Obesity and recovery from acute kidney injury (Ob AKI): a prospective cohort feasibility study.

OBJECTIVES: To test the methodology of recruitment, retention and data completeness in a prospective cohort recruited after a hospitalised episode of acute kidney injury (AKI), to inform a future prospective cohort study examining the effect of obesity on AKI outcomes. DESIGN: Feasibility study. SETTING: Single centre, multi-site UK tertiary hospital. PARTICIPANTS: 101 participants (67M; 34F) with a median age of 64 (IQR 53-73) years, with and without obesity, recruited within 3 months of a hospitalised episode of AKI. OUTCOME MEASURES: Feasibility outcomes were recruitment (>15% meeting inclusion criteria recruited), participant retention at 6 and 12 months (≥80%) and completeness of data collection. Exploratory measures included recovery from AKI (regaining >75% of pre-AKI estimated glomerular filtration rate [eGFR]) at 6 months, development or progression of chronic kidney disease (CKD) (kidney function decrease of ≥25% + rise in CKD category) at 12 months, and associations with poorer kidney outcomes. RESULTS: 41% of eligible patients consented to take part, exceeding the target recruitment uptake rate of 15%. Retention was 86% at 6 months and 78% at 12 months; 10 patients died and three commenced dialysis during the study. Data were 90%-100% complete. Median BMI was 27.9 kg/m2 (range 18.1 kg/m2-54.3 kg/m2). 50% of the cohort had stage 3 AKI and 49% had pre-existing CKD. 46% of the cohort met the AKI recovery definition at 6 months. At 12 months, 20/51 patients developed CKD (39%) and CKD progression occurred in 11/49 patients (22%). Post-AKI interleukin-6 and cystatin-C were associated with 12 months decline in eGFR. CONCLUSIONS: Feasibility to conduct a long-term observational study addressing AKI outcomes associated with obesity was demonstrated. A fully powered prospective cohort study to examine the relationships between obesity and outcomes of AKI is warranted.

Prevalence, patterns of treatment, and control of hypertension in predialysis patients with chronic kidney disease.

BACKGROUND/AIMS: Data on the prevalence, treatment and control of hypertension in patients with advanced chronic kidney disease (CKD) are limited. This study aimed to examine the above factors in a cohort of predialysis patients. METHODS: During a period of 4 months, we recorded information on blood pressure (BP), comorbidities, medications and related parameters of patients followed up in the Low-Clearance Clinic of our Department. Control rates of hypertension were calculated at two thresholds: <130/80 and <140/90 mm Hg. Univariate and multiple linear regression analyses were employed to assess factors associated with BP control. RESULTS: In the population studied [n = 238, males 58.4%, age 66.21 ± 4.2 years (mean ± SD), estimated glomerular filtration rate 14.5 ± 4.8 ml/min/1.73 m(2)], the prevalence of hypertension was 95.0%. Treatment rate among hypertensives was at 99.1%. On average, 3.04 ± 1.32 antihypertensive drugs were used, ranging from 1 to 7 agents. BP control rates at the <130/80 and <140/90 mm Hg thresholds were 26.5% and 48.2%, respectively. The systolic goal was achieved in 31.0% and 50.4%, whereas the diastolic goal was achieved in 67.7% and 91.2% of patients, respectively. In multivariate analysis, only black race was independently and inversely related with hypertension control (ß = -0.187, p = 0.030). No specific antihypertensive class showed independent associations with control. CONCLUSIONS: Hypertension is highly prevalent in predialysis CKD patients. An almost universal treatment, employing a multi-agent regime, can help towards improved rates of control. Systolic BP is the main barrier to successful control and black race is associated with poorer control rates.

Prevalence and factors associated with hyperkalemia in predialysis patients followed in a low-clearance clinic.

BACKGROUND AND OBJECTIVES: Recent studies evaluated the prevalence of hyperkalemia and related risk factors in patients with CKD of various stages, but there is limited relevant information in predialysis patients. This study aimed to examine the prevalence and factors associated with hyperkalemia in the structured environment of a low-clearance clinic. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a cross-sectional fashion over a prespecified period of 4 months, information on serum potassium and relevant laboratory variables, comorbidities, medications, and dietician input in patients with advanced CKD under follow-up in the low-clearance clinic of our department was recorded. Univariate and multiple logistic regression analyses were used to identify factors associated with serum potassium ≥ 5.5 meq/L. RESULTS: The study population consisted of 238 patients aged 66.2 ± 4.2 years with estimated GFR of 14.5 ± 4.8 ml/min per 1.73 m(2). The prevalence of hyperkalemia. defined as potassium > 5.0, ≥ 5.5, and ≥ 6.0 meq/L., was at 54.2%, 31.5%, and 8.4%, respectively. In univariate comparisons, patients with potassium ≥ 5.5 meq/L had significantly higher urea and lower estimated GFR and serum bicarbonate; also, they were more often using sodium bicarbonate and had received potassium education and attempts for dietary potassium lowering. Use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers was not associated with hyperkalemia. In multivariate analyses, estimated GFR<15 ml/min per 1.73 m(2) and sodium bicarbonate use were independently associated with hyperkalemia. CONCLUSIONS: The prevalence of hyperkalemia in predialysis patients with CKD is high. Even at this range of renal function, low estimated GFR seems to be the most important factor associated with hyperkalemia among the wide range of demographic, clinical, and laboratory characteristics studied.