Characteristics of the Western diet that fueled the obesity epidemic may also impact kidney disease incidence and progression. Enlarging portion sizes over the past half century has been accompanied by increased intake of protein, sodium, and processed foods while consumption of fruits and vegetables has declined. Overall dietary patterns play a strong role for chronic disease risk including chronic kidney disease. While dietary patterns high in fresh fruits and vegetables and low in red meats, such as the Mediterranean diet, decrease the risk of chronic diseases, the Western diet, characterized by high intake of red meat, animal fat, sweets, and desserts and low intake of fresh fruits and vegetables and low-fat dairy products, increases risk of chronic diseases. In this article, we review the potential mechanisms whereby several key characteristics of the typical Western diet may impact kidney disease incidence and progression. We also discuss a public health policy initiative to improve dietary choices. Reducing protein intake to the recommended daily allowance of 0.8 g/kg/day and increasing intake of fruit and vegetables and fiber may mitigate kidney disease progression and reduce risk of cardiovascular disease and mortality.

PurposeTo examine the characteristics of the midstream urine microbiome in adults with stage 3–5 non-dialysis-dependent chronic kidney disease (CKD).MethodsPatients with non-dialysis-dependent CKD (estimated glomerular filtration rate [eGFR] < 60 ml/min/1.73 m2) and diuretic use were recruited from outpatient nephrology clinics. Midstream voided urine specimens were collected using the clean-catch method. The bacterial composition was determined by sequencing the hypervariable (V4) region of the bacterial 16S ribosomal RNA gene. Extraction negative controls (no urine) were included to assess the contribution of extraneous DNA from possible sources of contamination. Midstream urine microbiome diversity was assessed with the inverse Simpson, Chao and Shannon indices. The diversity measures were further examined by demographic characteristics and by comorbidities.ResultsThe cohort of 41 women and 36 men with detectable bacterial DNA in their urine samples had a mean age of 71.5 years (standard deviation [SD] 7.9) years (range 60–91 years). The majority were white (68.0%) and a substantial minority were African-American (29.3%) The mean eGFR was 27.2 (SD 13.6) ml/min/1.73 m2. Most men (72.2%) were circumcised and 16.6% reported a remote history of prostate cancer. Many midstream voided urine specimens were dominated (> 50% reads) by the genera Corynebacterium (n = 11), Staphylococcus (n = 9), Streptococcus (n = 7), Lactobacillus (n = 7), Gardnerella (n = 7), Prevotella (n = 4), Escherichia_Shigella (n = 3), and Enterobacteriaceae (n = 2); the rest lacked a dominant genus. The samples had high levels of diversity, as measured by the inverse Simpson [7.24 (95% CI 6.76, 7.81)], Chao [558.24 (95% CI 381.70, 879.35)], and Shannon indices [2.60 (95% CI 2.51, 2.69)]. Diversity measures were generally higher in participants with urgency urinary incontinence and higher estimated glomerular filtration rate (eGFR). After controlling for demographics and diabetes status, microbiome diversity was significantly associated with estimated eGFR (P < 0.05).ConclusionsThe midstream voided urine microbiome of older adults with stage 3–5 non-dialysis-dependent CKD is diverse. Greater microbiome diversity is associated with higher eGFR.

The objective of this study was to examine the temporal trends of the association between area-level poverty status and end-stage renal disease (ESRD) incidence. We hypothesized that the association between area-level poverty status and ESRD incidence has increased significantly over time. Patient data from the United States Renal Data System were linked with data from the 2000 and 2010 US census. Area-level poverty was defined as living in a zip code-defined area with ≥20% of households living below the federal poverty line. Negative binomial regression models were created to examine the association between area-level poverty status and ESRD incidence by time period in the US adult population while simultaneously adjusting for the distribution of age, sex, and race/ethnicity within a zip code. Time was categorized as January 1, 1995 through December 31, 2004 (Period 1) and January 1, 2005 through December 31, 2010 (Period 2). The percentage of adults initiating dialysis with area-level poverty increased from 27.4% during Period 1 to 34.0% in Period 2. After accounting for the distribution of age, sex, and race/ethnicity within a zip code, area-level poverty status was associated with a 1.24 (95% confidence interval [CI] 1.22, 1.25)-fold higher ESRD incidence. However, this association differed by time period with 1.04-fold (95% CI 1.02, 1.05) higher ESRD incidence associated with poverty status for Period 2 compared with the association between ESRD and poverty status in Period 1. Area-level poverty and its association with ESRD incidence is not static over time.