Diversity of the midstream urine microbiome in adults with chronic kidney disease.

PURPOSE: To examine the characteristics of the midstream urine microbiome in adults with stage 3-5 non-dialysis-dependent chronic kidney disease (CKD). METHODS: Patients 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. RESULTS: The 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). CONCLUSIONS: The 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.

Urinary incontinence and diuretic avoidance among adults with chronic kidney disease.

PURPOSE: Diuretics remain an important medication for hypertension management among adults with chronic kidney disease (CKD), but diuretics may also worsen urinary symptoms, especially urinary incontinence (UI). This single-center pilot study examined the prevalence of UI among adults age ≥60 years with CKD using diuretics and assessed diuretic avoidance due to urinary symptoms. METHODS: Patients with non-dialysis-dependent CKD (estimated glomerular filtration rate <60 ml/min/1.73 m(2)) and diuretic use were recruited from outpatient nephrology clinics. Urinary symptoms and diuretic avoidance were assessed using standardized questionnaires. RESULTS: The cohort of 44 women and 54 men had a mean age of 71.8 (8.4) years, and urgency-UI, stress-UI and mixed-UI (the presence of both urgency-UI and stress-UI) were reported by 44.9 % (n = 44), 36.7 % (n = 36) and 26.5 % (n = 26), respectively. Nocturia was noted in 68 % (n = 67). Overall, 15.3 % (6 men and 9 women) reported diuretic avoidance. Avoidance of diuretics was 27.3 % (n = 12), 25.5 % (n = 9) and 34.6 % (n = 9) among participants with urgency-UI, stress-UI and mixed-UI, respectively, while only 6.8 % (n = 3) of participants without any UI reported diuretic avoidance. After adjusting for age, sex and diuretic type (loop vs. others), both urgency-UI (odds ratio 5.9 95 % CI 1.5-22.8) and mixed-UI (odds ratio 5.7; 95 % CI 1.6-19.9) were significantly associated with diuretic avoidance compared to participants without urgency-UI, or mixed-UI, respectively. Stress-UI and nocturia were not significantly associated with diuretic avoidance. CONCLUSIONS: UI is common among older adults with CKD receiving diuretics. Patients with urgency-UI are more likely to avoid diuretics.