) and income (B). Chronic kidney disease is defined as estimated GFR <60 ml/min/1.73m² or urine albumin to creatinine ratio (UACR)>30 mg/g. Albuminuria is defined by UACR >30 mg/g. ORs are adjusted using logistic regression with the following covariates age, sex, race/ethnicity, food desert, income/poverty ratio. Black square represents odds ratio estimates and bars represent 95% CI.